[PATCH v2 00/25] powerpc: Switch signal 32 to using unsafe_put_user() and friends

[PATCH v2 00/25] powerpc: Switch signal 32 to using unsafe_put_user() and friends

[Christophe Leroy]

This series leads to a reduction from 2.55s to 1.73s of
the system CPU time with the following microbench app
on an mpc832x with KUAP (approx 32%)

This series replaces copies to users by unsafe_put_user() and friends
with user_write_access_begin() dance in signal32.

The advantages are:
- No KUAP unlock/lock at every copy
- More readable code.
- Better generated code.

Without KUAP, the difference is in the noise.

	void sigusr1(int sig) { }

	int main(int argc, char **argv)
	{
		int i = 100000;

		signal(SIGUSR1, sigusr1);
		for (;i--;)
		    raise(SIGUSR1);
		exit(0);
	}

An additional 0.10s reduction is achieved by removing
CONFIG_PPC_FPU, as the mpc832x has no FPU.

A bit less spectacular on an 8xx as KUAP is less heavy, prior to
the series (with KUAP) it ran in 8.10 ms. Once applies the removal
of FPU regs handling, we get 7.05s. With the full series, we get 6.9s.
If artificially re-activating FPU regs handling with the full series,
we get 7.6s.

So for the 8xx, the removal of the FPU regs copy is what makes the
difference, but the rework of handle_signal also have a benefit.

Same as above, without KUAP the difference is in the noise.

Difference since v1(RFC):
- Almost copies to user are now replaced by unsafe_ alternative.
- Reworked a bit the FPU registers handling following feedback from Michael.
- Fixed a few build failures reported by Mr Robot on the RFC.

Christophe Leroy (25):
  powerpc/signal: Move inline functions in signal.h
  powerpc/ptrace: Move declaration of ptrace_get_reg() and
    ptrace_set_reg()
  powerpc/ptrace: Consolidate reg index calculation
  powerpc/ptrace: Create ptrace_get_fpr() and ptrace_put_fpr()
  powerpc/signal: Don't manage floating point regs when no FPU
  powerpc/32s: Allow deselecting CONFIG_PPC_FPU on mpc832x
  powerpc/signal: Remove BUG_ON() in handler_signal functions
  powerpc/signal: Move access_ok() out of get_sigframe()
  powerpc/signal: Remove get_clean_sp()
  powerpc/signal: Call get_tm_stackpointer() from get_sigframe()
  powerpc/signal: Refactor bad frame logging
  powerpc/signal32: Simplify logging in handle_rt_signal32()
  powerpc/signal32: Move handle_signal32() close to handle_rt_signal32()
  powerpc/signal32: Rename local pointers in handle_rt_signal32()
  powerpc/signal32: Misc changes to make handle_[rt_]_signal32() more
    similar
  powerpc/signal32: Move signal trampoline setup to handle_[rt_]signal32
  powerpc/signal32: Switch handle_signal32() to user_access_begin()
    logic
  powerpc/signal32: Switch handle_rt_signal32() to user_access_begin()
    logic
  powerpc/signal32: Remove ifdefery in middle of if/else
  signal: Add unsafe_put_compat_sigset()
  powerpc/signal32: Add and use unsafe_put_sigset_t()
  powerpc/signal32: Switch swap_context() to user_access_begin() logic
  powerpc/signal: Create 'unsafe' versions of
    copy_[ck][fpr/vsx]_to_user()
  powerpc/signal32: Isolate non-copy actions in save_user_regs() and
    save_tm_user_regs()
  powerpc/signal32: Transform save_user_regs() and save_tm_user_regs()
    in 'unsafe' version

 arch/powerpc/Kconfig                     |   1 +
 arch/powerpc/include/asm/processor.h     |  16 +-
 arch/powerpc/include/asm/ptrace.h        |   6 -
 arch/powerpc/kernel/asm-offsets.c        |   2 +
 arch/powerpc/kernel/head_32.S            |   4 +
 arch/powerpc/kernel/process.c            |   4 +
 arch/powerpc/kernel/ptrace/Makefile      |   3 +-
 arch/powerpc/kernel/ptrace/ptrace-decl.h |  21 +
 arch/powerpc/kernel/ptrace/ptrace-fpu.c  |  40 ++
 arch/powerpc/kernel/ptrace/ptrace-view.c |   2 +
 arch/powerpc/kernel/ptrace/ptrace.c      |  54 +-
 arch/powerpc/kernel/ptrace/ptrace32.c    |   2 +
 arch/powerpc/kernel/signal.c             |  59 +--
 arch/powerpc/kernel/signal.h             | 115 ++++-
 arch/powerpc/kernel/signal_32.c          | 598 +++++++++++------------
 arch/powerpc/kernel/signal_64.c          |  21 +-
 arch/powerpc/kernel/traps.c              |   2 +
 arch/powerpc/platforms/Kconfig.cputype   |  15 +-
 include/linux/compat.h                   |  32 ++
 19 files changed, 566 insertions(+), 431 deletions(-)
 create mode 100644 arch/powerpc/kernel/ptrace/ptrace-fpu.c

-- 
2.25.0

[PATCH v2 00/25] powerpc: Switch signal 32 to using unsafe_put_user() and friends

[Christophe Leroy]

This series leads to a reduction from 2.55s to 1.73s of
the system CPU time with the following microbench app
on an mpc832x with KUAP (approx 32%)

This series replaces copies to users by unsafe_put_user() and friends
with user_write_access_begin() dance in signal32.

The advantages are:
- No KUAP unlock/lock at every copy
- More readable code.
- Better generated code.

Without KUAP, the difference is in the noise.

	void sigusr1(int sig) { }

	int main(int argc, char **argv)
	{
		int i = 100000;

		signal(SIGUSR1, sigusr1);
		for (;i--;)
		    raise(SIGUSR1);
		exit(0);
	}

An additional 0.10s reduction is achieved by removing
CONFIG_PPC_FPU, as the mpc832x has no FPU.

A bit less spectacular on an 8xx as KUAP is less heavy, prior to
the series (with KUAP) it ran in 8.10 ms. Once applies the removal
of FPU regs handling, we get 7.05s. With the full series, we get 6.9s.
If artificially re-activating FPU regs handling with the full series,
we get 7.6s.

So for the 8xx, the removal of the FPU regs copy is what makes the
difference, but the rework of handle_signal also have a benefit.

Same as above, without KUAP the difference is in the noise.

Difference since v1(RFC):
- Almost copies to user are now replaced by unsafe_ alternative.
- Reworked a bit the FPU registers handling following feedback from Michael.
- Fixed a few build failures reported by Mr Robot on the RFC.

Christophe Leroy (25):
  powerpc/signal: Move inline functions in signal.h
  powerpc/ptrace: Move declaration of ptrace_get_reg() and
    ptrace_set_reg()
  powerpc/ptrace: Consolidate reg index calculation
  powerpc/ptrace: Create ptrace_get_fpr() and ptrace_put_fpr()
  powerpc/signal: Don't manage floating point regs when no FPU
  powerpc/32s: Allow deselecting CONFIG_PPC_FPU on mpc832x
  powerpc/signal: Remove BUG_ON() in handler_signal functions
  powerpc/signal: Move access_ok() out of get_sigframe()
  powerpc/signal: Remove get_clean_sp()
  powerpc/signal: Call get_tm_stackpointer() from get_sigframe()
  powerpc/signal: Refactor bad frame logging
  powerpc/signal32: Simplify logging in handle_rt_signal32()
  powerpc/signal32: Move handle_signal32() close to handle_rt_signal32()
  powerpc/signal32: Rename local pointers in handle_rt_signal32()
  powerpc/signal32: Misc changes to make handle_[rt_]_signal32() more
    similar
  powerpc/signal32: Move signal trampoline setup to handle_[rt_]signal32
  powerpc/signal32: Switch handle_signal32() to user_access_begin()
    logic
  powerpc/signal32: Switch handle_rt_signal32() to user_access_begin()
    logic
  powerpc/signal32: Remove ifdefery in middle of if/else
  signal: Add unsafe_put_compat_sigset()
  powerpc/signal32: Add and use unsafe_put_sigset_t()
  powerpc/signal32: Switch swap_context() to user_access_begin() logic
  powerpc/signal: Create 'unsafe' versions of
    copy_[ck][fpr/vsx]_to_user()
  powerpc/signal32: Isolate non-copy actions in save_user_regs() and
    save_tm_user_regs()
  powerpc/signal32: Transform save_user_regs() and save_tm_user_regs()
    in 'unsafe' version

 arch/powerpc/Kconfig                     |   1 +
 arch/powerpc/include/asm/processor.h     |  16 +-
 arch/powerpc/include/asm/ptrace.h        |   6 -
 arch/powerpc/kernel/asm-offsets.c        |   2 +
 arch/powerpc/kernel/head_32.S            |   4 +
 arch/powerpc/kernel/process.c            |   4 +
 arch/powerpc/kernel/ptrace/Makefile      |   3 +-
 arch/powerpc/kernel/ptrace/ptrace-decl.h |  21 +
 arch/powerpc/kernel/ptrace/ptrace-fpu.c  |  40 ++
 arch/powerpc/kernel/ptrace/ptrace-view.c |   2 +
 arch/powerpc/kernel/ptrace/ptrace.c      |  54 +-
 arch/powerpc/kernel/ptrace/ptrace32.c    |   2 +
 arch/powerpc/kernel/signal.c             |  59 +--
 arch/powerpc/kernel/signal.h             | 115 ++++-
 arch/powerpc/kernel/signal_32.c          | 598 +++++++++++------------
 arch/powerpc/kernel/signal_64.c          |  21 +-
 arch/powerpc/kernel/traps.c              |   2 +
 arch/powerpc/platforms/Kconfig.cputype   |  15 +-
 include/linux/compat.h                   |  32 ++
 19 files changed, 566 insertions(+), 431 deletions(-)
 create mode 100644 arch/powerpc/kernel/ptrace/ptrace-fpu.c

-- 
2.25.0

[PATCH v2 01/25] powerpc/signal: Move inline functions in signal.h

[Christophe Leroy]

To really be inlined, the functions need to be defined in the
same C file as the caller, or in an included header.

Move functions defined inline from signal .c in signal.h

Fixes: 3dd4eb83a9c0 ("powerpc: move common register copy functions from signal_32.c to signal.c")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal.c | 30 --------------------------
 arch/powerpc/kernel/signal.h | 41 +++++++++++++++++++++++++++++-------
 2 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index d15a98c758b8..3b56db02b762 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -133,36 +133,6 @@ unsigned long copy_ckvsx_from_user(struct task_struct *task,
 	return 0;
 }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
-#else
-inline unsigned long copy_fpr_to_user(void __user *to,
-				      struct task_struct *task)
-{
-	return __copy_to_user(to, task->thread.fp_state.fpr,
-			      ELF_NFPREG * sizeof(double));
-}
-
-inline unsigned long copy_fpr_from_user(struct task_struct *task,
-					void __user *from)
-{
-	return __copy_from_user(task->thread.fp_state.fpr, from,
-			      ELF_NFPREG * sizeof(double));
-}
-
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-inline unsigned long copy_ckfpr_to_user(void __user *to,
-					 struct task_struct *task)
-{
-	return __copy_to_user(to, task->thread.ckfp_state.fpr,
-			      ELF_NFPREG * sizeof(double));
-}
-
-inline unsigned long copy_ckfpr_from_user(struct task_struct *task,
-						 void __user *from)
-{
-	return __copy_from_user(task->thread.ckfp_state.fpr, from,
-				ELF_NFPREG * sizeof(double));
-}
-#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 #endif
 
 /* Log an error when sending an unhandled signal to a process. Controlled
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index d396efca4068..4626d39cc0f0 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -19,14 +19,6 @@ extern int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 extern int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 			      struct task_struct *tsk);
 
-extern unsigned long copy_fpr_to_user(void __user *to,
-				      struct task_struct *task);
-extern unsigned long copy_ckfpr_to_user(void __user *to,
-					       struct task_struct *task);
-extern unsigned long copy_fpr_from_user(struct task_struct *task,
-					void __user *from);
-extern unsigned long copy_ckfpr_from_user(struct task_struct *task,
-						 void __user *from);
 extern unsigned long get_tm_stackpointer(struct task_struct *tsk);
 
 #ifdef CONFIG_VSX
@@ -38,6 +30,39 @@ extern unsigned long copy_vsx_from_user(struct task_struct *task,
 					void __user *from);
 extern unsigned long copy_ckvsx_from_user(struct task_struct *task,
 						 void __user *from);
+unsigned long copy_fpr_to_user(void __user *to, struct task_struct *task);
+unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct *task);
+unsigned long copy_fpr_from_user(struct task_struct *task, void __user *from);
+unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
+#else
+static inline unsigned long
+copy_fpr_to_user(void __user *to, struct task_struct *task)
+{
+	return __copy_to_user(to, task->thread.fp_state.fpr,
+			      ELF_NFPREG * sizeof(double));
+}
+
+static inline unsigned long
+copy_fpr_from_user(struct task_struct *task, void __user *from)
+{
+	return __copy_from_user(task->thread.fp_state.fpr, from,
+			      ELF_NFPREG * sizeof(double));
+}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+inline unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct *task)
+{
+	return __copy_to_user(to, task->thread.ckfp_state.fpr,
+			      ELF_NFPREG * sizeof(double));
+}
+
+static inline unsigned long
+copy_ckfpr_from_user(struct task_struct *task, void __user *from)
+{
+	return __copy_from_user(task->thread.ckfp_state.fpr, from,
+				ELF_NFPREG * sizeof(double));
+}
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 #endif
 
 #ifdef CONFIG_PPC64
-- 
2.25.0

[PATCH v2 01/25] powerpc/signal: Move inline functions in signal.h

[Christophe Leroy]

To really be inlined, the functions need to be defined in the
same C file as the caller, or in an included header.

Move functions defined inline from signal .c in signal.h

Fixes: 3dd4eb83a9c0 ("powerpc: move common register copy functions from signal_32.c to signal.c")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal.c | 30 --------------------------
 arch/powerpc/kernel/signal.h | 41 +++++++++++++++++++++++++++++-------
 2 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index d15a98c758b8..3b56db02b762 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -133,36 +133,6 @@ unsigned long copy_ckvsx_from_user(struct task_struct *task,
 	return 0;
 }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
-#else
-inline unsigned long copy_fpr_to_user(void __user *to,
-				      struct task_struct *task)
-{
-	return __copy_to_user(to, task->thread.fp_state.fpr,
-			      ELF_NFPREG * sizeof(double));
-}
-
-inline unsigned long copy_fpr_from_user(struct task_struct *task,
-					void __user *from)
-{
-	return __copy_from_user(task->thread.fp_state.fpr, from,
-			      ELF_NFPREG * sizeof(double));
-}
-
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-inline unsigned long copy_ckfpr_to_user(void __user *to,
-					 struct task_struct *task)
-{
-	return __copy_to_user(to, task->thread.ckfp_state.fpr,
-			      ELF_NFPREG * sizeof(double));
-}
-
-inline unsigned long copy_ckfpr_from_user(struct task_struct *task,
-						 void __user *from)
-{
-	return __copy_from_user(task->thread.ckfp_state.fpr, from,
-				ELF_NFPREG * sizeof(double));
-}
-#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 #endif
 
 /* Log an error when sending an unhandled signal to a process. Controlled
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index d396efca4068..4626d39cc0f0 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -19,14 +19,6 @@ extern int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 extern int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 			      struct task_struct *tsk);
 
-extern unsigned long copy_fpr_to_user(void __user *to,
-				      struct task_struct *task);
-extern unsigned long copy_ckfpr_to_user(void __user *to,
-					       struct task_struct *task);
-extern unsigned long copy_fpr_from_user(struct task_struct *task,
-					void __user *from);
-extern unsigned long copy_ckfpr_from_user(struct task_struct *task,
-						 void __user *from);
 extern unsigned long get_tm_stackpointer(struct task_struct *tsk);
 
 #ifdef CONFIG_VSX
@@ -38,6 +30,39 @@ extern unsigned long copy_vsx_from_user(struct task_struct *task,
 					void __user *from);
 extern unsigned long copy_ckvsx_from_user(struct task_struct *task,
 						 void __user *from);
+unsigned long copy_fpr_to_user(void __user *to, struct task_struct *task);
+unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct *task);
+unsigned long copy_fpr_from_user(struct task_struct *task, void __user *from);
+unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
+#else
+static inline unsigned long
+copy_fpr_to_user(void __user *to, struct task_struct *task)
+{
+	return __copy_to_user(to, task->thread.fp_state.fpr,
+			      ELF_NFPREG * sizeof(double));
+}
+
+static inline unsigned long
+copy_fpr_from_user(struct task_struct *task, void __user *from)
+{
+	return __copy_from_user(task->thread.fp_state.fpr, from,
+			      ELF_NFPREG * sizeof(double));
+}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+inline unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct *task)
+{
+	return __copy_to_user(to, task->thread.ckfp_state.fpr,
+			      ELF_NFPREG * sizeof(double));
+}
+
+static inline unsigned long
+copy_ckfpr_from_user(struct task_struct *task, void __user *from)
+{
+	return __copy_from_user(task->thread.ckfp_state.fpr, from,
+				ELF_NFPREG * sizeof(double));
+}
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 #endif
 
 #ifdef CONFIG_PPC64
-- 
2.25.0

[PATCH v2 02/25] powerpc/ptrace: Move declaration of ptrace_get_reg() and ptrace_set_reg()

[Christophe Leroy]

ptrace_get_reg() and ptrace_set_reg() are only used internally by
ptrace.

Move them in arch/powerpc/kernel/ptrace/ptrace-decl.h

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/ptrace.h        | 6 ------
 arch/powerpc/kernel/ptrace/ptrace-decl.h | 3 +++
 arch/powerpc/kernel/ptrace/ptrace32.c    | 2 ++
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 155a197c0aa1..3c3cf537c3bf 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -171,12 +171,6 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
 		set_thread_flag(TIF_NOERROR); \
 	} while(0)
 
-struct task_struct;
-extern int ptrace_get_reg(struct task_struct *task, int regno,
-			  unsigned long *data);
-extern int ptrace_put_reg(struct task_struct *task, int regno,
-			  unsigned long data);
-
 #define current_pt_regs() \
 	((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1)
 
diff --git a/arch/powerpc/kernel/ptrace/ptrace-decl.h b/arch/powerpc/kernel/ptrace/ptrace-decl.h
index 67447a6197eb..2ddc68412fa8 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-decl.h
+++ b/arch/powerpc/kernel/ptrace/ptrace-decl.h
@@ -159,6 +159,9 @@ int tm_cgpr32_set(struct task_struct *target, const struct user_regset *regset,
 
 /* ptrace-view */
 
+int ptrace_get_reg(struct task_struct *task, int regno, unsigned long *data);
+int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data);
+
 extern const struct user_regset_view user_ppc_native_view;
 
 /* ptrace-(no)adv */
diff --git a/arch/powerpc/kernel/ptrace/ptrace32.c b/arch/powerpc/kernel/ptrace/ptrace32.c
index 7589a9665ffb..d30b9ad70edc 100644
--- a/arch/powerpc/kernel/ptrace/ptrace32.c
+++ b/arch/powerpc/kernel/ptrace/ptrace32.c
@@ -23,6 +23,8 @@
 
 #include <asm/switch_to.h>
 
+#include "ptrace-decl.h"
+
 /*
  * does not yet catch signals sent when the child dies.
  * in exit.c or in signal.c.
-- 
2.25.0

[PATCH v2 02/25] powerpc/ptrace: Move declaration of ptrace_get_reg() and ptrace_set_reg()

[Christophe Leroy]

ptrace_get_reg() and ptrace_set_reg() are only used internally by
ptrace.

Move them in arch/powerpc/kernel/ptrace/ptrace-decl.h

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/ptrace.h        | 6 ------
 arch/powerpc/kernel/ptrace/ptrace-decl.h | 3 +++
 arch/powerpc/kernel/ptrace/ptrace32.c    | 2 ++
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 155a197c0aa1..3c3cf537c3bf 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -171,12 +171,6 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
 		set_thread_flag(TIF_NOERROR); \
 	} while(0)
 
-struct task_struct;
-extern int ptrace_get_reg(struct task_struct *task, int regno,
-			  unsigned long *data);
-extern int ptrace_put_reg(struct task_struct *task, int regno,
-			  unsigned long data);
-
 #define current_pt_regs() \
 	((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1)
 
diff --git a/arch/powerpc/kernel/ptrace/ptrace-decl.h b/arch/powerpc/kernel/ptrace/ptrace-decl.h
index 67447a6197eb..2ddc68412fa8 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-decl.h
+++ b/arch/powerpc/kernel/ptrace/ptrace-decl.h
@@ -159,6 +159,9 @@ int tm_cgpr32_set(struct task_struct *target, const struct user_regset *regset,
 
 /* ptrace-view */
 
+int ptrace_get_reg(struct task_struct *task, int regno, unsigned long *data);
+int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data);
+
 extern const struct user_regset_view user_ppc_native_view;
 
 /* ptrace-(no)adv */
diff --git a/arch/powerpc/kernel/ptrace/ptrace32.c b/arch/powerpc/kernel/ptrace/ptrace32.c
index 7589a9665ffb..d30b9ad70edc 100644
--- a/arch/powerpc/kernel/ptrace/ptrace32.c
+++ b/arch/powerpc/kernel/ptrace/ptrace32.c
@@ -23,6 +23,8 @@
 
 #include <asm/switch_to.h>
 
+#include "ptrace-decl.h"
+
 /*
  * does not yet catch signals sent when the child dies.
  * in exit.c or in signal.c.
-- 
2.25.0

[PATCH v2 03/25] powerpc/ptrace: Consolidate reg index calculation

[Christophe Leroy]

Today we have:

	#ifdef CONFIG_PPC32
		index = addr >> 2;
		if ((addr & 3) || child->thread.regs == NULL)
	#else
		index = addr >> 3;
		if ((addr & 7))
	#endif

sizeof(long) has value 4 for PPC32 and value 8 for PPC64.

Dividing by 4 is equivalent to >> 2 and dividing by 8 is equivalent
to >> 3.

And 3 and 7 are respectively (sizeof(long) - 1).

Use sizeof(long) to get rid of the #ifdef CONFIG_PPC32 and consolidate
the calculation and checking.

thread.regs have to be not NULL on both PPC32 and PPC64 so adding
that test on PPC64 is harmless.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/ptrace/ptrace.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
index f6e51be47c6e..51557a9c0765 100644
--- a/arch/powerpc/kernel/ptrace/ptrace.c
+++ b/arch/powerpc/kernel/ptrace/ptrace.c
@@ -55,14 +55,9 @@ long arch_ptrace(struct task_struct *child, long request,
 
 		ret = -EIO;
 		/* convert to index and check */
-#ifdef CONFIG_PPC32
-		index = addr >> 2;
-		if ((addr & 3) || (index > PT_FPSCR)
+		index = addr / sizeof(long);
+		if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR)
 		    || (child->thread.regs == NULL))
-#else
-		index = addr >> 3;
-		if ((addr & 7) || (index > PT_FPSCR))
-#endif
 			break;
 
 		CHECK_FULL_REGS(child->thread.regs);
@@ -90,14 +85,9 @@ long arch_ptrace(struct task_struct *child, long request,
 
 		ret = -EIO;
 		/* convert to index and check */
-#ifdef CONFIG_PPC32
-		index = addr >> 2;
-		if ((addr & 3) || (index > PT_FPSCR)
+		index = addr / sizeof(long);
+		if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR)
 		    || (child->thread.regs == NULL))
-#else
-		index = addr >> 3;
-		if ((addr & 7) || (index > PT_FPSCR))
-#endif
 			break;
 
 		CHECK_FULL_REGS(child->thread.regs);
-- 
2.25.0

[PATCH v2 03/25] powerpc/ptrace: Consolidate reg index calculation

[Christophe Leroy]

Today we have:

	#ifdef CONFIG_PPC32
		index = addr >> 2;
		if ((addr & 3) || child->thread.regs == NULL)
	#else
		index = addr >> 3;
		if ((addr & 7))
	#endif

sizeof(long) has value 4 for PPC32 and value 8 for PPC64.

Dividing by 4 is equivalent to >> 2 and dividing by 8 is equivalent
to >> 3.

And 3 and 7 are respectively (sizeof(long) - 1).

Use sizeof(long) to get rid of the #ifdef CONFIG_PPC32 and consolidate
the calculation and checking.

thread.regs have to be not NULL on both PPC32 and PPC64 so adding
that test on PPC64 is harmless.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/ptrace/ptrace.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
index f6e51be47c6e..51557a9c0765 100644
--- a/arch/powerpc/kernel/ptrace/ptrace.c
+++ b/arch/powerpc/kernel/ptrace/ptrace.c
@@ -55,14 +55,9 @@ long arch_ptrace(struct task_struct *child, long request,
 
 		ret = -EIO;
 		/* convert to index and check */
-#ifdef CONFIG_PPC32
-		index = addr >> 2;
-		if ((addr & 3) || (index > PT_FPSCR)
+		index = addr / sizeof(long);
+		if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR)
 		    || (child->thread.regs == NULL))
-#else
-		index = addr >> 3;
-		if ((addr & 7) || (index > PT_FPSCR))
-#endif
 			break;
 
 		CHECK_FULL_REGS(child->thread.regs);
@@ -90,14 +85,9 @@ long arch_ptrace(struct task_struct *child, long request,
 
 		ret = -EIO;
 		/* convert to index and check */
-#ifdef CONFIG_PPC32
-		index = addr >> 2;
-		if ((addr & 3) || (index > PT_FPSCR)
+		index = addr / sizeof(long);
+		if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR)
 		    || (child->thread.regs == NULL))
-#else
-		index = addr >> 3;
-		if ((addr & 7) || (index > PT_FPSCR))
-#endif
 			break;
 
 		CHECK_FULL_REGS(child->thread.regs);
-- 
2.25.0

[PATCH v2 04/25] powerpc/ptrace: Create ptrace_get_fpr() and ptrace_put_fpr()

[Christophe Leroy]

On the same model as ptrace_get_reg() and ptrace_put_reg(),
create ptrace_get_fpr() and ptrace_put_fpr() to get/set
the floating points registers.

We move the boundary checkings in them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/ptrace/Makefile      |  1 +
 arch/powerpc/kernel/ptrace/ptrace-decl.h |  4 +++
 arch/powerpc/kernel/ptrace/ptrace-fpu.c  | 40 ++++++++++++++++++++++++
 arch/powerpc/kernel/ptrace/ptrace.c      | 40 +++++++-----------------
 4 files changed, 56 insertions(+), 29 deletions(-)
 create mode 100644 arch/powerpc/kernel/ptrace/ptrace-fpu.c

diff --git a/arch/powerpc/kernel/ptrace/Makefile b/arch/powerpc/kernel/ptrace/Makefile
index c2f2402ebc8c..77abd1a5a508 100644
--- a/arch/powerpc/kernel/ptrace/Makefile
+++ b/arch/powerpc/kernel/ptrace/Makefile
@@ -6,6 +6,7 @@
 CFLAGS_ptrace-view.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
 
 obj-y				+= ptrace.o ptrace-view.o
+obj-y				+= ptrace-fpu.o
 obj-$(CONFIG_COMPAT)		+= ptrace32.o
 obj-$(CONFIG_VSX)		+= ptrace-vsx.o
 ifneq ($(CONFIG_VSX),y)
diff --git a/arch/powerpc/kernel/ptrace/ptrace-decl.h b/arch/powerpc/kernel/ptrace/ptrace-decl.h
index 2ddc68412fa8..eafe5f0f6289 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-decl.h
+++ b/arch/powerpc/kernel/ptrace/ptrace-decl.h
@@ -164,6 +164,10 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data);
 
 extern const struct user_regset_view user_ppc_native_view;
 
+/* ptrace-fpu */
+int ptrace_get_fpr(struct task_struct *child, int index, unsigned long *data);
+int ptrace_put_fpr(struct task_struct *child, int index, unsigned long data);
+
 /* ptrace-(no)adv */
 void ppc_gethwdinfo(struct ppc_debug_info *dbginfo);
 int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
diff --git a/arch/powerpc/kernel/ptrace/ptrace-fpu.c b/arch/powerpc/kernel/ptrace/ptrace-fpu.c
new file mode 100644
index 000000000000..8301cb52dd99
--- /dev/null
+++ b/arch/powerpc/kernel/ptrace/ptrace-fpu.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/regset.h>
+
+#include <asm/switch_to.h>
+
+#include "ptrace-decl.h"
+
+int ptrace_get_fpr(struct task_struct *child, int index, unsigned long *data)
+{
+	unsigned int fpidx = index - PT_FPR0;
+
+	if (index > PT_FPSCR)
+		return -EIO;
+
+	flush_fp_to_thread(child);
+	if (fpidx < (PT_FPSCR - PT_FPR0))
+		memcpy(data, &child->thread.TS_FPR(fpidx), sizeof(long));
+	else
+		*data = child->thread.fp_state.fpscr;
+
+	return 0;
+}
+
+int ptrace_put_fpr(struct task_struct *child, int index, unsigned long data)
+{
+	unsigned int fpidx = index - PT_FPR0;
+
+	if (index > PT_FPSCR)
+		return -EIO;
+
+	flush_fp_to_thread(child);
+	if (fpidx < (PT_FPSCR - PT_FPR0))
+		memcpy(&child->thread.TS_FPR(fpidx), &data, sizeof(long));
+	else
+		child->thread.fp_state.fpscr = data;
+
+	return 0;
+}
+
diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
index 51557a9c0765..3d44b73adb83 100644
--- a/arch/powerpc/kernel/ptrace/ptrace.c
+++ b/arch/powerpc/kernel/ptrace/ptrace.c
@@ -56,25 +56,17 @@ long arch_ptrace(struct task_struct *child, long request,
 		ret = -EIO;
 		/* convert to index and check */
 		index = addr / sizeof(long);
-		if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR)
-		    || (child->thread.regs == NULL))
+		if ((addr & (sizeof(long) - 1)) || !child->thread.regs)
 			break;
 
 		CHECK_FULL_REGS(child->thread.regs);
-		if (index < PT_FPR0) {
+		if (index < PT_FPR0)
 			ret = ptrace_get_reg(child, (int) index, &tmp);
-			if (ret)
-				break;
-		} else {
-			unsigned int fpidx = index - PT_FPR0;
-
-			flush_fp_to_thread(child);
-			if (fpidx < (PT_FPSCR - PT_FPR0))
-				memcpy(&tmp, &child->thread.TS_FPR(fpidx),
-				       sizeof(long));
-			else
-				tmp = child->thread.fp_state.fpscr;
-		}
+		else
+			ret = ptrace_get_fpr(child, index, &tmp);
+
+		if (ret)
+			break;
 		ret = put_user(tmp, datalp);
 		break;
 	}
@@ -86,24 +78,14 @@ long arch_ptrace(struct task_struct *child, long request,
 		ret = -EIO;
 		/* convert to index and check */
 		index = addr / sizeof(long);
-		if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR)
-		    || (child->thread.regs == NULL))
+		if ((addr & (sizeof(long) - 1)) || !child->thread.regs)
 			break;
 
 		CHECK_FULL_REGS(child->thread.regs);
-		if (index < PT_FPR0) {
+		if (index < PT_FPR0)
 			ret = ptrace_put_reg(child, index, data);
-		} else {
-			unsigned int fpidx = index - PT_FPR0;
-
-			flush_fp_to_thread(child);
-			if (fpidx < (PT_FPSCR - PT_FPR0))
-				memcpy(&child->thread.TS_FPR(fpidx), &data,
-				       sizeof(long));
-			else
-				child->thread.fp_state.fpscr = data;
-			ret = 0;
-		}
+		else
+			ret = ptrace_put_fpr(child, index, data);
 		break;
 	}
 
-- 
2.25.0

[PATCH v2 04/25] powerpc/ptrace: Create ptrace_get_fpr() and ptrace_put_fpr()

[Christophe Leroy]

On the same model as ptrace_get_reg() and ptrace_put_reg(),
create ptrace_get_fpr() and ptrace_put_fpr() to get/set
the floating points registers.

We move the boundary checkings in them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/ptrace/Makefile      |  1 +
 arch/powerpc/kernel/ptrace/ptrace-decl.h |  4 +++
 arch/powerpc/kernel/ptrace/ptrace-fpu.c  | 40 ++++++++++++++++++++++++
 arch/powerpc/kernel/ptrace/ptrace.c      | 40 +++++++-----------------
 4 files changed, 56 insertions(+), 29 deletions(-)
 create mode 100644 arch/powerpc/kernel/ptrace/ptrace-fpu.c

diff --git a/arch/powerpc/kernel/ptrace/Makefile b/arch/powerpc/kernel/ptrace/Makefile
index c2f2402ebc8c..77abd1a5a508 100644
--- a/arch/powerpc/kernel/ptrace/Makefile
+++ b/arch/powerpc/kernel/ptrace/Makefile
@@ -6,6 +6,7 @@
 CFLAGS_ptrace-view.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
 
 obj-y				+= ptrace.o ptrace-view.o
+obj-y				+= ptrace-fpu.o
 obj-$(CONFIG_COMPAT)		+= ptrace32.o
 obj-$(CONFIG_VSX)		+= ptrace-vsx.o
 ifneq ($(CONFIG_VSX),y)
diff --git a/arch/powerpc/kernel/ptrace/ptrace-decl.h b/arch/powerpc/kernel/ptrace/ptrace-decl.h
index 2ddc68412fa8..eafe5f0f6289 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-decl.h
+++ b/arch/powerpc/kernel/ptrace/ptrace-decl.h
@@ -164,6 +164,10 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data);
 
 extern const struct user_regset_view user_ppc_native_view;
 
+/* ptrace-fpu */
+int ptrace_get_fpr(struct task_struct *child, int index, unsigned long *data);
+int ptrace_put_fpr(struct task_struct *child, int index, unsigned long data);
+
 /* ptrace-(no)adv */
 void ppc_gethwdinfo(struct ppc_debug_info *dbginfo);
 int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
diff --git a/arch/powerpc/kernel/ptrace/ptrace-fpu.c b/arch/powerpc/kernel/ptrace/ptrace-fpu.c
new file mode 100644
index 000000000000..8301cb52dd99
--- /dev/null
+++ b/arch/powerpc/kernel/ptrace/ptrace-fpu.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/regset.h>
+
+#include <asm/switch_to.h>
+
+#include "ptrace-decl.h"
+
+int ptrace_get_fpr(struct task_struct *child, int index, unsigned long *data)
+{
+	unsigned int fpidx = index - PT_FPR0;
+
+	if (index > PT_FPSCR)
+		return -EIO;
+
+	flush_fp_to_thread(child);
+	if (fpidx < (PT_FPSCR - PT_FPR0))
+		memcpy(data, &child->thread.TS_FPR(fpidx), sizeof(long));
+	else
+		*data = child->thread.fp_state.fpscr;
+
+	return 0;
+}
+
+int ptrace_put_fpr(struct task_struct *child, int index, unsigned long data)
+{
+	unsigned int fpidx = index - PT_FPR0;
+
+	if (index > PT_FPSCR)
+		return -EIO;
+
+	flush_fp_to_thread(child);
+	if (fpidx < (PT_FPSCR - PT_FPR0))
+		memcpy(&child->thread.TS_FPR(fpidx), &data, sizeof(long));
+	else
+		child->thread.fp_state.fpscr = data;
+
+	return 0;
+}
+
diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
index 51557a9c0765..3d44b73adb83 100644
--- a/arch/powerpc/kernel/ptrace/ptrace.c
+++ b/arch/powerpc/kernel/ptrace/ptrace.c
@@ -56,25 +56,17 @@ long arch_ptrace(struct task_struct *child, long request,
 		ret = -EIO;
 		/* convert to index and check */
 		index = addr / sizeof(long);
-		if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR)
-		    || (child->thread.regs == NULL))
+		if ((addr & (sizeof(long) - 1)) || !child->thread.regs)
 			break;
 
 		CHECK_FULL_REGS(child->thread.regs);
-		if (index < PT_FPR0) {
+		if (index < PT_FPR0)
 			ret = ptrace_get_reg(child, (int) index, &tmp);
-			if (ret)
-				break;
-		} else {
-			unsigned int fpidx = index - PT_FPR0;
-
-			flush_fp_to_thread(child);
-			if (fpidx < (PT_FPSCR - PT_FPR0))
-				memcpy(&tmp, &child->thread.TS_FPR(fpidx),
-				       sizeof(long));
-			else
-				tmp = child->thread.fp_state.fpscr;
-		}
+		else
+			ret = ptrace_get_fpr(child, index, &tmp);
+
+		if (ret)
+			break;
 		ret = put_user(tmp, datalp);
 		break;
 	}
@@ -86,24 +78,14 @@ long arch_ptrace(struct task_struct *child, long request,
 		ret = -EIO;
 		/* convert to index and check */
 		index = addr / sizeof(long);
-		if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR)
-		    || (child->thread.regs == NULL))
+		if ((addr & (sizeof(long) - 1)) || !child->thread.regs)
 			break;
 
 		CHECK_FULL_REGS(child->thread.regs);
-		if (index < PT_FPR0) {
+		if (index < PT_FPR0)
 			ret = ptrace_put_reg(child, index, data);
-		} else {
-			unsigned int fpidx = index - PT_FPR0;
-
-			flush_fp_to_thread(child);
-			if (fpidx < (PT_FPSCR - PT_FPR0))
-				memcpy(&child->thread.TS_FPR(fpidx), &data,
-				       sizeof(long));
-			else
-				child->thread.fp_state.fpscr = data;
-			ret = 0;
-		}
+		else
+			ret = ptrace_put_fpr(child, index, data);
 		break;
 	}
 
-- 
2.25.0

[PATCH v2 05/25] powerpc/signal: Don't manage floating point regs when no FPU

[Christophe Leroy]

There is no point in copying floating point regs when there
is no FPU and MATH_EMULATION is not selected.

Create a new CONFIG_PPC_FPU_REGS bool that is selected by
CONFIG_MATH_EMULATION and CONFIG_PPC_FPU, and use it to
opt out everything related to fp_state in thread_struct.

