[PATCH 0/8] x86 signal code cleanups

[PATCH 0/8] x86 signal code cleanups

[Brian Gerst]

The 32-bit signal code has significant differences from 64-bit, and
those are duplicated for native and compat modes.  This patch series
merges the 32-bit code into one file, and does some general cleanups
in the x86 signal code.  There should be no functional changes.

Brian Gerst (8):
  x86/signal: Remove sig parameter from frame setup functions
  x86/signal: Remove sigset_t parameter from frame setup functions
  signal/compat: Remove compat_sigset_t override
  x86: Remove __USER32_DS
  x86/signal: Merge get_sigframe()
  x86/signal: Add ABI prefixes to frame setup functions
  x86/signal/32: Merge native and compat 32-bit signal code
  x86/signal/64: Move 64-bit signal code to its own file

 arch/x86/entry/entry_64_compat.S              |   4 +-
 arch/x86/ia32/Makefile                        |   2 -
 arch/x86/include/asm/elf.h                    |   4 -
 arch/x86/include/asm/fpu/signal.h             |   7 -
 arch/x86/include/asm/segment.h                |   2 +-
 arch/x86/include/asm/sighandling.h            |   9 +
 arch/x86/include/asm/signal.h                 |   5 -
 arch/x86/kernel/Makefile                      |   4 +-
 arch/x86/kernel/signal.c                      | 654 +-----------------
 .../ia32_signal.c => kernel/signal_32.c}      | 117 ++--
 arch/x86/kernel/signal_64.c                   | 383 ++++++++++
 arch/x86/xen/xen-asm.S                        |   8 +-
 include/linux/compat.h                        |   2 -
 include/linux/syscalls.h                      |   2 +
 14 files changed, 493 insertions(+), 710 deletions(-)
 rename arch/x86/{ia32/ia32_signal.c => kernel/signal_32.c} (82%)
 create mode 100644 arch/x86/kernel/signal_64.c

-- 
2.35.3

[PATCH 1/8] x86/signal: Remove sig parameter from frame setup functions

[Brian Gerst]

Passing the signal number as a seperate parameter is unnecessary, since
it is always ksig->sig.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/ia32/ia32_signal.c       | 12 ++++++------
 arch/x86/include/asm/fpu/signal.h |  4 ++--
 arch/x86/kernel/signal.c          | 23 +++++++++++------------
 3 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index c9c3859322fa..390347ab92de 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -230,7 +230,7 @@ static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
 	return (void __user *) sp;
 }
 
-int ia32_setup_frame(int sig, struct ksignal *ksig,
+int ia32_setup_frame(struct ksignal *ksig,
 		     compat_sigset_t *set, struct pt_regs *regs)
 {
 	struct sigframe_ia32 __user *frame;
@@ -264,7 +264,7 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
 
-	unsafe_put_user(sig, &frame->sig, Efault);
+	unsafe_put_user(ksig->sig, &frame->sig, Efault);
 	unsafe_put_sigcontext32(&frame->sc, fp, regs, set, Efault);
 	unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
 	unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
@@ -280,7 +280,7 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
 	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
 
 	/* Make -mregparm=3 work */
-	regs->ax = sig;
+	regs->ax = ksig->sig;
 	regs->dx = 0;
 	regs->cx = 0;
 
@@ -296,7 +296,7 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
 	return -EFAULT;
 }
 
-int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
+int ia32_setup_rt_frame(struct ksignal *ksig,
 			compat_sigset_t *set, struct pt_regs *regs)
 {
 	struct rt_sigframe_ia32 __user *frame;
@@ -321,7 +321,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
 
-	unsafe_put_user(sig, &frame->sig, Efault);
+	unsafe_put_user(ksig->sig, &frame->sig, Efault);
 	unsafe_put_user(ptr_to_compat(&frame->info), &frame->pinfo, Efault);
 	unsafe_put_user(ptr_to_compat(&frame->uc), &frame->puc, Efault);
 
@@ -357,7 +357,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
 	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
 