The asm const used only by fpu.S are opted out with CONFIG_PPC_FPU
as fpu.S build is conditionnal to CONFIG_PPC_FPU.

The following app spends approx 8.1 seconds system time on an 8xx
without the patch, and 7.0 seconds with the patch (13.5% reduction).

On an 832x, it spends approx 2.6 seconds system time without
the patch and 2.1 seconds with the patch (19% reduction).

	void sigusr1(int sig) { }

	int main(int argc, char **argv)
	{
		int i = 100000;

		signal(SIGUSR1, sigusr1);
		for (;i--;)
			raise(SIGUSR1);
		exit(0);
	}

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/Kconfig                     |  1 +
 arch/powerpc/include/asm/processor.h     |  2 ++
 arch/powerpc/kernel/asm-offsets.c        |  2 ++
 arch/powerpc/kernel/process.c            |  4 ++++
 arch/powerpc/kernel/ptrace/Makefile      |  4 ++--
 arch/powerpc/kernel/ptrace/ptrace-decl.h | 14 ++++++++++++++
 arch/powerpc/kernel/ptrace/ptrace-view.c |  2 ++
 arch/powerpc/kernel/signal.h             | 14 +++++++++++++-
 arch/powerpc/kernel/signal_32.c          |  4 ++++
 arch/powerpc/kernel/traps.c              |  2 ++
 arch/powerpc/platforms/Kconfig.cputype   |  4 ++++
 11 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1f48bbfb3ce9..a2611880b904 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -416,6 +416,7 @@ config HUGETLB_PAGE_SIZE_VARIABLE
 config MATH_EMULATION
 	bool "Math emulation"
 	depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE
+	select PPC_FPU_REGS
 	help
 	  Some PowerPC chips designed for embedded applications do not have
 	  a floating-point unit and therefore do not implement the
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index ed0d633ab5aa..e20b0c5abe62 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -175,8 +175,10 @@ struct thread_struct {
 #endif
 	/* Debug Registers */
 	struct debug_reg debug;
+#ifdef CONFIG_PPC_FPU_REGS
 	struct thread_fp_state	fp_state;
 	struct thread_fp_state	*fp_save_area;
+#endif
 	int		fpexc_mode;	/* floating-point exception mode */
 	unsigned int	align_ctl;	/* alignment handling control */
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 8711c2164b45..6cb36c341c70 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -110,9 +110,11 @@ int main(void)
 #ifdef CONFIG_BOOKE
 	OFFSET(THREAD_NORMSAVES, thread_struct, normsave[0]);
 #endif
+#ifdef CONFIG_PPC_FPU
 	OFFSET(THREAD_FPEXC_MODE, thread_struct, fpexc_mode);
 	OFFSET(THREAD_FPSTATE, thread_struct, fp_state.fpr);
 	OFFSET(THREAD_FPSAVEAREA, thread_struct, fp_save_area);
+#endif
 	OFFSET(FPSTATE_FPSCR, thread_fp_state, fpscr);
 	OFFSET(THREAD_LOAD_FP, thread_struct, load_fp);
 #ifdef CONFIG_ALTIVEC
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 016bd831908e..7e0082ac0a39 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1694,7 +1694,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 		p->thread.ptrace_bps[i] = NULL;
 #endif
 
+#ifdef CONFIG_PPC_FPU_REGS
 	p->thread.fp_save_area = NULL;
+#endif
 #ifdef CONFIG_ALTIVEC
 	p->thread.vr_save_area = NULL;
 #endif
@@ -1821,8 +1823,10 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 #endif
 	current->thread.load_slb = 0;
 	current->thread.load_fp = 0;
+#ifdef CONFIG_PPC_FPU_REGS
 	memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
 	current->thread.fp_save_area = NULL;
+#endif
 #ifdef CONFIG_ALTIVEC
 	memset(&current->thread.vr_state, 0, sizeof(current->thread.vr_state));
 	current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
diff --git a/arch/powerpc/kernel/ptrace/Makefile b/arch/powerpc/kernel/ptrace/Makefile
index 77abd1a5a508..8ebc11d1168d 100644
--- a/arch/powerpc/kernel/ptrace/Makefile
+++ b/arch/powerpc/kernel/ptrace/Makefile
@@ -6,11 +6,11 @@
 CFLAGS_ptrace-view.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
 
 obj-y				+= ptrace.o ptrace-view.o
-obj-y				+= ptrace-fpu.o
+obj-$(CONFIG_PPC_FPU_REGS)	+= ptrace-fpu.o
 obj-$(CONFIG_COMPAT)		+= ptrace32.o
 obj-$(CONFIG_VSX)		+= ptrace-vsx.o
 ifneq ($(CONFIG_VSX),y)
-obj-y				+= ptrace-novsx.o
+obj-$(CONFIG_PPC_FPU_REGS)	+= ptrace-novsx.o
 endif
 obj-$(CONFIG_ALTIVEC)		+= ptrace-altivec.o
 obj-$(CONFIG_SPE)		+= ptrace-spe.o
diff --git a/arch/powerpc/kernel/ptrace/ptrace-decl.h b/arch/powerpc/kernel/ptrace/ptrace-decl.h
index eafe5f0f6289..3487f2c9735c 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-decl.h
+++ b/arch/powerpc/kernel/ptrace/ptrace-decl.h
@@ -165,8 +165,22 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data);
 extern const struct user_regset_view user_ppc_native_view;
 
 /* ptrace-fpu */
+#ifdef CONFIG_PPC_FPU_REGS
 int ptrace_get_fpr(struct task_struct *child, int index, unsigned long *data);
 int ptrace_put_fpr(struct task_struct *child, int index, unsigned long data);
+#else
+static inline int
+ptrace_get_fpr(struct task_struct *child, int index, unsigned long *data)
+{
+	return -EIO;
+}
+
+static inline int
+ptrace_put_fpr(struct task_struct *child, int index, unsigned long data)
+{
+	return -EIO;
+}
+#endif
 
 /* ptrace-(no)adv */
 void ppc_gethwdinfo(struct ppc_debug_info *dbginfo);
diff --git a/arch/powerpc/kernel/ptrace/ptrace-view.c b/arch/powerpc/kernel/ptrace/ptrace-view.c
index 7e6478e7ed07..f1df8c62baf1 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-view.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-view.c
@@ -520,11 +520,13 @@ static const struct user_regset native_regsets[] = {
 		.size = sizeof(long), .align = sizeof(long),
 		.regset_get = gpr_get, .set = gpr_set
 	},
+#ifdef CONFIG_PPC_FPU_REGS
 	[REGSET_FPR] = {
 		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
 		.size = sizeof(double), .align = sizeof(double),
 		.regset_get = fpr_get, .set = fpr_set
 	},
+#endif
 #ifdef CONFIG_ALTIVEC
 	[REGSET_VMX] = {
 		.core_note_type = NT_PPC_VMX, .n = 34,
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index 4626d39cc0f0..6c2a33ab042c 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -34,7 +34,7 @@ unsigned long copy_fpr_to_user(void __user *to, struct task_struct *task);
 unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct *task);
 unsigned long copy_fpr_from_user(struct task_struct *task, void __user *from);
 unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
-#else
+#elif defined(CONFIG_PPC_FPU_REGS)
 static inline unsigned long
 copy_fpr_to_user(void __user *to, struct task_struct *task)
 {
@@ -63,6 +63,18 @@ copy_ckfpr_from_user(struct task_struct *task, void __user *from)
 				ELF_NFPREG * sizeof(double));
 }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+#else
+static inline unsigned long
+copy_fpr_to_user(void __user *to, struct task_struct *task)
+{
+	return 0;
+}
+
+static inline unsigned long
+copy_fpr_from_user(struct task_struct *task, void __user *from)
+{
+	return 0;
+}
 #endif
 
 #ifdef CONFIG_PPC64
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 96950f189b5a..7b291707eb31 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -814,7 +814,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	}
 	regs->link = tramp;
 
+#ifdef CONFIG_PPC_FPU_REGS
 	tsk->thread.fp_state.fpscr = 0;	/* turn off all fp exceptions */
+#endif
 
 	/* create a stack frame for the caller of the handler */
 	newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
@@ -1271,7 +1273,9 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	regs->link = tramp;
 
+#ifdef CONFIG_PPC_FPU_REGS
 	tsk->thread.fp_state.fpscr = 0;	/* turn off all fp exceptions */
+#endif
 
 	/* create a stack frame for the caller of the handler */
 	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index d1ebe152f210..5c68f0de905c 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1194,7 +1194,9 @@ static void parse_fpe(struct pt_regs *regs)
 
 	flush_fp_to_thread(current);
 
+#ifdef CONFIG_PPC_FPU_REGS
 	code = __parse_fpscr(current->thread.fp_state.fpscr);
+#endif
 
 	_exception(SIGFPE, regs, code, regs->nip);
 }
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 87737ec86d39..40ffcdba42b8 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -225,9 +225,13 @@ config PPC_E500MC
 	  such as e5500/e6500), and must be disabled for running on
 	  e500v1 or e500v2.
 
+config PPC_FPU_REGS
+	bool
+
 config PPC_FPU
 	bool
 	default y if PPC64
+	select PPC_FPU_REGS
 
 config FSL_EMB_PERFMON
 	bool "Freescale Embedded Perfmon"
-- 
2.25.0

[PATCH v2 05/25] powerpc/signal: Don't manage floating point regs when no FPU

[Christophe Leroy]

There is no point in copying floating point regs when there
is no FPU and MATH_EMULATION is not selected.

Create a new CONFIG_PPC_FPU_REGS bool that is selected by
CONFIG_MATH_EMULATION and CONFIG_PPC_FPU, and use it to
opt out everything related to fp_state in thread_struct.

The asm const used only by fpu.S are opted out with CONFIG_PPC_FPU
as fpu.S build is conditionnal to CONFIG_PPC_FPU.

The following app spends approx 8.1 seconds system time on an 8xx
without the patch, and 7.0 seconds with the patch (13.5% reduction).

On an 832x, it spends approx 2.6 seconds system time without
the patch and 2.1 seconds with the patch (19% reduction).

	void sigusr1(int sig) { }

	int main(int argc, char **argv)
	{
		int i = 100000;

		signal(SIGUSR1, sigusr1);
		for (;i--;)
			raise(SIGUSR1);
		exit(0);
	}

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/Kconfig                     |  1 +
 arch/powerpc/include/asm/processor.h     |  2 ++
 arch/powerpc/kernel/asm-offsets.c        |  2 ++
 arch/powerpc/kernel/process.c            |  4 ++++
 arch/powerpc/kernel/ptrace/Makefile      |  4 ++--
 arch/powerpc/kernel/ptrace/ptrace-decl.h | 14 ++++++++++++++
 arch/powerpc/kernel/ptrace/ptrace-view.c |  2 ++
 arch/powerpc/kernel/signal.h             | 14 +++++++++++++-
 arch/powerpc/kernel/signal_32.c          |  4 ++++
 arch/powerpc/kernel/traps.c              |  2 ++
 arch/powerpc/platforms/Kconfig.cputype   |  4 ++++
 11 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1f48bbfb3ce9..a2611880b904 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -416,6 +416,7 @@ config HUGETLB_PAGE_SIZE_VARIABLE
 config MATH_EMULATION
 	bool "Math emulation"
 	depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE
+	select PPC_FPU_REGS
 	help
 	  Some PowerPC chips designed for embedded applications do not have
 	  a floating-point unit and therefore do not implement the
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index ed0d633ab5aa..e20b0c5abe62 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -175,8 +175,10 @@ struct thread_struct {
 #endif
 	/* Debug Registers */
 	struct debug_reg debug;
+#ifdef CONFIG_PPC_FPU_REGS
 	struct thread_fp_state	fp_state;
 	struct thread_fp_state	*fp_save_area;
+#endif
 	int		fpexc_mode;	/* floating-point exception mode */
 	unsigned int	align_ctl;	/* alignment handling control */
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 8711c2164b45..6cb36c341c70 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -110,9 +110,11 @@ int main(void)
 #ifdef CONFIG_BOOKE
 	OFFSET(THREAD_NORMSAVES, thread_struct, normsave[0]);
 #endif
+#ifdef CONFIG_PPC_FPU
 	OFFSET(THREAD_FPEXC_MODE, thread_struct, fpexc_mode);
 	OFFSET(THREAD_FPSTATE, thread_struct, fp_state.fpr);
 	OFFSET(THREAD_FPSAVEAREA, thread_struct, fp_save_area);
+#endif
 	OFFSET(FPSTATE_FPSCR, thread_fp_state, fpscr);
 	OFFSET(THREAD_LOAD_FP, thread_struct, load_fp);
 #ifdef CONFIG_ALTIVEC
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 016bd831908e..7e0082ac0a39 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1694,7 +1694,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 		p->thread.ptrace_bps[i] = NULL;
 #endif
 
+#ifdef CONFIG_PPC_FPU_REGS
 	p->thread.fp_save_area = NULL;
+#endif
 #ifdef CONFIG_ALTIVEC
 	p->thread.vr_save_area = NULL;
 #endif
@@ -1821,8 +1823,10 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 #endif
 	current->thread.load_slb = 0;
 	current->thread.load_fp = 0;
+#ifdef CONFIG_PPC_FPU_REGS
 	memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
 	current->thread.fp_save_area = NULL;
+#endif
 #ifdef CONFIG_ALTIVEC
 	memset(&current->thread.vr_state, 0, sizeof(current->thread.vr_state));
 	current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
diff --git a/arch/powerpc/kernel/ptrace/Makefile b/arch/powerpc/kernel/ptrace/Makefile
index 77abd1a5a508..8ebc11d1168d 100644
--- a/arch/powerpc/kernel/ptrace/Makefile
+++ b/arch/powerpc/kernel/ptrace/Makefile
@@ -6,11 +6,11 @@
 CFLAGS_ptrace-view.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
 
 obj-y				+= ptrace.o ptrace-view.o
-obj-y				+= ptrace-fpu.o
+obj-$(CONFIG_PPC_FPU_REGS)	+= ptrace-fpu.o
 obj-$(CONFIG_COMPAT)		+= ptrace32.o
 obj-$(CONFIG_VSX)		+= ptrace-vsx.o
 ifneq ($(CONFIG_VSX),y)
-obj-y				+= ptrace-novsx.o
+obj-$(CONFIG_PPC_FPU_REGS)	+= ptrace-novsx.o
 endif
 obj-$(CONFIG_ALTIVEC)		+= ptrace-altivec.o
 obj-$(CONFIG_SPE)		+= ptrace-spe.o
diff --git a/arch/powerpc/kernel/ptrace/ptrace-decl.h b/arch/powerpc/kernel/ptrace/ptrace-decl.h
index eafe5f0f6289..3487f2c9735c 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-decl.h
+++ b/arch/powerpc/kernel/ptrace/ptrace-decl.h
@@ -165,8 +165,22 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data);
 extern const struct user_regset_view user_ppc_native_view;
 
 /* ptrace-fpu */
+#ifdef CONFIG_PPC_FPU_REGS
 int ptrace_get_fpr(struct task_struct *child, int index, unsigned long *data);
 int ptrace_put_fpr(struct task_struct *child, int index, unsigned long data);
+#else
+static inline int
+ptrace_get_fpr(struct task_struct *child, int index, unsigned long *data)
+{
+	return -EIO;
+}
+
+static inline int
+ptrace_put_fpr(struct task_struct *child, int index, unsigned long data)
+{
+	return -EIO;
+}
+#endif
 
 /* ptrace-(no)adv */
 void ppc_gethwdinfo(struct ppc_debug_info *dbginfo);
diff --git a/arch/powerpc/kernel/ptrace/ptrace-view.c b/arch/powerpc/kernel/ptrace/ptrace-view.c
index 7e6478e7ed07..f1df8c62baf1 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-view.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-view.c
@@ -520,11 +520,13 @@ static const struct user_regset native_regsets[] = {
 		.size = sizeof(long), .align = sizeof(long),
 		.regset_get = gpr_get, .set = gpr_set
 	},
+#ifdef CONFIG_PPC_FPU_REGS
 	[REGSET_FPR] = {
 		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
 		.size = sizeof(double), .align = sizeof(double),
 		.regset_get = fpr_get, .set = fpr_set
 	},
+#endif
 #ifdef CONFIG_ALTIVEC
 	[REGSET_VMX] = {
 		.core_note_type = NT_PPC_VMX, .n = 34,
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index 4626d39cc0f0..6c2a33ab042c 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -34,7 +34,7 @@ unsigned long copy_fpr_to_user(void __user *to, struct task_struct *task);
 unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct *task);
 unsigned long copy_fpr_from_user(struct task_struct *task, void __user *from);
 unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
-#else
+#elif defined(CONFIG_PPC_FPU_REGS)
 static inline unsigned long
 copy_fpr_to_user(void __user *to, struct task_struct *task)
 {
@@ -63,6 +63,18 @@ copy_ckfpr_from_user(struct task_struct *task, void __user *from)
 				ELF_NFPREG * sizeof(double));
 }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+#else
+static inline unsigned long
+copy_fpr_to_user(void __user *to, struct task_struct *task)
+{
+	return 0;
+}
+
+static inline unsigned long
+copy_fpr_from_user(struct task_struct *task, void __user *from)
+{
+	return 0;
+}
 #endif
 
 #ifdef CONFIG_PPC64
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 96950f189b5a..7b291707eb31 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -814,7 +814,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	}
 	regs->link = tramp;
 
+#ifdef CONFIG_PPC_FPU_REGS
 	tsk->thread.fp_state.fpscr = 0;	/* turn off all fp exceptions */
+#endif
 
 	/* create a stack frame for the caller of the handler */
 	newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
@@ -1271,7 +1273,9 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	regs->link = tramp;
 
+#ifdef CONFIG_PPC_FPU_REGS
 	tsk->thread.fp_state.fpscr = 0;	/* turn off all fp exceptions */
+#endif
 
 	/* create a stack frame for the caller of the handler */
 	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index d1ebe152f210..5c68f0de905c 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1194,7 +1194,9 @@ static void parse_fpe(struct pt_regs *regs)
 
 	flush_fp_to_thread(current);
 
+#ifdef CONFIG_PPC_FPU_REGS
 	code = __parse_fpscr(current->thread.fp_state.fpscr);
+#endif
 
 	_exception(SIGFPE, regs, code, regs->nip);
 }
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 87737ec86d39..40ffcdba42b8 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -225,9 +225,13 @@ config PPC_E500MC
 	  such as e5500/e6500), and must be disabled for running on
 	  e500v1 or e500v2.
 
+config PPC_FPU_REGS
+	bool
+
 config PPC_FPU
 	bool
 	default y if PPC64
+	select PPC_FPU_REGS
 
 config FSL_EMB_PERFMON
 	bool "Freescale Embedded Perfmon"
-- 
2.25.0

[PATCH v2 06/25] powerpc/32s: Allow deselecting CONFIG_PPC_FPU on mpc832x

[Christophe Leroy]

The e300c2 core which is embedded in mpc832x CPU doesn't have
an FPU.

Make it possible to not select CONFIG_PPC_FPU when building a
kernel dedicated to that target.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.S          |  4 ++++
 arch/powerpc/platforms/Kconfig.cputype | 11 +++++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index f3ab94d73936..588fe8644df6 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -413,6 +413,7 @@ Alignment:
 	. = 0x800
 	DO_KVM  0x800
 FPUnavailable:
+#ifdef CONFIG_PPC_FPU
 BEGIN_FTR_SECTION
 /*
  * Certain Freescale cores don't have a FPU and treat fp instructions
@@ -426,6 +427,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
 	b	fast_exception_return
 1:	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_LITE(0x800, kernel_fp_unavailable_exception)
+#else
+	b 	ProgramCheck
+#endif
 
 /* Decrementer */
 	EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 40ffcdba42b8..d4fd109f177e 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -32,7 +32,7 @@ choice
 config PPC_BOOK3S_6xx
 	bool "512x/52xx/6xx/7xx/74xx/82xx/83xx/86xx except 601"
 	select PPC_BOOK3S_32
-	select PPC_FPU
+	imply PPC_FPU
 	select PPC_HAVE_PMU_SUPPORT
 	select PPC_HAVE_KUEP
 	select PPC_HAVE_KUAP
@@ -229,9 +229,16 @@ config PPC_FPU_REGS
 	bool
 
 config PPC_FPU
-	bool
+	bool "Support for Floating Point Unit (FPU)" if PPC_MPC832x
 	default y if PPC64
 	select PPC_FPU_REGS
+	help
+	  This must be enabled to support the Floating Point Unit
+	  Most 6xx have an FPU but e300c2 core (mpc832x) don't have
+	  an FPU, so when building an embedded kernel for that target
+	  you can disable FPU support.
+
+	  If unsure say Y.
 
 config FSL_EMB_PERFMON
 	bool "Freescale Embedded Perfmon"
-- 
2.25.0

[PATCH v2 06/25] powerpc/32s: Allow deselecting CONFIG_PPC_FPU on mpc832x

[Christophe Leroy]

The e300c2 core which is embedded in mpc832x CPU doesn't have
an FPU.

Make it possible to not select CONFIG_PPC_FPU when building a
kernel dedicated to that target.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.S          |  4 ++++
 arch/powerpc/platforms/Kconfig.cputype | 11 +++++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index f3ab94d73936..588fe8644df6 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -413,6 +413,7 @@ Alignment:
 	. = 0x800
 	DO_KVM  0x800
 FPUnavailable:
+#ifdef CONFIG_PPC_FPU
 BEGIN_FTR_SECTION
 /*
  * Certain Freescale cores don't have a FPU and treat fp instructions
@@ -426,6 +427,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
 	b	fast_exception_return
 1:	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_LITE(0x800, kernel_fp_unavailable_exception)
+#else
+	b 	ProgramCheck
+#endif
 
 /* Decrementer */
 	EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 40ffcdba42b8..d4fd109f177e 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -32,7 +32,7 @@ choice
 config PPC_BOOK3S_6xx
 	bool "512x/52xx/6xx/7xx/74xx/82xx/83xx/86xx except 601"
 	select PPC_BOOK3S_32
-	select PPC_FPU
+	imply PPC_FPU
 	select PPC_HAVE_PMU_SUPPORT
 	select PPC_HAVE_KUEP
 	select PPC_HAVE_KUAP
@@ -229,9 +229,16 @@ config PPC_FPU_REGS
 	bool
 
 config PPC_FPU
-	bool
+	bool "Support for Floating Point Unit (FPU)" if PPC_MPC832x
 	default y if PPC64
 	select PPC_FPU_REGS
+	help
+	  This must be enabled to support the Floating Point Unit
+	  Most 6xx have an FPU but e300c2 core (mpc832x) don't have
+	  an FPU, so when building an embedded kernel for that target
+	  you can disable FPU support.
+
+	  If unsure say Y.
 
 config FSL_EMB_PERFMON
 	bool "Freescale Embedded Perfmon"
-- 
2.25.0

[PATCH v2 07/25] powerpc/signal: Remove BUG_ON() in handler_signal functions

[Christophe Leroy]

There is already the same BUG_ON() check in do_signal() which
is the only caller of handle_rt_signal64() handle_rt_signal32() and
handle_signal32().

Remove those three redundant BUG_ON().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 4 ----
 arch/powerpc/kernel/signal_64.c | 2 --
 2 files changed, 6 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 7b291707eb31..8cbc9ac1343d 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -764,8 +764,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	unsigned long msr = regs->msr;
 #endif
 
-	BUG_ON(tsk != current);
-
 	/* Set up Signal Frame */
 	/* Put a Real Time Context onto stack */
 	rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1);
@@ -1227,8 +1225,6 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	unsigned long msr = regs->msr;
 #endif
 
-	BUG_ON(tsk != current);
-
 	/* Set up Signal Frame */
 	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1);
 	if (unlikely(frame == NULL))
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index bfc939360bad..cae612bdde5f 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -822,8 +822,6 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 	unsigned long msr = regs->msr;
 #endif
 
-	BUG_ON(tsk != current);
-
 	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
 	if (unlikely(frame == NULL))
 		goto badframe;
-- 
2.25.0

[PATCH v2 07/25] powerpc/signal: Remove BUG_ON() in handler_signal functions

[Christophe Leroy]

There is already the same BUG_ON() check in do_signal() which
is the only caller of handle_rt_signal64() handle_rt_signal32() and
handle_signal32().

Remove those three redundant BUG_ON().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 4 ----
 arch/powerpc/kernel/signal_64.c | 2 --
 2 files changed, 6 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 7b291707eb31..8cbc9ac1343d 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -764,8 +764,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	unsigned long msr = regs->msr;
 #endif
 
-	BUG_ON(tsk != current);
-
 	/* Set up Signal Frame */
 	/* Put a Real Time Context onto stack */
 	rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1);
@@ -1227,8 +1225,6 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	unsigned long msr = regs->msr;
 #endif
 
-	BUG_ON(tsk != current);
-
 	/* Set up Signal Frame */
 	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1);
 	if (unlikely(frame == NULL))
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index bfc939360bad..cae612bdde5f 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -822,8 +822,6 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 	unsigned long msr = regs->msr;
 #endif
 
-	BUG_ON(tsk != current);
-
 	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
 	if (unlikely(frame == NULL))
 		goto badframe;
-- 
2.25.0

[PATCH v2 08/25] powerpc/signal: Move access_ok() out of get_sigframe()

[Christophe Leroy]

This access_ok() will soon be performed by user_access_begin().
So move it out of get_sigframe().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal.c    | 4 ----
 arch/powerpc/kernel/signal_32.c | 4 ++--
 arch/powerpc/kernel/signal_64.c | 2 +-
 3 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 3b56db02b762..1be5fd01f866 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -154,10 +154,6 @@ void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
 	oldsp = sigsp(oldsp, ksig);
 	newsp = (oldsp - frame_size) & ~0xFUL;
 
-	/* Check access */
-	if (!access_ok((void __user *)newsp, oldsp - newsp))
-		return NULL;
-
         return (void __user *)newsp;
 }
 
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 8cbc9ac1343d..61621acacc63 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -768,7 +768,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	/* Put a Real Time Context onto stack */
 	rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1);
 	addr = rt_sf;
-	if (unlikely(rt_sf == NULL))
+	if (!access_ok(rt_sf, sizeof(*rt_sf)))
 		goto badframe;
 
 	/* Put the siginfo & fill in most of the ucontext */
@@ -1227,7 +1227,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Set up Signal Frame */
 	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1);
-	if (unlikely(frame == NULL))
+	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 	sc = (struct sigcontext __user *) &frame->sctx;
 
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index cae612bdde5f..d3db78732070 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -823,7 +823,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 #endif
 
 	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
-	if (unlikely(frame == NULL))
+	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 
 	err |= __put_user(&frame->info, &frame->pinfo);
-- 
2.25.0

[PATCH v2 08/25] powerpc/signal: Move access_ok() out of get_sigframe()

[Christophe Leroy]

This access_ok() will soon be performed by user_access_begin().
So move it out of get_sigframe().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal.c    | 4 ----
 arch/powerpc/kernel/signal_32.c | 4 ++--
 arch/powerpc/kernel/signal_64.c | 2 +-
 3 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 3b56db02b762..1be5fd01f866 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -154,10 +154,6 @@ void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
 	oldsp = sigsp(oldsp, ksig);
 	newsp = (oldsp - frame_size) & ~0xFUL;
 
-	/* Check access */
-	if (!access_ok((void __user *)newsp, oldsp - newsp))
-		return NULL;
-
         return (void __user *)newsp;
 }
 
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 8cbc9ac1343d..61621acacc63 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -768,7 +768,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	/* Put a Real Time Context onto stack */
 	rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1);
 	addr = rt_sf;
-	if (unlikely(rt_sf == NULL))
+	if (!access_ok(rt_sf, sizeof(*rt_sf)))
 		goto badframe;
 
 	/* Put the siginfo & fill in most of the ucontext */
@@ -1227,7 +1227,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Set up Signal Frame */
 	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1);
-	if (unlikely(frame == NULL))
+	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 	sc = (struct sigcontext __user *) &frame->sctx;
 
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index cae612bdde5f..d3db78732070 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -823,7 +823,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 #endif
 
 	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
-	if (unlikely(frame == NULL))
+	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 
 	err |= __put_user(&frame->info, &frame->pinfo);
-- 
2.25.0

[PATCH v2 09/25] powerpc/signal: Remove get_clean_sp()

[Christophe Leroy]

get_clean_sp() is only used once in kernel/signal.c .

GCC is smart enough to see that x & 0xffffffff is a nop
calculation on PPC32, no need of a special PPC32 trivial version.

Include the logic from the PPC64 version of get_clean_sp() directly
in get_sigframe().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/processor.h | 14 --------------
 arch/powerpc/kernel/signal.c         |  5 ++++-
 2 files changed, 4 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index e20b0c5abe62..8320aedbdca3 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -406,20 +406,6 @@ static inline void prefetchw(const void *x)
 
 #define HAVE_ARCH_PICK_MMAP_LAYOUT
 
-#ifdef CONFIG_PPC64
-static inline unsigned long get_clean_sp(unsigned long sp, int is_32)
-{
-	if (is_32)
-		return sp & 0x0ffffffffUL;
-	return sp;
-}
-#else
-static inline unsigned long get_clean_sp(unsigned long sp, int is_32)
-{
-	return sp;
-}
-#endif
-
 /* asm stubs */
 extern unsigned long isa300_idle_stop_noloss(unsigned long psscr_val);
 extern unsigned long isa300_idle_stop_mayloss(unsigned long psscr_val);
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 1be5fd01f866..a295d482adec 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -150,7 +150,10 @@ void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
         unsigned long oldsp, newsp;
 
         /* Default to using normal stack */
-        oldsp = get_clean_sp(sp, is_32);
+	if (is_32)
+		oldsp = sp & 0x0ffffffffUL;
+	else
+		oldsp = sp;
 	oldsp = sigsp(oldsp, ksig);
 	newsp = (oldsp - frame_size) & ~0xFUL;
 
-- 
2.25.0

[PATCH v2 09/25] powerpc/signal: Remove get_clean_sp()

[Christophe Leroy]

get_clean_sp() is only used once in kernel/signal.c .

GCC is smart enough to see that x & 0xffffffff is a nop
calculation on PPC32, no need of a special PPC32 trivial version.

Include the logic from the PPC64 version of get_clean_sp() directly
in get_sigframe().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/processor.h | 14 --------------
 arch/powerpc/kernel/signal.c         |  5 ++++-
 2 files changed, 4 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index e20b0c5abe62..8320aedbdca3 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -406,20 +406,6 @@ static inline void prefetchw(const void *x)
 
 #define HAVE_ARCH_PICK_MMAP_LAYOUT
 
-#ifdef CONFIG_PPC64
-static inline unsigned long get_clean_sp(unsigned long sp, int is_32)
-{
-	if (is_32)
-		return sp & 0x0ffffffffUL;
-	return sp;
-}
-#else
-static inline unsigned long get_clean_sp(unsigned long sp, int is_32)
-{
-	return sp;
-}
-#endif
-
 /* asm stubs */
 extern unsigned long isa300_idle_stop_noloss(unsigned long psscr_val);
 extern unsigned long isa300_idle_stop_mayloss(unsigned long psscr_val);
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 1be5fd01f866..a295d482adec 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -150,7 +150,10 @@ void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
         unsigned long oldsp, newsp;
 
         /* Default to using normal stack */
-        oldsp = get_clean_sp(sp, is_32);
+	if (is_32)
+		oldsp = sp & 0x0ffffffffUL;
+	else
+		oldsp = sp;
 	oldsp = sigsp(oldsp, ksig);
 	newsp = (oldsp - frame_size) & ~0xFUL;
 
-- 
2.25.0

[PATCH v2 10/25] powerpc/signal: Call get_tm_stackpointer() from get_sigframe()

[Christophe Leroy]

Instead of calling get_tm_stackpointer() from the caller, call it
directly from get_sigframe(). This avoids a double call and
allows get_tm_stackpointer() to become static and be inlined
into get_sigframe() by GCC.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal.c    | 9 ++++++---
 arch/powerpc/kernel/signal.h    | 6 ++----
 arch/powerpc/kernel/signal_32.c | 4 ++--
 arch/powerpc/kernel/signal_64.c | 2 +-
 4 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index a295d482adec..5edded5c5d20 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -144,10 +144,13 @@ int show_unhandled_signals = 1;
 /*
  * Allocate space for the signal frame
  */
-void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
-			   size_t frame_size, int is_32)
+static unsigned long get_tm_stackpointer(struct task_struct *tsk);
+
+void __user *get_sigframe(struct ksignal *ksig, struct task_struct *tsk,
+			  size_t frame_size, int is_32)
 {
         unsigned long oldsp, newsp;
+	unsigned long sp = get_tm_stackpointer(tsk);
 
         /* Default to using normal stack */
 	if (is_32)
@@ -304,7 +307,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 	user_enter();
 }
 
-unsigned long get_tm_stackpointer(struct task_struct *tsk)
+static unsigned long get_tm_stackpointer(struct task_struct *tsk)
 {
 	/* When in an active transaction that takes a signal, we need to be
 	 * careful with the stack.  It's possible that the stack has moved back
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index 6c2a33ab042c..fb98731348c3 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -10,8 +10,8 @@
 #ifndef _POWERPC_ARCH_SIGNAL_H
 #define _POWERPC_ARCH_SIGNAL_H
 
-extern void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
-				  size_t frame_size, int is_32);
+void __user *get_sigframe(struct ksignal *ksig, struct task_struct *tsk,
+			  size_t frame_size, int is_32);
 
 extern int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 			   struct task_struct *tsk);
@@ -19,8 +19,6 @@ extern int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 extern int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 			      struct task_struct *tsk);
 
-extern unsigned long get_tm_stackpointer(struct task_struct *tsk);
-
 #ifdef CONFIG_VSX
 extern unsigned long copy_vsx_to_user(void __user *to,
 				      struct task_struct *task);
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 61621acacc63..e5b2801a94ac 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -766,7 +766,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Set up Signal Frame */
 	/* Put a Real Time Context onto stack */
-	rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1);
+	rt_sf = get_sigframe(ksig, tsk, sizeof(*rt_sf), 1);
 	addr = rt_sf;
 	if (!access_ok(rt_sf, sizeof(*rt_sf)))
 		goto badframe;
@@ -1226,7 +1226,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 #endif
 
 	/* Set up Signal Frame */
-	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1);
+	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 	sc = (struct sigcontext __user *) &frame->sctx;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index d3db78732070..fec27d599e87 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -822,7 +822,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 	unsigned long msr = regs->msr;
 #endif
 
-	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
+	frame = get_sigframe(ksig, tsk, sizeof(*frame), 0);
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 
-- 
2.25.0

[PATCH v2 10/25] powerpc/signal: Call get_tm_stackpointer() from get_sigframe()

[Christophe Leroy]

Instead of calling get_tm_stackpointer() from the caller, call it
directly from get_sigframe(). This avoids a double call and
allows get_tm_stackpointer() to become static and be inlined
into get_sigframe() by GCC.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal.c    | 9 ++++++---
 arch/powerpc/kernel/signal.h    | 6 ++----
 arch/powerpc/kernel/signal_32.c | 4 ++--
 arch/powerpc/kernel/signal_64.c | 2 +-
 4 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index a295d482adec..5edded5c5d20 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -144,10 +144,13 @@ int show_unhandled_signals = 1;
 /*
  * Allocate space for the signal frame
  */
-void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
-			   size_t frame_size, int is_32)
+static unsigned long get_tm_stackpointer(struct task_struct *tsk);
+
+void __user *get_sigframe(struct ksignal *ksig, struct task_struct *tsk,
+			  size_t frame_size, int is_32)
 {
         unsigned long oldsp, newsp;
+	unsigned long sp = get_tm_stackpointer(tsk);
 
         /* Default to using normal stack */
 	if (is_32)
@@ -304,7 +307,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 	user_enter();
 }
 
-unsigned long get_tm_stackpointer(struct task_struct *tsk)
+static unsigned long get_tm_stackpointer(struct task_struct *tsk)
 {
 	/* When in an active transaction that takes a signal, we need to be
 	 * careful with the stack.  It's possible that the stack has moved back
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index 6c2a33ab042c..fb98731348c3 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -10,8 +10,8 @@
 #ifndef _POWERPC_ARCH_SIGNAL_H
 #define _POWERPC_ARCH_SIGNAL_H
 
-extern void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
-				  size_t frame_size, int is_32);
+void __user *get_sigframe(struct ksignal *ksig, struct task_struct *tsk,
+			  size_t frame_size, int is_32);
 
 extern int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 			   struct task_struct *tsk);
@@ -19,8 +19,6 @@ extern int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 extern int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 			      struct task_struct *tsk);
 
-extern unsigned long get_tm_stackpointer(struct task_struct *tsk);
-
 #ifdef CONFIG_VSX
 extern unsigned long copy_vsx_to_user(void __user *to,
 				      struct task_struct *task);
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 61621acacc63..e5b2801a94ac 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -766,7 +766,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Set up Signal Frame */
 	/* Put a Real Time Context onto stack */
-	rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1);
+	rt_sf = get_sigframe(ksig, tsk, sizeof(*rt_sf), 1);
 	addr = rt_sf;
 	if (!access_ok(rt_sf, sizeof(*rt_sf)))
 		goto badframe;
@@ -1226,7 +1226,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 #endif
 
 	/* Set up Signal Frame */
-	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1);
+	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 	sc = (struct sigcontext __user *) &frame->sctx;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index d3db78732070..fec27d599e87 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -822,7 +822,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 	unsigned long msr = regs->msr;
 #endif
 
-	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
+	frame = get_sigframe(ksig, tsk, sizeof(*frame), 0);
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 
-- 
2.25.0

[PATCH v2 11/25] powerpc/signal: Refactor bad frame logging

[Christophe Leroy]

The logging of bad frame appears half a dozen of times
and is pretty similar.

Create signal_fault() fonction to perform that logging.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal.c    | 11 +++++++++++
 arch/powerpc/kernel/signal.h    |  3 +++
 arch/powerpc/kernel/signal_32.c | 35 +++++----------------------------
 arch/powerpc/kernel/signal_64.c | 15 ++------------
 4 files changed, 21 insertions(+), 43 deletions(-)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 5edded5c5d20..a1d31d26dbd6 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -355,3 +355,14 @@ static unsigned long get_tm_stackpointer(struct task_struct *tsk)
 #endif
 	return ret;
 }
+
+static const char fm32[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %08lx lr %08lx\n";
+static const char fm64[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %016lx lr %016lx\n";
+
+void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
+		  const char *where, void __user *ptr)
+{
+	if (show_unhandled_signals)
+		printk_ratelimited(regs->msr & MSR_64BIT ? fm64 : fm32, tsk->comm,
+				   task_pid_nr(tsk), where, ptr, regs->nip, regs->link);
+}
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index fb98731348c3..f610cfafa478 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -93,4 +93,7 @@ static inline int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 
 #endif /* !defined(CONFIG_PPC64) */
 
+void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
+		  const char *where, void __user *ptr);
+
 #endif  /* _POWERPC_ARCH_SIGNAL_H */
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index e5b2801a94ac..deb729c8b79d 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -835,12 +835,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in handle_rt_signal32: "
-				   "%p nip %08lx lr %08lx\n",
-				   tsk->comm, tsk->pid,
-				   addr, regs->nip, regs->link);
+	signal_fault(tsk, regs, "handle_rt_signal32", addr);
 
 	return 1;
 }
@@ -1092,12 +1087,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
 	return 0;
 
  bad:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in sys_rt_sigreturn: "
-				   "%p nip %08lx lr %08lx\n",
-				   current->comm, current->pid,
-				   rt_sf, regs->nip, regs->link);
+	signal_fault(current, regs, "sys_rt_sigreturn", rt_sf);
 
 	force_sig(SIGSEGV);
 	return 0;
@@ -1181,12 +1171,7 @@ SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx,
 	 * We kill the task with a SIGSEGV in this situation.
 	 */
 	if (do_setcontext(ctx, regs, 1)) {
-		if (show_unhandled_signals)
-			printk_ratelimited(KERN_INFO "%s[%d]: bad frame in "
-					   "sys_debug_setcontext: %p nip %08lx "
-					   "lr %08lx\n",
-					   current->comm, current->pid,
-					   ctx, regs->nip, regs->link);
+		signal_fault(current, regs, "sys_debug_setcontext", ctx);
 
 		force_sig(SIGSEGV);
 		goto out;
@@ -1287,12 +1272,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in handle_signal32: "
-				   "%p nip %08lx lr %08lx\n",
-				   tsk->comm, tsk->pid,
-				   frame, regs->nip, regs->link);
+	signal_fault(tsk, regs, "handle_signal32", frame);
 
 	return 1;
 }
@@ -1363,12 +1343,7 @@ SYSCALL_DEFINE0(sigreturn)
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in sys_sigreturn: "
-				   "%p nip %08lx lr %08lx\n",
-				   current->comm, current->pid,
-				   addr, regs->nip, regs->link);
+	signal_fault(current, regs, "sys_sigreturn", addr);
 
 	force_sig(SIGSEGV);
 	return 0;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index fec27d599e87..7df088b9ad0f 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -66,11 +66,6 @@ struct rt_sigframe {
 	char abigap[USER_REDZONE_SIZE];
 } __attribute__ ((aligned (16)));
 
-static const char fmt32[] = KERN_INFO \
-	"%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
-static const char fmt64[] = KERN_INFO \
-	"%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
-
 /*
  * This computes a quad word aligned pointer inside the vmx_reserve array
  * element. For historical reasons sigcontext might not be quad word aligned,
@@ -801,10 +796,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
-				   current->comm, current->pid, "rt_sigreturn",
-				   (long)uc, regs->nip, regs->link);
+	signal_fault(current, regs, "rt_sigreturn", uc);
 
 	force_sig(SIGSEGV);
 	return 0;
@@ -911,10 +903,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
-				   tsk->comm, tsk->pid, "setup_rt_frame",
-				   (long)frame, regs->nip, regs->link);
+	signal_fault(current, regs, "handle_rt_signal64", frame);
 
 	return 1;
 }
-- 
2.25.0

[PATCH v2 11/25] powerpc/signal: Refactor bad frame logging

[Christophe Leroy]

The logging of bad frame appears half a dozen of times
and is pretty similar.

Create signal_fault() fonction to perform that logging.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal.c    | 11 +++++++++++
 arch/powerpc/kernel/signal.h    |  3 +++
 arch/powerpc/kernel/signal_32.c | 35 +++++----------------------------
 arch/powerpc/kernel/signal_64.c | 15 ++------------
 4 files changed, 21 insertions(+), 43 deletions(-)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 5edded5c5d20..a1d31d26dbd6 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -355,3 +355,14 @@ static unsigned long get_tm_stackpointer(struct task_struct *tsk)
 #endif
 	return ret;
 }
+
+static const char fm32[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %08lx lr %08lx\n";
+static const char fm64[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %016lx lr %016lx\n";
+
+void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
+		  const char *where, void __user *ptr)
+{
+	if (show_unhandled_signals)
+		printk_ratelimited(regs->msr & MSR_64BIT ? fm64 : fm32, tsk->comm,
+				   task_pid_nr(tsk), where, ptr, regs->nip, regs->link);
+}
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index fb98731348c3..f610cfafa478 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -93,4 +93,7 @@ static inline int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 
 #endif /* !defined(CONFIG_PPC64) */
 
+void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
+		  const char *where, void __user *ptr);
+
 #endif  /* _POWERPC_ARCH_SIGNAL_H */
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index e5b2801a94ac..deb729c8b79d 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -835,12 +835,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in handle_rt_signal32: "
-				   "%p nip %08lx lr %08lx\n",
-				   tsk->comm, tsk->pid,
-				   addr, regs->nip, regs->link);
+	signal_fault(tsk, regs, "handle_rt_signal32", addr);
 
 	return 1;
 }
@@ -1092,12 +1087,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
 	return 0;
 
  bad:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in sys_rt_sigreturn: "
-				   "%p nip %08lx lr %08lx\n",
-				   current->comm, current->pid,
-				   rt_sf, regs->nip, regs->link);
+	signal_fault(current, regs, "sys_rt_sigreturn", rt_sf);
 
 	force_sig(SIGSEGV);
 	return 0;
@@ -1181,12 +1171,7 @@ SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx,
 	 * We kill the task with a SIGSEGV in this situation.
 	 */
 	if (do_setcontext(ctx, regs, 1)) {
-		if (show_unhandled_signals)
-			printk_ratelimited(KERN_INFO "%s[%d]: bad frame in "
-					   "sys_debug_setcontext: %p nip %08lx "
-					   "lr %08lx\n",
-					   current->comm, current->pid,
-					   ctx, regs->nip, regs->link);
+		signal_fault(current, regs, "sys_debug_setcontext", ctx);
 
 		force_sig(SIGSEGV);
 		goto out;
@@ -1287,12 +1272,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in handle_signal32: "
-				   "%p nip %08lx lr %08lx\n",
-				   tsk->comm, tsk->pid,
-				   frame, regs->nip, regs->link);
+	signal_fault(tsk, regs, "handle_signal32", frame);
 
 	return 1;
 }
@@ -1363,12 +1343,7 @@ SYSCALL_DEFINE0(sigreturn)
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in sys_sigreturn: "
-				   "%p nip %08lx lr %08lx\n",
-				   current->comm, current->pid,
-				   addr, regs->nip, regs->link);
+	signal_fault(current, regs, "sys_sigreturn", addr);
 
 	force_sig(SIGSEGV);
 	return 0;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index fec27d599e87..7df088b9ad0f 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -66,11 +66,6 @@ struct rt_sigframe {
 	char abigap[USER_REDZONE_SIZE];
 } __attribute__ ((aligned (16)));
 
-static const char fmt32[] = KERN_INFO \
-	"%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
-static const char fmt64[] = KERN_INFO \
-	"%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
-
 /*
  * This computes a quad word aligned pointer inside the vmx_reserve array
  * element. For historical reasons sigcontext might not be quad word aligned,
@@ -801,10 +796,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
-				   current->comm, current->pid, "rt_sigreturn",
-				   (long)uc, regs->nip, regs->link);
+	signal_fault(current, regs, "rt_sigreturn", uc);
 
 	force_sig(SIGSEGV);
 	return 0;
@@ -911,10 +903,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
-				   tsk->comm, tsk->pid, "setup_rt_frame",
-				   (long)frame, regs->nip, regs->link);
+	signal_fault(current, regs, "handle_rt_signal64", frame);
 
 	return 1;
 }
-- 
2.25.0

Re: [PATCH v2 11/25] powerpc/signal: Refactor bad frame logging

[Joe Perches]

On Tue, 2020-08-18 at 17:19 +0000, Christophe Leroy wrote:
> The logging of bad frame appears half a dozen of times
> and is pretty similar.
[]
> diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
[]
> @@ -355,3 +355,14 @@ static unsigned long get_tm_stackpointer(struct task_struct *tsk)
>  #endif
>  	return ret;
>  }
> +
> +static const char fm32[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %08lx lr %08lx\n";
> +static const char fm64[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %016lx lr %016lx\n";

Why not remove this and use it in place with
%08lx/%016x used as %px with a case to (void *)?

> +void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
> +		  const char *where, void __user *ptr)
> +{
> +	if (show_unhandled_signals)
> +		printk_ratelimited(regs->msr & MSR_64BIT ? fm64 : fm32, tsk->comm,
> +				   task_pid_nr(tsk), where, ptr, regs->nip, regs->link);

	pr_info_ratelimited("%s[%d]: bad frame in %s: %p nip %016lx lr %016lx\n",
			    tsk->comm, task_pid_nr(tsk), where, ptr,
			    (void *)regs->nip, (void *)regs->link);

Re: [PATCH v2 11/25] powerpc/signal: Refactor bad frame logging

[Joe Perches]

On Tue, 2020-08-18 at 17:19 +0000, Christophe Leroy wrote:
> The logging of bad frame appears half a dozen of times
> and is pretty similar.
[]
> diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
[]
> @@ -355,3 +355,14 @@ static unsigned long get_tm_stackpointer(struct task_struct *tsk)
>  #endif
>  	return ret;
>  }
> +
> +static const char fm32[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %08lx lr %08lx\n";
> +static const char fm64[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %016lx lr %016lx\n";

Why not remove this and use it in place with
%08lx/%016x used as %px with a case to (void *)?

> +void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
> +		  const char *where, void __user *ptr)
> +{
> +	if (show_unhandled_signals)
> +		printk_ratelimited(regs->msr & MSR_64BIT ? fm64 : fm32, tsk->comm,
> +				   task_pid_nr(tsk), where, ptr, regs->nip, regs->link);

	pr_info_ratelimited("%s[%d]: bad frame in %s: %p nip %016lx lr %016lx\n",
			    tsk->comm, task_pid_nr(tsk), where, ptr,
			    (void *)regs->nip, (void *)regs->link);

[PATCH v2 12/25] powerpc/signal32: Simplify logging in handle_rt_signal32()

[Christophe Leroy]

If something is bad in the frame, there is no point in
knowing which part of the frame exactly is wrong as it
got allocated as a single block.

Always print the root address of the frame in case of
failed user access, just like handle_signal32().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index deb729c8b79d..44a46911ff98 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -754,7 +754,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	struct rt_sigframe __user *rt_sf;
 	struct mcontext __user *frame;
 	struct mcontext __user *tm_frame = NULL;
-	void __user *addr;
 	unsigned long newsp = 0;
 	int sigret;
 	unsigned long tramp;
@@ -767,7 +766,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	/* Set up Signal Frame */
 	/* Put a Real Time Context onto stack */
 	rt_sf = get_sigframe(ksig, tsk, sizeof(*rt_sf), 1);
-	addr = rt_sf;
 	if (!access_ok(rt_sf, sizeof(*rt_sf)))
 		goto badframe;
 
@@ -782,7 +780,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Save user registers on the stack */
 	frame = &rt_sf->uc.uc_mcontext;
-	addr = frame;
 	if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
 		sigret = 0;
 		tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
@@ -818,7 +815,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* create a stack frame for the caller of the handler */
 	newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
-	addr = (void __user *)regs->gpr[1];
 	if (put_user(regs->gpr[1], (u32 __user *)newsp))
 		goto badframe;
 
@@ -835,7 +831,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 0;
 
 badframe:
-	signal_fault(tsk, regs, "handle_rt_signal32", addr);
+	signal_fault(tsk, regs, "handle_rt_signal32", rt_sf);
 
 	return 1;
 }
-- 
2.25.0

[PATCH v2 12/25] powerpc/signal32: Simplify logging in handle_rt_signal32()

[Christophe Leroy]

If something is bad in the frame, there is no point in
knowing which part of the frame exactly is wrong as it
got allocated as a single block.

Always print the root address of the frame in case of
failed user access, just like handle_signal32().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index deb729c8b79d..44a46911ff98 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -754,7 +754,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	struct rt_sigframe __user *rt_sf;
 	struct mcontext __user *frame;
 	struct mcontext __user *tm_frame = NULL;
-	void __user *addr;
 	unsigned long newsp = 0;
 	int sigret;
 	unsigned long tramp;
@@ -767,7 +766,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	/* Set up Signal Frame */
 	/* Put a Real Time Context onto stack */
 	rt_sf = get_sigframe(ksig, tsk, sizeof(*rt_sf), 1);
-	addr = rt_sf;
 	if (!access_ok(rt_sf, sizeof(*rt_sf)))
 		goto badframe;
 
@@ -782,7 +780,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Save user registers on the stack */
 	frame = &rt_sf->uc.uc_mcontext;
-	addr = frame;
 	if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
 		sigret = 0;
 		tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
@@ -818,7 +815,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* create a stack frame for the caller of the handler */
 	newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
-	addr = (void __user *)regs->gpr[1];
 	if (put_user(regs->gpr[1], (u32 __user *)newsp))
 		goto badframe;
 
@@ -835,7 +831,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 0;
 
 badframe:
-	signal_fault(tsk, regs, "handle_rt_signal32", addr);
+	signal_fault(tsk, regs, "handle_rt_signal32", rt_sf);
 
 	return 1;
 }
-- 
2.25.0

[PATCH v2 13/25] powerpc/signal32: Move handle_signal32() close to handle_rt_signal32()

[Christophe Leroy]

Those two functions are similar and serving the same purpose.
To ease refactorisation, move them close to each other.

This is pure move, no code change, no cosmetic. Yes, checkpatch is
not happy, most will clear later.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 170 ++++++++++++++++----------------
 1 file changed, 85 insertions(+), 85 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 44a46911ff98..2cc686b9f566 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -836,6 +836,91 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 1;
 }
 
+/*
+ * OK, we're invoking a handler
+ */
+int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
+		struct task_struct *tsk)
+{
+	struct sigcontext __user *sc;
+	struct sigframe __user *frame;
+	struct mcontext __user *tm_mctx = NULL;
+	unsigned long newsp = 0;
+	int sigret;
+	unsigned long tramp;
+	struct pt_regs *regs = tsk->thread.regs;
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	/* Save the thread's msr before get_tm_stackpointer() changes it */
+	unsigned long msr = regs->msr;
+#endif
+
+	/* Set up Signal Frame */
+	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+	sc = (struct sigcontext __user *) &frame->sctx;
+
+#if _NSIG != 64
+#error "Please adjust handle_signal()"
+#endif
+	if (__put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler)
+	    || __put_user(oldset->sig[0], &sc->oldmask)
+#ifdef CONFIG_PPC64
+	    || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
+#else
+	    || __put_user(oldset->sig[1], &sc->_unused[3])
+#endif
+	    || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
+	    || __put_user(ksig->sig, &sc->signal))
+		goto badframe;
+
+	if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
+		sigret = 0;
+		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
+	} else {
+		sigret = __NR_sigreturn;
+		tramp = (unsigned long) frame->mctx.tramp;
+	}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	tm_mctx = &frame->mctx_transact;
+	if (MSR_TM_ACTIVE(msr)) {
+		if (save_tm_user_regs(regs, &frame->mctx, &frame->mctx_transact,
+				      sigret, msr))
+			goto badframe;
+	}
+	else
+#endif
+	{
+		if (save_user_regs(regs, &frame->mctx, tm_mctx, sigret, 1))
+			goto badframe;
+	}
+
+	regs->link = tramp;
+
+#ifdef CONFIG_PPC_FPU_REGS
+	tsk->thread.fp_state.fpscr = 0;	/* turn off all fp exceptions */
+#endif
+
+	/* create a stack frame for the caller of the handler */
+	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
+	if (put_user(regs->gpr[1], (u32 __user *)newsp))
+		goto badframe;
+
+	regs->gpr[1] = newsp;
+	regs->gpr[3] = ksig->sig;
+	regs->gpr[4] = (unsigned long) sc;
+	regs->nip = (unsigned long) (unsigned long)ksig->ka.sa.sa_handler;
+	/* enter the signal handler in big-endian mode */
+	regs->msr &= ~MSR_LE;
+	return 0;
+
+badframe:
+	signal_fault(tsk, regs, "handle_signal32", frame);
+
+	return 1;
+}
+
 static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
 {
 	sigset_t set;
@@ -1188,91 +1273,6 @@ SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx,
 }
 #endif
 
-/*
- * OK, we're invoking a handler
- */
-int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
-		struct task_struct *tsk)
-{
-	struct sigcontext __user *sc;
-	struct sigframe __user *frame;
-	struct mcontext __user *tm_mctx = NULL;
-	unsigned long newsp = 0;
-	int sigret;
-	unsigned long tramp;
-	struct pt_regs *regs = tsk->thread.regs;
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-	/* Save the thread's msr before get_tm_stackpointer() changes it */
-	unsigned long msr = regs->msr;
-#endif
-
-	/* Set up Signal Frame */
-	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
-	if (!access_ok(frame, sizeof(*frame)))
-		goto badframe;
-	sc = (struct sigcontext __user *) &frame->sctx;
-
-#if _NSIG != 64
-#error "Please adjust handle_signal()"
-#endif
-	if (__put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler)
-	    || __put_user(oldset->sig[0], &sc->oldmask)
-#ifdef CONFIG_PPC64
-	    || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
-#else
-	    || __put_user(oldset->sig[1], &sc->_unused[3])
-#endif
-	    || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
-	    || __put_user(ksig->sig, &sc->signal))
-		goto badframe;
-
-	if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
-		sigret = 0;
-		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
-	} else {
-		sigret = __NR_sigreturn;
-		tramp = (unsigned long) frame->mctx.tramp;
-	}
-
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-	tm_mctx = &frame->mctx_transact;
-	if (MSR_TM_ACTIVE(msr)) {
-		if (save_tm_user_regs(regs, &frame->mctx, &frame->mctx_transact,
-				      sigret, msr))
-			goto badframe;
-	}
-	else
-#endif
-	{
-		if (save_user_regs(regs, &frame->mctx, tm_mctx, sigret, 1))
-			goto badframe;
-	}
-
-	regs->link = tramp;
-
-#ifdef CONFIG_PPC_FPU_REGS
-	tsk->thread.fp_state.fpscr = 0;	/* turn off all fp exceptions */
-#endif
-
-	/* create a stack frame for the caller of the handler */
-	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
-	if (put_user(regs->gpr[1], (u32 __user *)newsp))
-		goto badframe;
-
-	regs->gpr[1] = newsp;
-	regs->gpr[3] = ksig->sig;
-	regs->gpr[4] = (unsigned long) sc;
-	regs->nip = (unsigned long) (unsigned long)ksig->ka.sa.sa_handler;
-	/* enter the signal handler in big-endian mode */
-	regs->msr &= ~MSR_LE;
-	return 0;
-
-badframe:
-	signal_fault(tsk, regs, "handle_signal32", frame);
-
-	return 1;
-}
-
 /*
  * Do a signal return; undo the signal stack.
  */
-- 
2.25.0

[PATCH v2 13/25] powerpc/signal32: Move handle_signal32() close to handle_rt_signal32()

[Christophe Leroy]

Those two functions are similar and serving the same purpose.
To ease refactorisation, move them close to each other.

This is pure move, no code change, no cosmetic. Yes, checkpatch is
not happy, most will clear later.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 170 ++++++++++++++++----------------
 1 file changed, 85 insertions(+), 85 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 44a46911ff98..2cc686b9f566 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -836,6 +836,91 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 1;
 }
 
+/*
+ * OK, we're invoking a handler
+ */
+int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
+		struct task_struct *tsk)
+{
+	struct sigcontext __user *sc;
+	struct sigframe __user *frame;
+	struct mcontext __user *tm_mctx = NULL;
+	unsigned long newsp = 0;
+	int sigret;
+	unsigned long tramp;
+	struct pt_regs *regs = tsk->thread.regs;
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	/* Save the thread's msr before get_tm_stackpointer() changes it */
+	unsigned long msr = regs->msr;
+#endif
+
+	/* Set up Signal Frame */
+	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+	sc = (struct sigcontext __user *) &frame->sctx;
+
+#if _NSIG != 64
+#error "Please adjust handle_signal()"
+#endif
+	if (__put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler)
+	    || __put_user(oldset->sig[0], &sc->oldmask)
+#ifdef CONFIG_PPC64
+	    || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
+#else
+	    || __put_user(oldset->sig[1], &sc->_unused[3])
+#endif
+	    || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
+	    || __put_user(ksig->sig, &sc->signal))
+		goto badframe;
+
+	if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
+		sigret = 0;
+		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
+	} else {
+		sigret = __NR_sigreturn;
+		tramp = (unsigned long) frame->mctx.tramp;
+	}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	tm_mctx = &frame->mctx_transact;
+	if (MSR_TM_ACTIVE(msr)) {
+		if (save_tm_user_regs(regs, &frame->mctx, &frame->mctx_transact,
+				      sigret, msr))
+			goto badframe;
+	}
+	else
+#endif
+	{
+		if (save_user_regs(regs, &frame->mctx, tm_mctx, sigret, 1))
+			goto badframe;
+	}
+
+	regs->link = tramp;
+
+#ifdef CONFIG_PPC_FPU_REGS
+	tsk->thread.fp_state.fpscr = 0;	/* turn off all fp exceptions */
+#endif
+
+	/* create a stack frame for the caller of the handler */
+	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
+	if (put_user(regs->gpr[1], (u32 __user *)newsp))
+		goto badframe;
+
+	regs->gpr[1] = newsp;
+	regs->gpr[3] = ksig->sig;
+	regs->gpr[4] = (unsigned long) sc;
+	regs->nip = (unsigned long) (unsigned long)ksig->ka.sa.sa_handler;
+	/* enter the signal handler in big-endian mode */
+	regs->msr &= ~MSR_LE;
+	return 0;
+
+badframe:
+	signal_fault(tsk, regs, "handle_signal32", frame);
+
+	return 1;
+}
+
 static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
 {
 	sigset_t set;
@@ -1188,91 +1273,6 @@ SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx,
 }
 #endif
 
-/*
- * OK, we're invoking a handler
- */
-int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
-		struct task_struct *tsk)
-{
-	struct sigcontext __user *sc;
-	struct sigframe __user *frame;
-	struct mcontext __user *tm_mctx = NULL;
-	unsigned long newsp = 0;
-	int sigret;
-	unsigned long tramp;
-	struct pt_regs *regs = tsk->thread.regs;
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-	/* Save the thread's msr before get_tm_stackpointer() changes it */
-	unsigned long msr = regs->msr;
-#endif
-
-	/* Set up Signal Frame */
-	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
-	if (!access_ok(frame, sizeof(*frame)))
-		goto badframe;
-	sc = (struct sigcontext __user *) &frame->sctx;
-
-#if _NSIG != 64
-#error "Please adjust handle_signal()"
-#endif
-	if (__put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler)
-	    || __put_user(oldset->sig[0], &sc->oldmask)
-#ifdef CONFIG_PPC64
-	    || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
-#else
-	    || __put_user(oldset->sig[1], &sc->_unused[3])
-#endif
-	    || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
-	    || __put_user(ksig->sig, &sc->signal))
-		goto badframe;
-
-	if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
-		sigret = 0;
-		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
-	} else {
-		sigret = __NR_sigreturn;
-		tramp = (unsigned long) frame->mctx.tramp;
-	}
-
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-	tm_mctx = &frame->mctx_transact;
-	if (MSR_TM_ACTIVE(msr)) {
-		if (save_tm_user_regs(regs, &frame->mctx, &frame->mctx_transact,
-				      sigret, msr))
-			goto badframe;
-	}
-	else
-#endif
-	{
-		if (save_user_regs(regs, &frame->mctx, tm_mctx, sigret, 1))
-			goto badframe;
-	}
-
-	regs->link = tramp;
-
-#ifdef CONFIG_PPC_FPU_REGS
-	tsk->thread.fp_state.fpscr = 0;	/* turn off all fp exceptions */
-#endif
-
-	/* create a stack frame for the caller of the handler */
-	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
-	if (put_user(regs->gpr[1], (u32 __user *)newsp))
-		goto badframe;
-
-	regs->gpr[1] = newsp;
-	regs->gpr[3] = ksig->sig;
-	regs->gpr[4] = (unsigned long) sc;
-	regs->nip = (unsigned long) (unsigned long)ksig->ka.sa.sa_handler;
-	/* enter the signal handler in big-endian mode */
-	regs->msr &= ~MSR_LE;
-	return 0;
-
-badframe:
-	signal_fault(tsk, regs, "handle_signal32", frame);
-
-	return 1;
-}
-
 /*
  * Do a signal return; undo the signal stack.
  */
-- 
2.25.0

[PATCH v2 14/25] powerpc/signal32: Rename local pointers in handle_rt_signal32()

[Christophe Leroy]

Rename pointers in handle_rt_signal32() to make it more similar to
handle_signal32()

tm_frame becomes tm_mctx
frame becomes mctx
rt_sf becomes frame

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 51 ++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 26 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 2cc686b9f566..d0fcb3de66aa 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -751,9 +751,9 @@ static long restore_tm_user_regs(struct pt_regs *regs,
 int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 		       struct task_struct *tsk)
 {
-	struct rt_sigframe __user *rt_sf;
-	struct mcontext __user *frame;
-	struct mcontext __user *tm_frame = NULL;
+	struct rt_sigframe __user *frame;
+	struct mcontext __user *mctx;
+	struct mcontext __user *tm_mctx = NULL;
 	unsigned long newsp = 0;
 	int sigret;
 	unsigned long tramp;
@@ -765,46 +765,45 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Set up Signal Frame */
 	/* Put a Real Time Context onto stack */
-	rt_sf = get_sigframe(ksig, tsk, sizeof(*rt_sf), 1);
-	if (!access_ok(rt_sf, sizeof(*rt_sf)))
+	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
+	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 
 	/* Put the siginfo & fill in most of the ucontext */
-	if (copy_siginfo_to_user(&rt_sf->info, &ksig->info)
-	    || __put_user(0, &rt_sf->uc.uc_flags)
-	    || __save_altstack(&rt_sf->uc.uc_stack, regs->gpr[1])
-	    || __put_user(to_user_ptr(&rt_sf->uc.uc_mcontext),
-		    &rt_sf->uc.uc_regs)
-	    || put_sigset_t(&rt_sf->uc.uc_sigmask, oldset))
+	if (copy_siginfo_to_user(&frame->info, &ksig->info) ||
+	    __put_user(0, &frame->uc.uc_flags) ||
+	    __save_altstack(&frame->uc.uc_stack, regs->gpr[1]) ||
+	    __put_user(to_user_ptr(&frame->uc.uc_mcontext), &frame->uc.uc_regs) ||
+	    put_sigset_t(&frame->uc.uc_sigmask, oldset))
 		goto badframe;
 
 	/* Save user registers on the stack */
-	frame = &rt_sf->uc.uc_mcontext;
+	mctx = &frame->uc.uc_mcontext;
 	if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
 		sigret = 0;
 		tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
 	} else {
 		sigret = __NR_rt_sigreturn;
-		tramp = (unsigned long) frame->tramp;
+		tramp = (unsigned long)mctx->tramp;
 	}
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-	tm_frame = &rt_sf->uc_transact.uc_mcontext;
+	tm_mctx = &frame->uc_transact.uc_mcontext;
 	if (MSR_TM_ACTIVE(msr)) {
-		if (__put_user((unsigned long)&rt_sf->uc_transact,
-			       &rt_sf->uc.uc_link) ||
-		    __put_user((unsigned long)tm_frame,
-			       &rt_sf->uc_transact.uc_regs))
+		if (__put_user((unsigned long)&frame->uc_transact,
+			       &frame->uc.uc_link) ||
+		    __put_user((unsigned long)tm_mctx,
+			       &frame->uc_transact.uc_regs))
 			goto badframe;
-		if (save_tm_user_regs(regs, frame, tm_frame, sigret, msr))
+		if (save_tm_user_regs(regs, mctx, tm_mctx, sigret, msr))
 			goto badframe;
 	}
 	else
 #endif
 	{
-		if (__put_user(0, &rt_sf->uc.uc_link))
+		if (__put_user(0, &frame->uc.uc_link))
 			goto badframe;
-		if (save_user_regs(regs, frame, tm_frame, sigret, 1))
+		if (save_user_regs(regs, mctx, tm_mctx, sigret, 1))
 			goto badframe;
 	}
 	regs->link = tramp;
@@ -814,16 +813,16 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 #endif
 
 	/* create a stack frame for the caller of the handler */
-	newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
+	newsp = ((unsigned long)frame) - (__SIGNAL_FRAMESIZE + 16);
 	if (put_user(regs->gpr[1], (u32 __user *)newsp))
 		goto badframe;
 
 	/* Fill registers for signal handler */
 	regs->gpr[1] = newsp;
 	regs->gpr[3] = ksig->sig;
-	regs->gpr[4] = (unsigned long) &rt_sf->info;
-	regs->gpr[5] = (unsigned long) &rt_sf->uc;
-	regs->gpr[6] = (unsigned long) rt_sf;
+	regs->gpr[4] = (unsigned long)&frame->info;
+	regs->gpr[5] = (unsigned long)&frame->uc;
+	regs->gpr[6] = (unsigned long)frame;
 	regs->nip = (unsigned long) ksig->ka.sa.sa_handler;
 	/* enter the signal handler in native-endian mode */
 	regs->msr &= ~MSR_LE;
@@ -831,7 +830,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 0;
 
 badframe:
-	signal_fault(tsk, regs, "handle_rt_signal32", rt_sf);
+	signal_fault(tsk, regs, "handle_rt_signal32", frame);
 
 	return 1;
 }
-- 
2.25.0

[PATCH v2 14/25] powerpc/signal32: Rename local pointers in handle_rt_signal32()

[Christophe Leroy]

Rename pointers in handle_rt_signal32() to make it more similar to
handle_signal32()

tm_frame becomes tm_mctx
frame becomes mctx
rt_sf becomes frame

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 51 ++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 26 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 2cc686b9f566..d0fcb3de66aa 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -751,9 +751,9 @@ static long restore_tm_user_regs(struct pt_regs *regs,
 int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 		       struct task_struct *tsk)
 {
-	struct rt_sigframe __user *rt_sf;
-	struct mcontext __user *frame;
-	struct mcontext __user *tm_frame = NULL;
+	struct rt_sigframe __user *frame;
+	struct mcontext __user *mctx;
+	struct mcontext __user *tm_mctx = NULL;
 	unsigned long newsp = 0;
 	int sigret;
 	unsigned long tramp;
@@ -765,46 +765,45 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Set up Signal Frame */
 	/* Put a Real Time Context onto stack */
-	rt_sf = get_sigframe(ksig, tsk, sizeof(*rt_sf), 1);
-	if (!access_ok(rt_sf, sizeof(*rt_sf)))
+	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
+	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 
 	/* Put the siginfo & fill in most of the ucontext */
-	if (copy_siginfo_to_user(&rt_sf->info, &ksig->info)
-	    || __put_user(0, &rt_sf->uc.uc_flags)
-	    || __save_altstack(&rt_sf->uc.uc_stack, regs->gpr[1])
-	    || __put_user(to_user_ptr(&rt_sf->uc.uc_mcontext),
-		    &rt_sf->uc.uc_regs)
-	    || put_sigset_t(&rt_sf->uc.uc_sigmask, oldset))
+	if (copy_siginfo_to_user(&frame->info, &ksig->info) ||
+	    __put_user(0, &frame->uc.uc_flags) ||
+	    __save_altstack(&frame->uc.uc_stack, regs->gpr[1]) ||
+	    __put_user(to_user_ptr(&frame->uc.uc_mcontext), &frame->uc.uc_regs) ||
+	    put_sigset_t(&frame->uc.uc_sigmask, oldset))
 		goto badframe;
 
 	/* Save user registers on the stack */
-	frame = &rt_sf->uc.uc_mcontext;
+	mctx = &frame->uc.uc_mcontext;
 	if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
 		sigret = 0;
 		tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
 	} else {
 		sigret = __NR_rt_sigreturn;
-		tramp = (unsigned long) frame->tramp;
+		tramp = (unsigned long)mctx->tramp;
 	}
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-	tm_frame = &rt_sf->uc_transact.uc_mcontext;
+	tm_mctx = &frame->uc_transact.uc_mcontext;
 	if (MSR_TM_ACTIVE(msr)) {
-		if (__put_user((unsigned long)&rt_sf->uc_transact,
-			       &rt_sf->uc.uc_link) ||
-		    __put_user((unsigned long)tm_frame,
-			       &rt_sf->uc_transact.uc_regs))
+		if (__put_user((unsigned long)&frame->uc_transact,
+			       &frame->uc.uc_link) ||
+		    __put_user((unsigned long)tm_mctx,
+			       &frame->uc_transact.uc_regs))
 			goto badframe;
-		if (save_tm_user_regs(regs, frame, tm_frame, sigret, msr))
+		if (save_tm_user_regs(regs, mctx, tm_mctx, sigret, msr))
 			goto badframe;
 	}
 	else
 #endif
 	{
-		if (__put_user(0, &rt_sf->uc.uc_link))
+		if (__put_user(0, &frame->uc.uc_link))
 			goto badframe;
-		if (save_user_regs(regs, frame, tm_frame, sigret, 1))
+		if (save_user_regs(regs, mctx, tm_mctx, sigret, 1))
 			goto badframe;
 	}
 	regs->link = tramp;
@@ -814,16 +813,16 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 #endif
 
 	/* create a stack frame for the caller of the handler */
-	newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
+	newsp = ((unsigned long)frame) - (__SIGNAL_FRAMESIZE + 16);
 	if (put_user(regs->gpr[1], (u32 __user *)newsp))
 		goto badframe;
 
 	/* Fill registers for signal handler */
 	regs->gpr[1] = newsp;
 	regs->gpr[3] = ksig->sig;
-	regs->gpr[4] = (unsigned long) &rt_sf->info;
-	regs->gpr[5] = (unsigned long) &rt_sf->uc;
-	regs->gpr[6] = (unsigned long) rt_sf;
+	regs->gpr[4] = (unsigned long)&frame->info;
+	regs->gpr[5] = (unsigned long)&frame->uc;
+	regs->gpr[6] = (unsigned long)frame;
 	regs->nip = (unsigned long) ksig->ka.sa.sa_handler;
 	/* enter the signal handler in native-endian mode */
 	regs->msr &= ~MSR_LE;
@@ -831,7 +830,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 0;
 
 badframe:
-	signal_fault(tsk, regs, "handle_rt_signal32", rt_sf);
+	signal_fault(tsk, regs, "handle_rt_signal32", frame);
 
 	return 1;
 }
-- 
2.25.0

[PATCH v2 15/25] powerpc/signal32: Misc changes to make handle_[rt_]_signal32() more similar

[Christophe Leroy]

Miscellaneous changes to clean and make handle_signal32() and
handle_rt_signal32() even more similar.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index d0fcb3de66aa..ab8c8cb98b15 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -764,8 +764,11 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 #endif
 
 	/* Set up Signal Frame */
-	/* Put a Real Time Context onto stack */
 	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
+	mctx = &frame->uc.uc_mcontext;
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	tm_mctx = &frame->uc_transact.uc_mcontext;
+#endif
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 
@@ -778,7 +781,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 		goto badframe;
 
 	/* Save user registers on the stack */
-	mctx = &frame->uc.uc_mcontext;
 	if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
 		sigret = 0;
 		tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
@@ -788,7 +790,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	}
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-	tm_mctx = &frame->uc_transact.uc_mcontext;
 	if (MSR_TM_ACTIVE(msr)) {
 		if (__put_user((unsigned long)&frame->uc_transact,
 			       &frame->uc.uc_link) ||
@@ -843,6 +844,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 {
 	struct sigcontext __user *sc;
 	struct sigframe __user *frame;
+	struct mcontext __user *mctx;
 	struct mcontext __user *tm_mctx = NULL;
 	unsigned long newsp = 0;
 	int sigret;
@@ -855,6 +857,10 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Set up Signal Frame */
 	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
+	mctx = &frame->mctx;
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	tm_mctx = &frame->mctx_transact;
+#endif
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 	sc = (struct sigcontext __user *) &frame->sctx;
@@ -869,7 +875,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 #else
 	    || __put_user(oldset->sig[1], &sc->_unused[3])
 #endif
-	    || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
+	    || __put_user(to_user_ptr(mctx), &sc->regs)
 	    || __put_user(ksig->sig, &sc->signal))
 		goto badframe;
 
@@ -878,20 +884,18 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
 	} else {
 		sigret = __NR_sigreturn;
-		tramp = (unsigned long) frame->mctx.tramp;
+		tramp = (unsigned long)mctx->tramp;
 	}
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-	tm_mctx = &frame->mctx_transact;
 	if (MSR_TM_ACTIVE(msr)) {
-		if (save_tm_user_regs(regs, &frame->mctx, &frame->mctx_transact,
-				      sigret, msr))
+		if (save_tm_user_regs(regs, mctx, tm_mctx, sigret, msr))
 			goto badframe;
 	}
 	else
 #endif
 	{
-		if (save_user_regs(regs, &frame->mctx, tm_mctx, sigret, 1))
+		if (save_user_regs(regs, mctx, tm_mctx, sigret, 1))
 			goto badframe;
 	}
 
@@ -909,7 +913,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	regs->gpr[1] = newsp;
 	regs->gpr[3] = ksig->sig;
 	regs->gpr[4] = (unsigned long) sc;
-	regs->nip = (unsigned long) (unsigned long)ksig->ka.sa.sa_handler;
+	regs->nip = (unsigned long)ksig->ka.sa.sa_handler;
 	/* enter the signal handler in big-endian mode */
 	regs->msr &= ~MSR_LE;
 	return 0;
-- 
2.25.0

[PATCH v2 15/25] powerpc/signal32: Misc changes to make handle_[rt_]_signal32() more similar

[Christophe Leroy]

Miscellaneous changes to clean and make handle_signal32() and
handle_rt_signal32() even more similar.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index d0fcb3de66aa..ab8c8cb98b15 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -764,8 +764,11 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 #endif
 
 	/* Set up Signal Frame */
-	/* Put a Real Time Context onto stack */
 	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
+	mctx = &frame->uc.uc_mcontext;
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	tm_mctx = &frame->uc_transact.uc_mcontext;
+#endif
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 
@@ -778,7 +781,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 		goto badframe;
 
 	/* Save user registers on the stack */
-	mctx = &frame->uc.uc_mcontext;
 	if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
 		sigret = 0;
 		tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
@@ -788,7 +790,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	}
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-	tm_mctx = &frame->uc_transact.uc_mcontext;
 	if (MSR_TM_ACTIVE(msr)) {
 		if (__put_user((unsigned long)&frame->uc_transact,
 			       &frame->uc.uc_link) ||
@@ -843,6 +844,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 {
 	struct sigcontext __user *sc;
 	struct sigframe __user *frame;
+	struct mcontext __user *mctx;
 	struct mcontext __user *tm_mctx = NULL;
 	unsigned long newsp = 0;
 	int sigret;
@@ -855,6 +857,10 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Set up Signal Frame */
 	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
+	mctx = &frame->mctx;
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	tm_mctx = &frame->mctx_transact;
+#endif
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 	sc = (struct sigcontext __user *) &frame->sctx;
@@ -869,7 +875,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 #else
 	    || __put_user(oldset->sig[1], &sc->_unused[3])
 #endif
-	    || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
+	    || __put_user(to_user_ptr(mctx), &sc->regs)
 	    || __put_user(ksig->sig, &sc->signal))
 		goto badframe;
 
@@ -878,20 +884,18 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
 	} else {
 		sigret = __NR_sigreturn;
-		tramp = (unsigned long) frame->mctx.tramp;
+		tramp = (unsigned long)mctx->tramp;
 	}
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-	tm_mctx = &frame->mctx_transact;
 	if (MSR_TM_ACTIVE(msr)) {
-		if (save_tm_user_regs(regs, &frame->mctx, &frame->mctx_transact,
-				      sigret, msr))
+		if (save_tm_user_regs(regs, mctx, tm_mctx, sigret, msr))
 			goto badframe;
 	}
 	else
 #endif
 	{
-		if (save_user_regs(regs, &frame->mctx, tm_mctx, sigret, 1))
+		if (save_user_regs(regs, mctx, tm_mctx, sigret, 1))
 			goto badframe;
 	}
 
@@ -909,7 +913,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	regs->gpr[1] = newsp;
 	regs->gpr[3] = ksig->sig;
 	regs->gpr[4] = (unsigned long) sc;
-	regs->nip = (unsigned long) (unsigned long)ksig->ka.sa.sa_handler;
+	regs->nip = (unsigned long)ksig->ka.sa.sa_handler;
 	/* enter the signal handler in big-endian mode */
 	regs->msr &= ~MSR_LE;
 	return 0;
-- 
2.25.0

[PATCH v2 16/25] powerpc/signal32: Move signal trampoline setup to handle_[rt_]signal32

[Christophe Leroy]

Move signal trampoline setup into handle_signal32()
and handle_rt_signal32().