 	/* Make -mregparm=3 work */
-	regs->ax = sig;
+	regs->ax = ksig->sig;
 	regs->dx = (unsigned long) &frame->info;
 	regs->cx = (unsigned long) &frame->uc;
 
diff --git a/arch/x86/include/asm/fpu/signal.h b/arch/x86/include/asm/fpu/signal.h
index e1c9df9102a5..08826ad0254d 100644
--- a/arch/x86/include/asm/fpu/signal.h
+++ b/arch/x86/include/asm/fpu/signal.h
@@ -14,9 +14,9 @@
 # include <uapi/asm/sigcontext.h>
 # include <asm/user32.h>
 struct ksignal;
-int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
+int ia32_setup_rt_frame(struct ksignal *ksig,
 			compat_sigset_t *set, struct pt_regs *regs);
-int ia32_setup_frame(int sig, struct ksignal *ksig,
+int ia32_setup_frame(struct ksignal *ksig,
 		     compat_sigset_t *set, struct pt_regs *regs);
 #else
 # define user_i387_ia32_struct	user_i387_struct
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 9c7265b524c7..40b1373bb70b 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -324,7 +324,7 @@ static const struct {
 };
 
 static int
-__setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
+__setup_frame(struct ksignal *ksig, sigset_t *set,
 	      struct pt_regs *regs)
 {
 	struct sigframe __user *frame;
@@ -336,7 +336,7 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
 
-	unsafe_put_user(sig, &frame->sig, Efault);
+	unsafe_put_user(ksig->sig, &frame->sig, Efault);
 	unsafe_put_sigcontext(&frame->sc, fp, regs, set, Efault);
 	unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
 	if (current->mm->context.vdso)
@@ -363,7 +363,7 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
 	/* Set up registers for signal handler */
 	regs->sp = (unsigned long)frame;
 	regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
-	regs->ax = (unsigned long)sig;
+	regs->ax = (unsigned long)ksig->sig;
 	regs->dx = 0;
 	regs->cx = 0;
 
@@ -379,7 +379,7 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
 	return -EFAULT;
 }
 
-static int __setup_rt_frame(int sig, struct ksignal *ksig,
+static int __setup_rt_frame(struct ksignal *ksig,
 			    sigset_t *set, struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame;
@@ -391,7 +391,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
 
-	unsafe_put_user(sig, &frame->sig, Efault);
+	unsafe_put_user(ksig->sig, &frame->sig, Efault);
 	unsafe_put_user(&frame->info, &frame->pinfo, Efault);
 	unsafe_put_user(&frame->uc, &frame->puc, Efault);
 
@@ -428,7 +428,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
 	/* Set up registers for signal handler */
 	regs->sp = (unsigned long)frame;
 	regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
-	regs->ax = (unsigned long)sig;
+	regs->ax = (unsigned long)ksig->sig;
 	regs->dx = (unsigned long)&frame->info;
 	regs->cx = (unsigned long)&frame->uc;
 
@@ -458,7 +458,7 @@ static unsigned long frame_uc_flags(struct pt_regs *regs)
 	return flags;
 }
 
-static int __setup_rt_frame(int sig, struct ksignal *ksig,
+static int __setup_rt_frame(struct ksignal *ksig,
 			    sigset_t *set, struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame;
@@ -493,7 +493,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
 	}
 
 	/* Set up registers for signal handler */
-	regs->di = sig;
+	regs->di = ksig->sig;
 	/* In case the signal handler was declared without prototypes */
 	regs->ax = 0;
 
@@ -763,7 +763,6 @@ static inline int is_x32_frame(struct ksignal *ksig)
 static int
 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
-	int usig = ksig->sig;
 	sigset_t *set = sigmask_to_save();
 	compat_sigset_t *cset = (compat_sigset_t *) set;
 