At the same time, remove the define which hides the mc_pad field
used for trampoline.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 61 ++++++++++++---------------------
 1 file changed, 22 insertions(+), 39 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index ab8c8cb98b15..d8c3843102df 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -199,9 +199,6 @@ struct sigframe {
 	int			abigap[56];
 };
 
-/* We use the mc_pad field for the signal return trampoline. */
-#define tramp	mc_pad
-
 /*
  *  When we have rt signals to deliver, we set up on the
  *  user stack, going down from the original stack pointer:
@@ -236,8 +233,7 @@ struct rt_sigframe {
  * altivec/spe instructions at some point.
  */
 static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
-			  struct mcontext __user *tm_frame, int sigret,
-			  int ctx_has_vsx_region)
+			  struct mcontext __user *tm_frame, int ctx_has_vsx_region)
 {
 	unsigned long msr = regs->msr;
 
@@ -320,15 +316,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	if (tm_frame && __put_user(0, &tm_frame->mc_gregs[PT_MSR]))
 		return 1;
 
-	if (sigret) {
-		/* Set up the sigreturn trampoline: li 0,sigret; sc */
-		if (__put_user(PPC_INST_ADDI + sigret, &frame->tramp[0])
-		    || __put_user(PPC_INST_SC, &frame->tramp[1]))
-			return 1;
-		flush_icache_range((unsigned long) &frame->tramp[0],
-				   (unsigned long) &frame->tramp[2]);
-	}
-
 	return 0;
 }
 
@@ -342,10 +329,8 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
  *
  * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
  */
-static int save_tm_user_regs(struct pt_regs *regs,
-			     struct mcontext __user *frame,
-			     struct mcontext __user *tm_frame, int sigret,
-			     unsigned long msr)
+static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
+			     struct mcontext __user *tm_frame, unsigned long msr)
 {
 	WARN_ON(tm_suspend_disabled);
 
@@ -461,14 +446,6 @@ static int save_tm_user_regs(struct pt_regs *regs,
 
 	if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
 		return 1;
-	if (sigret) {
-		/* Set up the sigreturn trampoline: li 0,sigret; sc */
-		if (__put_user(PPC_INST_ADDI + sigret, &frame->tramp[0])
-		    || __put_user(PPC_INST_SC, &frame->tramp[1]))
-			return 1;
-		flush_icache_range((unsigned long) &frame->tramp[0],
-				   (unsigned long) &frame->tramp[2]);
-	}
 
 	return 0;
 }
@@ -755,7 +732,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	struct mcontext __user *mctx;
 	struct mcontext __user *tm_mctx = NULL;
 	unsigned long newsp = 0;
-	int sigret;
 	unsigned long tramp;
 	struct pt_regs *regs = tsk->thread.regs;
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@@ -782,11 +758,15 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Save user registers on the stack */
 	if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
-		sigret = 0;
 		tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
 	} else {
-		sigret = __NR_rt_sigreturn;
-		tramp = (unsigned long)mctx->tramp;
+		tramp = (unsigned long)mctx->mc_pad;
+		/* Set up the sigreturn trampoline: li r0,sigret; sc */
+		if (__put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0]))
+			goto badframe;
+		if (__put_user(PPC_INST_SC, &mctx->mc_pad[1]))
+			goto badframe;
+		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 	}
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@@ -796,7 +776,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 		    __put_user((unsigned long)tm_mctx,
 			       &frame->uc_transact.uc_regs))
 			goto badframe;
-		if (save_tm_user_regs(regs, mctx, tm_mctx, sigret, msr))
+		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
 	}
 	else
@@ -804,7 +784,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	{
 		if (__put_user(0, &frame->uc.uc_link))
 			goto badframe;
-		if (save_user_regs(regs, mctx, tm_mctx, sigret, 1))
+		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
 	regs->link = tramp;
@@ -847,7 +827,6 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	struct mcontext __user *mctx;
 	struct mcontext __user *tm_mctx = NULL;
 	unsigned long newsp = 0;
-	int sigret;
 	unsigned long tramp;
 	struct pt_regs *regs = tsk->thread.regs;
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@@ -880,22 +859,26 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 		goto badframe;
 
 	if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
-		sigret = 0;
 		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
 	} else {
-		sigret = __NR_sigreturn;
-		tramp = (unsigned long)mctx->tramp;
+		tramp = (unsigned long)mctx->mc_pad;
+		/* Set up the sigreturn trampoline: li r0,sigret; sc */
+		if (__put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0]))
+			goto badframe;
+		if (__put_user(PPC_INST_SC, &mctx->mc_pad[1]))
+			goto badframe;
+		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 	}
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (MSR_TM_ACTIVE(msr)) {
-		if (save_tm_user_regs(regs, mctx, tm_mctx, sigret, msr))
+		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
 	}
 	else
 #endif
 	{
-		if (save_user_regs(regs, mctx, tm_mctx, sigret, 1))
+		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
 
@@ -1047,7 +1030,7 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 		mctx = (struct mcontext __user *)
 			((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
 		if (!access_ok(old_ctx, ctx_size)
-		    || save_user_regs(regs, mctx, NULL, 0, ctx_has_vsx_region)
+		    || save_user_regs(regs, mctx, NULL, ctx_has_vsx_region)
 		    || put_sigset_t(&old_ctx->uc_sigmask, &current->blocked)
 		    || __put_user(to_user_ptr(mctx), &old_ctx->uc_regs))
 			return -EFAULT;
-- 
2.25.0

[PATCH v2 16/25] powerpc/signal32: Move signal trampoline setup to handle_[rt_]signal32

[Christophe Leroy]

Move signal trampoline setup into handle_signal32()
and handle_rt_signal32().

At the same time, remove the define which hides the mc_pad field
used for trampoline.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 61 ++++++++++++---------------------
 1 file changed, 22 insertions(+), 39 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index ab8c8cb98b15..d8c3843102df 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -199,9 +199,6 @@ struct sigframe {
 	int			abigap[56];
 };
 
-/* We use the mc_pad field for the signal return trampoline. */
-#define tramp	mc_pad
-
 /*
  *  When we have rt signals to deliver, we set up on the
  *  user stack, going down from the original stack pointer:
@@ -236,8 +233,7 @@ struct rt_sigframe {
  * altivec/spe instructions at some point.
  */
 static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
-			  struct mcontext __user *tm_frame, int sigret,
-			  int ctx_has_vsx_region)
+			  struct mcontext __user *tm_frame, int ctx_has_vsx_region)
 {
 	unsigned long msr = regs->msr;
 
@@ -320,15 +316,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	if (tm_frame && __put_user(0, &tm_frame->mc_gregs[PT_MSR]))
 		return 1;
 
-	if (sigret) {
-		/* Set up the sigreturn trampoline: li 0,sigret; sc */
-		if (__put_user(PPC_INST_ADDI + sigret, &frame->tramp[0])
-		    || __put_user(PPC_INST_SC, &frame->tramp[1]))
-			return 1;
-		flush_icache_range((unsigned long) &frame->tramp[0],
-				   (unsigned long) &frame->tramp[2]);
-	}
-
 	return 0;
 }
 
@@ -342,10 +329,8 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
  *
  * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
  */
-static int save_tm_user_regs(struct pt_regs *regs,
-			     struct mcontext __user *frame,
-			     struct mcontext __user *tm_frame, int sigret,
-			     unsigned long msr)
+static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
+			     struct mcontext __user *tm_frame, unsigned long msr)
 {
 	WARN_ON(tm_suspend_disabled);
 
@@ -461,14 +446,6 @@ static int save_tm_user_regs(struct pt_regs *regs,
 
 	if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
 		return 1;
-	if (sigret) {
-		/* Set up the sigreturn trampoline: li 0,sigret; sc */
-		if (__put_user(PPC_INST_ADDI + sigret, &frame->tramp[0])
-		    || __put_user(PPC_INST_SC, &frame->tramp[1]))
-			return 1;
-		flush_icache_range((unsigned long) &frame->tramp[0],
-				   (unsigned long) &frame->tramp[2]);
-	}
 
 	return 0;
 }
@@ -755,7 +732,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	struct mcontext __user *mctx;
 	struct mcontext __user *tm_mctx = NULL;
 	unsigned long newsp = 0;
-	int sigret;
 	unsigned long tramp;
 	struct pt_regs *regs = tsk->thread.regs;
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@@ -782,11 +758,15 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Save user registers on the stack */
 	if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
-		sigret = 0;
 		tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
 	} else {
-		sigret = __NR_rt_sigreturn;
-		tramp = (unsigned long)mctx->tramp;
+		tramp = (unsigned long)mctx->mc_pad;
+		/* Set up the sigreturn trampoline: li r0,sigret; sc */
+		if (__put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0]))
+			goto badframe;
+		if (__put_user(PPC_INST_SC, &mctx->mc_pad[1]))
+			goto badframe;
+		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 	}
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@@ -796,7 +776,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 		    __put_user((unsigned long)tm_mctx,
 			       &frame->uc_transact.uc_regs))
 			goto badframe;
-		if (save_tm_user_regs(regs, mctx, tm_mctx, sigret, msr))
+		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
 	}
 	else
@@ -804,7 +784,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	{
 		if (__put_user(0, &frame->uc.uc_link))
 			goto badframe;
-		if (save_user_regs(regs, mctx, tm_mctx, sigret, 1))
+		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
 	regs->link = tramp;
@@ -847,7 +827,6 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	struct mcontext __user *mctx;
 	struct mcontext __user *tm_mctx = NULL;
 	unsigned long newsp = 0;
-	int sigret;
 	unsigned long tramp;
 	struct pt_regs *regs = tsk->thread.regs;
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@@ -880,22 +859,26 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 		goto badframe;
 
 	if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
-		sigret = 0;
 		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
 	} else {
-		sigret = __NR_sigreturn;
-		tramp = (unsigned long)mctx->tramp;
+		tramp = (unsigned long)mctx->mc_pad;
+		/* Set up the sigreturn trampoline: li r0,sigret; sc */
+		if (__put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0]))
+			goto badframe;
+		if (__put_user(PPC_INST_SC, &mctx->mc_pad[1]))
+			goto badframe;
+		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 	}
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (MSR_TM_ACTIVE(msr)) {
-		if (save_tm_user_regs(regs, mctx, tm_mctx, sigret, msr))
+		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
 	}
 	else
 #endif
 	{
-		if (save_user_regs(regs, mctx, tm_mctx, sigret, 1))
+		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
 
@@ -1047,7 +1030,7 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 		mctx = (struct mcontext __user *)
 			((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
 		if (!access_ok(old_ctx, ctx_size)
-		    || save_user_regs(regs, mctx, NULL, 0, ctx_has_vsx_region)
+		    || save_user_regs(regs, mctx, NULL, ctx_has_vsx_region)
 		    || put_sigset_t(&old_ctx->uc_sigmask, &current->blocked)
 		    || __put_user(to_user_ptr(mctx), &old_ctx->uc_regs))
 			return -EFAULT;
-- 
2.25.0

[PATCH v2 17/25] powerpc/signal32: Switch handle_signal32() to user_access_begin() logic

[Christophe Leroy]

Replace the access_ok() by user_access_begin() and change all user
accesses to unsafe_ version.

Move flush_icache_range() outside the user access block.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index d8c3843102df..fc8ba4b29edf 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -840,35 +840,35 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	tm_mctx = &frame->mctx_transact;
 #endif
-	if (!access_ok(frame, sizeof(*frame)))
+	if (!user_write_access_begin(frame, sizeof(*frame)))
 		goto badframe;
 	sc = (struct sigcontext __user *) &frame->sctx;
 
 #if _NSIG != 64
 #error "Please adjust handle_signal()"
 #endif
-	if (__put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler)
-	    || __put_user(oldset->sig[0], &sc->oldmask)
+	unsafe_put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler, failed);
+	unsafe_put_user(oldset->sig[0], &sc->oldmask, failed);
 #ifdef CONFIG_PPC64
-	    || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
+	unsafe_put_user((oldset->sig[0] >> 32), &sc->_unused[3], failed);
 #else
-	    || __put_user(oldset->sig[1], &sc->_unused[3])
+	unsafe_put_user(oldset->sig[1], &sc->_unused[3], failed);
 #endif
-	    || __put_user(to_user_ptr(mctx), &sc->regs)
-	    || __put_user(ksig->sig, &sc->signal))
-		goto badframe;
+	unsafe_put_user(to_user_ptr(mctx), &sc->regs, failed);
+	unsafe_put_user(ksig->sig, &sc->signal, failed);
 
 	if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
 		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
 	} else {
 		tramp = (unsigned long)mctx->mc_pad;
 		/* Set up the sigreturn trampoline: li r0,sigret; sc */
-		if (__put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0]))
-			goto badframe;
-		if (__put_user(PPC_INST_SC, &mctx->mc_pad[1]))
-			goto badframe;
-		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
+		unsafe_put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0], failed);
+		unsafe_put_user(PPC_INST_SC, &mctx->mc_pad[1], failed);
 	}
+	user_write_access_end();
+
+	if (tramp == (unsigned long)mctx->mc_pad)
+		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (MSR_TM_ACTIVE(msr)) {
@@ -901,6 +901,9 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	regs->msr &= ~MSR_LE;
 	return 0;
 
+failed:
+	user_write_access_end();
+
 badframe:
 	signal_fault(tsk, regs, "handle_signal32", frame);
 
-- 
2.25.0

[PATCH v2 17/25] powerpc/signal32: Switch handle_signal32() to user_access_begin() logic

[Christophe Leroy]

Replace the access_ok() by user_access_begin() and change all user
accesses to unsafe_ version.

Move flush_icache_range() outside the user access block.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index d8c3843102df..fc8ba4b29edf 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -840,35 +840,35 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	tm_mctx = &frame->mctx_transact;
 #endif
-	if (!access_ok(frame, sizeof(*frame)))
+	if (!user_write_access_begin(frame, sizeof(*frame)))
 		goto badframe;
 	sc = (struct sigcontext __user *) &frame->sctx;
 
 #if _NSIG != 64
 #error "Please adjust handle_signal()"
 #endif
-	if (__put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler)
-	    || __put_user(oldset->sig[0], &sc->oldmask)
+	unsafe_put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler, failed);
+	unsafe_put_user(oldset->sig[0], &sc->oldmask, failed);
 #ifdef CONFIG_PPC64
-	    || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
+	unsafe_put_user((oldset->sig[0] >> 32), &sc->_unused[3], failed);
 #else
-	    || __put_user(oldset->sig[1], &sc->_unused[3])
+	unsafe_put_user(oldset->sig[1], &sc->_unused[3], failed);
 #endif
-	    || __put_user(to_user_ptr(mctx), &sc->regs)
-	    || __put_user(ksig->sig, &sc->signal))
-		goto badframe;
+	unsafe_put_user(to_user_ptr(mctx), &sc->regs, failed);
+	unsafe_put_user(ksig->sig, &sc->signal, failed);
 
 	if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
 		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
 	} else {
 		tramp = (unsigned long)mctx->mc_pad;
 		/* Set up the sigreturn trampoline: li r0,sigret; sc */
-		if (__put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0]))
-			goto badframe;
-		if (__put_user(PPC_INST_SC, &mctx->mc_pad[1]))
-			goto badframe;
-		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
+		unsafe_put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0], failed);
+		unsafe_put_user(PPC_INST_SC, &mctx->mc_pad[1], failed);
 	}
+	user_write_access_end();
+
+	if (tramp == (unsigned long)mctx->mc_pad)
+		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (MSR_TM_ACTIVE(msr)) {
@@ -901,6 +901,9 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	regs->msr &= ~MSR_LE;
 	return 0;
 
+failed:
+	user_write_access_end();
+
 badframe:
 	signal_fault(tsk, regs, "handle_signal32", frame);
 
-- 
2.25.0

[PATCH v2 18/25] powerpc/signal32: Switch handle_rt_signal32() to user_access_begin() logic

[Christophe Leroy]

On the same way as handle_signal32(), replace all user
accesses with equivalent unsafe_ versions, and move the
trampoline code icache flush outside the user access block.

Functions that have no unsafe_ equivalent also remains outside
the access block.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 55 ++++++++++++++++++++-------------
 1 file changed, 34 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index fc8ba4b29edf..93c2d6304831 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -58,8 +58,6 @@
 #define mcontext	mcontext32
 #define ucontext	ucontext32
 
-#define __save_altstack __compat_save_altstack
-
 /*
  * Userspace code may pass a ucontext which doesn't include VSX added
  * at the end.  We need to check for this case.
@@ -745,16 +743,28 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	tm_mctx = &frame->uc_transact.uc_mcontext;
 #endif
-	if (!access_ok(frame, sizeof(*frame)))
+	if (!user_write_access_begin(frame, sizeof(*frame)))
 		goto badframe;
 
 	/* Put the siginfo & fill in most of the ucontext */
-	if (copy_siginfo_to_user(&frame->info, &ksig->info) ||
-	    __put_user(0, &frame->uc.uc_flags) ||
-	    __save_altstack(&frame->uc.uc_stack, regs->gpr[1]) ||
-	    __put_user(to_user_ptr(&frame->uc.uc_mcontext), &frame->uc.uc_regs) ||
-	    put_sigset_t(&frame->uc.uc_sigmask, oldset))
-		goto badframe;
+	unsafe_put_user(0, &frame->uc.uc_flags, failed);
+#ifdef CONFIG_PPC64
+	unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed);
+#else
+	unsafe_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed);
+#endif
+	unsafe_put_user(to_user_ptr(&frame->uc.uc_mcontext), &frame->uc.uc_regs, failed);
+
+	if (MSR_TM_ACTIVE(msr)) {
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+		unsafe_put_user((unsigned long)&frame->uc_transact,
+				&frame->uc.uc_link, failed);
+		unsafe_put_user((unsigned long)tm_mctx,
+				&frame->uc_transact.uc_regs, failed);
+#endif
+	} else {
+		unsafe_put_user(0, &frame->uc.uc_link, failed);
+	}
 
 	/* Save user registers on the stack */
 	if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
@@ -762,28 +772,28 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	} else {
 		tramp = (unsigned long)mctx->mc_pad;
 		/* Set up the sigreturn trampoline: li r0,sigret; sc */
-		if (__put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0]))
-			goto badframe;
-		if (__put_user(PPC_INST_SC, &mctx->mc_pad[1]))
-			goto badframe;
-		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
+		unsafe_put_user(PPC_INST_ADDI + __NR_rt_sigreturn, &mctx->mc_pad[0],
+				failed);
+		unsafe_put_user(PPC_INST_SC, &mctx->mc_pad[1], failed);
 	}
+	user_write_access_end();
+
+	if (put_sigset_t(&frame->uc.uc_sigmask, oldset))
+		goto badframe;
+	if (copy_siginfo_to_user(&frame->info, &ksig->info))
+		goto badframe;
+
+	if (tramp == (unsigned long)mctx->mc_pad)
+		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (MSR_TM_ACTIVE(msr)) {
-		if (__put_user((unsigned long)&frame->uc_transact,
-			       &frame->uc.uc_link) ||
-		    __put_user((unsigned long)tm_mctx,
-			       &frame->uc_transact.uc_regs))
-			goto badframe;
 		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
 	}
 	else
 #endif
 	{
-		if (__put_user(0, &frame->uc.uc_link))
-			goto badframe;
 		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
@@ -810,6 +820,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	regs->msr |= (MSR_KERNEL & MSR_LE);
 	return 0;
 
+failed:
+	user_write_access_end();
+
 badframe:
 	signal_fault(tsk, regs, "handle_rt_signal32", frame);
 
-- 
2.25.0

[PATCH v2 18/25] powerpc/signal32: Switch handle_rt_signal32() to user_access_begin() logic

[Christophe Leroy]

On the same way as handle_signal32(), replace all user
accesses with equivalent unsafe_ versions, and move the
trampoline code icache flush outside the user access block.

Functions that have no unsafe_ equivalent also remains outside
the access block.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 55 ++++++++++++++++++++-------------
 1 file changed, 34 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index fc8ba4b29edf..93c2d6304831 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -58,8 +58,6 @@
 #define mcontext	mcontext32
 #define ucontext	ucontext32
 
-#define __save_altstack __compat_save_altstack
-
 /*
  * Userspace code may pass a ucontext which doesn't include VSX added
  * at the end.  We need to check for this case.
@@ -745,16 +743,28 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	tm_mctx = &frame->uc_transact.uc_mcontext;
 #endif
-	if (!access_ok(frame, sizeof(*frame)))
+	if (!user_write_access_begin(frame, sizeof(*frame)))
 		goto badframe;
 
 	/* Put the siginfo & fill in most of the ucontext */
-	if (copy_siginfo_to_user(&frame->info, &ksig->info) ||
-	    __put_user(0, &frame->uc.uc_flags) ||
-	    __save_altstack(&frame->uc.uc_stack, regs->gpr[1]) ||
-	    __put_user(to_user_ptr(&frame->uc.uc_mcontext), &frame->uc.uc_regs) ||
-	    put_sigset_t(&frame->uc.uc_sigmask, oldset))
-		goto badframe;
+	unsafe_put_user(0, &frame->uc.uc_flags, failed);
+#ifdef CONFIG_PPC64
+	unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed);
+#else
+	unsafe_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed);
+#endif
+	unsafe_put_user(to_user_ptr(&frame->uc.uc_mcontext), &frame->uc.uc_regs, failed);
+
+	if (MSR_TM_ACTIVE(msr)) {
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+		unsafe_put_user((unsigned long)&frame->uc_transact,
+				&frame->uc.uc_link, failed);
+		unsafe_put_user((unsigned long)tm_mctx,
+				&frame->uc_transact.uc_regs, failed);
+#endif
+	} else {
+		unsafe_put_user(0, &frame->uc.uc_link, failed);
+	}
 
 	/* Save user registers on the stack */
 	if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
@@ -762,28 +772,28 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	} else {
 		tramp = (unsigned long)mctx->mc_pad;
 		/* Set up the sigreturn trampoline: li r0,sigret; sc */
-		if (__put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0]))
-			goto badframe;
-		if (__put_user(PPC_INST_SC, &mctx->mc_pad[1]))
-			goto badframe;
-		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
+		unsafe_put_user(PPC_INST_ADDI + __NR_rt_sigreturn, &mctx->mc_pad[0],
+				failed);
+		unsafe_put_user(PPC_INST_SC, &mctx->mc_pad[1], failed);
 	}
+	user_write_access_end();
+
+	if (put_sigset_t(&frame->uc.uc_sigmask, oldset))
+		goto badframe;
+	if (copy_siginfo_to_user(&frame->info, &ksig->info))
+		goto badframe;
+
+	if (tramp == (unsigned long)mctx->mc_pad)
+		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (MSR_TM_ACTIVE(msr)) {
-		if (__put_user((unsigned long)&frame->uc_transact,
-			       &frame->uc.uc_link) ||
-		    __put_user((unsigned long)tm_mctx,
-			       &frame->uc_transact.uc_regs))
-			goto badframe;
 		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
 	}
 	else
 #endif
 	{
-		if (__put_user(0, &frame->uc.uc_link))
-			goto badframe;
 		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
@@ -810,6 +820,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	regs->msr |= (MSR_KERNEL & MSR_LE);
 	return 0;
 
+failed:
+	user_write_access_end();
+
 badframe:
 	signal_fault(tsk, regs, "handle_rt_signal32", frame);
 
-- 
2.25.0

[PATCH v2 19/25] powerpc/signal32: Remove ifdefery in middle of if/else

[Christophe Leroy]

MSR_TM_ACTIVE() is always defined and returns always 0 when
CONFIG_PPC_TRANSACTIONAL_MEM is not selected, so the awful
ifdefery in the middle of an if/else can be removed.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 93c2d6304831..310d3b8d9ad5 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -447,6 +447,12 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 
 	return 0;
 }
+#else
+static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
+			     struct mcontext __user *tm_frame, unsigned long msr)
+{
+	return 0;
+}
 #endif
 
 /*
@@ -732,10 +738,8 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	unsigned long newsp = 0;
 	unsigned long tramp;
 	struct pt_regs *regs = tsk->thread.regs;
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	/* Save the thread's msr before get_tm_stackpointer() changes it */
 	unsigned long msr = regs->msr;
-#endif
 
 	/* Set up Signal Frame */
 	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
@@ -786,14 +790,10 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	if (tramp == (unsigned long)mctx->mc_pad)
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (MSR_TM_ACTIVE(msr)) {
 		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
-	}
-	else
-#endif
-	{
+	} else {
 		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
@@ -842,10 +842,8 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	unsigned long newsp = 0;
 	unsigned long tramp;
 	struct pt_regs *regs = tsk->thread.regs;
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	/* Save the thread's msr before get_tm_stackpointer() changes it */
 	unsigned long msr = regs->msr;
-#endif
 
 	/* Set up Signal Frame */
 	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
@@ -883,14 +881,10 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	if (tramp == (unsigned long)mctx->mc_pad)
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (MSR_TM_ACTIVE(msr)) {
 		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
-	}
-	else
-#endif
-	{
+	} else {
 		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
-- 
2.25.0

[PATCH v2 19/25] powerpc/signal32: Remove ifdefery in middle of if/else

[Christophe Leroy]

MSR_TM_ACTIVE() is always defined and returns always 0 when
CONFIG_PPC_TRANSACTIONAL_MEM is not selected, so the awful
ifdefery in the middle of an if/else can be removed.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 93c2d6304831..310d3b8d9ad5 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -447,6 +447,12 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 
 	return 0;
 }
+#else
+static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
+			     struct mcontext __user *tm_frame, unsigned long msr)
+{
+	return 0;
+}
 #endif
 
 /*
@@ -732,10 +738,8 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	unsigned long newsp = 0;
 	unsigned long tramp;
 	struct pt_regs *regs = tsk->thread.regs;
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	/* Save the thread's msr before get_tm_stackpointer() changes it */
 	unsigned long msr = regs->msr;
-#endif
 
 	/* Set up Signal Frame */
 	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
@@ -786,14 +790,10 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	if (tramp == (unsigned long)mctx->mc_pad)
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (MSR_TM_ACTIVE(msr)) {
 		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
-	}
-	else
-#endif
-	{
+	} else {
 		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
@@ -842,10 +842,8 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	unsigned long newsp = 0;
 	unsigned long tramp;
 	struct pt_regs *regs = tsk->thread.regs;
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	/* Save the thread's msr before get_tm_stackpointer() changes it */
 	unsigned long msr = regs->msr;
-#endif
 
 	/* Set up Signal Frame */
 	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
@@ -883,14 +881,10 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	if (tramp == (unsigned long)mctx->mc_pad)
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (MSR_TM_ACTIVE(msr)) {
 		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
-	}
-	else
-#endif
-	{
+	} else {
 		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
-- 
2.25.0

[PATCH v2 20/25] signal: Add unsafe_put_compat_sigset()

[Christophe Leroy]

Implement 'unsafe' version of put_compat_sigset()

For the bigendian, use unsafe_put_user() directly
to avoid intermediate copy through the stack.

For the littleendian, use a straight unsafe_copy_to_user().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 include/linux/compat.h | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index d38c4d7e83bd..7ec6e44b093b 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -442,6 +442,38 @@ put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set,
 #endif
 }
 
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define unsafe_put_compat_sigset(compat, set, label) do {		\
+	compat_sigset_t __user *__c = compat;				\
+	const sigset_t *__s = set;					\
+									\
+	switch (_NSIG_WORDS) {						\
+	case 4:								\
+		unsafe_put_user(__s->sig[3] >> 32, &__c->sig[7], label);	\
+		unsafe_put_user(__s->sig[3], &__c->sig[6], label);	\
+		fallthrough;						\
+	case 3:								\
+		unsafe_put_user(__s->sig[2] >> 32, &__c->sig[5], label);	\
+		unsafe_put_user(__s->sig[2], &__c->sig[4], label);	\
+		fallthrough;						\
+	case 2:								\
+		unsafe_put_user(__s->sig[1] >> 32, &__c->sig[3], label);	\
+		unsafe_put_user(__s->sig[1], &__c->sig[2], label);	\
+		fallthrough;						\
+	case 1:								\
+		unsafe_put_user(__s->sig[0] >> 32, &__c->sig[1], label);	\
+		unsafe_put_user(__s->sig[0], &__c->sig[0], label);	\
+	}								\
+} while (0)
+#else
+#define unsafe_put_compat_sigset(compat, set, label) do {		\
+	compat_sigset_t __user *__c = compat;				\
+	const sigset_t *__s = set;					\
+									\
+	unsafe_copy_to_user(__c, __s, sizeof(*__c), label);		\
+} while (0)
+#endif
+
 extern int compat_ptrace_request(struct task_struct *child,
 				 compat_long_t request,
 				 compat_ulong_t addr, compat_ulong_t data);
-- 
2.25.0

[PATCH v2 20/25] signal: Add unsafe_put_compat_sigset()

[Christophe Leroy]

Implement 'unsafe' version of put_compat_sigset()

For the bigendian, use unsafe_put_user() directly
to avoid intermediate copy through the stack.

For the littleendian, use a straight unsafe_copy_to_user().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 include/linux/compat.h | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index d38c4d7e83bd..7ec6e44b093b 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -442,6 +442,38 @@ put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set,
 #endif
 }
 
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define unsafe_put_compat_sigset(compat, set, label) do {		\
+	compat_sigset_t __user *__c = compat;				\
+	const sigset_t *__s = set;					\
+									\
+	switch (_NSIG_WORDS) {						\
+	case 4:								\
+		unsafe_put_user(__s->sig[3] >> 32, &__c->sig[7], label);	\
+		unsafe_put_user(__s->sig[3], &__c->sig[6], label);	\
+		fallthrough;						\
+	case 3:								\
+		unsafe_put_user(__s->sig[2] >> 32, &__c->sig[5], label);	\
+		unsafe_put_user(__s->sig[2], &__c->sig[4], label);	\
+		fallthrough;						\
+	case 2:								\
+		unsafe_put_user(__s->sig[1] >> 32, &__c->sig[3], label);	\
+		unsafe_put_user(__s->sig[1], &__c->sig[2], label);	\
+		fallthrough;						\
+	case 1:								\
+		unsafe_put_user(__s->sig[0] >> 32, &__c->sig[1], label);	\
+		unsafe_put_user(__s->sig[0], &__c->sig[0], label);	\
+	}								\
+} while (0)
+#else
+#define unsafe_put_compat_sigset(compat, set, label) do {		\
+	compat_sigset_t __user *__c = compat;				\
+	const sigset_t *__s = set;					\
+									\
+	unsafe_copy_to_user(__c, __s, sizeof(*__c), label);		\
+} while (0)
+#endif
+
 extern int compat_ptrace_request(struct task_struct *child,
 				 compat_long_t request,
 				 compat_ulong_t addr, compat_ulong_t data);
-- 
2.25.0

[PATCH v2 21/25] powerpc/signal32: Add and use unsafe_put_sigset_t()

[Christophe Leroy]

put_sigset_t() calls copy_to_user() for copying two words.

This is terribly inefficient for copying two words.

By switching to unsafe_put_user(), we end up with something as
simple as:

 3cc:   81 3d 00 00     lwz     r9,0(r29)
 3d0:   91 26 00 b4     stw     r9,180(r6)
 3d4:   81 3d 00 04     lwz     r9,4(r29)
 3d8:   91 26 00 b8     stw     r9,184(r6)

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 310d3b8d9ad5..3f9f315dd036 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -87,6 +87,8 @@ static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
 	return put_compat_sigset(uset, set, sizeof(*uset));
 }
 
+#define unsafe_put_sigset_t	unsafe_put_compat_sigset
+
 static inline int get_sigset_t(sigset_t *set,
 			       const compat_sigset_t __user *uset)
 {
@@ -141,6 +143,13 @@ static inline int put_sigset_t(sigset_t __user *uset, sigset_t *set)
 	return copy_to_user(uset, set, sizeof(*uset));
 }
 
+#define unsafe_put_sigset_t(uset, set, label) do {			\
+	sigset_t __user *__us = uset	;				\
+	const sigset_t *__s = set;					\
+									\
+	unsafe_copy_to_user(__us, __s, sizeof(*__us), label);		\
+} while (0)
+
 static inline int get_sigset_t(sigset_t *set, const sigset_t __user *uset)
 {
 	return copy_from_user(set, uset, sizeof(*uset));
@@ -780,10 +789,10 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 				failed);
 		unsafe_put_user(PPC_INST_SC, &mctx->mc_pad[1], failed);
 	}
+	unsafe_put_sigset_t(&frame->uc.uc_sigmask, oldset, failed);
+
 	user_write_access_end();
 
-	if (put_sigset_t(&frame->uc.uc_sigmask, oldset))
-		goto badframe;
 	if (copy_siginfo_to_user(&frame->info, &ksig->info))
 		goto badframe;
 
-- 
2.25.0

[PATCH v2 21/25] powerpc/signal32: Add and use unsafe_put_sigset_t()

[Christophe Leroy]

put_sigset_t() calls copy_to_user() for copying two words.

This is terribly inefficient for copying two words.

By switching to unsafe_put_user(), we end up with something as
simple as:

 3cc:   81 3d 00 00     lwz     r9,0(r29)
 3d0:   91 26 00 b4     stw     r9,180(r6)
 3d4:   81 3d 00 04     lwz     r9,4(r29)
 3d8:   91 26 00 b8     stw     r9,184(r6)

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 310d3b8d9ad5..3f9f315dd036 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -87,6 +87,8 @@ static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
 	return put_compat_sigset(uset, set, sizeof(*uset));
 }
 
+#define unsafe_put_sigset_t	unsafe_put_compat_sigset
+
 static inline int get_sigset_t(sigset_t *set,
 			       const compat_sigset_t __user *uset)
 {
@@ -141,6 +143,13 @@ static inline int put_sigset_t(sigset_t __user *uset, sigset_t *set)
 	return copy_to_user(uset, set, sizeof(*uset));
 }
 
+#define unsafe_put_sigset_t(uset, set, label) do {			\
+	sigset_t __user *__us = uset	;				\
+	const sigset_t *__s = set;					\
+									\
+	unsafe_copy_to_user(__us, __s, sizeof(*__us), label);		\
+} while (0)
+
 static inline int get_sigset_t(sigset_t *set, const sigset_t __user *uset)
 {
 	return copy_from_user(set, uset, sizeof(*uset));
@@ -780,10 +789,10 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 				failed);
 		unsafe_put_user(PPC_INST_SC, &mctx->mc_pad[1], failed);
 	}
+	unsafe_put_sigset_t(&frame->uc.uc_sigmask, oldset, failed);
+
 	user_write_access_end();
 
-	if (put_sigset_t(&frame->uc.uc_sigmask, oldset))
-		goto badframe;
 	if (copy_siginfo_to_user(&frame->info, &ksig->info))
 		goto badframe;
 
-- 
2.25.0

[PATCH v2 22/25] powerpc/signal32: Switch swap_context() to user_access_begin() logic

[Christophe Leroy]

As this was the last user of put_sigset_t(), remove it as well.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 3f9f315dd036..5b8a4ede142c 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -82,11 +82,6 @@
  * Functions for flipping sigsets (thanks to brain dead generic
  * implementation that makes things simple for little endian only)
  */
-static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
-{
-	return put_compat_sigset(uset, set, sizeof(*uset));
-}
-
 #define unsafe_put_sigset_t	unsafe_put_compat_sigset
 
 static inline int get_sigset_t(sigset_t *set,
@@ -138,11 +133,6 @@ static inline int restore_general_regs(struct pt_regs *regs,
 
 #define GP_REGS_SIZE	min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
 
-static inline int put_sigset_t(sigset_t __user *uset, sigset_t *set)
-{
-	return copy_to_user(uset, set, sizeof(*uset));
-}
-
 #define unsafe_put_sigset_t(uset, set, label) do {			\
 	sigset_t __user *__us = uset	;				\
 	const sigset_t *__s = set;					\
@@ -1048,11 +1038,13 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 		 */
 		mctx = (struct mcontext __user *)
 			((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
-		if (!access_ok(old_ctx, ctx_size)
-		    || save_user_regs(regs, mctx, NULL, ctx_has_vsx_region)
-		    || put_sigset_t(&old_ctx->uc_sigmask, &current->blocked)
-		    || __put_user(to_user_ptr(mctx), &old_ctx->uc_regs))
+		if (save_user_regs(regs, mctx, NULL, ctx_has_vsx_region))
+			return -EFAULT;
+		if (!user_write_access_begin(old_ctx, ctx_size))
 			return -EFAULT;
+		unsafe_put_sigset_t(&old_ctx->uc_sigmask, &current->blocked, failed);
+		unsafe_put_user(to_user_ptr(mctx), &old_ctx->uc_regs, failed);
+		user_write_access_end();
 	}
 	if (new_ctx == NULL)
 		return 0;
@@ -1076,6 +1068,10 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 
 	set_thread_flag(TIF_RESTOREALL);
 	return 0;
+
+failed:
+	user_write_access_end();
+	return -EFAULT;
 }
 
 #ifdef CONFIG_PPC64
-- 
2.25.0

[PATCH v2 22/25] powerpc/signal32: Switch swap_context() to user_access_begin() logic

[Christophe Leroy]

As this was the last user of put_sigset_t(), remove it as well.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 3f9f315dd036..5b8a4ede142c 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -82,11 +82,6 @@
  * Functions for flipping sigsets (thanks to brain dead generic
  * implementation that makes things simple for little endian only)
  */
-static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
-{
-	return put_compat_sigset(uset, set, sizeof(*uset));
-}
-
 #define unsafe_put_sigset_t	unsafe_put_compat_sigset
 
 static inline int get_sigset_t(sigset_t *set,
@@ -138,11 +133,6 @@ static inline int restore_general_regs(struct pt_regs *regs,
 
 #define GP_REGS_SIZE	min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
 
-static inline int put_sigset_t(sigset_t __user *uset, sigset_t *set)
-{
-	return copy_to_user(uset, set, sizeof(*uset));
-}
-
 #define unsafe_put_sigset_t(uset, set, label) do {			\
 	sigset_t __user *__us = uset	;				\
 	const sigset_t *__s = set;					\
@@ -1048,11 +1038,13 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 		 */
 		mctx = (struct mcontext __user *)
 			((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
-		if (!access_ok(old_ctx, ctx_size)
-		    || save_user_regs(regs, mctx, NULL, ctx_has_vsx_region)
-		    || put_sigset_t(&old_ctx->uc_sigmask, &current->blocked)
-		    || __put_user(to_user_ptr(mctx), &old_ctx->uc_regs))
+		if (save_user_regs(regs, mctx, NULL, ctx_has_vsx_region))
+			return -EFAULT;
+		if (!user_write_access_begin(old_ctx, ctx_size))
 			return -EFAULT;
+		unsafe_put_sigset_t(&old_ctx->uc_sigmask, &current->blocked, failed);
+		unsafe_put_user(to_user_ptr(mctx), &old_ctx->uc_regs, failed);
+		user_write_access_end();
 	}
 	if (new_ctx == NULL)
 		return 0;
@@ -1076,6 +1068,10 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 
 	set_thread_flag(TIF_RESTOREALL);
 	return 0;
+
+failed:
+	user_write_access_end();
+	return -EFAULT;
 }
 
 #ifdef CONFIG_PPC64
-- 
2.25.0

[PATCH v2 23/25] powerpc/signal: Create 'unsafe' versions of copy_[ck][fpr/vsx]_to_user()

[Christophe Leroy]

For the non VSX version, that's trivial. Just use unsafe_copy_to_user()
instead of __copy_to_user().

For the VSX version, remove the intermediate step through a buffer and
use unsafe_put_user() directly. This generates a far smaller code which
is acceptable to inline, see below:

Standard VSX version:

0000000000000000 <.copy_fpr_to_user>:
   0:	7c 08 02 a6 	mflr    r0
   4:	fb e1 ff f8 	std     r31,-8(r1)
   8:	39 00 00 20 	li      r8,32
   c:	39 24 0b 80 	addi    r9,r4,2944
  10:	7d 09 03 a6 	mtctr   r8
  14:	f8 01 00 10 	std     r0,16(r1)
  18:	f8 21 fe 71 	stdu    r1,-400(r1)
  1c:	39 41 00 68 	addi    r10,r1,104
  20:	e9 09 00 00 	ld      r8,0(r9)
  24:	39 4a 00 08 	addi    r10,r10,8
  28:	39 29 00 10 	addi    r9,r9,16
  2c:	f9 0a 00 00 	std     r8,0(r10)
  30:	42 00 ff f0 	bdnz    20 <.copy_fpr_to_user+0x20>
  34:	e9 24 0d 80 	ld      r9,3456(r4)
  38:	3d 42 00 00 	addis   r10,r2,0
			3a: R_PPC64_TOC16_HA	.toc
  3c:	eb ea 00 00 	ld      r31,0(r10)
			3e: R_PPC64_TOC16_LO_DS	.toc
  40:	f9 21 01 70 	std     r9,368(r1)
  44:	e9 3f 00 00 	ld      r9,0(r31)
  48:	81 29 00 20 	lwz     r9,32(r9)
  4c:	2f 89 00 00 	cmpwi   cr7,r9,0
  50:	40 9c 00 18 	bge     cr7,68 <.copy_fpr_to_user+0x68>
  54:	4c 00 01 2c 	isync
  58:	3d 20 40 00 	lis     r9,16384
  5c:	79 29 07 c6 	rldicr  r9,r9,32,31
  60:	7d 3d 03 a6 	mtspr   29,r9
  64:	4c 00 01 2c 	isync
  68:	38 a0 01 08 	li      r5,264
  6c:	38 81 00 70 	addi    r4,r1,112
  70:	48 00 00 01 	bl      70 <.copy_fpr_to_user+0x70>
			70: R_PPC64_REL24	.__copy_tofrom_user
  74:	60 00 00 00 	nop
  78:	e9 3f 00 00 	ld      r9,0(r31)
  7c:	81 29 00 20 	lwz     r9,32(r9)
  80:	2f 89 00 00 	cmpwi   cr7,r9,0
  84:	40 9c 00 18 	bge     cr7,9c <.copy_fpr_to_user+0x9c>
  88:	4c 00 01 2c 	isync
  8c:	39 20 ff ff 	li      r9,-1
  90:	79 29 00 44 	rldicr  r9,r9,0,1
  94:	7d 3d 03 a6 	mtspr   29,r9
  98:	4c 00 01 2c 	isync
  9c:	38 21 01 90 	addi    r1,r1,400
  a0:	e8 01 00 10 	ld      r0,16(r1)
  a4:	eb e1 ff f8 	ld      r31,-8(r1)
  a8:	7c 08 03 a6 	mtlr    r0
  ac:	4e 80 00 20 	blr

'unsafe' simulated VSX version (The ... are only nops) using
unsafe_copy_fpr_to_user() macro:

unsigned long copy_fpr_to_user(void __user *to,
			       struct task_struct *task)
{
	unsafe_copy_fpr_to_user(to, task, failed);
	return 0;
failed:
	return 1;
}

0000000000000000 <.copy_fpr_to_user>:
   0:	39 00 00 20 	li      r8,32
   4:	39 44 0b 80 	addi    r10,r4,2944
   8:	7d 09 03 a6 	mtctr   r8
   c:	7c 69 1b 78 	mr      r9,r3
...
  20:	e9 0a 00 00 	ld      r8,0(r10)
  24:	f9 09 00 00 	std     r8,0(r9)
  28:	39 4a 00 10 	addi    r10,r10,16
  2c:	39 29 00 08 	addi    r9,r9,8
  30:	42 00 ff f0 	bdnz    20 <.copy_fpr_to_user+0x20>
  34:	e9 24 0d 80 	ld      r9,3456(r4)
  38:	f9 23 01 00 	std     r9,256(r3)
  3c:	38 60 00 00 	li      r3,0
  40:	4e 80 00 20 	blr
...
  50:	38 60 00 01 	li      r3,1
  54:	4e 80 00 20 	blr

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal.h | 53 ++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index f610cfafa478..2559a681536e 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -32,7 +32,54 @@ unsigned long copy_fpr_to_user(void __user *to, struct task_struct *task);
 unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct *task);
 unsigned long copy_fpr_from_user(struct task_struct *task, void __user *from);
 unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
+
+#define unsafe_copy_fpr_to_user(to, task, label)	do {		\
+	struct task_struct *__t = task;					\
+	u64 __user *buf = (u64 __user *)to;				\
+	int i;								\
+									\
+	for (i = 0; i < ELF_NFPREG - 1 ; i++)				\
+		unsafe_put_user(__t->thread.TS_FPR(i), &buf[i], label); \
+	unsafe_put_user(__t->thread.fp_state.fpscr, &buf[i], label);	\
+} while (0)
+
+#define unsafe_copy_vsx_to_user(to, task, label)	do {		\
+	struct task_struct *__t = task;					\
+	u64 __user *buf = (u64 __user *)to;				\
+	int i;								\
+									\
+	for (i = 0; i < ELF_NVSRHALFREG ; i++)				\
+		unsafe_put_user(__t->thread.fp_state.fpr[i][TS_VSRLOWOFFSET], \
+				&buf[i], label);\
+} while (0)
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+#define unsafe_copy_ckfpr_to_user(to, task, label)	do {		\
+	struct task_struct *__t = task;					\
+	u64 __user *buf = (u64 __user *)to;				\
+	int i;								\
+									\
+	for (i = 0; i < ELF_NFPREG - 1 ; i++)				\
+		unsafe_put_user(__t->thread.TS_CKFPR(i), &buf[i], label);\
+	unsafe_put_user(__t->thread.ckfp_state.fpscr, &buf[i], label);	\
+} while (0)
+
+#define unsafe_copy_ckvsx_to_user(to, task, label)	do {		\
+	struct task_struct *__t = task;					\
+	u64 __user *buf = (u64 __user *)to;				\
+	int i;								\
+									\
+	for (i = 0; i < ELF_NVSRHALFREG ; i++)				\
+		unsafe_put_user(__t->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET], \
+				&buf[i], label);\
+} while (0)
+#endif
 #elif defined(CONFIG_PPC_FPU_REGS)
+
+#define unsafe_copy_fpr_to_user(to, task, label)		\
+	unsafe_copy_to_user(to, (task)->thread.fp_state.fpr,	\
+			    ELF_NFPREG * sizeof(double), label)
+
 static inline unsigned long
 copy_fpr_to_user(void __user *to, struct task_struct *task)
 {
@@ -48,6 +95,10 @@ copy_fpr_from_user(struct task_struct *task, void __user *from)
 }
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+#define unsafe_copy_ckfpr_to_user(to, task, label)		\
+	unsafe_copy_to_user(to, (task)->thread.ckfp_state.fpr,	\
+			    ELF_NFPREG * sizeof(double), label)
+
 inline unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct *task)
 {
 	return __copy_to_user(to, task->thread.ckfp_state.fpr,
@@ -62,6 +113,8 @@ copy_ckfpr_from_user(struct task_struct *task, void __user *from)
 }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 #else
+#define unsafe_copy_fpr_to_user(to, task, label) do { } while (0)
+
 static inline unsigned long
 copy_fpr_to_user(void __user *to, struct task_struct *task)
 {
-- 
2.25.0

[PATCH v2 23/25] powerpc/signal: Create 'unsafe' versions of copy_[ck][fpr/vsx]_to_user()

[Christophe Leroy]

For the non VSX version, that's trivial. Just use unsafe_copy_to_user()
instead of __copy_to_user().

For the VSX version, remove the intermediate step through a buffer and
use unsafe_put_user() directly. This generates a far smaller code which
is acceptable to inline, see below:

Standard VSX version:

0000000000000000 <.copy_fpr_to_user>:
   0:	7c 08 02 a6 	mflr    r0
   4:	fb e1 ff f8 	std     r31,-8(r1)
   8:	39 00 00 20 	li      r8,32
   c:	39 24 0b 80 	addi    r9,r4,2944
  10:	7d 09 03 a6 	mtctr   r8
  14:	f8 01 00 10 	std     r0,16(r1)
  18:	f8 21 fe 71 	stdu    r1,-400(r1)
  1c:	39 41 00 68 	addi    r10,r1,104
  20:	e9 09 00 00 	ld      r8,0(r9)
  24:	39 4a 00 08 	addi    r10,r10,8
  28:	39 29 00 10 	addi    r9,r9,16
  2c:	f9 0a 00 00 	std     r8,0(r10)
  30:	42 00 ff f0 	bdnz    20 <.copy_fpr_to_user+0x20>
  34:	e9 24 0d 80 	ld      r9,3456(r4)
  38:	3d 42 00 00 	addis   r10,r2,0
			3a: R_PPC64_TOC16_HA	.toc
  3c:	eb ea 00 00 	ld      r31,0(r10)
			3e: R_PPC64_TOC16_LO_DS	.toc
  40:	f9 21 01 70 	std     r9,368(r1)
  44:	e9 3f 00 00 	ld      r9,0(r31)
  48:	81 29 00 20 	lwz     r9,32(r9)
  4c:	2f 89 00 00 	cmpwi   cr7,r9,0
  50:	40 9c 00 18 	bge     cr7,68 <.copy_fpr_to_user+0x68>
  54:	4c 00 01 2c 	isync
  58:	3d 20 40 00 	lis     r9,16384
  5c:	79 29 07 c6 	rldicr  r9,r9,32,31
  60:	7d 3d 03 a6 	mtspr   29,r9
  64:	4c 00 01 2c 	isync
  68:	38 a0 01 08 	li      r5,264
  6c:	38 81 00 70 	addi    r4,r1,112
  70:	48 00 00 01 	bl      70 <.copy_fpr_to_user+0x70>
			70: R_PPC64_REL24	.__copy_tofrom_user
  74:	60 00 00 00 	nop
  78:	e9 3f 00 00 	ld      r9,0(r31)
  7c:	81 29 00 20 	lwz     r9,32(r9)
  80:	2f 89 00 00 	cmpwi   cr7,r9,0
  84:	40 9c 00 18 	bge     cr7,9c <.copy_fpr_to_user+0x9c>
  88:	4c 00 01 2c 	isync
  8c:	39 20 ff ff 	li      r9,-1
  90:	79 29 00 44 	rldicr  r9,r9,0,1
  94:	7d 3d 03 a6 	mtspr   29,r9
  98:	4c 00 01 2c 	isync
  9c:	38 21 01 90 	addi    r1,r1,400
  a0:	e8 01 00 10 	ld      r0,16(r1)
  a4:	eb e1 ff f8 	ld      r31,-8(r1)
  a8:	7c 08 03 a6 	mtlr    r0
  ac:	4e 80 00 20 	blr

'unsafe' simulated VSX version (The ... are only nops) using
unsafe_copy_fpr_to_user() macro:

unsigned long copy_fpr_to_user(void __user *to,
			       struct task_struct *task)
{
	unsafe_copy_fpr_to_user(to, task, failed);
	return 0;
failed:
	return 1;
}

0000000000000000 <.copy_fpr_to_user>:
   0:	39 00 00 20 	li      r8,32
   4:	39 44 0b 80 	addi    r10,r4,2944
   8:	7d 09 03 a6 	mtctr   r8
   c:	7c 69 1b 78 	mr      r9,r3
...
  20:	e9 0a 00 00 	ld      r8,0(r10)
  24:	f9 09 00 00 	std     r8,0(r9)
  28:	39 4a 00 10 	addi    r10,r10,16
  2c:	39 29 00 08 	addi    r9,r9,8
  30:	42 00 ff f0 	bdnz    20 <.copy_fpr_to_user+0x20>
  34:	e9 24 0d 80 	ld      r9,3456(r4)
  38:	f9 23 01 00 	std     r9,256(r3)
  3c:	38 60 00 00 	li      r3,0
  40:	4e 80 00 20 	blr
...
  50:	38 60 00 01 	li      r3,1
  54:	4e 80 00 20 	blr

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal.h | 53 ++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index f610cfafa478..2559a681536e 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -32,7 +32,54 @@ unsigned long copy_fpr_to_user(void __user *to, struct task_struct *task);
 unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct *task);
 unsigned long copy_fpr_from_user(struct task_struct *task, void __user *from);
 unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
+
+#define unsafe_copy_fpr_to_user(to, task, label)	do {		\
+	struct task_struct *__t = task;					\
+	u64 __user *buf = (u64 __user *)to;				\
+	int i;								\
+									\
+	for (i = 0; i < ELF_NFPREG - 1 ; i++)				\
+		unsafe_put_user(__t->thread.TS_FPR(i), &buf[i], label); \
+	unsafe_put_user(__t->thread.fp_state.fpscr, &buf[i], label);	\
+} while (0)
+
+#define unsafe_copy_vsx_to_user(to, task, label)	do {		\
+	struct task_struct *__t = task;					\
+	u64 __user *buf = (u64 __user *)to;				\
+	int i;								\
+									\
+	for (i = 0; i < ELF_NVSRHALFREG ; i++)				\
+		unsafe_put_user(__t->thread.fp_state.fpr[i][TS_VSRLOWOFFSET], \
+				&buf[i], label);\
+} while (0)
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+#define unsafe_copy_ckfpr_to_user(to, task, label)	do {		\
+	struct task_struct *__t = task;					\
+	u64 __user *buf = (u64 __user *)to;				\
+	int i;								\
+									\
+	for (i = 0; i < ELF_NFPREG - 1 ; i++)				\
+		unsafe_put_user(__t->thread.TS_CKFPR(i), &buf[i], label);\
+	unsafe_put_user(__t->thread.ckfp_state.fpscr, &buf[i], label);	\
+} while (0)
+
+#define unsafe_copy_ckvsx_to_user(to, task, label)	do {		\
+	struct task_struct *__t = task;					\
+	u64 __user *buf = (u64 __user *)to;				\
+	int i;								\
+									\
+	for (i = 0; i < ELF_NVSRHALFREG ; i++)				\
+		unsafe_put_user(__t->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET], \
+				&buf[i], label);\
+} while (0)
+#endif
 #elif defined(CONFIG_PPC_FPU_REGS)
+
+#define unsafe_copy_fpr_to_user(to, task, label)		\
+	unsafe_copy_to_user(to, (task)->thread.fp_state.fpr,	\
+			    ELF_NFPREG * sizeof(double), label)
+
 static inline unsigned long
 copy_fpr_to_user(void __user *to, struct task_struct *task)
 {
@@ -48,6 +95,10 @@ copy_fpr_from_user(struct task_struct *task, void __user *from)
 }
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+#define unsafe_copy_ckfpr_to_user(to, task, label)		\
+	unsafe_copy_to_user(to, (task)->thread.ckfp_state.fpr,	\
+			    ELF_NFPREG * sizeof(double), label)
+
 inline unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct *task)
 {
 	return __copy_to_user(to, task->thread.ckfp_state.fpr,
@@ -62,6 +113,8 @@ copy_ckfpr_from_user(struct task_struct *task, void __user *from)
 }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 #else
+#define unsafe_copy_fpr_to_user(to, task, label) do { } while (0)
+
 static inline unsigned long
 copy_fpr_to_user(void __user *to, struct task_struct *task)
 {
-- 
2.25.0

Re: [PATCH v2 23/25] powerpc/signal: Create 'unsafe' versions of copy_[ck][fpr/vsx]_to_user()

[Christopher M. Riedl]

On Tue Aug 18, 2020 at 12:19 PM CDT, Christophe Leroy wrote:
> For the non VSX version, that's trivial. Just use unsafe_copy_to_user()
> instead of __copy_to_user().
>
> For the VSX version, remove the intermediate step through a buffer and
> use unsafe_put_user() directly. This generates a far smaller code which
> is acceptable to inline, see below:
>
> Standard VSX version:
>
> 0000000000000000 <.copy_fpr_to_user>:
> 0: 7c 08 02 a6 mflr r0
> 4: fb e1 ff f8 std r31,-8(r1)
> 8: 39 00 00 20 li r8,32
> c: 39 24 0b 80 addi r9,r4,2944
> 10: 7d 09 03 a6 mtctr r8
> 14: f8 01 00 10 std r0,16(r1)
> 18: f8 21 fe 71 stdu r1,-400(r1)
> 1c: 39 41 00 68 addi r10,r1,104
> 20: e9 09 00 00 ld r8,0(r9)
> 24: 39 4a 00 08 addi r10,r10,8
> 28: 39 29 00 10 addi r9,r9,16
> 2c: f9 0a 00 00 std r8,0(r10)
> 30: 42 00 ff f0 bdnz 20 <.copy_fpr_to_user+0x20>
> 34: e9 24 0d 80 ld r9,3456(r4)
> 38: 3d 42 00 00 addis r10,r2,0
> 3a: R_PPC64_TOC16_HA .toc
> 3c: eb ea 00 00 ld r31,0(r10)
> 3e: R_PPC64_TOC16_LO_DS .toc
> 40: f9 21 01 70 std r9,368(r1)
> 44: e9 3f 00 00 ld r9,0(r31)
> 48: 81 29 00 20 lwz r9,32(r9)
> 4c: 2f 89 00 00 cmpwi cr7,r9,0
> 50: 40 9c 00 18 bge cr7,68 <.copy_fpr_to_user+0x68>
> 54: 4c 00 01 2c isync
> 58: 3d 20 40 00 lis r9,16384
> 5c: 79 29 07 c6 rldicr r9,r9,32,31
> 60: 7d 3d 03 a6 mtspr 29,r9
> 64: 4c 00 01 2c isync
> 68: 38 a0 01 08 li r5,264
> 6c: 38 81 00 70 addi r4,r1,112
> 70: 48 00 00 01 bl 70 <.copy_fpr_to_user+0x70>
> 70: R_PPC64_REL24 .__copy_tofrom_user
> 74: 60 00 00 00 nop
> 78: e9 3f 00 00 ld r9,0(r31)
> 7c: 81 29 00 20 lwz r9,32(r9)
> 80: 2f 89 00 00 cmpwi cr7,r9,0
> 84: 40 9c 00 18 bge cr7,9c <.copy_fpr_to_user+0x9c>
> 88: 4c 00 01 2c isync
> 8c: 39 20 ff ff li r9,-1
> 90: 79 29 00 44 rldicr r9,r9,0,1
> 94: 7d 3d 03 a6 mtspr 29,r9
> 98: 4c 00 01 2c isync
> 9c: 38 21 01 90 addi r1,r1,400
> a0: e8 01 00 10 ld r0,16(r1)
> a4: eb e1 ff f8 ld r31,-8(r1)
> a8: 7c 08 03 a6 mtlr r0
> ac: 4e 80 00 20 blr
>
> 'unsafe' simulated VSX version (The ... are only nops) using
> unsafe_copy_fpr_to_user() macro:
>
> unsigned long copy_fpr_to_user(void __user *to,
> struct task_struct *task)
> {
> unsafe_copy_fpr_to_user(to, task, failed);
> return 0;
> failed:
> return 1;
> }
>
> 0000000000000000 <.copy_fpr_to_user>:
> 0: 39 00 00 20 li r8,32
> 4: 39 44 0b 80 addi r10,r4,2944
> 8: 7d 09 03 a6 mtctr r8
> c: 7c 69 1b 78 mr r9,r3
> ...
> 20: e9 0a 00 00 ld r8,0(r10)
> 24: f9 09 00 00 std r8,0(r9)
> 28: 39 4a 00 10 addi r10,r10,16
> 2c: 39 29 00 08 addi r9,r9,8
> 30: 42 00 ff f0 bdnz 20 <.copy_fpr_to_user+0x20>
> 34: e9 24 0d 80 ld r9,3456(r4)
> 38: f9 23 01 00 std r9,256(r3)
> 3c: 38 60 00 00 li r3,0
> 40: 4e 80 00 20 blr
> ...
> 50: 38 60 00 01 li r3,1
> 54: 4e 80 00 20 blr
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> arch/powerpc/kernel/signal.h | 53 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 53 insertions(+)
>
> diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
> index f610cfafa478..2559a681536e 100644
> --- a/arch/powerpc/kernel/signal.h
> +++ b/arch/powerpc/kernel/signal.h
> @@ -32,7 +32,54 @@ unsigned long copy_fpr_to_user(void __user *to,
> struct task_struct *task);
> unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct
> *task);
> unsigned long copy_fpr_from_user(struct task_struct *task, void __user
> *from);
> unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user
> *from);
> +
> +#define unsafe_copy_fpr_to_user(to, task, label) do { \
> + struct task_struct *__t = task; \
> + u64 __user *buf = (u64 __user *)to; \
> + int i; \
> + \
> + for (i = 0; i < ELF_NFPREG - 1 ; i++) \
> + unsafe_put_user(__t->thread.TS_FPR(i), &buf[i], label); \
> + unsafe_put_user(__t->thread.fp_state.fpscr, &buf[i], label); \
> +} while (0)
> +

I've been working on the PPC64 side of this "unsafe" rework using this
series as a basis. One question here - I don't really understand what
the benefit of re-implementing this logic in macros (similarly for the
other copy_* functions below) is?

I am considering  a "__unsafe_copy_*" implementation in signal.c for
each (just the original implementation w/ using the "unsafe_" variants
of the uaccess stuff) which gets called by the "safe" functions w/ the
appropriate "user_*_access_begin/user_*_access_end". Something like
(pseudo-ish code):

	/* signal.c */
	unsigned long __unsafe_copy_fpr_to_user(...)
	{
		...
		unsafe_copy_to_user(..., bad);
		return 0;
	bad:
		return 1; /* -EFAULT? */
	}

	unsigned long copy_fpr_to_user(...)
	{
		unsigned long err;
		if (!user_write_access_begin(...))
			return 1; /* -EFAULT? */

		err = __unsafe_copy_fpr_to_user(...);

		user_write_access_end();
		return err;
	}

	/* signal.h */
	unsigned long __unsafe_copy_fpr_to_user(...);
	#define unsafe_copy_fpr_to_user(..., label) \
		unsafe_op_wrap(__unsafe_copy_fpr_to_user(...), label)

This way there is a single implementation for each copy routine "body".
The "unsafe" wrappers then just exist as simple macros similar to what
x86 does: "unsafe_" macro wraps "__unsafe" functions for the goto label.

Granted this does pollute "signal.h" w/ the "__unsafe_copy_*"
prototypes...

> +#define unsafe_copy_vsx_to_user(to, task, label) do { \
> + struct task_struct *__t = task; \
> + u64 __user *buf = (u64 __user *)to; \
> + int i; \
> + \
> + for (i = 0; i < ELF_NVSRHALFREG ; i++) \
> + unsafe_put_user(__t->thread.fp_state.fpr[i][TS_VSRLOWOFFSET], \
> + &buf[i], label);\
> +} while (0)
> +
> +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> +#define unsafe_copy_ckfpr_to_user(to, task, label) do { \
> + struct task_struct *__t = task; \
> + u64 __user *buf = (u64 __user *)to; \
> + int i; \
> + \
> + for (i = 0; i < ELF_NFPREG - 1 ; i++) \
> + unsafe_put_user(__t->thread.TS_CKFPR(i), &buf[i], label);\
> + unsafe_put_user(__t->thread.ckfp_state.fpscr, &buf[i], label); \
> +} while (0)
> +
> +#define unsafe_copy_ckvsx_to_user(to, task, label) do { \
> + struct task_struct *__t = task; \
> + u64 __user *buf = (u64 __user *)to; \
> + int i; \
> + \
> + for (i = 0; i < ELF_NVSRHALFREG ; i++) \
> + unsafe_put_user(__t->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET], \
> + &buf[i], label);\
> +} while (0)
> +#endif
> #elif defined(CONFIG_PPC_FPU_REGS)
> +
> +#define unsafe_copy_fpr_to_user(to, task, label) \
> + unsafe_copy_to_user(to, (task)->thread.fp_state.fpr, \
> + ELF_NFPREG * sizeof(double), label)
> +
> static inline unsigned long
> copy_fpr_to_user(void __user *to, struct task_struct *task)
> {
> @@ -48,6 +95,10 @@ copy_fpr_from_user(struct task_struct *task, void
> __user *from)
> }
>  
> #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> +#define unsafe_copy_ckfpr_to_user(to, task, label) \
> + unsafe_copy_to_user(to, (task)->thread.ckfp_state.fpr, \
> + ELF_NFPREG * sizeof(double), label)
> +
> inline unsigned long copy_ckfpr_to_user(void __user *to, struct
> task_struct *task)
> {
> return __copy_to_user(to, task->thread.ckfp_state.fpr,
> @@ -62,6 +113,8 @@ copy_ckfpr_from_user(struct task_struct *task, void
> __user *from)
> }
> #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
> #else
> +#define unsafe_copy_fpr_to_user(to, task, label) do { } while (0)
> +
> static inline unsigned long
> copy_fpr_to_user(void __user *to, struct task_struct *task)
> {
> --
> 2.25.0

Re: [PATCH v2 23/25] powerpc/signal: Create 'unsafe' versions of copy_[ck][fpr/vsx]_to_user()

[Christopher M. Riedl]

On Tue Aug 18, 2020 at 12:19 PM CDT, Christophe Leroy wrote:
> For the non VSX version, that's trivial. Just use unsafe_copy_to_user()
> instead of __copy_to_user().
>
> For the VSX version, remove the intermediate step through a buffer and
> use unsafe_put_user() directly. This generates a far smaller code which
> is acceptable to inline, see below:
>
> Standard VSX version:
>
> 0000000000000000 <.copy_fpr_to_user>:
> 0: 7c 08 02 a6 mflr r0
> 4: fb e1 ff f8 std r31,-8(r1)
> 8: 39 00 00 20 li r8,32
> c: 39 24 0b 80 addi r9,r4,2944
> 10: 7d 09 03 a6 mtctr r8
> 14: f8 01 00 10 std r0,16(r1)
> 18: f8 21 fe 71 stdu r1,-400(r1)
> 1c: 39 41 00 68 addi r10,r1,104
> 20: e9 09 00 00 ld r8,0(r9)
> 24: 39 4a 00 08 addi r10,r10,8
> 28: 39 29 00 10 addi r9,r9,16
> 2c: f9 0a 00 00 std r8,0(r10)
> 30: 42 00 ff f0 bdnz 20 <.copy_fpr_to_user+0x20>
> 34: e9 24 0d 80 ld r9,3456(r4)
> 38: 3d 42 00 00 addis r10,r2,0
> 3a: R_PPC64_TOC16_HA .toc
> 3c: eb ea 00 00 ld r31,0(r10)
> 3e: R_PPC64_TOC16_LO_DS .toc
> 40: f9 21 01 70 std r9,368(r1)
> 44: e9 3f 00 00 ld r9,0(r31)
> 48: 81 29 00 20 lwz r9,32(r9)
> 4c: 2f 89 00 00 cmpwi cr7,r9,0
> 50: 40 9c 00 18 bge cr7,68 <.copy_fpr_to_user+0x68>
> 54: 4c 00 01 2c isync
> 58: 3d 20 40 00 lis r9,16384
> 5c: 79 29 07 c6 rldicr r9,r9,32,31
> 60: 7d 3d 03 a6 mtspr 29,r9
> 64: 4c 00 01 2c isync
> 68: 38 a0 01 08 li r5,264
> 6c: 38 81 00 70 addi r4,r1,112
> 70: 48 00 00 01 bl 70 <.copy_fpr_to_user+0x70>
> 70: R_PPC64_REL24 .__copy_tofrom_user
> 74: 60 00 00 00 nop
> 78: e9 3f 00 00 ld r9,0(r31)
> 7c: 81 29 00 20 lwz r9,32(r9)
> 80: 2f 89 00 00 cmpwi cr7,r9,0
> 84: 40 9c 00 18 bge cr7,9c <.copy_fpr_to_user+0x9c>
> 88: 4c 00 01 2c isync
> 8c: 39 20 ff ff li r9,-1
> 90: 79 29 00 44 rldicr r9,r9,0,1
> 94: 7d 3d 03 a6 mtspr 29,r9
> 98: 4c 00 01 2c isync
> 9c: 38 21 01 90 addi r1,r1,400
> a0: e8 01 00 10 ld r0,16(r1)
> a4: eb e1 ff f8 ld r31,-8(r1)
> a8: 7c 08 03 a6 mtlr r0
> ac: 4e 80 00 20 blr
>
> 'unsafe' simulated VSX version (The ... are only nops) using
> unsafe_copy_fpr_to_user() macro:
>
> unsigned long copy_fpr_to_user(void __user *to,
> struct task_struct *task)
> {
> unsafe_copy_fpr_to_user(to, task, failed);
> return 0;
> failed:
> return 1;
> }
>
> 0000000000000000 <.copy_fpr_to_user>:
> 0: 39 00 00 20 li r8,32
> 4: 39 44 0b 80 addi r10,r4,2944
> 8: 7d 09 03 a6 mtctr r8
> c: 7c 69 1b 78 mr r9,r3
> ...
> 20: e9 0a 00 00 ld r8,0(r10)
> 24: f9 09 00 00 std r8,0(r9)
> 28: 39 4a 00 10 addi r10,r10,16
> 2c: 39 29 00 08 addi r9,r9,8
> 30: 42 00 ff f0 bdnz 20 <.copy_fpr_to_user+0x20>
> 34: e9 24 0d 80 ld r9,3456(r4)
> 38: f9 23 01 00 std r9,256(r3)
> 3c: 38 60 00 00 li r3,0
> 40: 4e 80 00 20 blr
> ...
> 50: 38 60 00 01 li r3,1
> 54: 4e 80 00 20 blr
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> arch/powerpc/kernel/signal.h | 53 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 53 insertions(+)
>
> diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
> index f610cfafa478..2559a681536e 100644
> --- a/arch/powerpc/kernel/signal.h
> +++ b/arch/powerpc/kernel/signal.h
> @@ -32,7 +32,54 @@ unsigned long copy_fpr_to_user(void __user *to,
> struct task_struct *task);
> unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct
> *task);
> unsigned long copy_fpr_from_user(struct task_struct *task, void __user
> *from);
> unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user
> *from);
> +
> +#define unsafe_copy_fpr_to_user(to, task, label) do { \
> + struct task_struct *__t = task; \
> + u64 __user *buf = (u64 __user *)to; \
> + int i; \
> + \
> + for (i = 0; i < ELF_NFPREG - 1 ; i++) \
> + unsafe_put_user(__t->thread.TS_FPR(i), &buf[i], label); \
> + unsafe_put_user(__t->thread.fp_state.fpscr, &buf[i], label); \
> +} while (0)
> +

I've been working on the PPC64 side of this "unsafe" rework using this
series as a basis. One question here - I don't really understand what
the benefit of re-implementing this logic in macros (similarly for the
other copy_* functions below) is?

I am considering  a "__unsafe_copy_*" implementation in signal.c for
each (just the original implementation w/ using the "unsafe_" variants
of the uaccess stuff) which gets called by the "safe" functions w/ the
appropriate "user_*_access_begin/user_*_access_end". Something like
(pseudo-ish code):

	/* signal.c */
	unsigned long __unsafe_copy_fpr_to_user(...)
	{
		...
		unsafe_copy_to_user(..., bad);
		return 0;
	bad:
		return 1; /* -EFAULT? */
	}

	unsigned long copy_fpr_to_user(...)
	{
		unsigned long err;
		if (!user_write_access_begin(...))
			return 1; /* -EFAULT? */

		err = __unsafe_copy_fpr_to_user(...);

		user_write_access_end();
		return err;
	}

	/* signal.h */
	unsigned long __unsafe_copy_fpr_to_user(...);
	#define unsafe_copy_fpr_to_user(..., label) \
		unsafe_op_wrap(__unsafe_copy_fpr_to_user(...), label)

This way there is a single implementation for each copy routine "body".
The "unsafe" wrappers then just exist as simple macros similar to what
x86 does: "unsafe_" macro wraps "__unsafe" functions for the goto label.

Granted this does pollute "signal.h" w/ the "__unsafe_copy_*"
prototypes...