@@ -773,13 +772,13 @@ setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	/* Set up the stack frame */
 	if (is_ia32_frame(ksig)) {
 		if (ksig->ka.sa.sa_flags & SA_SIGINFO)
-			return ia32_setup_rt_frame(usig, ksig, cset, regs);
+			return ia32_setup_rt_frame(ksig, cset, regs);
 		else
-			return ia32_setup_frame(usig, ksig, cset, regs);
+			return ia32_setup_frame(ksig, cset, regs);
 	} else if (is_x32_frame(ksig)) {
 		return x32_setup_rt_frame(ksig, cset, regs);
 	} else {
-		return __setup_rt_frame(ksig->sig, ksig, set, regs);
+		return __setup_rt_frame(ksig, set, regs);
 	}
 }
 
-- 
2.35.3

[tip: x86/misc] x86/signal: Remove sig parameter from frame setup functions

[tip-bot2 for Brian Gerst]

The following commit has been merged into the x86/misc branch of tip:

Commit-ID:     8bb2d28e2b92ef220e82369ff31a22f39831cf2f
Gitweb:        https://git.kernel.org/tip/8bb2d28e2b92ef220e82369ff31a22f39831cf2f
Author:        Brian Gerst <brgerst@gmail.com>
AuthorDate:    Mon, 06 Jun 2022 16:37:55 -04:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 19 Oct 2022 09:58:48 +02:00

x86/signal: Remove sig parameter from frame setup functions

Passing the signal number as a separate parameter is unnecessary, since
it is always ksig->sig.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/20220606203802.158958-2-brgerst@gmail.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/ia32/ia32_signal.c       | 12 ++++++------
 arch/x86/include/asm/fpu/signal.h |  4 ++--
 arch/x86/kernel/signal.c          | 23 +++++++++++------------
 3 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index c9c3859..390347a 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -230,7 +230,7 @@ static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
 	return (void __user *) sp;
 }
 
-int ia32_setup_frame(int sig, struct ksignal *ksig,
+int ia32_setup_frame(struct ksignal *ksig,
 		     compat_sigset_t *set, struct pt_regs *regs)
 {
 	struct sigframe_ia32 __user *frame;
@@ -264,7 +264,7 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
 
-	unsafe_put_user(sig, &frame->sig, Efault);
+	unsafe_put_user(ksig->sig, &frame->sig, Efault);
 	unsafe_put_sigcontext32(&frame->sc, fp, regs, set, Efault);
 	unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
 	unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
@@ -280,7 +280,7 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
 	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
 
 	/* Make -mregparm=3 work */
-	regs->ax = sig;
+	regs->ax = ksig->sig;
 	regs->dx = 0;
 	regs->cx = 0;
 
@@ -296,7 +296,7 @@ Efault:
 	return -EFAULT;
 }
 
-int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
+int ia32_setup_rt_frame(struct ksignal *ksig,
 			compat_sigset_t *set, struct pt_regs *regs)
 {
 	struct rt_sigframe_ia32 __user *frame;
@@ -321,7 +321,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
 
-	unsafe_put_user(sig, &frame->sig, Efault);
+	unsafe_put_user(ksig->sig, &frame->sig, Efault);
 	unsafe_put_user(ptr_to_compat(&frame->info), &frame->pinfo, Efault);
 	unsafe_put_user(ptr_to_compat(&frame->uc), &frame->puc, Efault);
 
@@ -357,7 +357,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
 	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
 
 	/* Make -mregparm=3 work */
-	regs->ax = sig;
+	regs->ax = ksig->sig;
 	regs->dx = (unsigned long) &frame->info;
 	regs->cx = (unsigned long) &frame->uc;
 
diff --git a/arch/x86/include/asm/fpu/signal.h b/arch/x86/include/asm/fpu/signal.h
index e1c9df9..08826ad 100644
--- a/arch/x86/include/asm/fpu/signal.h
+++ b/arch/x86/include/asm/fpu/signal.h
@@ -14,9 +14,9 @@
 # include <uapi/asm/sigcontext.h>
 # include <asm/user32.h>
 struct ksignal;
-int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
+int ia32_setup_rt_frame(struct ksignal *ksig,
 			compat_sigset_t *set, struct pt_regs *regs);
-int ia32_setup_frame(int sig, struct ksignal *ksig,
+int ia32_setup_frame(struct ksignal *ksig,
 		     compat_sigset_t *set, struct pt_regs *regs);
 #else
 # define user_i387_ia32_struct	user_i387_struct
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 9c7265b..40b1373 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -324,7 +324,7 @@ static const struct {
 };
 
 static int
-__setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
+__setup_frame(struct ksignal *ksig, sigset_t *set,
 	      struct pt_regs *regs)
 {
 	struct sigframe __user *frame;
@@ -336,7 +336,7 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
 
-	unsafe_put_user(sig, &frame->sig, Efault);
+	unsafe_put_user(ksig->sig, &frame->sig, Efault);
 	unsafe_put_sigcontext(&frame->sc, fp, regs, set, Efault);
 	unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
 	if (current->mm->context.vdso)
@@ -363,7 +363,7 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
 	/* Set up registers for signal handler */
 	regs->sp = (unsigned long)frame;
 	regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
-	regs->ax = (unsigned long)sig;
+	regs->ax = (unsigned long)ksig->sig;
 	regs->dx = 0;
 	regs->cx = 0;
 
@@ -379,7 +379,7 @@ Efault:
 	return -EFAULT;
 }
 
-static int __setup_rt_frame(int sig, struct ksignal *ksig,
+static int __setup_rt_frame(struct ksignal *ksig,
 			    sigset_t *set, struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame;
@@ -391,7 +391,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
 
-	unsafe_put_user(sig, &frame->sig, Efault);
+	unsafe_put_user(ksig->sig, &frame->sig, Efault);
 	unsafe_put_user(&frame->info, &frame->pinfo, Efault);
 	unsafe_put_user(&frame->uc, &frame->puc, Efault);
 
@@ -428,7 +428,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
 	/* Set up registers for signal handler */
 	regs->sp = (unsigned long)frame;
 	regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
-	regs->ax = (unsigned long)sig;
+	regs->ax = (unsigned long)ksig->sig;
 	regs->dx = (unsigned long)&frame->info;
 	regs->cx = (unsigned long)&frame->uc;
 
@@ -458,7 +458,7 @@ static unsigned long frame_uc_flags(struct pt_regs *regs)
 	return flags;
 }
 
-static int __setup_rt_frame(int sig, struct ksignal *ksig,
+static int __setup_rt_frame(struct ksignal *ksig,
 			    sigset_t *set, struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame;
@@ -493,7 +493,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
 	}
 
 	/* Set up registers for signal handler */
-	regs->di = sig;
+	regs->di = ksig->sig;
 	/* In case the signal handler was declared without prototypes */
 	regs->ax = 0;
 
@@ -763,7 +763,6 @@ static inline int is_x32_frame(struct ksignal *ksig)
 static int
 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
-	int usig = ksig->sig;
 	sigset_t *set = sigmask_to_save();
 	compat_sigset_t *cset = (compat_sigset_t *) set;
 
@@ -773,13 +772,13 @@ setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	/* Set up the stack frame */
 	if (is_ia32_frame(ksig)) {
 		if (ksig->ka.sa.sa_flags & SA_SIGINFO)
-			return ia32_setup_rt_frame(usig, ksig, cset, regs);
+			return ia32_setup_rt_frame(ksig, cset, regs);
 		else
-			return ia32_setup_frame(usig, ksig, cset, regs);
+			return ia32_setup_frame(ksig, cset, regs);
 	} else if (is_x32_frame(ksig)) {
 		return x32_setup_rt_frame(ksig, cset, regs);
 	} else {
-		return __setup_rt_frame(ksig->sig, ksig, set, regs);
+		return __setup_rt_frame(ksig, set, regs);
 	}
 }
 

[PATCH 2/8] x86/signal: Remove sigset_t parameter from frame setup functions

[Brian Gerst]