> +#define unsafe_copy_vsx_to_user(to, task, label) do { \
> + struct task_struct *__t = task; \
> + u64 __user *buf = (u64 __user *)to; \
> + int i; \
> + \
> + for (i = 0; i < ELF_NVSRHALFREG ; i++) \
> + unsafe_put_user(__t->thread.fp_state.fpr[i][TS_VSRLOWOFFSET], \
> + &buf[i], label);\
> +} while (0)
> +
> +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> +#define unsafe_copy_ckfpr_to_user(to, task, label) do { \
> + struct task_struct *__t = task; \
> + u64 __user *buf = (u64 __user *)to; \
> + int i; \
> + \
> + for (i = 0; i < ELF_NFPREG - 1 ; i++) \
> + unsafe_put_user(__t->thread.TS_CKFPR(i), &buf[i], label);\
> + unsafe_put_user(__t->thread.ckfp_state.fpscr, &buf[i], label); \
> +} while (0)
> +
> +#define unsafe_copy_ckvsx_to_user(to, task, label) do { \
> + struct task_struct *__t = task; \
> + u64 __user *buf = (u64 __user *)to; \
> + int i; \
> + \
> + for (i = 0; i < ELF_NVSRHALFREG ; i++) \
> + unsafe_put_user(__t->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET], \
> + &buf[i], label);\
> +} while (0)
> +#endif
> #elif defined(CONFIG_PPC_FPU_REGS)
> +
> +#define unsafe_copy_fpr_to_user(to, task, label) \
> + unsafe_copy_to_user(to, (task)->thread.fp_state.fpr, \
> + ELF_NFPREG * sizeof(double), label)
> +
> static inline unsigned long
> copy_fpr_to_user(void __user *to, struct task_struct *task)
> {
> @@ -48,6 +95,10 @@ copy_fpr_from_user(struct task_struct *task, void
> __user *from)
> }
>  
> #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> +#define unsafe_copy_ckfpr_to_user(to, task, label) \
> + unsafe_copy_to_user(to, (task)->thread.ckfp_state.fpr, \
> + ELF_NFPREG * sizeof(double), label)
> +
> inline unsigned long copy_ckfpr_to_user(void __user *to, struct
> task_struct *task)
> {
> return __copy_to_user(to, task->thread.ckfp_state.fpr,
> @@ -62,6 +113,8 @@ copy_ckfpr_from_user(struct task_struct *task, void
> __user *from)
> }
> #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
> #else
> +#define unsafe_copy_fpr_to_user(to, task, label) do { } while (0)
> +
> static inline unsigned long
> copy_fpr_to_user(void __user *to, struct task_struct *task)
> {
> --
> 2.25.0

Re: [PATCH v2 23/25] powerpc/signal: Create 'unsafe' versions of copy_[ck][fpr/vsx]_to_user()

[Christophe Leroy]

Le 29/09/2020 à 04:04, Christopher M. Riedl a écrit :
> On Tue Aug 18, 2020 at 12:19 PM CDT, Christophe Leroy wrote:
>> For the non VSX version, that's trivial. Just use unsafe_copy_to_user()
>> instead of __copy_to_user().
>>
>> For the VSX version, remove the intermediate step through a buffer and
>> use unsafe_put_user() directly. This generates a far smaller code which
>> is acceptable to inline, see below:
>>
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>> arch/powerpc/kernel/signal.h | 53 ++++++++++++++++++++++++++++++++++++
>> 1 file changed, 53 insertions(+)
>>
>> diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
>> index f610cfafa478..2559a681536e 100644
>> --- a/arch/powerpc/kernel/signal.h
>> +++ b/arch/powerpc/kernel/signal.h
>> @@ -32,7 +32,54 @@ unsigned long copy_fpr_to_user(void __user *to,
>> struct task_struct *task);
>> unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct
>> *task);
>> unsigned long copy_fpr_from_user(struct task_struct *task, void __user
>> *from);
>> unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user
>> *from);
>> +
>> +#define unsafe_copy_fpr_to_user(to, task, label) do { \
>> + struct task_struct *__t = task; \
>> + u64 __user *buf = (u64 __user *)to; \
>> + int i; \
>> + \
>> + for (i = 0; i < ELF_NFPREG - 1 ; i++) \
>> + unsafe_put_user(__t->thread.TS_FPR(i), &buf[i], label); \
>> + unsafe_put_user(__t->thread.fp_state.fpscr, &buf[i], label); \
>> +} while (0)
>> +
> 
> I've been working on the PPC64 side of this "unsafe" rework using this
> series as a basis. One question here - I don't really understand what
> the benefit of re-implementing this logic in macros (similarly for the
> other copy_* functions below) is?

Not sure either.

The whole purpose is to not manage the error through a local var but exclusively use labels.
However, GCC is probably smart enough to understand it and drop the local var while inlining.

One important thing however is to make sure we won't end up with an outline function, otherwise you 
completely loose the benefit of the label stuff. And you get a function call inside a user access, 
which is what we want to avoid.

> 
> I am considering  a "__unsafe_copy_*" implementation in signal.c for
> each (just the original implementation w/ using the "unsafe_" variants
> of the uaccess stuff) which gets called by the "safe" functions w/ the
> appropriate "user_*_access_begin/user_*_access_end". Something like
> (pseudo-ish code):

Good idea, however ...

> 
> 	/* signal.c */
> 	unsigned long __unsafe_copy_fpr_to_user(...)
> 	{
> 		...
> 		unsafe_copy_to_user(..., bad);
> 		return 0;
> 	bad:
> 		return 1; /* -EFAULT? */
> 	}

This __unsafe_copy_fpr_to_user() has to be in signal.h and must be tagged 'static __always_inline' 
for the reasons explained above.

> 
> 	unsigned long copy_fpr_to_user(...)
> 	{
> 		unsigned long err;
> 		if (!user_write_access_begin(...))
> 			return 1; /* -EFAULT? */
> 
> 		err = __unsafe_copy_fpr_to_user(...);
> 
> 		user_write_access_end();
> 		return err;
> 	}
> 
> 	/* signal.h */
> 	unsigned long __unsafe_copy_fpr_to_user(...);
> 	#define unsafe_copy_fpr_to_user(..., label) \
> 		unsafe_op_wrap(__unsafe_copy_fpr_to_user(...), label)
> 
> This way there is a single implementation for each copy routine "body".
> The "unsafe" wrappers then just exist as simple macros similar to what
> x86 does: "unsafe_" macro wraps "__unsafe" functions for the goto label.

Yes, good point.

Christophe

Re: [PATCH v2 23/25] powerpc/signal: Create 'unsafe' versions of copy_[ck][fpr/vsx]_to_user()

[Christophe Leroy]

Le 29/09/2020 à 07:22, Christophe Leroy a écrit :
> 
> 
> Le 29/09/2020 à 04:04, Christopher M. Riedl a écrit :
>> On Tue Aug 18, 2020 at 12:19 PM CDT, Christophe Leroy wrote:
>>> For the non VSX version, that's trivial. Just use unsafe_copy_to_user()
>>> instead of __copy_to_user().
>>>
>>> For the VSX version, remove the intermediate step through a buffer and
>>> use unsafe_put_user() directly. This generates a far smaller code which
>>> is acceptable to inline, see below:
>>>
>>>
>>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>>> ---
>>> arch/powerpc/kernel/signal.h | 53 ++++++++++++++++++++++++++++++++++++
>>> 1 file changed, 53 insertions(+)
>>>
>>> diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
>>> index f610cfafa478..2559a681536e 100644
>>> --- a/arch/powerpc/kernel/signal.h
>>> +++ b/arch/powerpc/kernel/signal.h
>>> @@ -32,7 +32,54 @@ unsigned long copy_fpr_to_user(void __user *to,
>>> struct task_struct *task);
>>> unsigned long copy_ckfpr_to_user(void __user *to, struct task_struct
>>> *task);
>>> unsigned long copy_fpr_from_user(struct task_struct *task, void __user
>>> *from);
>>> unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user
>>> *from);
>>> +
>>> +#define unsafe_copy_fpr_to_user(to, task, label) do { \
>>> + struct task_struct *__t = task; \
>>> + u64 __user *buf = (u64 __user *)to; \
>>> + int i; \
>>> + \
>>> + for (i = 0; i < ELF_NFPREG - 1 ; i++) \
>>> + unsafe_put_user(__t->thread.TS_FPR(i), &buf[i], label); \
>>> + unsafe_put_user(__t->thread.fp_state.fpscr, &buf[i], label); \
>>> +} while (0)
>>> +
>>
>> I've been working on the PPC64 side of this "unsafe" rework using this
>> series as a basis. One question here - I don't really understand what
>> the benefit of re-implementing this logic in macros (similarly for the
>> other copy_* functions below) is?
> 
> Not sure either.
> 
> The whole purpose is to not manage the error through a local var but exclusively use labels.
> However, GCC is probably smart enough to understand it and drop the local var while inlining.
> 
> One important thing however is to make sure we won't end up with an outline function, otherwise you 
> completely loose the benefit of the label stuff. And you get a function call inside a user access, 
> which is what we want to avoid.
> 
>>
>> I am considering  a "__unsafe_copy_*" implementation in signal.c for
>> each (just the original implementation w/ using the "unsafe_" variants
>> of the uaccess stuff) which gets called by the "safe" functions w/ the
>> appropriate "user_*_access_begin/user_*_access_end". Something like
>> (pseudo-ish code):
> 
> Good idea, however ...
> 
>>
>>     /* signal.c */
>>     unsigned long __unsafe_copy_fpr_to_user(...)
>>     {
>>         ...
>>         unsafe_copy_to_user(..., bad);
>>         return 0;
>>     bad:
>>         return 1; /* -EFAULT? */
>>     }
> 
> This __unsafe_copy_fpr_to_user() has to be in signal.h and must be tagged 'static __always_inline' 
> for the reasons explained above.
> 
>>
>>     unsigned long copy_fpr_to_user(...)
>>     {
>>         unsigned long err;
>>         if (!user_write_access_begin(...))
>>             return 1; /* -EFAULT? */
>>
>>         err = __unsafe_copy_fpr_to_user(...);
>>
>>         user_write_access_end();
>>         return err;
>>     }

Also note that at the end (ie when both PPC32 and PPC64 signal code are using "unsafe" versions), 
the "safe" version won't be used anymore and will be dropped.

Christophe

[PATCH v2 24/25] powerpc/signal32: Isolate non-copy actions in save_user_regs() and save_tm_user_regs()

[Christophe Leroy]

Reorder actions in save_user_regs() and save_tm_user_regs() to
regroup copies together in order to switch to user_access_begin()
logic in a later patch.

Move non-copy actions into new functions called
prepare_save_user_regs() and prepare_save_tm_user_regs().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 54 +++++++++++++++++++++++++--------
 1 file changed, 41 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 5b8a4ede142c..86539a4e0514 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -229,14 +229,31 @@ struct rt_sigframe {
  * We only save the altivec/spe registers if the process has used
  * altivec/spe instructions at some point.
  */
+static void prepare_save_user_regs(int ctx_has_vsx_region)
+{
+	/* Make sure floating point registers are stored in regs */
+	flush_fp_to_thread(current);
+#ifdef CONFIG_ALTIVEC
+	if (current->thread.used_vr)
+		flush_altivec_to_thread(current);
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		current->thread.vrsave = mfspr(SPRN_VRSAVE);
+#endif
+#ifdef CONFIG_VSX
+	if (current->thread.used_vsr && ctx_has_vsx_region)
+		flush_vsx_to_thread(current);
+#endif
+#ifdef CONFIG_SPE
+	if (current->thread.used_spe)
+		flush_spe_to_thread(current);
+#endif
+}
+
 static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 			  struct mcontext __user *tm_frame, int ctx_has_vsx_region)
 {
 	unsigned long msr = regs->msr;
 
-	/* Make sure floating point registers are stored in regs */
-	flush_fp_to_thread(current);
-
 	/* save general registers */
 	if (save_general_regs(regs, frame))
 		return 1;
@@ -244,7 +261,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 #ifdef CONFIG_ALTIVEC
 	/* save altivec registers */
 	if (current->thread.used_vr) {
-		flush_altivec_to_thread(current);
 		if (__copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
 				   ELF_NVRREG * sizeof(vector128)))
 			return 1;
@@ -260,8 +276,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	 * most significant bits of that same vector. --BenH
 	 * Note that the current VRSAVE value is in the SPR at this point.
 	 */
-	if (cpu_has_feature(CPU_FTR_ALTIVEC))
-		current->thread.vrsave = mfspr(SPRN_VRSAVE);
 	if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
 		return 1;
 #endif /* CONFIG_ALTIVEC */
@@ -281,7 +295,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	 * contains valid data
 	 */
 	if (current->thread.used_vsr && ctx_has_vsx_region) {
-		flush_vsx_to_thread(current);
 		if (copy_vsx_to_user(&frame->mc_vsregs, current))
 			return 1;
 		msr |= MSR_VSX;
@@ -290,7 +303,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 #ifdef CONFIG_SPE
 	/* save spe registers */
 	if (current->thread.used_spe) {
-		flush_spe_to_thread(current);
 		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
 				   ELF_NEVRREG * sizeof(u32)))
 			return 1;
@@ -326,11 +338,23 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
  *
  * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
  */
-static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
-			     struct mcontext __user *tm_frame, unsigned long msr)
+static void prepare_save_tm_user_regs(void)
 {
 	WARN_ON(tm_suspend_disabled);
 
+#ifdef CONFIG_ALTIVEC
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		current->thread.ckvrsave = mfspr(SPRN_VRSAVE);
+#endif
+#ifdef CONFIG_SPE
+	if (current->thread.used_spe)
+		flush_spe_to_thread(current);
+#endif
+}
+
+static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
+			     struct mcontext __user *tm_frame, unsigned long msr)
+{
 	/* Save both sets of general registers */
 	if (save_general_regs(&current->thread.ckpt_regs, frame)
 	    || save_general_regs(regs, tm_frame))
@@ -374,8 +398,6 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
 	 * most significant bits of that same vector. --BenH
 	 */
-	if (cpu_has_feature(CPU_FTR_ALTIVEC))
-		current->thread.ckvrsave = mfspr(SPRN_VRSAVE);
 	if (__put_user(current->thread.ckvrsave,
 		       (u32 __user *)&frame->mc_vregs[32]))
 		return 1;
@@ -427,7 +449,6 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	 * simply the same as in save_user_regs().
 	 */
 	if (current->thread.used_spe) {
-		flush_spe_to_thread(current);
 		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
 				   ELF_NEVRREG * sizeof(u32)))
 			return 1;
@@ -447,6 +468,8 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	return 0;
 }
 #else
+static void prepare_save_tm_user_regs(void) { }
+
 static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 			     struct mcontext __user *tm_frame, unsigned long msr)
 {
@@ -790,9 +813,11 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
 	if (MSR_TM_ACTIVE(msr)) {
+		prepare_save_tm_user_regs();
 		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
 	} else {
+		prepare_save_user_regs(1);
 		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
@@ -881,9 +906,11 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
 	if (MSR_TM_ACTIVE(msr)) {
+		prepare_save_tm_user_regs();
 		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
 	} else {
+		prepare_save_user_regs(1);
 		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
@@ -1038,6 +1065,7 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 		 */
 		mctx = (struct mcontext __user *)
 			((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
+		prepare_save_user_regs(ctx_has_vsx_region);
 		if (save_user_regs(regs, mctx, NULL, ctx_has_vsx_region))
 			return -EFAULT;
 		if (!user_write_access_begin(old_ctx, ctx_size))
-- 
2.25.0

[PATCH v2 24/25] powerpc/signal32: Isolate non-copy actions in save_user_regs() and save_tm_user_regs()

[Christophe Leroy]

Reorder actions in save_user_regs() and save_tm_user_regs() to
regroup copies together in order to switch to user_access_begin()
logic in a later patch.

Move non-copy actions into new functions called
prepare_save_user_regs() and prepare_save_tm_user_regs().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 54 +++++++++++++++++++++++++--------
 1 file changed, 41 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 5b8a4ede142c..86539a4e0514 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -229,14 +229,31 @@ struct rt_sigframe {
  * We only save the altivec/spe registers if the process has used
  * altivec/spe instructions at some point.
  */
+static void prepare_save_user_regs(int ctx_has_vsx_region)
+{
+	/* Make sure floating point registers are stored in regs */
+	flush_fp_to_thread(current);
+#ifdef CONFIG_ALTIVEC
+	if (current->thread.used_vr)
+		flush_altivec_to_thread(current);
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		current->thread.vrsave = mfspr(SPRN_VRSAVE);
+#endif
+#ifdef CONFIG_VSX
+	if (current->thread.used_vsr && ctx_has_vsx_region)
+		flush_vsx_to_thread(current);
+#endif
+#ifdef CONFIG_SPE
+	if (current->thread.used_spe)
+		flush_spe_to_thread(current);
+#endif
+}
+
 static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 			  struct mcontext __user *tm_frame, int ctx_has_vsx_region)
 {
 	unsigned long msr = regs->msr;
 
-	/* Make sure floating point registers are stored in regs */
-	flush_fp_to_thread(current);
-
 	/* save general registers */
 	if (save_general_regs(regs, frame))
 		return 1;
@@ -244,7 +261,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 #ifdef CONFIG_ALTIVEC
 	/* save altivec registers */
 	if (current->thread.used_vr) {
-		flush_altivec_to_thread(current);
 		if (__copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
 				   ELF_NVRREG * sizeof(vector128)))
 			return 1;
@@ -260,8 +276,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	 * most significant bits of that same vector. --BenH
 	 * Note that the current VRSAVE value is in the SPR at this point.
 	 */
-	if (cpu_has_feature(CPU_FTR_ALTIVEC))
-		current->thread.vrsave = mfspr(SPRN_VRSAVE);
 	if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
 		return 1;
 #endif /* CONFIG_ALTIVEC */
@@ -281,7 +295,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	 * contains valid data
 	 */
 	if (current->thread.used_vsr && ctx_has_vsx_region) {
-		flush_vsx_to_thread(current);
 		if (copy_vsx_to_user(&frame->mc_vsregs, current))
 			return 1;
 		msr |= MSR_VSX;
@@ -290,7 +303,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 #ifdef CONFIG_SPE
 	/* save spe registers */
 	if (current->thread.used_spe) {
-		flush_spe_to_thread(current);
 		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
 				   ELF_NEVRREG * sizeof(u32)))
 			return 1;
@@ -326,11 +338,23 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
  *
  * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
  */
-static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
-			     struct mcontext __user *tm_frame, unsigned long msr)
+static void prepare_save_tm_user_regs(void)
 {
 	WARN_ON(tm_suspend_disabled);
 
+#ifdef CONFIG_ALTIVEC
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		current->thread.ckvrsave = mfspr(SPRN_VRSAVE);
+#endif
+#ifdef CONFIG_SPE
+	if (current->thread.used_spe)
+		flush_spe_to_thread(current);
+#endif
+}
+
+static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
+			     struct mcontext __user *tm_frame, unsigned long msr)
+{
 	/* Save both sets of general registers */
 	if (save_general_regs(&current->thread.ckpt_regs, frame)
 	    || save_general_regs(regs, tm_frame))
@@ -374,8 +398,6 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
 	 * most significant bits of that same vector. --BenH
 	 */
-	if (cpu_has_feature(CPU_FTR_ALTIVEC))
-		current->thread.ckvrsave = mfspr(SPRN_VRSAVE);
 	if (__put_user(current->thread.ckvrsave,
 		       (u32 __user *)&frame->mc_vregs[32]))
 		return 1;
@@ -427,7 +449,6 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	 * simply the same as in save_user_regs().
 	 */
 	if (current->thread.used_spe) {
-		flush_spe_to_thread(current);
 		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
 				   ELF_NEVRREG * sizeof(u32)))
 			return 1;
@@ -447,6 +468,8 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	return 0;
 }
 #else
+static void prepare_save_tm_user_regs(void) { }
+
 static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 			     struct mcontext __user *tm_frame, unsigned long msr)
 {
@@ -790,9 +813,11 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
 	if (MSR_TM_ACTIVE(msr)) {
+		prepare_save_tm_user_regs();
 		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
 	} else {
+		prepare_save_user_regs(1);
 		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
@@ -881,9 +906,11 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
 	if (MSR_TM_ACTIVE(msr)) {
+		prepare_save_tm_user_regs();
 		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
 			goto badframe;
 	} else {
+		prepare_save_user_regs(1);
 		if (save_user_regs(regs, mctx, tm_mctx, 1))
 			goto badframe;
 	}
@@ -1038,6 +1065,7 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 		 */
 		mctx = (struct mcontext __user *)
 			((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
+		prepare_save_user_regs(ctx_has_vsx_region);
 		if (save_user_regs(regs, mctx, NULL, ctx_has_vsx_region))
 			return -EFAULT;
 		if (!user_write_access_begin(old_ctx, ctx_size))
-- 
2.25.0

[PATCH v2 25/25] powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version

[Christophe Leroy]

Change those two functions to be used within a user access block.

For that, change save_general_regs() to and unsafe_save_general_regs(),
then replace all user accesses by unsafe_ versions.

This series leads to a reduction from 2.55s to 1.73s of
the system CPU time with the following microbench app
on an mpc832x with KUAP (approx 32%)

Without KUAP, the difference is in the noise.

	void sigusr1(int sig) { }

	int main(int argc, char **argv)
	{
		int i = 100000;

		signal(SIGUSR1, sigusr1);
		for (;i--;)
		    raise(SIGUSR1);
		exit(0);
	}

An additional 0.10s reduction is achieved by removing
CONFIG_PPC_FPU, as the mpc832x has no FPU.

A bit less spectacular on an 8xx as KUAP is less heavy, prior to
the series (with KUAP) it ran in 8.10 ms. Once applies the removal
of FPU regs handling, we get 7.05s. With the full series, we get 6.9s.
If artificially re-activating FPU regs handling with the full series,
we get 7.6s.

So for the 8xx, the removal of the FPU regs copy is what makes the
difference, but the rework of handle_signal also have a benefit.

Same as above, without KUAP the difference is in the noise.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 224 ++++++++++++++++----------------
 1 file changed, 111 insertions(+), 113 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 86539a4e0514..f795fe0240a1 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -93,8 +93,8 @@ static inline int get_sigset_t(sigset_t *set,
 #define to_user_ptr(p)		ptr_to_compat(p)
 #define from_user_ptr(p)	compat_ptr(p)
 
-static inline int save_general_regs(struct pt_regs *regs,
-		struct mcontext __user *frame)
+static __always_inline int
+save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame)
 {
 	elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
 	int val, i;
@@ -108,10 +108,12 @@ static inline int save_general_regs(struct pt_regs *regs,
 		else
 			val = gregs[i];
 
-		if (__put_user(val, &frame->mc_gregs[i]))
-			return -EFAULT;
+		unsafe_put_user(val, &frame->mc_gregs[i], failed);
 	}
 	return 0;
+
+failed:
+	return 1;
 }
 
 static inline int restore_general_regs(struct pt_regs *regs,
@@ -148,11 +150,15 @@ static inline int get_sigset_t(sigset_t *set, const sigset_t __user *uset)
 #define to_user_ptr(p)		((unsigned long)(p))
 #define from_user_ptr(p)	((void __user *)(p))
 
-static inline int save_general_regs(struct pt_regs *regs,
-		struct mcontext __user *frame)
+static __always_inline int
+save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame)
 {
 	WARN_ON(!FULL_REGS(regs));
-	return __copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE);
+	unsafe_copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE, failed);
+	return 0;
+
+failed:
+	return 1;
 }
 
 static inline int restore_general_regs(struct pt_regs *regs,
@@ -170,6 +176,11 @@ static inline int restore_general_regs(struct pt_regs *regs,
 }
 #endif
 
+#define unsafe_save_general_regs(regs, frame, label) do {	\
+	if (save_general_regs_unsafe(regs, frame))	\
+		goto label;					\
+} while (0)
+
 /*
  * When we have signals to deliver, we set up on the
  * user stack, going down from the original stack pointer:
@@ -249,21 +260,19 @@ static void prepare_save_user_regs(int ctx_has_vsx_region)
 #endif
 }
 
-static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
-			  struct mcontext __user *tm_frame, int ctx_has_vsx_region)
+static int save_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame,
+				 struct mcontext __user *tm_frame, int ctx_has_vsx_region)
 {
 	unsigned long msr = regs->msr;
 
 	/* save general registers */
-	if (save_general_regs(regs, frame))
-		return 1;
+	unsafe_save_general_regs(regs, frame, failed);
 
 #ifdef CONFIG_ALTIVEC
 	/* save altivec registers */
 	if (current->thread.used_vr) {
-		if (__copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
-				   ELF_NVRREG * sizeof(vector128)))
-			return 1;
+		unsafe_copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
+				    ELF_NVRREG * sizeof(vector128), failed);
 		/* set MSR_VEC in the saved MSR value to indicate that
 		   frame->mc_vregs contains valid data */
 		msr |= MSR_VEC;
@@ -276,11 +285,10 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	 * most significant bits of that same vector. --BenH
 	 * Note that the current VRSAVE value is in the SPR at this point.
 	 */
-	if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
-		return 1;
+	unsafe_put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32],
+			failed);
 #endif /* CONFIG_ALTIVEC */
-	if (copy_fpr_to_user(&frame->mc_fregs, current))
-		return 1;
+	unsafe_copy_fpr_to_user(&frame->mc_fregs, current, failed);
 
 	/*
 	 * Clear the MSR VSX bit to indicate there is no valid state attached
@@ -295,17 +303,15 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	 * contains valid data
 	 */
 	if (current->thread.used_vsr && ctx_has_vsx_region) {
-		if (copy_vsx_to_user(&frame->mc_vsregs, current))
-			return 1;
+		unsafe_copy_vsx_to_user(&frame->mc_vsregs, current, failed);
 		msr |= MSR_VSX;
 	}
 #endif /* CONFIG_VSX */
 #ifdef CONFIG_SPE
 	/* save spe registers */
 	if (current->thread.used_spe) {
-		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
-				   ELF_NEVRREG * sizeof(u32)))
-			return 1;
+		unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
+				    ELF_NEVRREG * sizeof(u32)), failed);
 		/* set MSR_SPE in the saved MSR value to indicate that
 		   frame->mc_vregs contains valid data */
 		msr |= MSR_SPE;
@@ -313,21 +319,29 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	/* else assert((regs->msr & MSR_SPE) == 0) */
 
 	/* We always copy to/from spefscr */
-	if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG))
-		return 1;
+	unsafe_put_user(current->thread.spefscr,
+			(u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed);
 #endif /* CONFIG_SPE */
 
-	if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
-		return 1;
+	unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
+
 	/* We need to write 0 the MSR top 32 bits in the tm frame so that we
 	 * can check it on the restore to see if TM is active
 	 */
-	if (tm_frame && __put_user(0, &tm_frame->mc_gregs[PT_MSR]))
-		return 1;
+	if (tm_frame)
+		unsafe_put_user(0, &tm_frame->mc_gregs[PT_MSR], failed);
 
 	return 0;
+
+failed:
+	return 1;
 }
 
+#define unsafe_save_user_regs(regs, frame, tm_frame, has_vsx, label) do { \
+	if (save_user_regs_unsafe(regs, frame, tm_frame, has_vsx))	\
+		goto label;						\
+} while (0)
+
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 /*
  * Save the current user registers on the user stack.
@@ -336,7 +350,7 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
  * We also save the transactional registers to a second ucontext in the
  * frame.
  *
- * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
+ * See save_user_regs_unsafe() and signal_64.c:setup_tm_sigcontexts().
  */
 static void prepare_save_tm_user_regs(void)
 {
@@ -352,13 +366,12 @@ static void prepare_save_tm_user_regs(void)
 #endif
 }
 
-static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
-			     struct mcontext __user *tm_frame, unsigned long msr)
+static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame,
+				    struct mcontext __user *tm_frame, unsigned long msr)
 {
 	/* Save both sets of general registers */
-	if (save_general_regs(&current->thread.ckpt_regs, frame)
-	    || save_general_regs(regs, tm_frame))
-		return 1;
+	unsafe_save_general_regs(&current->thread.ckpt_regs, frame, failed);
+	unsafe_save_general_regs(regs, tm_frame, failed);
 
 	/* Stash the top half of the 64bit MSR into the 32bit MSR word
 	 * of the transactional mcontext.  This way we have a backward-compatible
@@ -366,26 +379,21 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	 * also look at what type of transaction (T or S) was active at the
 	 * time of the signal.
 	 */
-	if (__put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR]))
-		return 1;
+	unsafe_put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR], failed);
 
 #ifdef CONFIG_ALTIVEC
 	/* save altivec registers */
 	if (current->thread.used_vr) {
-		if (__copy_to_user(&frame->mc_vregs, &current->thread.ckvr_state,
-				   ELF_NVRREG * sizeof(vector128)))
-			return 1;
-		if (msr & MSR_VEC) {
-			if (__copy_to_user(&tm_frame->mc_vregs,
-					   &current->thread.vr_state,
-					   ELF_NVRREG * sizeof(vector128)))
-				return 1;
-		} else {
-			if (__copy_to_user(&tm_frame->mc_vregs,
-					   &current->thread.ckvr_state,
-					   ELF_NVRREG * sizeof(vector128)))
-				return 1;
-		}
+		unsafe_copy_to_user(&frame->mc_vregs, &current->thread.ckvr_state,
+				    ELF_NVRREG * sizeof(vector128), failed);
+		if (msr & MSR_VEC)
+			unsafe_copy_to_user(&tm_frame->mc_vregs,
+					    &current->thread.vr_state,
+					    ELF_NVRREG * sizeof(vector128), failed);
+		else
+			unsafe_copy_to_user(&tm_frame->mc_vregs,
+					    &current->thread.ckvr_state,
+					    ELF_NVRREG * sizeof(vector128), failed);
 
 		/* set MSR_VEC in the saved MSR value to indicate that
 		 * frame->mc_vregs contains valid data
@@ -398,29 +406,21 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
 	 * most significant bits of that same vector. --BenH
 	 */
-	if (__put_user(current->thread.ckvrsave,
-		       (u32 __user *)&frame->mc_vregs[32]))
-		return 1;
-	if (msr & MSR_VEC) {
-		if (__put_user(current->thread.vrsave,
-			       (u32 __user *)&tm_frame->mc_vregs[32]))
-			return 1;
-	} else {
-		if (__put_user(current->thread.ckvrsave,
-			       (u32 __user *)&tm_frame->mc_vregs[32]))
-			return 1;
-	}
+	unsafe_put_user(current->thread.ckvrsave,
+			(u32 __user *)&frame->mc_vregs[32], failed);
+	if (msr & MSR_VEC)
+		unsafe_put_user(current->thread.vrsave,
+				(u32 __user *)&tm_frame->mc_vregs[32], failed);
+	else
+		unsafe_put_user(current->thread.ckvrsave,
+				(u32 __user *)&tm_frame->mc_vregs[32], failed);
 #endif /* CONFIG_ALTIVEC */
 
-	if (copy_ckfpr_to_user(&frame->mc_fregs, current))
-		return 1;
-	if (msr & MSR_FP) {
-		if (copy_fpr_to_user(&tm_frame->mc_fregs, current))
-			return 1;
-	} else {
-		if (copy_ckfpr_to_user(&tm_frame->mc_fregs, current))
-			return 1;
-	}
+	unsafe_copy_ckfpr_to_user(&frame->mc_fregs, current, failed);
+	if (msr & MSR_FP)
+		unsafe_copy_fpr_to_user(&tm_frame->mc_fregs, current, failed);
+	else
+		unsafe_copy_ckfpr_to_user(&tm_frame->mc_fregs, current, failed);
 
 #ifdef CONFIG_VSX
 	/*
@@ -430,53 +430,54 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	 * contains valid data
 	 */
 	if (current->thread.used_vsr) {
-		if (copy_ckvsx_to_user(&frame->mc_vsregs, current))
-			return 1;
-		if (msr & MSR_VSX) {
-			if (copy_vsx_to_user(&tm_frame->mc_vsregs,
-						      current))
-				return 1;
-		} else {
-			if (copy_ckvsx_to_user(&tm_frame->mc_vsregs, current))
-				return 1;
-		}
+		unsafe_copy_ckvsx_to_user(&frame->mc_vsregs, current, failed);
+		if (msr & MSR_VSX)
+			unsafe_copy_vsx_to_user(&tm_frame->mc_vsregs, current, failed);
+		else
+			unsafe_copy_ckvsx_to_user(&tm_frame->mc_vsregs, current, failed);
 
 		msr |= MSR_VSX;
 	}
 #endif /* CONFIG_VSX */
 #ifdef CONFIG_SPE
 	/* SPE regs are not checkpointed with TM, so this section is
-	 * simply the same as in save_user_regs().
+	 * simply the same as in save_user_regs_unsafe().
 	 */
 	if (current->thread.used_spe) {
-		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
-				   ELF_NEVRREG * sizeof(u32)))
-			return 1;
+		unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
+				    ELF_NEVRREG * sizeof(u32), failed);
 		/* set MSR_SPE in the saved MSR value to indicate that
 		 * frame->mc_vregs contains valid data */
 		msr |= MSR_SPE;
 	}
 
 	/* We always copy to/from spefscr */
-	if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG))
-		return 1;
+	unsafe_put_user(current->thread.spefscr,
+			(u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed);
 #endif /* CONFIG_SPE */
 
-	if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
-		return 1;
+	unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
 
 	return 0;
+
+failed:
+	return 1;
 }
 #else
 static void prepare_save_tm_user_regs(void) { }
 
-static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
-			     struct mcontext __user *tm_frame, unsigned long msr)
+static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame,
+				    struct mcontext __user *tm_frame, unsigned long msr)
 {
 	return 0;
 }
 #endif
 
+#define unsafe_save_tm_user_regs(regs, frame, tm_frame, msr, label) do { \
+	if (save_tm_user_regs_unsafe(regs, frame, tm_frame, msr))	\
+		goto label;						\
+} while (0)
+
 /*
  * Restore the current user register values from the user stack,
  * (except for MSR).
@@ -769,6 +770,11 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	tm_mctx = &frame->uc_transact.uc_mcontext;
 #endif
+	if (MSR_TM_ACTIVE(msr))
+		prepare_save_tm_user_regs();
+	else
+		prepare_save_user_regs(1);
+
 	if (!user_write_access_begin(frame, sizeof(*frame)))
 		goto badframe;
 
@@ -788,8 +794,10 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 		unsafe_put_user((unsigned long)tm_mctx,
 				&frame->uc_transact.uc_regs, failed);
 #endif
+		unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
 	} else {
 		unsafe_put_user(0, &frame->uc.uc_link, failed);
+		unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
 	}
 
 	/* Save user registers on the stack */
@@ -812,15 +820,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	if (tramp == (unsigned long)mctx->mc_pad)
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
-	if (MSR_TM_ACTIVE(msr)) {
-		prepare_save_tm_user_regs();
-		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
-			goto badframe;
-	} else {
-		prepare_save_user_regs(1);
-		if (save_user_regs(regs, mctx, tm_mctx, 1))
-			goto badframe;
-	}
 	regs->link = tramp;
 
 #ifdef CONFIG_PPC_FPU_REGS
@@ -875,6 +874,11 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	tm_mctx = &frame->mctx_transact;
 #endif
+	if (MSR_TM_ACTIVE(msr))
+		prepare_save_tm_user_regs();
+	else
+		prepare_save_user_regs(1);
+
 	if (!user_write_access_begin(frame, sizeof(*frame)))
 		goto badframe;
 	sc = (struct sigcontext __user *) &frame->sctx;
@@ -892,6 +896,11 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	unsafe_put_user(to_user_ptr(mctx), &sc->regs, failed);
 	unsafe_put_user(ksig->sig, &sc->signal, failed);
 
+	if (MSR_TM_ACTIVE(msr))
+		unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
+	else
+		unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
+
 	if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
 		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
 	} else {
@@ -905,16 +914,6 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	if (tramp == (unsigned long)mctx->mc_pad)
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
-	if (MSR_TM_ACTIVE(msr)) {
-		prepare_save_tm_user_regs();
-		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
-			goto badframe;
-	} else {
-		prepare_save_user_regs(1);
-		if (save_user_regs(regs, mctx, tm_mctx, 1))
-			goto badframe;
-	}
-
 	regs->link = tramp;
 
 #ifdef CONFIG_PPC_FPU_REGS
@@ -1066,10 +1065,9 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 		mctx = (struct mcontext __user *)
 			((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
 		prepare_save_user_regs(ctx_has_vsx_region);
-		if (save_user_regs(regs, mctx, NULL, ctx_has_vsx_region))
-			return -EFAULT;
 		if (!user_write_access_begin(old_ctx, ctx_size))
 			return -EFAULT;
+		unsafe_save_user_regs(regs, mctx, NULL, ctx_has_vsx_region, failed);
 		unsafe_put_sigset_t(&old_ctx->uc_sigmask, &current->blocked, failed);
 		unsafe_put_user(to_user_ptr(mctx), &old_ctx->uc_regs, failed);
 		user_write_access_end();
-- 
2.25.0

[PATCH v2 25/25] powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version

[Christophe Leroy]

Change those two functions to be used within a user access block.

For that, change save_general_regs() to and unsafe_save_general_regs(),
then replace all user accesses by unsafe_ versions.

This series leads to a reduction from 2.55s to 1.73s of
the system CPU time with the following microbench app
on an mpc832x with KUAP (approx 32%)

Without KUAP, the difference is in the noise.

	void sigusr1(int sig) { }

	int main(int argc, char **argv)
	{
		int i = 100000;

		signal(SIGUSR1, sigusr1);
		for (;i--;)
		    raise(SIGUSR1);
		exit(0);
	}

An additional 0.10s reduction is achieved by removing
CONFIG_PPC_FPU, as the mpc832x has no FPU.

A bit less spectacular on an 8xx as KUAP is less heavy, prior to
the series (with KUAP) it ran in 8.10 ms. Once applies the removal
of FPU regs handling, we get 7.05s. With the full series, we get 6.9s.
If artificially re-activating FPU regs handling with the full series,
we get 7.6s.

So for the 8xx, the removal of the FPU regs copy is what makes the
difference, but the rework of handle_signal also have a benefit.