Push down the call to sigmask_to_save() into the frame setup functions.
This removes the use of compat_sigset_t outside of the compat code.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/ia32/ia32_signal.c       |  8 ++++----
 arch/x86/include/asm/fpu/signal.h |  6 ++----
 arch/x86/include/asm/signal.h     |  5 -----
 arch/x86/kernel/signal.c          | 28 ++++++++++++----------------
 4 files changed, 18 insertions(+), 29 deletions(-)

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 390347ab92de..b67e27685d46 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -230,9 +230,9 @@ static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
 	return (void __user *) sp;
 }
 
-int ia32_setup_frame(struct ksignal *ksig,
-		     compat_sigset_t *set, struct pt_regs *regs)
+int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
+	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
 	struct sigframe_ia32 __user *frame;
 	void __user *restorer;
 	void __user *fp = NULL;
@@ -296,9 +296,9 @@ int ia32_setup_frame(struct ksignal *ksig,
 	return -EFAULT;
 }
 
-int ia32_setup_rt_frame(struct ksignal *ksig,
-			compat_sigset_t *set, struct pt_regs *regs)
+int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
+	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
 	struct rt_sigframe_ia32 __user *frame;
 	void __user *restorer;
 	void __user *fp = NULL;
diff --git a/arch/x86/include/asm/fpu/signal.h b/arch/x86/include/asm/fpu/signal.h
index 08826ad0254d..2f255aca5622 100644
--- a/arch/x86/include/asm/fpu/signal.h
+++ b/arch/x86/include/asm/fpu/signal.h
@@ -14,10 +14,8 @@
 # include <uapi/asm/sigcontext.h>
 # include <asm/user32.h>
 struct ksignal;
-int ia32_setup_rt_frame(struct ksignal *ksig,
-			compat_sigset_t *set, struct pt_regs *regs);
-int ia32_setup_frame(struct ksignal *ksig,
-		     compat_sigset_t *set, struct pt_regs *regs);
+int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
+int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs);
 #else
 # define user_i387_ia32_struct	user_i387_struct
 # define user32_fxsr_struct	user_fxsr_struct
diff --git a/arch/x86/include/asm/signal.h b/arch/x86/include/asm/signal.h
index 2dfb5fea13af..4a4043ca6493 100644
--- a/arch/x86/include/asm/signal.h
+++ b/arch/x86/include/asm/signal.h
@@ -28,11 +28,6 @@ typedef struct {
 #define SA_IA32_ABI	0x02000000u
 #define SA_X32_ABI	0x01000000u
 
-#ifndef CONFIG_COMPAT
-#define compat_sigset_t compat_sigset_t
-typedef sigset_t compat_sigset_t;
-#endif
-
 #endif /* __ASSEMBLY__ */
 #include <uapi/asm/signal.h>
 #ifndef __ASSEMBLY__
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 40b1373bb70b..489a0859afd2 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -324,9 +324,9 @@ static const struct {
 };
 
 static int
-__setup_frame(struct ksignal *ksig, sigset_t *set,
-	      struct pt_regs *regs)
+__setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
+	sigset_t *set = sigmask_to_save();
 	struct sigframe __user *frame;
 	void __user *restorer;
 	void __user *fp = NULL;
@@ -379,9 +379,9 @@ __setup_frame(struct ksignal *ksig, sigset_t *set,
 	return -EFAULT;
 }
 
-static int __setup_rt_frame(struct ksignal *ksig,
-			    sigset_t *set, struct pt_regs *regs)
+static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
+	sigset_t *set = sigmask_to_save();
 	struct rt_sigframe __user *frame;
 	void __user *restorer;
 	void __user *fp = NULL;
@@ -458,9 +458,9 @@ static unsigned long frame_uc_flags(struct pt_regs *regs)
 	return flags;
 }
 
-static int __setup_rt_frame(struct ksignal *ksig,
-			    sigset_t *set, struct pt_regs *regs)
+static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
+	sigset_t *set = sigmask_to_save();
 	struct rt_sigframe __user *frame;
 	void __user *fp = NULL;
 	unsigned long uc_flags;
@@ -560,11 +560,10 @@ int copy_siginfo_to_user32(struct compat_siginfo __user *to,
 }
 #endif /* CONFIG_X86_X32_ABI */
 