Same as above, without KUAP the difference is in the noise.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 224 ++++++++++++++++----------------
 1 file changed, 111 insertions(+), 113 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 86539a4e0514..f795fe0240a1 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -93,8 +93,8 @@ static inline int get_sigset_t(sigset_t *set,
 #define to_user_ptr(p)		ptr_to_compat(p)
 #define from_user_ptr(p)	compat_ptr(p)
 
-static inline int save_general_regs(struct pt_regs *regs,
-		struct mcontext __user *frame)
+static __always_inline int
+save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame)
 {
 	elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
 	int val, i;
@@ -108,10 +108,12 @@ static inline int save_general_regs(struct pt_regs *regs,
 		else
 			val = gregs[i];
 
-		if (__put_user(val, &frame->mc_gregs[i]))
-			return -EFAULT;
+		unsafe_put_user(val, &frame->mc_gregs[i], failed);
 	}
 	return 0;
+
+failed:
+	return 1;
 }
 
 static inline int restore_general_regs(struct pt_regs *regs,
@@ -148,11 +150,15 @@ static inline int get_sigset_t(sigset_t *set, const sigset_t __user *uset)
 #define to_user_ptr(p)		((unsigned long)(p))
 #define from_user_ptr(p)	((void __user *)(p))
 
-static inline int save_general_regs(struct pt_regs *regs,
-		struct mcontext __user *frame)
+static __always_inline int
+save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame)
 {
 	WARN_ON(!FULL_REGS(regs));
-	return __copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE);
+	unsafe_copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE, failed);
+	return 0;
+
+failed:
+	return 1;
 }
 
 static inline int restore_general_regs(struct pt_regs *regs,
@@ -170,6 +176,11 @@ static inline int restore_general_regs(struct pt_regs *regs,
 }
 #endif
 
+#define unsafe_save_general_regs(regs, frame, label) do {	\
+	if (save_general_regs_unsafe(regs, frame))	\
+		goto label;					\
+} while (0)
+
 /*
  * When we have signals to deliver, we set up on the
  * user stack, going down from the original stack pointer:
@@ -249,21 +260,19 @@ static void prepare_save_user_regs(int ctx_has_vsx_region)
 #endif
 }
 
-static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
-			  struct mcontext __user *tm_frame, int ctx_has_vsx_region)
+static int save_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame,
+				 struct mcontext __user *tm_frame, int ctx_has_vsx_region)
 {
 	unsigned long msr = regs->msr;
 
 	/* save general registers */
-	if (save_general_regs(regs, frame))
-		return 1;
+	unsafe_save_general_regs(regs, frame, failed);
 
 #ifdef CONFIG_ALTIVEC
 	/* save altivec registers */
 	if (current->thread.used_vr) {
-		if (__copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
-				   ELF_NVRREG * sizeof(vector128)))
-			return 1;
+		unsafe_copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
+				    ELF_NVRREG * sizeof(vector128), failed);
 		/* set MSR_VEC in the saved MSR value to indicate that
 		   frame->mc_vregs contains valid data */
 		msr |= MSR_VEC;
@@ -276,11 +285,10 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	 * most significant bits of that same vector. --BenH
 	 * Note that the current VRSAVE value is in the SPR at this point.
 	 */
-	if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
-		return 1;
+	unsafe_put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32],
+			failed);
 #endif /* CONFIG_ALTIVEC */
-	if (copy_fpr_to_user(&frame->mc_fregs, current))
-		return 1;
+	unsafe_copy_fpr_to_user(&frame->mc_fregs, current, failed);
 
 	/*
 	 * Clear the MSR VSX bit to indicate there is no valid state attached
@@ -295,17 +303,15 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	 * contains valid data
 	 */
 	if (current->thread.used_vsr && ctx_has_vsx_region) {
-		if (copy_vsx_to_user(&frame->mc_vsregs, current))
-			return 1;
+		unsafe_copy_vsx_to_user(&frame->mc_vsregs, current, failed);
 		msr |= MSR_VSX;
 	}
 #endif /* CONFIG_VSX */
 #ifdef CONFIG_SPE
 	/* save spe registers */
 	if (current->thread.used_spe) {
-		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
-				   ELF_NEVRREG * sizeof(u32)))
-			return 1;
+		unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
+				    ELF_NEVRREG * sizeof(u32)), failed);
 		/* set MSR_SPE in the saved MSR value to indicate that
 		   frame->mc_vregs contains valid data */
 		msr |= MSR_SPE;
@@ -313,21 +319,29 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	/* else assert((regs->msr & MSR_SPE) == 0) */
 
 	/* We always copy to/from spefscr */
-	if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG))
-		return 1;
+	unsafe_put_user(current->thread.spefscr,
+			(u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed);
 #endif /* CONFIG_SPE */
 
-	if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
-		return 1;
+	unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
+
 	/* We need to write 0 the MSR top 32 bits in the tm frame so that we
 	 * can check it on the restore to see if TM is active
 	 */
-	if (tm_frame && __put_user(0, &tm_frame->mc_gregs[PT_MSR]))
-		return 1;
+	if (tm_frame)
+		unsafe_put_user(0, &tm_frame->mc_gregs[PT_MSR], failed);
 
 	return 0;
+
+failed:
+	return 1;
 }
 
+#define unsafe_save_user_regs(regs, frame, tm_frame, has_vsx, label) do { \
+	if (save_user_regs_unsafe(regs, frame, tm_frame, has_vsx))	\
+		goto label;						\
+} while (0)
+
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 /*
  * Save the current user registers on the user stack.
@@ -336,7 +350,7 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
  * We also save the transactional registers to a second ucontext in the
  * frame.
  *
- * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
+ * See save_user_regs_unsafe() and signal_64.c:setup_tm_sigcontexts().
  */
 static void prepare_save_tm_user_regs(void)
 {
@@ -352,13 +366,12 @@ static void prepare_save_tm_user_regs(void)
 #endif
 }
 
-static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
-			     struct mcontext __user *tm_frame, unsigned long msr)
+static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame,
+				    struct mcontext __user *tm_frame, unsigned long msr)
 {
 	/* Save both sets of general registers */
-	if (save_general_regs(&current->thread.ckpt_regs, frame)
-	    || save_general_regs(regs, tm_frame))
-		return 1;
+	unsafe_save_general_regs(&current->thread.ckpt_regs, frame, failed);
+	unsafe_save_general_regs(regs, tm_frame, failed);
 
 	/* Stash the top half of the 64bit MSR into the 32bit MSR word
 	 * of the transactional mcontext.  This way we have a backward-compatible
@@ -366,26 +379,21 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	 * also look at what type of transaction (T or S) was active at the
 	 * time of the signal.
 	 */
-	if (__put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR]))
-		return 1;
+	unsafe_put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR], failed);
 
 #ifdef CONFIG_ALTIVEC
 	/* save altivec registers */
 	if (current->thread.used_vr) {
-		if (__copy_to_user(&frame->mc_vregs, &current->thread.ckvr_state,
-				   ELF_NVRREG * sizeof(vector128)))
-			return 1;
-		if (msr & MSR_VEC) {
-			if (__copy_to_user(&tm_frame->mc_vregs,
-					   &current->thread.vr_state,
-					   ELF_NVRREG * sizeof(vector128)))
-				return 1;
-		} else {
-			if (__copy_to_user(&tm_frame->mc_vregs,
-					   &current->thread.ckvr_state,
-					   ELF_NVRREG * sizeof(vector128)))
-				return 1;
-		}
+		unsafe_copy_to_user(&frame->mc_vregs, &current->thread.ckvr_state,
+				    ELF_NVRREG * sizeof(vector128), failed);
+		if (msr & MSR_VEC)
+			unsafe_copy_to_user(&tm_frame->mc_vregs,
+					    &current->thread.vr_state,
+					    ELF_NVRREG * sizeof(vector128), failed);
+		else
+			unsafe_copy_to_user(&tm_frame->mc_vregs,
+					    &current->thread.ckvr_state,
+					    ELF_NVRREG * sizeof(vector128), failed);
 
 		/* set MSR_VEC in the saved MSR value to indicate that
 		 * frame->mc_vregs contains valid data
@@ -398,29 +406,21 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
 	 * most significant bits of that same vector. --BenH
 	 */
-	if (__put_user(current->thread.ckvrsave,
-		       (u32 __user *)&frame->mc_vregs[32]))
-		return 1;
-	if (msr & MSR_VEC) {
-		if (__put_user(current->thread.vrsave,
-			       (u32 __user *)&tm_frame->mc_vregs[32]))
-			return 1;
-	} else {
-		if (__put_user(current->thread.ckvrsave,
-			       (u32 __user *)&tm_frame->mc_vregs[32]))
-			return 1;
-	}
+	unsafe_put_user(current->thread.ckvrsave,
+			(u32 __user *)&frame->mc_vregs[32], failed);
+	if (msr & MSR_VEC)
+		unsafe_put_user(current->thread.vrsave,
+				(u32 __user *)&tm_frame->mc_vregs[32], failed);
+	else
+		unsafe_put_user(current->thread.ckvrsave,
+				(u32 __user *)&tm_frame->mc_vregs[32], failed);
 #endif /* CONFIG_ALTIVEC */
 
-	if (copy_ckfpr_to_user(&frame->mc_fregs, current))
-		return 1;
-	if (msr & MSR_FP) {
-		if (copy_fpr_to_user(&tm_frame->mc_fregs, current))
-			return 1;
-	} else {
-		if (copy_ckfpr_to_user(&tm_frame->mc_fregs, current))
-			return 1;
-	}
+	unsafe_copy_ckfpr_to_user(&frame->mc_fregs, current, failed);
+	if (msr & MSR_FP)
+		unsafe_copy_fpr_to_user(&tm_frame->mc_fregs, current, failed);
+	else
+		unsafe_copy_ckfpr_to_user(&tm_frame->mc_fregs, current, failed);
 
 #ifdef CONFIG_VSX
 	/*
@@ -430,53 +430,54 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame
 	 * contains valid data
 	 */
 	if (current->thread.used_vsr) {
-		if (copy_ckvsx_to_user(&frame->mc_vsregs, current))
-			return 1;
-		if (msr & MSR_VSX) {
-			if (copy_vsx_to_user(&tm_frame->mc_vsregs,
-						      current))
-				return 1;
-		} else {
-			if (copy_ckvsx_to_user(&tm_frame->mc_vsregs, current))
-				return 1;
-		}
+		unsafe_copy_ckvsx_to_user(&frame->mc_vsregs, current, failed);
+		if (msr & MSR_VSX)
+			unsafe_copy_vsx_to_user(&tm_frame->mc_vsregs, current, failed);
+		else
+			unsafe_copy_ckvsx_to_user(&tm_frame->mc_vsregs, current, failed);
 
 		msr |= MSR_VSX;
 	}
 #endif /* CONFIG_VSX */
 #ifdef CONFIG_SPE
 	/* SPE regs are not checkpointed with TM, so this section is
-	 * simply the same as in save_user_regs().
+	 * simply the same as in save_user_regs_unsafe().
 	 */
 	if (current->thread.used_spe) {
-		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
-				   ELF_NEVRREG * sizeof(u32)))
-			return 1;
+		unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
+				    ELF_NEVRREG * sizeof(u32), failed);
 		/* set MSR_SPE in the saved MSR value to indicate that
 		 * frame->mc_vregs contains valid data */
 		msr |= MSR_SPE;
 	}
 
 	/* We always copy to/from spefscr */
-	if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG))
-		return 1;
+	unsafe_put_user(current->thread.spefscr,
+			(u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed);
 #endif /* CONFIG_SPE */
 
-	if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
-		return 1;
+	unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
 
 	return 0;
+
+failed:
+	return 1;
 }
 #else
 static void prepare_save_tm_user_regs(void) { }
 
-static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
-			     struct mcontext __user *tm_frame, unsigned long msr)
+static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame,
+				    struct mcontext __user *tm_frame, unsigned long msr)
 {
 	return 0;
 }
 #endif
 
+#define unsafe_save_tm_user_regs(regs, frame, tm_frame, msr, label) do { \
+	if (save_tm_user_regs_unsafe(regs, frame, tm_frame, msr))	\
+		goto label;						\
+} while (0)
+
 /*
  * Restore the current user register values from the user stack,
  * (except for MSR).
@@ -769,6 +770,11 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	tm_mctx = &frame->uc_transact.uc_mcontext;
 #endif
+	if (MSR_TM_ACTIVE(msr))
+		prepare_save_tm_user_regs();
+	else
+		prepare_save_user_regs(1);
+
 	if (!user_write_access_begin(frame, sizeof(*frame)))
 		goto badframe;
 
@@ -788,8 +794,10 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 		unsafe_put_user((unsigned long)tm_mctx,
 				&frame->uc_transact.uc_regs, failed);
 #endif
+		unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
 	} else {
 		unsafe_put_user(0, &frame->uc.uc_link, failed);
+		unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
 	}
 
 	/* Save user registers on the stack */
@@ -812,15 +820,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	if (tramp == (unsigned long)mctx->mc_pad)
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
-	if (MSR_TM_ACTIVE(msr)) {
-		prepare_save_tm_user_regs();
-		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
-			goto badframe;
-	} else {
-		prepare_save_user_regs(1);
-		if (save_user_regs(regs, mctx, tm_mctx, 1))
-			goto badframe;
-	}
 	regs->link = tramp;
 
 #ifdef CONFIG_PPC_FPU_REGS
@@ -875,6 +874,11 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	tm_mctx = &frame->mctx_transact;
 #endif
+	if (MSR_TM_ACTIVE(msr))
+		prepare_save_tm_user_regs();
+	else
+		prepare_save_user_regs(1);
+
 	if (!user_write_access_begin(frame, sizeof(*frame)))
 		goto badframe;
 	sc = (struct sigcontext __user *) &frame->sctx;
@@ -892,6 +896,11 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	unsafe_put_user(to_user_ptr(mctx), &sc->regs, failed);
 	unsafe_put_user(ksig->sig, &sc->signal, failed);
 
+	if (MSR_TM_ACTIVE(msr))
+		unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
+	else
+		unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
+
 	if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
 		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
 	} else {
@@ -905,16 +914,6 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	if (tramp == (unsigned long)mctx->mc_pad)
 		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
 
-	if (MSR_TM_ACTIVE(msr)) {
-		prepare_save_tm_user_regs();
-		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
-			goto badframe;
-	} else {
-		prepare_save_user_regs(1);
-		if (save_user_regs(regs, mctx, tm_mctx, 1))
-			goto badframe;
-	}
-
 	regs->link = tramp;
 
 #ifdef CONFIG_PPC_FPU_REGS
@@ -1066,10 +1065,9 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 		mctx = (struct mcontext __user *)
 			((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
 		prepare_save_user_regs(ctx_has_vsx_region);
-		if (save_user_regs(regs, mctx, NULL, ctx_has_vsx_region))
-			return -EFAULT;
 		if (!user_write_access_begin(old_ctx, ctx_size))
 			return -EFAULT;
+		unsafe_save_user_regs(regs, mctx, NULL, ctx_has_vsx_region, failed);
 		unsafe_put_sigset_t(&old_ctx->uc_sigmask, &current->blocked, failed);
 		unsafe_put_user(to_user_ptr(mctx), &old_ctx->uc_regs, failed);
 		user_write_access_end();
-- 
2.25.0

Re: [PATCH v2 25/25] powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 6970 bytes --]

Hi Christophe,

I love your patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on linus/master v5.9-rc2 next-20200827]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Christophe-Leroy/powerpc-Switch-signal-32-to-using-unsafe_put_user-and-friends/20200819-012411
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc64-randconfig-r005-20200827 (attached as .config)
compiler: powerpc-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   arch/powerpc/kernel/signal_32.c: In function 'save_user_regs_unsafe':
>> arch/powerpc/kernel/signal_32.c:314:34: error: macro "unsafe_copy_to_user" requires 4 arguments, but only 3 given
     314 |         ELF_NEVRREG * sizeof(u32)), failed);
         |                                  ^
   In file included from include/linux/uaccess.h:9,
                    from include/linux/sched/task.h:11,
                    from include/linux/sched/signal.h:9,
                    from include/linux/rcuwait.h:6,
                    from include/linux/percpu-rwsem.h:7,
                    from include/linux/fs.h:33,
                    from include/linux/huge_mm.h:8,
                    from include/linux/mm.h:672,
                    from arch/powerpc/kernel/signal_32.c:17:
   arch/powerpc/include/asm/uaccess.h:605: note: macro "unsafe_copy_to_user" defined here
     605 | #define unsafe_copy_to_user(d, s, l, e) \
         | 
>> arch/powerpc/kernel/signal_32.c:313:3: error: 'unsafe_copy_to_user' undeclared (first use in this function); did you mean 'raw_copy_to_user'?
     313 |   unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
         |   ^~~~~~~~~~~~~~~~~~~
         |   raw_copy_to_user
   arch/powerpc/kernel/signal_32.c:313:3: note: each undeclared identifier is reported only once for each function it appears in
>> arch/powerpc/kernel/signal_32.c:314:37: error: 'failed' undeclared (first use in this function)
     314 |         ELF_NEVRREG * sizeof(u32)), failed);
         |                                     ^~~~~~
   arch/powerpc/kernel/signal_32.c:314:35: warning: left-hand operand of comma expression has no effect [-Wunused-value]
     314 |         ELF_NEVRREG * sizeof(u32)), failed);
         |                                   ^
>> arch/powerpc/kernel/signal_32.c:314:43: error: expected ';' before ')' token
     314 |         ELF_NEVRREG * sizeof(u32)), failed);
         |                                           ^
         |                                           ;
>> arch/powerpc/kernel/signal_32.c:314:43: error: expected statement before ')' token

# https://github.com/0day-ci/linux/commit/2706ef40840de32202abda6d2d7e0c9ea96c511c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Christophe-Leroy/powerpc-Switch-signal-32-to-using-unsafe_put_user-and-friends/20200819-012411
git checkout 2706ef40840de32202abda6d2d7e0c9ea96c511c
vim +/unsafe_copy_to_user +314 arch/powerpc/kernel/signal_32.c

   262	
   263	static int save_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame,
   264					 struct mcontext __user *tm_frame, int ctx_has_vsx_region)
   265	{
   266		unsigned long msr = regs->msr;
   267	
   268		/* save general registers */
   269		unsafe_save_general_regs(regs, frame, failed);
   270	
   271	#ifdef CONFIG_ALTIVEC
   272		/* save altivec registers */
   273		if (current->thread.used_vr) {
   274			unsafe_copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
   275					    ELF_NVRREG * sizeof(vector128), failed);
   276			/* set MSR_VEC in the saved MSR value to indicate that
   277			   frame->mc_vregs contains valid data */
   278			msr |= MSR_VEC;
   279		}
   280		/* else assert((regs->msr & MSR_VEC) == 0) */
   281	
   282		/* We always copy to/from vrsave, it's 0 if we don't have or don't
   283		 * use altivec. Since VSCR only contains 32 bits saved in the least
   284		 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
   285		 * most significant bits of that same vector. --BenH
   286		 * Note that the current VRSAVE value is in the SPR at this point.
   287		 */
   288		unsafe_put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32],
   289				failed);
   290	#endif /* CONFIG_ALTIVEC */
   291		unsafe_copy_fpr_to_user(&frame->mc_fregs, current, failed);
   292	
   293		/*
   294		 * Clear the MSR VSX bit to indicate there is no valid state attached
   295		 * to this context, except in the specific case below where we set it.
   296		 */
   297		msr &= ~MSR_VSX;
   298	#ifdef CONFIG_VSX
   299		/*
   300		 * Copy VSR 0-31 upper half from thread_struct to local
   301		 * buffer, then write that to userspace.  Also set MSR_VSX in
   302		 * the saved MSR value to indicate that frame->mc_vregs
   303		 * contains valid data
   304		 */
   305		if (current->thread.used_vsr && ctx_has_vsx_region) {
   306			unsafe_copy_vsx_to_user(&frame->mc_vsregs, current, failed);
   307			msr |= MSR_VSX;
   308		}
   309	#endif /* CONFIG_VSX */
   310	#ifdef CONFIG_SPE
   311		/* save spe registers */
   312		if (current->thread.used_spe) {
 > 313			unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
 > 314					    ELF_NEVRREG * sizeof(u32)), failed);
   315			/* set MSR_SPE in the saved MSR value to indicate that
   316			   frame->mc_vregs contains valid data */
   317			msr |= MSR_SPE;
   318		}
   319		/* else assert((regs->msr & MSR_SPE) == 0) */
   320	
   321		/* We always copy to/from spefscr */
   322		unsafe_put_user(current->thread.spefscr,
   323				(u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed);
   324	#endif /* CONFIG_SPE */
   325	
   326		unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
   327	
   328		/* We need to write 0 the MSR top 32 bits in the tm frame so that we
   329		 * can check it on the restore to see if TM is active
   330		 */
   331		if (tm_frame)
   332			unsafe_put_user(0, &tm_frame->mc_gregs[PT_MSR], failed);
   333	
   334		return 0;
   335	
   336	failed:
   337		return 1;
   338	}
   339	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 22980 bytes --]

Re: [PATCH v2 25/25] powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version

[Christophe Leroy]

Le 27/08/2020 à 11:07, kernel test robot a écrit :
> Hi Christophe,
> 
> I love your patch! Yet something to improve:
> 
> [auto build test ERROR on powerpc/next]
> [also build test ERROR on linus/master v5.9-rc2 next-20200827]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]
> 
> url:    https://github.com/0day-ci/linux/commits/Christophe-Leroy/powerpc-Switch-signal-32-to-using-unsafe_put_user-and-friends/20200819-012411
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
> config: powerpc64-randconfig-r005-20200827 (attached as .config)
> compiler: powerpc-linux-gcc (GCC) 9.3.0
> reproduce (this is a W=1 build):
>          wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>          chmod +x ~/bin/make.cross
>          # save the attached .config to linux build tree
>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc64
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
>     arch/powerpc/kernel/signal_32.c: In function 'save_user_regs_unsafe':
>>> arch/powerpc/kernel/signal_32.c:314:34: error: macro "unsafe_copy_to_user" requires 4 arguments, but only 3 given
>       314 |         ELF_NEVRREG * sizeof(u32)), failed);
>           |                                  ^
>     In file included from include/linux/uaccess.h:9,
>                      from include/linux/sched/task.h:11,
>                      from include/linux/sched/signal.h:9,
>                      from include/linux/rcuwait.h:6,
>                      from include/linux/percpu-rwsem.h:7,
>                      from include/linux/fs.h:33,
>                      from include/linux/huge_mm.h:8,
>                      from include/linux/mm.h:672,
>                      from arch/powerpc/kernel/signal_32.c:17:
>     arch/powerpc/include/asm/uaccess.h:605: note: macro "unsafe_copy_to_user" defined here
>       605 | #define unsafe_copy_to_user(d, s, l, e) \
>           |
>>> arch/powerpc/kernel/signal_32.c:313:3: error: 'unsafe_copy_to_user' undeclared (first use in this function); did you mean 'raw_copy_to_user'?
>       313 |   unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
>           |   ^~~~~~~~~~~~~~~~~~~
>           |   raw_copy_to_user
>     arch/powerpc/kernel/signal_32.c:313:3: note: each undeclared identifier is reported only once for each function it appears in
>>> arch/powerpc/kernel/signal_32.c:314:37: error: 'failed' undeclared (first use in this function)
>       314 |         ELF_NEVRREG * sizeof(u32)), failed);
>           |                                     ^~~~~~
>     arch/powerpc/kernel/signal_32.c:314:35: warning: left-hand operand of comma expression has no effect [-Wunused-value]
>       314 |         ELF_NEVRREG * sizeof(u32)), failed);
>           |                                   ^
>>> arch/powerpc/kernel/signal_32.c:314:43: error: expected ';' before ')' token
>       314 |         ELF_NEVRREG * sizeof(u32)), failed);
>           |                                           ^
>           |                                           ;
>>> arch/powerpc/kernel/signal_32.c:314:43: error: expected statement before ')' token
> 

Should be fixed by:

diff --git a/arch/powerpc/kernel/signal_32.c 
b/arch/powerpc/kernel/signal_32.c
index f795fe0240a1..123682299d4f 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -311,7 +311,7 @@ static int save_user_regs_unsafe(struct pt_regs 
*regs, struct mcontext __user *f
  	/* save spe registers */
  	if (current->thread.used_spe) {
  		unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
-				    ELF_NEVRREG * sizeof(u32)), failed);
+				    ELF_NEVRREG * sizeof(u32), failed);
  		/* set MSR_SPE in the saved MSR value to indicate that
  		   frame->mc_vregs contains valid data */
  		msr |= MSR_SPE;

---
Christophe

Re: [PATCH v2 25/25] powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version

[Christopher M. Riedl]

On Tue Aug 18, 2020 at 12:19 PM CDT, Christophe Leroy wrote:
> Change those two functions to be used within a user access block.
>
> For that, change save_general_regs() to and unsafe_save_general_regs(),
> then replace all user accesses by unsafe_ versions.
>
> This series leads to a reduction from 2.55s to 1.73s of
> the system CPU time with the following microbench app
> on an mpc832x with KUAP (approx 32%)
>
> Without KUAP, the difference is in the noise.
>
> void sigusr1(int sig) { }
>
> int main(int argc, char **argv)
> {
> int i = 100000;
>
> signal(SIGUSR1, sigusr1);
> for (;i--;)
> raise(SIGUSR1);
> exit(0);
> }
>
> An additional 0.10s reduction is achieved by removing
> CONFIG_PPC_FPU, as the mpc832x has no FPU.
>
> A bit less spectacular on an 8xx as KUAP is less heavy, prior to
> the series (with KUAP) it ran in 8.10 ms. Once applies the removal
> of FPU regs handling, we get 7.05s. With the full series, we get 6.9s.
> If artificially re-activating FPU regs handling with the full series,
> we get 7.6s.
>
> So for the 8xx, the removal of the FPU regs copy is what makes the
> difference, but the rework of handle_signal also have a benefit.
>
> Same as above, without KUAP the difference is in the noise.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> arch/powerpc/kernel/signal_32.c | 224 ++++++++++++++++----------------
> 1 file changed, 111 insertions(+), 113 deletions(-)
>
> diff --git a/arch/powerpc/kernel/signal_32.c
> b/arch/powerpc/kernel/signal_32.c
> index 86539a4e0514..f795fe0240a1 100644
> --- a/arch/powerpc/kernel/signal_32.c
> +++ b/arch/powerpc/kernel/signal_32.c
> @@ -93,8 +93,8 @@ static inline int get_sigset_t(sigset_t *set,
> #define to_user_ptr(p) ptr_to_compat(p)
> #define from_user_ptr(p) compat_ptr(p)
>  
> -static inline int save_general_regs(struct pt_regs *regs,
> - struct mcontext __user *frame)
> +static __always_inline int
> +save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user
> *frame)
> {
> elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
> int val, i;
> @@ -108,10 +108,12 @@ static inline int save_general_regs(struct pt_regs
> *regs,
> else
> val = gregs[i];
>  
> - if (__put_user(val, &frame->mc_gregs[i]))
> - return -EFAULT;
> + unsafe_put_user(val, &frame->mc_gregs[i], failed);
> }
> return 0;
> +
> +failed:
> + return 1;
> }
>  
> static inline int restore_general_regs(struct pt_regs *regs,
> @@ -148,11 +150,15 @@ static inline int get_sigset_t(sigset_t *set,
> const sigset_t __user *uset)
> #define to_user_ptr(p) ((unsigned long)(p))
> #define from_user_ptr(p) ((void __user *)(p))
>  
> -static inline int save_general_regs(struct pt_regs *regs,
> - struct mcontext __user *frame)
> +static __always_inline int
> +save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user
> *frame)
> {
> WARN_ON(!FULL_REGS(regs));
> - return __copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE);
> + unsafe_copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE, failed);
> + return 0;
> +
> +failed:
> + return 1;
> }
>  
> static inline int restore_general_regs(struct pt_regs *regs,
> @@ -170,6 +176,11 @@ static inline int restore_general_regs(struct
> pt_regs *regs,
> }
> #endif
>  
> +#define unsafe_save_general_regs(regs, frame, label) do { \
> + if (save_general_regs_unsafe(regs, frame)) \

Minor nitpick (sorry); this naming seems a bit strange to me, in x86 it
is "__unsafe_" as a prefix instead of "_unsafe" as a suffix. That sounds
a bit better to me, what do you think? Unless there is some convention I
am not aware of here apart from "unsafe_" using a goto label for errors.

> + goto label; \
> +} while (0)
> +
> /*
> * When we have signals to deliver, we set up on the
> * user stack, going down from the original stack pointer:
> @@ -249,21 +260,19 @@ static void prepare_save_user_regs(int
> ctx_has_vsx_region)
> #endif
> }
>  
> -static int save_user_regs(struct pt_regs *regs, struct mcontext __user
> *frame,
> - struct mcontext __user *tm_frame, int ctx_has_vsx_region)
> +static int save_user_regs_unsafe(struct pt_regs *regs, struct mcontext
> __user *frame,
> + struct mcontext __user *tm_frame, int ctx_has_vsx_region)
> {
> unsigned long msr = regs->msr;
>  
> /* save general registers */
> - if (save_general_regs(regs, frame))
> - return 1;
> + unsafe_save_general_regs(regs, frame, failed);
>  
> #ifdef CONFIG_ALTIVEC
> /* save altivec registers */
> if (current->thread.used_vr) {
> - if (__copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
> - ELF_NVRREG * sizeof(vector128)))
> - return 1;
> + unsafe_copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
> + ELF_NVRREG * sizeof(vector128), failed);
> /* set MSR_VEC in the saved MSR value to indicate that
> frame->mc_vregs contains valid data */
> msr |= MSR_VEC;
> @@ -276,11 +285,10 @@ static int save_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame,
> * most significant bits of that same vector. --BenH
> * Note that the current VRSAVE value is in the SPR at this point.
> */
> - if (__put_user(current->thread.vrsave, (u32 __user
> *)&frame->mc_vregs[32]))
> - return 1;
> + unsafe_put_user(current->thread.vrsave, (u32 __user
> *)&frame->mc_vregs[32],
> + failed);
> #endif /* CONFIG_ALTIVEC */
> - if (copy_fpr_to_user(&frame->mc_fregs, current))
> - return 1;
> + unsafe_copy_fpr_to_user(&frame->mc_fregs, current, failed);
>  
> /*
> * Clear the MSR VSX bit to indicate there is no valid state attached
> @@ -295,17 +303,15 @@ static int save_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame,
> * contains valid data
> */
> if (current->thread.used_vsr && ctx_has_vsx_region) {
> - if (copy_vsx_to_user(&frame->mc_vsregs, current))
> - return 1;
> + unsafe_copy_vsx_to_user(&frame->mc_vsregs, current, failed);
> msr |= MSR_VSX;
> }
> #endif /* CONFIG_VSX */
> #ifdef CONFIG_SPE
> /* save spe registers */
> if (current->thread.used_spe) {
> - if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
> - ELF_NEVRREG * sizeof(u32)))
> - return 1;
> + unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
> + ELF_NEVRREG * sizeof(u32)), failed);
> /* set MSR_SPE in the saved MSR value to indicate that
> frame->mc_vregs contains valid data */
> msr |= MSR_SPE;
> @@ -313,21 +319,29 @@ static int save_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame,
> /* else assert((regs->msr & MSR_SPE) == 0) */
>  
> /* We always copy to/from spefscr */
> - if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs
> + ELF_NEVRREG))
> - return 1;
> + unsafe_put_user(current->thread.spefscr,
> + (u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed);
> #endif /* CONFIG_SPE */
>  
> - if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
> - return 1;
> + unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
> +
> /* We need to write 0 the MSR top 32 bits in the tm frame so that we
> * can check it on the restore to see if TM is active
> */
> - if (tm_frame && __put_user(0, &tm_frame->mc_gregs[PT_MSR]))
> - return 1;
> + if (tm_frame)
> + unsafe_put_user(0, &tm_frame->mc_gregs[PT_MSR], failed);
>  
> return 0;
> +
> +failed:
> + return 1;
> }
>  
> +#define unsafe_save_user_regs(regs, frame, tm_frame, has_vsx, label) do
> { \
> + if (save_user_regs_unsafe(regs, frame, tm_frame, has_vsx)) \
> + goto label; \
> +} while (0)
> +
> #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> /*
> * Save the current user registers on the user stack.
> @@ -336,7 +350,7 @@ static int save_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame,
> * We also save the transactional registers to a second ucontext in the
> * frame.
> *
> - * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
> + * See save_user_regs_unsafe() and signal_64.c:setup_tm_sigcontexts().
> */
> static void prepare_save_tm_user_regs(void)
> {
> @@ -352,13 +366,12 @@ static void prepare_save_tm_user_regs(void)
> #endif
> }
>  
> -static int save_tm_user_regs(struct pt_regs *regs, struct mcontext
> __user *frame,
> - struct mcontext __user *tm_frame, unsigned long msr)
> +static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct
> mcontext __user *frame,
> + struct mcontext __user *tm_frame, unsigned long msr)
> {
> /* Save both sets of general registers */
> - if (save_general_regs(&current->thread.ckpt_regs, frame)
> - || save_general_regs(regs, tm_frame))
> - return 1;
> + unsafe_save_general_regs(&current->thread.ckpt_regs, frame, failed);
> + unsafe_save_general_regs(regs, tm_frame, failed);
>  
> /* Stash the top half of the 64bit MSR into the 32bit MSR word
> * of the transactional mcontext. This way we have a backward-compatible
> @@ -366,26 +379,21 @@ static int save_tm_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame
> * also look at what type of transaction (T or S) was active at the
> * time of the signal.
> */
> - if (__put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR]))
> - return 1;
> + unsafe_put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR], failed);
>  
> #ifdef CONFIG_ALTIVEC
> /* save altivec registers */
> if (current->thread.used_vr) {
> - if (__copy_to_user(&frame->mc_vregs, &current->thread.ckvr_state,
> - ELF_NVRREG * sizeof(vector128)))
> - return 1;
> - if (msr & MSR_VEC) {
> - if (__copy_to_user(&tm_frame->mc_vregs,
> - &current->thread.vr_state,
> - ELF_NVRREG * sizeof(vector128)))
> - return 1;
> - } else {
> - if (__copy_to_user(&tm_frame->mc_vregs,
> - &current->thread.ckvr_state,
> - ELF_NVRREG * sizeof(vector128)))
> - return 1;
> - }
> + unsafe_copy_to_user(&frame->mc_vregs, &current->thread.ckvr_state,
> + ELF_NVRREG * sizeof(vector128), failed);
> + if (msr & MSR_VEC)
> + unsafe_copy_to_user(&tm_frame->mc_vregs,
> + &current->thread.vr_state,
> + ELF_NVRREG * sizeof(vector128), failed);
> + else
> + unsafe_copy_to_user(&tm_frame->mc_vregs,
> + &current->thread.ckvr_state,
> + ELF_NVRREG * sizeof(vector128), failed);
>  
> /* set MSR_VEC in the saved MSR value to indicate that
> * frame->mc_vregs contains valid data
> @@ -398,29 +406,21 @@ static int save_tm_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame
> * significant bits of a vector, we "cheat" and stuff VRSAVE in the
> * most significant bits of that same vector. --BenH
> */
> - if (__put_user(current->thread.ckvrsave,
> - (u32 __user *)&frame->mc_vregs[32]))
> - return 1;
> - if (msr & MSR_VEC) {
> - if (__put_user(current->thread.vrsave,
> - (u32 __user *)&tm_frame->mc_vregs[32]))
> - return 1;
> - } else {
> - if (__put_user(current->thread.ckvrsave,
> - (u32 __user *)&tm_frame->mc_vregs[32]))
> - return 1;
> - }
> + unsafe_put_user(current->thread.ckvrsave,
> + (u32 __user *)&frame->mc_vregs[32], failed);
> + if (msr & MSR_VEC)
> + unsafe_put_user(current->thread.vrsave,
> + (u32 __user *)&tm_frame->mc_vregs[32], failed);
> + else
> + unsafe_put_user(current->thread.ckvrsave,
> + (u32 __user *)&tm_frame->mc_vregs[32], failed);
> #endif /* CONFIG_ALTIVEC */
>  
> - if (copy_ckfpr_to_user(&frame->mc_fregs, current))
> - return 1;
> - if (msr & MSR_FP) {
> - if (copy_fpr_to_user(&tm_frame->mc_fregs, current))
> - return 1;
> - } else {
> - if (copy_ckfpr_to_user(&tm_frame->mc_fregs, current))
> - return 1;
> - }
> + unsafe_copy_ckfpr_to_user(&frame->mc_fregs, current, failed);
> + if (msr & MSR_FP)
> + unsafe_copy_fpr_to_user(&tm_frame->mc_fregs, current, failed);
> + else
> + unsafe_copy_ckfpr_to_user(&tm_frame->mc_fregs, current, failed);
>  
> #ifdef CONFIG_VSX
> /*
> @@ -430,53 +430,54 @@ static int save_tm_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame
> * contains valid data
> */
> if (current->thread.used_vsr) {
> - if (copy_ckvsx_to_user(&frame->mc_vsregs, current))
> - return 1;
> - if (msr & MSR_VSX) {
> - if (copy_vsx_to_user(&tm_frame->mc_vsregs,
> - current))
> - return 1;
> - } else {
> - if (copy_ckvsx_to_user(&tm_frame->mc_vsregs, current))
> - return 1;
> - }
> + unsafe_copy_ckvsx_to_user(&frame->mc_vsregs, current, failed);
> + if (msr & MSR_VSX)
> + unsafe_copy_vsx_to_user(&tm_frame->mc_vsregs, current, failed);
> + else
> + unsafe_copy_ckvsx_to_user(&tm_frame->mc_vsregs, current, failed);
>  
> msr |= MSR_VSX;
> }
> #endif /* CONFIG_VSX */
> #ifdef CONFIG_SPE
> /* SPE regs are not checkpointed with TM, so this section is
> - * simply the same as in save_user_regs().
> + * simply the same as in save_user_regs_unsafe().
> */
> if (current->thread.used_spe) {
> - if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
> - ELF_NEVRREG * sizeof(u32)))
> - return 1;
> + unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
> + ELF_NEVRREG * sizeof(u32), failed);
> /* set MSR_SPE in the saved MSR value to indicate that
> * frame->mc_vregs contains valid data */
> msr |= MSR_SPE;
> }
>  
> /* We always copy to/from spefscr */
> - if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs
> + ELF_NEVRREG))
> - return 1;
> + unsafe_put_user(current->thread.spefscr,
> + (u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed);
> #endif /* CONFIG_SPE */
>  
> - if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
> - return 1;
> + unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
>  
> return 0;
> +
> +failed:
> + return 1;
> }
> #else
> static void prepare_save_tm_user_regs(void) { }
>  
> -static int save_tm_user_regs(struct pt_regs *regs, struct mcontext
> __user *frame,
> - struct mcontext __user *tm_frame, unsigned long msr)
> +static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct
> mcontext __user *frame,
> + struct mcontext __user *tm_frame, unsigned long msr)
> {
> return 0;
> }
> #endif
>  
> +#define unsafe_save_tm_user_regs(regs, frame, tm_frame, msr, label) do
> { \
> + if (save_tm_user_regs_unsafe(regs, frame, tm_frame, msr)) \
> + goto label; \
> +} while (0)
> +
> /*
> * Restore the current user register values from the user stack,
> * (except for MSR).
> @@ -769,6 +770,11 @@ int handle_rt_signal32(struct ksignal *ksig,
> sigset_t *oldset,
> #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> tm_mctx = &frame->uc_transact.uc_mcontext;
> #endif
> + if (MSR_TM_ACTIVE(msr))
> + prepare_save_tm_user_regs();
> + else
> + prepare_save_user_regs(1);
> +
> if (!user_write_access_begin(frame, sizeof(*frame)))
> goto badframe;
>  
> @@ -788,8 +794,10 @@ int handle_rt_signal32(struct ksignal *ksig,
> sigset_t *oldset,
> unsafe_put_user((unsigned long)tm_mctx,
> &frame->uc_transact.uc_regs, failed);
> #endif
> + unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
> } else {
> unsafe_put_user(0, &frame->uc.uc_link, failed);
> + unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
> }
>  
> /* Save user registers on the stack */
> @@ -812,15 +820,6 @@ int handle_rt_signal32(struct ksignal *ksig,
> sigset_t *oldset,
> if (tramp == (unsigned long)mctx->mc_pad)
> flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
>  
> - if (MSR_TM_ACTIVE(msr)) {
> - prepare_save_tm_user_regs();
> - if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
> - goto badframe;
> - } else {
> - prepare_save_user_regs(1);
> - if (save_user_regs(regs, mctx, tm_mctx, 1))
> - goto badframe;
> - }
> regs->link = tramp;
>  
> #ifdef CONFIG_PPC_FPU_REGS
> @@ -875,6 +874,11 @@ int handle_signal32(struct ksignal *ksig, sigset_t
> *oldset,
> #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> tm_mctx = &frame->mctx_transact;
> #endif
> + if (MSR_TM_ACTIVE(msr))
> + prepare_save_tm_user_regs();
> + else
> + prepare_save_user_regs(1);
> +
> if (!user_write_access_begin(frame, sizeof(*frame)))
> goto badframe;
> sc = (struct sigcontext __user *) &frame->sctx;
> @@ -892,6 +896,11 @@ int handle_signal32(struct ksignal *ksig, sigset_t
> *oldset,
> unsafe_put_user(to_user_ptr(mctx), &sc->regs, failed);
> unsafe_put_user(ksig->sig, &sc->signal, failed);
>  
> + if (MSR_TM_ACTIVE(msr))
> + unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
> + else
> + unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
> +
> if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
> tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
> } else {
> @@ -905,16 +914,6 @@ int handle_signal32(struct ksignal *ksig, sigset_t
> *oldset,
> if (tramp == (unsigned long)mctx->mc_pad)
> flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
>  
> - if (MSR_TM_ACTIVE(msr)) {
> - prepare_save_tm_user_regs();
> - if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
> - goto badframe;
> - } else {
> - prepare_save_user_regs(1);
> - if (save_user_regs(regs, mctx, tm_mctx, 1))
> - goto badframe;
> - }
> -
> regs->link = tramp;
>  
> #ifdef CONFIG_PPC_FPU_REGS
> @@ -1066,10 +1065,9 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext
> __user *, old_ctx,
> mctx = (struct mcontext __user *)
> ((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
> prepare_save_user_regs(ctx_has_vsx_region);
> - if (save_user_regs(regs, mctx, NULL, ctx_has_vsx_region))
> - return -EFAULT;
> if (!user_write_access_begin(old_ctx, ctx_size))
> return -EFAULT;
> + unsafe_save_user_regs(regs, mctx, NULL, ctx_has_vsx_region, failed);
> unsafe_put_sigset_t(&old_ctx->uc_sigmask, &current->blocked, failed);
> unsafe_put_user(to_user_ptr(mctx), &old_ctx->uc_regs, failed);
> user_write_access_end();
> --
> 2.25.0

Re: [PATCH v2 25/25] powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version

[Christopher M. Riedl]

On Tue Aug 18, 2020 at 12:19 PM CDT, Christophe Leroy wrote:
> Change those two functions to be used within a user access block.
>
> For that, change save_general_regs() to and unsafe_save_general_regs(),
> then replace all user accesses by unsafe_ versions.
>
> This series leads to a reduction from 2.55s to 1.73s of
> the system CPU time with the following microbench app
> on an mpc832x with KUAP (approx 32%)
>
> Without KUAP, the difference is in the noise.
>
> void sigusr1(int sig) { }
>
> int main(int argc, char **argv)
> {
> int i = 100000;
>
> signal(SIGUSR1, sigusr1);
> for (;i--;)
> raise(SIGUSR1);
> exit(0);
> }
>
> An additional 0.10s reduction is achieved by removing
> CONFIG_PPC_FPU, as the mpc832x has no FPU.
>
> A bit less spectacular on an 8xx as KUAP is less heavy, prior to
> the series (with KUAP) it ran in 8.10 ms. Once applies the removal
> of FPU regs handling, we get 7.05s. With the full series, we get 6.9s.
> If artificially re-activating FPU regs handling with the full series,
> we get 7.6s.
>
> So for the 8xx, the removal of the FPU regs copy is what makes the
> difference, but the rework of handle_signal also have a benefit.
>
> Same as above, without KUAP the difference is in the noise.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> arch/powerpc/kernel/signal_32.c | 224 ++++++++++++++++----------------
> 1 file changed, 111 insertions(+), 113 deletions(-)
>
> diff --git a/arch/powerpc/kernel/signal_32.c
> b/arch/powerpc/kernel/signal_32.c
> index 86539a4e0514..f795fe0240a1 100644
> --- a/arch/powerpc/kernel/signal_32.c
> +++ b/arch/powerpc/kernel/signal_32.c
> @@ -93,8 +93,8 @@ static inline int get_sigset_t(sigset_t *set,
> #define to_user_ptr(p) ptr_to_compat(p)
> #define from_user_ptr(p) compat_ptr(p)
>  
> -static inline int save_general_regs(struct pt_regs *regs,
> - struct mcontext __user *frame)
> +static __always_inline int
> +save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user
> *frame)
> {
> elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
> int val, i;
> @@ -108,10 +108,12 @@ static inline int save_general_regs(struct pt_regs
> *regs,
> else
> val = gregs[i];
>  
> - if (__put_user(val, &frame->mc_gregs[i]))
> - return -EFAULT;
> + unsafe_put_user(val, &frame->mc_gregs[i], failed);
> }
> return 0;
> +
> +failed:
> + return 1;
> }
>  
> static inline int restore_general_regs(struct pt_regs *regs,
> @@ -148,11 +150,15 @@ static inline int get_sigset_t(sigset_t *set,
> const sigset_t __user *uset)
> #define to_user_ptr(p) ((unsigned long)(p))
> #define from_user_ptr(p) ((void __user *)(p))
>  
> -static inline int save_general_regs(struct pt_regs *regs,
> - struct mcontext __user *frame)
> +static __always_inline int
> +save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user
> *frame)
> {
> WARN_ON(!FULL_REGS(regs));
> - return __copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE);
> + unsafe_copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE, failed);
> + return 0;
> +
> +failed:
> + return 1;
> }
>  
> static inline int restore_general_regs(struct pt_regs *regs,
> @@ -170,6 +176,11 @@ static inline int restore_general_regs(struct
> pt_regs *regs,
> }
> #endif
>  
> +#define unsafe_save_general_regs(regs, frame, label) do { \
> + if (save_general_regs_unsafe(regs, frame)) \

Minor nitpick (sorry); this naming seems a bit strange to me, in x86 it
is "__unsafe_" as a prefix instead of "_unsafe" as a suffix. That sounds
a bit better to me, what do you think? Unless there is some convention I
am not aware of here apart from "unsafe_" using a goto label for errors.

> + goto label; \
> +} while (0)
> +
> /*
> * When we have signals to deliver, we set up on the
> * user stack, going down from the original stack pointer:
> @@ -249,21 +260,19 @@ static void prepare_save_user_regs(int
> ctx_has_vsx_region)
> #endif
> }
>  
> -static int save_user_regs(struct pt_regs *regs, struct mcontext __user
> *frame,
> - struct mcontext __user *tm_frame, int ctx_has_vsx_region)
> +static int save_user_regs_unsafe(struct pt_regs *regs, struct mcontext
> __user *frame,
> + struct mcontext __user *tm_frame, int ctx_has_vsx_region)
> {
> unsigned long msr = regs->msr;
>  
> /* save general registers */
> - if (save_general_regs(regs, frame))
> - return 1;
> + unsafe_save_general_regs(regs, frame, failed);
>  
> #ifdef CONFIG_ALTIVEC
> /* save altivec registers */
> if (current->thread.used_vr) {
> - if (__copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
> - ELF_NVRREG * sizeof(vector128)))
> - return 1;
> + unsafe_copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
> + ELF_NVRREG * sizeof(vector128), failed);
> /* set MSR_VEC in the saved MSR value to indicate that
> frame->mc_vregs contains valid data */
> msr |= MSR_VEC;
> @@ -276,11 +285,10 @@ static int save_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame,
> * most significant bits of that same vector. --BenH
> * Note that the current VRSAVE value is in the SPR at this point.
> */
> - if (__put_user(current->thread.vrsave, (u32 __user
> *)&frame->mc_vregs[32]))
> - return 1;
> + unsafe_put_user(current->thread.vrsave, (u32 __user
> *)&frame->mc_vregs[32],
> + failed);
> #endif /* CONFIG_ALTIVEC */
> - if (copy_fpr_to_user(&frame->mc_fregs, current))
> - return 1;
> + unsafe_copy_fpr_to_user(&frame->mc_fregs, current, failed);
>  
> /*
> * Clear the MSR VSX bit to indicate there is no valid state attached
> @@ -295,17 +303,15 @@ static int save_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame,
> * contains valid data
> */
> if (current->thread.used_vsr && ctx_has_vsx_region) {
> - if (copy_vsx_to_user(&frame->mc_vsregs, current))
> - return 1;
> + unsafe_copy_vsx_to_user(&frame->mc_vsregs, current, failed);
> msr |= MSR_VSX;
> }
> #endif /* CONFIG_VSX */
> #ifdef CONFIG_SPE
> /* save spe registers */
> if (current->thread.used_spe) {
> - if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
> - ELF_NEVRREG * sizeof(u32)))
> - return 1;
> + unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
> + ELF_NEVRREG * sizeof(u32)), failed);
> /* set MSR_SPE in the saved MSR value to indicate that
> frame->mc_vregs contains valid data */
> msr |= MSR_SPE;
> @@ -313,21 +319,29 @@ static int save_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame,
> /* else assert((regs->msr & MSR_SPE) == 0) */
>  
> /* We always copy to/from spefscr */
> - if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs
> + ELF_NEVRREG))
> - return 1;
> + unsafe_put_user(current->thread.spefscr,
> + (u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed);
> #endif /* CONFIG_SPE */
>  
> - if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
> - return 1;
> + unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
> +
> /* We need to write 0 the MSR top 32 bits in the tm frame so that we
> * can check it on the restore to see if TM is active
> */
> - if (tm_frame && __put_user(0, &tm_frame->mc_gregs[PT_MSR]))
> - return 1;
> + if (tm_frame)
> + unsafe_put_user(0, &tm_frame->mc_gregs[PT_MSR], failed);
>  
> return 0;
> +
> +failed:
> + return 1;
> }
>  
> +#define unsafe_save_user_regs(regs, frame, tm_frame, has_vsx, label) do
> { \
> + if (save_user_regs_unsafe(regs, frame, tm_frame, has_vsx)) \
> + goto label; \
> +} while (0)
> +
> #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> /*
> * Save the current user registers on the user stack.
> @@ -336,7 +350,7 @@ static int save_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame,
> * We also save the transactional registers to a second ucontext in the
> * frame.
> *
> - * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
> + * See save_user_regs_unsafe() and signal_64.c:setup_tm_sigcontexts().
> */
> static void prepare_save_tm_user_regs(void)
> {
> @@ -352,13 +366,12 @@ static void prepare_save_tm_user_regs(void)
> #endif
> }
>  
> -static int save_tm_user_regs(struct pt_regs *regs, struct mcontext
> __user *frame,
> - struct mcontext __user *tm_frame, unsigned long msr)
> +static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct
> mcontext __user *frame,
> + struct mcontext __user *tm_frame, unsigned long msr)
> {
> /* Save both sets of general registers */
> - if (save_general_regs(&current->thread.ckpt_regs, frame)
> - || save_general_regs(regs, tm_frame))
> - return 1;
> + unsafe_save_general_regs(&current->thread.ckpt_regs, frame, failed);
> + unsafe_save_general_regs(regs, tm_frame, failed);
>  
> /* Stash the top half of the 64bit MSR into the 32bit MSR word
> * of the transactional mcontext. This way we have a backward-compatible
> @@ -366,26 +379,21 @@ static int save_tm_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame
> * also look at what type of transaction (T or S) was active at the
> * time of the signal.
> */
> - if (__put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR]))
> - return 1;
> + unsafe_put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR], failed);
>  
> #ifdef CONFIG_ALTIVEC
> /* save altivec registers */
> if (current->thread.used_vr) {
> - if (__copy_to_user(&frame->mc_vregs, &current->thread.ckvr_state,
> - ELF_NVRREG * sizeof(vector128)))
> - return 1;
> - if (msr & MSR_VEC) {
> - if (__copy_to_user(&tm_frame->mc_vregs,
> - &current->thread.vr_state,
> - ELF_NVRREG * sizeof(vector128)))
> - return 1;
> - } else {
> - if (__copy_to_user(&tm_frame->mc_vregs,
> - &current->thread.ckvr_state,
> - ELF_NVRREG * sizeof(vector128)))
> - return 1;
> - }
> + unsafe_copy_to_user(&frame->mc_vregs, &current->thread.ckvr_state,
> + ELF_NVRREG * sizeof(vector128), failed);
> + if (msr & MSR_VEC)
> + unsafe_copy_to_user(&tm_frame->mc_vregs,
> + &current->thread.vr_state,
> + ELF_NVRREG * sizeof(vector128), failed);
> + else
> + unsafe_copy_to_user(&tm_frame->mc_vregs,
> + &current->thread.ckvr_state,
> + ELF_NVRREG * sizeof(vector128), failed);
>  
> /* set MSR_VEC in the saved MSR value to indicate that
> * frame->mc_vregs contains valid data
> @@ -398,29 +406,21 @@ static int save_tm_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame
> * significant bits of a vector, we "cheat" and stuff VRSAVE in the
> * most significant bits of that same vector. --BenH
> */
> - if (__put_user(current->thread.ckvrsave,
> - (u32 __user *)&frame->mc_vregs[32]))
> - return 1;
> - if (msr & MSR_VEC) {
> - if (__put_user(current->thread.vrsave,
> - (u32 __user *)&tm_frame->mc_vregs[32]))
> - return 1;
> - } else {
> - if (__put_user(current->thread.ckvrsave,
> - (u32 __user *)&tm_frame->mc_vregs[32]))
> - return 1;
> - }
> + unsafe_put_user(current->thread.ckvrsave,
> + (u32 __user *)&frame->mc_vregs[32], failed);
> + if (msr & MSR_VEC)
> + unsafe_put_user(current->thread.vrsave,
> + (u32 __user *)&tm_frame->mc_vregs[32], failed);
> + else
> + unsafe_put_user(current->thread.ckvrsave,
> + (u32 __user *)&tm_frame->mc_vregs[32], failed);
> #endif /* CONFIG_ALTIVEC */
>  
> - if (copy_ckfpr_to_user(&frame->mc_fregs, current))
> - return 1;
> - if (msr & MSR_FP) {
> - if (copy_fpr_to_user(&tm_frame->mc_fregs, current))
> - return 1;
> - } else {
> - if (copy_ckfpr_to_user(&tm_frame->mc_fregs, current))
> - return 1;
> - }
> + unsafe_copy_ckfpr_to_user(&frame->mc_fregs, current, failed);
> + if (msr & MSR_FP)
> + unsafe_copy_fpr_to_user(&tm_frame->mc_fregs, current, failed);
> + else
> + unsafe_copy_ckfpr_to_user(&tm_frame->mc_fregs, current, failed);
>  
> #ifdef CONFIG_VSX
> /*
> @@ -430,53 +430,54 @@ static int save_tm_user_regs(struct pt_regs *regs,
> struct mcontext __user *frame
> * contains valid data
> */
> if (current->thread.used_vsr) {
> - if (copy_ckvsx_to_user(&frame->mc_vsregs, current))
> - return 1;
> - if (msr & MSR_VSX) {
> - if (copy_vsx_to_user(&tm_frame->mc_vsregs,
> - current))
> - return 1;
> - } else {
> - if (copy_ckvsx_to_user(&tm_frame->mc_vsregs, current))
> - return 1;
> - }
> + unsafe_copy_ckvsx_to_user(&frame->mc_vsregs, current, failed);
> + if (msr & MSR_VSX)
> + unsafe_copy_vsx_to_user(&tm_frame->mc_vsregs, current, failed);
> + else
> + unsafe_copy_ckvsx_to_user(&tm_frame->mc_vsregs, current, failed);
>  
> msr |= MSR_VSX;
> }
> #endif /* CONFIG_VSX */
> #ifdef CONFIG_SPE
> /* SPE regs are not checkpointed with TM, so this section is
> - * simply the same as in save_user_regs().
> + * simply the same as in save_user_regs_unsafe().
> */
> if (current->thread.used_spe) {
> - if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
> - ELF_NEVRREG * sizeof(u32)))
> - return 1;
> + unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
> + ELF_NEVRREG * sizeof(u32), failed);
> /* set MSR_SPE in the saved MSR value to indicate that
> * frame->mc_vregs contains valid data */
> msr |= MSR_SPE;
> }
>  
> /* We always copy to/from spefscr */
> - if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs
> + ELF_NEVRREG))
> - return 1;
> + unsafe_put_user(current->thread.spefscr,
> + (u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed);
> #endif /* CONFIG_SPE */
>  
> - if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
> - return 1;
> + unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
>  
> return 0;
> +
> +failed:
> + return 1;
> }
> #else
> static void prepare_save_tm_user_regs(void) { }
>  
> -static int save_tm_user_regs(struct pt_regs *regs, struct mcontext
> __user *frame,
> - struct mcontext __user *tm_frame, unsigned long msr)
> +static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct
> mcontext __user *frame,
> + struct mcontext __user *tm_frame, unsigned long msr)
> {
> return 0;
> }
> #endif
>  
> +#define unsafe_save_tm_user_regs(regs, frame, tm_frame, msr, label) do
> { \
> + if (save_tm_user_regs_unsafe(regs, frame, tm_frame, msr)) \
> + goto label; \
> +} while (0)
> +
> /*
> * Restore the current user register values from the user stack,
> * (except for MSR).
> @@ -769,6 +770,11 @@ int handle_rt_signal32(struct ksignal *ksig,
> sigset_t *oldset,
> #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> tm_mctx = &frame->uc_transact.uc_mcontext;
> #endif
> + if (MSR_TM_ACTIVE(msr))
> + prepare_save_tm_user_regs();
> + else
> + prepare_save_user_regs(1);
> +
> if (!user_write_access_begin(frame, sizeof(*frame)))
> goto badframe;
>  
> @@ -788,8 +794,10 @@ int handle_rt_signal32(struct ksignal *ksig,
> sigset_t *oldset,
> unsafe_put_user((unsigned long)tm_mctx,
> &frame->uc_transact.uc_regs, failed);
> #endif
> + unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
> } else {
> unsafe_put_user(0, &frame->uc.uc_link, failed);
> + unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
> }
>  
> /* Save user registers on the stack */
> @@ -812,15 +820,6 @@ int handle_rt_signal32(struct ksignal *ksig,
> sigset_t *oldset,
> if (tramp == (unsigned long)mctx->mc_pad)
> flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
>  
> - if (MSR_TM_ACTIVE(msr)) {
> - prepare_save_tm_user_regs();
> - if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
> - goto badframe;
> - } else {
> - prepare_save_user_regs(1);
> - if (save_user_regs(regs, mctx, tm_mctx, 1))
> - goto badframe;
> - }
> regs->link = tramp;
>  
> #ifdef CONFIG_PPC_FPU_REGS
> @@ -875,6 +874,11 @@ int handle_signal32(struct ksignal *ksig, sigset_t
> *oldset,
> #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> tm_mctx = &frame->mctx_transact;
> #endif
> + if (MSR_TM_ACTIVE(msr))
> + prepare_save_tm_user_regs();
> + else
> + prepare_save_user_regs(1);
> +
> if (!user_write_access_begin(frame, sizeof(*frame)))
> goto badframe;
> sc = (struct sigcontext __user *) &frame->sctx;
> @@ -892,6 +896,11 @@ int handle_signal32(struct ksignal *ksig, sigset_t
> *oldset,
> unsafe_put_user(to_user_ptr(mctx), &sc->regs, failed);
> unsafe_put_user(ksig->sig, &sc->signal, failed);
>  
> + if (MSR_TM_ACTIVE(msr))
> + unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
> + else
> + unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
> +
> if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
> tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
> } else {
> @@ -905,16 +914,6 @@ int handle_signal32(struct ksignal *ksig, sigset_t
> *oldset,
> if (tramp == (unsigned long)mctx->mc_pad)
> flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
>  
> - if (MSR_TM_ACTIVE(msr)) {
> - prepare_save_tm_user_regs();
> - if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
> - goto badframe;
> - } else {
> - prepare_save_user_regs(1);
> - if (save_user_regs(regs, mctx, tm_mctx, 1))
> - goto badframe;
> - }
> -
> regs->link = tramp;
>  
> #ifdef CONFIG_PPC_FPU_REGS
> @@ -1066,10 +1065,9 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext
> __user *, old_ctx,
> mctx = (struct mcontext __user *)
> ((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
> prepare_save_user_regs(ctx_has_vsx_region);
> - if (save_user_regs(regs, mctx, NULL, ctx_has_vsx_region))
> - return -EFAULT;
> if (!user_write_access_begin(old_ctx, ctx_size))
> return -EFAULT;
> + unsafe_save_user_regs(regs, mctx, NULL, ctx_has_vsx_region, failed);
> unsafe_put_sigset_t(&old_ctx->uc_sigmask, &current->blocked, failed);
> unsafe_put_user(to_user_ptr(mctx), &old_ctx->uc_regs, failed);
> user_write_access_end();
> --
> 2.25.0

Re: [PATCH v2 25/25] powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version

[Christophe Leroy]

Le 29/09/2020 à 04:55, Christopher M. Riedl a écrit :
> On Tue Aug 18, 2020 at 12:19 PM CDT, Christophe Leroy wrote:
>> Change those two functions to be used within a user access block.
>>
>> For that, change save_general_regs() to and unsafe_save_general_regs(),
>> then replace all user accesses by unsafe_ versions.
>>
>> This series leads to a reduction from 2.55s to 1.73s of
>> the system CPU time with the following microbench app
>> on an mpc832x with KUAP (approx 32%)
>>
>> Without KUAP, the difference is in the noise.
>>
>> void sigusr1(int sig) { }
>>
>> int main(int argc, char **argv)
>> {
>> int i = 100000;
>>
>> signal(SIGUSR1, sigusr1);
>> for (;i--;)
>> raise(SIGUSR1);
>> exit(0);
>> }
>>
>> An additional 0.10s reduction is achieved by removing
>> CONFIG_PPC_FPU, as the mpc832x has no FPU.
>>
>> A bit less spectacular on an 8xx as KUAP is less heavy, prior to
>> the series (with KUAP) it ran in 8.10 ms. Once applies the removal
>> of FPU regs handling, we get 7.05s. With the full series, we get 6.9s.
>> If artificially re-activating FPU regs handling with the full series,
>> we get 7.6s.
>>
>> So for the 8xx, the removal of the FPU regs copy is what makes the
>> difference, but the rework of handle_signal also have a benefit.
>>
>> Same as above, without KUAP the difference is in the noise.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>> arch/powerpc/kernel/signal_32.c | 224 ++++++++++++++++----------------
>> 1 file changed, 111 insertions(+), 113 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/signal_32.c
>> b/arch/powerpc/kernel/signal_32.c
>> index 86539a4e0514..f795fe0240a1 100644
>> --- a/arch/powerpc/kernel/signal_32.c
>> +++ b/arch/powerpc/kernel/signal_32.c
>> @@ -93,8 +93,8 @@ static inline int get_sigset_t(sigset_t *set,
>> #define to_user_ptr(p) ptr_to_compat(p)
>> #define from_user_ptr(p) compat_ptr(p)
>>   
>> -static inline int save_general_regs(struct pt_regs *regs,
>> - struct mcontext __user *frame)
>> +static __always_inline int
>> +save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user
>> *frame)
>> {
>> elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
>> int val, i;
>> @@ -108,10 +108,12 @@ static inline int save_general_regs(struct pt_regs
>> *regs,
>> else
>> val = gregs[i];
>>   
>> - if (__put_user(val, &frame->mc_gregs[i]))
>> - return -EFAULT;
>> + unsafe_put_user(val, &frame->mc_gregs[i], failed);
>> }
>> return 0;
>> +
>> +failed:
>> + return 1;
>> }
>>   
>> static inline int restore_general_regs(struct pt_regs *regs,
>> @@ -148,11 +150,15 @@ static inline int get_sigset_t(sigset_t *set,
>> const sigset_t __user *uset)
>> #define to_user_ptr(p) ((unsigned long)(p))
>> #define from_user_ptr(p) ((void __user *)(p))
>>   
>> -static inline int save_general_regs(struct pt_regs *regs,
>> - struct mcontext __user *frame)
>> +static __always_inline int
>> +save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user
>> *frame)
>> {
>> WARN_ON(!FULL_REGS(regs));
>> - return __copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE);
>> + unsafe_copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE, failed);
>> + return 0;
>> +
>> +failed:
>> + return 1;
>> }
>>   
>> static inline int restore_general_regs(struct pt_regs *regs,
>> @@ -170,6 +176,11 @@ static inline int restore_general_regs(struct
>> pt_regs *regs,
>> }
>> #endif
>>   
>> +#define unsafe_save_general_regs(regs, frame, label) do { \
>> + if (save_general_regs_unsafe(regs, frame)) \
> 
> Minor nitpick (sorry); this naming seems a bit strange to me, in x86 it
> is "__unsafe_" as a prefix instead of "_unsafe" as a suffix. That sounds
> a bit better to me, what do you think? Unless there is some convention I
> am not aware of here apart from "unsafe_" using a goto label for errors.

You are probably right, I have never been good at naming stuff.

Christophe

Re: [PATCH v2 00/25] powerpc: Switch signal 32 to using unsafe_put_user() and friends

[Michael Ellerman]

On Tue, 18 Aug 2020 17:19:11 +0000 (UTC), Christophe Leroy wrote:
> This series leads to a reduction from 2.55s to 1.73s of
> the system CPU time with the following microbench app
> on an mpc832x with KUAP (approx 32%)
> 
> This series replaces copies to users by unsafe_put_user() and friends
> with user_write_access_begin() dance in signal32.
> 
> [...]

Applied to powerpc/next.

[01/25] powerpc/signal: Move inline functions in signal.h
        https://git.kernel.org/powerpc/c/95593e930d7d067ca9bbee996c845248930a01f9
[02/25] powerpc/ptrace: Move declaration of ptrace_get_reg() and ptrace_set_reg()
        https://git.kernel.org/powerpc/c/67e364b3295f9dbf3b820d0edde86fb7c95efc98
[03/25] powerpc/ptrace: Consolidate reg index calculation
        https://git.kernel.org/powerpc/c/e009fa433542cd09d6279e361b767a1f44ffd29a
[04/25] powerpc/ptrace: Create ptrace_get_fpr() and ptrace_put_fpr()
        https://git.kernel.org/powerpc/c/4d90eb97e292c7b14de8ba59fded35b340c73101
[05/25] powerpc/signal: Don't manage floating point regs when no FPU
        https://git.kernel.org/powerpc/c/b6254ced4da6cf28d49fbffe24ee4b3286dcb3f4
[06/25] powerpc/32s: Allow deselecting CONFIG_PPC_FPU on mpc832x
        https://git.kernel.org/powerpc/c/7d68c89169508064c460a1208f38ed0589d226fa
[07/25] powerpc/signal: Remove BUG_ON() in handler_signal functions
        https://git.kernel.org/powerpc/c/3fcfb5d1bf731bdbd847c29df57a5372d8ea58d3
[08/25] powerpc/signal: Move access_ok() out of get_sigframe()
        https://git.kernel.org/powerpc/c/454b1abb588b3942655638a8bcf1ea4501260579
[09/25] powerpc/signal: Remove get_clean_sp()
        https://git.kernel.org/powerpc/c/0ecbc6ad18e324012234183e21805423f5e0cc79
[10/25] powerpc/signal: Call get_tm_stackpointer() from get_sigframe()
        https://git.kernel.org/powerpc/c/c180cb305c9bba094657259487d563c8fbfb648b
[11/25] powerpc/signal: Refactor bad frame logging
        https://git.kernel.org/powerpc/c/7fe8f773ee248c726cec2addcdb94056049d6e34
[12/25] powerpc/signal32: Simplify logging in handle_rt_signal32()
        https://git.kernel.org/powerpc/c/debf122c777f361137a3114db7be8aecc65f6af2
[13/25] powerpc/signal32: Move handle_signal32() close to handle_rt_signal32()
        https://git.kernel.org/powerpc/c/3eea688be0ccba2221e047b7df6f9ae87361cdd6
[14/25] powerpc/signal32: Rename local pointers in handle_rt_signal32()
        https://git.kernel.org/powerpc/c/8e91cf8501f14d8b6727c71c98fd743e95e9b402
[15/25] powerpc/signal32: Misc changes to make handle_[rt_]_signal32() more similar
        https://git.kernel.org/powerpc/c/91b8ecd419cb46058e99b3a574184883c02b7729
[16/25] powerpc/signal32: Move signal trampoline setup to handle_[rt_]signal32
        https://git.kernel.org/powerpc/c/8d33001dd650b88e915a1a13e2ca807350e374df
[17/25] powerpc/signal32: Switch handle_signal32() to user_access_begin() logic
        https://git.kernel.org/powerpc/c/ad65f4909fd3736d84533784cd9ab76905536b34
[18/25] powerpc/signal32: Switch handle_rt_signal32() to user_access_begin() logic
        https://git.kernel.org/powerpc/c/9504db3e90b22dca19d8152ed5a82c68512dac0e
[19/25] powerpc/signal32: Remove ifdefery in middle of if/else
        https://git.kernel.org/powerpc/c/f1cf4f93de2ff66313a091320d7683735816a0bc
[20/25] signal: Add unsafe_put_compat_sigset()
        https://git.kernel.org/powerpc/c/14026b94ccfe626e512bc9fa01e0e72ee75c7a98
[21/25] powerpc/signal32: Add and use unsafe_put_sigset_t()
        https://git.kernel.org/powerpc/c/de781ebdf6b8a256742da4fd6b0e39bb22ed9fe3
[22/25] powerpc/signal32: Switch swap_context() to user_access_begin() logic
        https://git.kernel.org/powerpc/c/31147d7d6133ea17504b118114a191a8af85f3de
[23/25] powerpc/signal: Create 'unsafe' versions of copy_[ck][fpr/vsx]_to_user()
        https://git.kernel.org/powerpc/c/b3484a1d4d1fb54ad7b615a13003d8bc11919c96
[24/25] powerpc/signal32: Isolate non-copy actions in save_user_regs() and save_tm_user_regs()
        https://git.kernel.org/powerpc/c/968c4fccd1bb8b440326dac5078ad87d17af4a47
[25/25] powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version
        https://git.kernel.org/powerpc/c/ef75e73182949a94bde169a774de1b62ae21fbbc

cheers

Re: [PATCH v2 00/25] powerpc: Switch signal 32 to using unsafe_put_user() and friends

[Michael Ellerman]

On Tue, 18 Aug 2020 17:19:11 +0000 (UTC), Christophe Leroy wrote:
> This series leads to a reduction from 2.55s to 1.73s of
> the system CPU time with the following microbench app
> on an mpc832x with KUAP (approx 32%)
> 
> This series replaces copies to users by unsafe_put_user() and friends
> with user_write_access_begin() dance in signal32.
> 
> [...]

Applied to powerpc/next.

[01/25] powerpc/signal: Move inline functions in signal.h
        https://git.kernel.org/powerpc/c/95593e930d7d067ca9bbee996c845248930a01f9
[02/25] powerpc/ptrace: Move declaration of ptrace_get_reg() and ptrace_set_reg()
        https://git.kernel.org/powerpc/c/67e364b3295f9dbf3b820d0edde86fb7c95efc98
[03/25] powerpc/ptrace: Consolidate reg index calculation
        https://git.kernel.org/powerpc/c/e009fa433542cd09d6279e361b767a1f44ffd29a
[04/25] powerpc/ptrace: Create ptrace_get_fpr() and ptrace_put_fpr()
        https://git.kernel.org/powerpc/c/4d90eb97e292c7b14de8ba59fded35b340c73101
[05/25] powerpc/signal: Don't manage floating point regs when no FPU
        https://git.kernel.org/powerpc/c/b6254ced4da6cf28d49fbffe24ee4b3286dcb3f4
[06/25] powerpc/32s: Allow deselecting CONFIG_PPC_FPU on mpc832x
        https://git.kernel.org/powerpc/c/7d68c89169508064c460a1208f38ed0589d226fa
[07/25] powerpc/signal: Remove BUG_ON() in handler_signal functions
        https://git.kernel.org/powerpc/c/3fcfb5d1bf731bdbd847c29df57a5372d8ea58d3
[08/25] powerpc/signal: Move access_ok() out of get_sigframe()
        https://git.kernel.org/powerpc/c/454b1abb588b3942655638a8bcf1ea4501260579
[09/25] powerpc/signal: Remove get_clean_sp()
        https://git.kernel.org/powerpc/c/0ecbc6ad18e324012234183e21805423f5e0cc79
[10/25] powerpc/signal: Call get_tm_stackpointer() from get_sigframe()
        https://git.kernel.org/powerpc/c/c180cb305c9bba094657259487d563c8fbfb648b
[11/25] powerpc/signal: Refactor bad frame logging
        https://git.kernel.org/powerpc/c/7fe8f773ee248c726cec2addcdb94056049d6e34
[12/25] powerpc/signal32: Simplify logging in handle_rt_signal32()
        https://git.kernel.org/powerpc/c/debf122c777f361137a3114db7be8aecc65f6af2
[13/25] powerpc/signal32: Move handle_signal32() close to handle_rt_signal32()
        https://git.kernel.org/powerpc/c/3eea688be0ccba2221e047b7df6f9ae87361cdd6
[14/25] powerpc/signal32: Rename local pointers in handle_rt_signal32()
        https://git.kernel.org/powerpc/c/8e91cf8501f14d8b6727c71c98fd743e95e9b402
[15/25] powerpc/signal32: Misc changes to make handle_[rt_]_signal32() more similar
        https://git.kernel.org/powerpc/c/91b8ecd419cb46058e99b3a574184883c02b7729
[16/25] powerpc/signal32: Move signal trampoline setup to handle_[rt_]signal32
        https://git.kernel.org/powerpc/c/8d33001dd650b88e915a1a13e2ca807350e374df
[17/25] powerpc/signal32: Switch handle_signal32() to user_access_begin() logic
        https://git.kernel.org/powerpc/c/ad65f4909fd3736d84533784cd9ab76905536b34
[18/25] powerpc/signal32: Switch handle_rt_signal32() to user_access_begin() logic
        https://git.kernel.org/powerpc/c/9504db3e90b22dca19d8152ed5a82c68512dac0e
[19/25] powerpc/signal32: Remove ifdefery in middle of if/else
        https://git.kernel.org/powerpc/c/f1cf4f93de2ff66313a091320d7683735816a0bc
[20/25] signal: Add unsafe_put_compat_sigset()
        https://git.kernel.org/powerpc/c/14026b94ccfe626e512bc9fa01e0e72ee75c7a98
[21/25] powerpc/signal32: Add and use unsafe_put_sigset_t()
        https://git.kernel.org/powerpc/c/de781ebdf6b8a256742da4fd6b0e39bb22ed9fe3
[22/25] powerpc/signal32: Switch swap_context() to user_access_begin() logic
        https://git.kernel.org/powerpc/c/31147d7d6133ea17504b118114a191a8af85f3de
[23/25] powerpc/signal: Create 'unsafe' versions of copy_[ck][fpr/vsx]_to_user()
        https://git.kernel.org/powerpc/c/b3484a1d4d1fb54ad7b615a13003d8bc11919c96
[24/25] powerpc/signal32: Isolate non-copy actions in save_user_regs() and save_tm_user_regs()
        https://git.kernel.org/powerpc/c/968c4fccd1bb8b440326dac5078ad87d17af4a47
[25/25] powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version
        https://git.kernel.org/powerpc/c/ef75e73182949a94bde169a774de1b62ae21fbbc

cheers