-static int x32_setup_rt_frame(struct ksignal *ksig,
-			      compat_sigset_t *set,
-			      struct pt_regs *regs)
+static int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
 #ifdef CONFIG_X86_X32_ABI
+	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
 	struct rt_sigframe_x32 __user *frame;
 	unsigned long uc_flags;
 	void __user *restorer;
@@ -763,22 +762,19 @@ static inline int is_x32_frame(struct ksignal *ksig)
 static int
 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
-	sigset_t *set = sigmask_to_save();
-	compat_sigset_t *cset = (compat_sigset_t *) set;
-
 	/* Perform fixup for the pre-signal frame. */
 	rseq_signal_deliver(ksig, regs);
 
 	/* Set up the stack frame */
 	if (is_ia32_frame(ksig)) {
 		if (ksig->ka.sa.sa_flags & SA_SIGINFO)
-			return ia32_setup_rt_frame(ksig, cset, regs);
+			return ia32_setup_rt_frame(ksig, regs);
 		else
-			return ia32_setup_frame(ksig, cset, regs);
+			return ia32_setup_frame(ksig, regs);
 	} else if (is_x32_frame(ksig)) {
-		return x32_setup_rt_frame(ksig, cset, regs);
+		return x32_setup_rt_frame(ksig, regs);
 	} else {
-		return __setup_rt_frame(ksig, set, regs);
+		return __setup_rt_frame(ksig, regs);
 	}
 }
 
-- 
2.35.3

[tip: x86/misc] x86/signal: Remove sigset_t parameter from frame setup functions

[tip-bot2 for Brian Gerst]

The following commit has been merged into the x86/misc branch of tip:

Commit-ID:     f544822ea587ce08932640d5ba3978261148cbc7
Gitweb:        https://git.kernel.org/tip/f544822ea587ce08932640d5ba3978261148cbc7
Author:        Brian Gerst <brgerst@gmail.com>
AuthorDate:    Mon, 06 Jun 2022 16:37:56 -04:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 19 Oct 2022 09:58:48 +02:00

x86/signal: Remove sigset_t parameter from frame setup functions

Push down the call to sigmask_to_save() into the frame setup functions.
Thus, remove the use of compat_sigset_t outside of the compat code.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/20220606203802.158958-3-brgerst@gmail.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/ia32/ia32_signal.c       |  8 ++++----
 arch/x86/include/asm/fpu/signal.h |  6 ++----
 arch/x86/include/asm/signal.h     |  5 -----
 arch/x86/kernel/signal.c          | 28 ++++++++++++----------------
 4 files changed, 18 insertions(+), 29 deletions(-)

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 390347a..b67e276 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -230,9 +230,9 @@ static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
 	return (void __user *) sp;
 }
 
-int ia32_setup_frame(struct ksignal *ksig,
-		     compat_sigset_t *set, struct pt_regs *regs)
+int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
+	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
 	struct sigframe_ia32 __user *frame;
 	void __user *restorer;
 	void __user *fp = NULL;
@@ -296,9 +296,9 @@ Efault:
 	return -EFAULT;
 }
 
-int ia32_setup_rt_frame(struct ksignal *ksig,
-			compat_sigset_t *set, struct pt_regs *regs)
+int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
+	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
 	struct rt_sigframe_ia32 __user *frame;
 	void __user *restorer;
 	void __user *fp = NULL;
diff --git a/arch/x86/include/asm/fpu/signal.h b/arch/x86/include/asm/fpu/signal.h
index 08826ad..2f255ac 100644
--- a/arch/x86/include/asm/fpu/signal.h
+++ b/arch/x86/include/asm/fpu/signal.h
@@ -14,10 +14,8 @@
 # include <uapi/asm/sigcontext.h>
 # include <asm/user32.h>
 struct ksignal;
-int ia32_setup_rt_frame(struct ksignal *ksig,
-			compat_sigset_t *set, struct pt_regs *regs);
-int ia32_setup_frame(struct ksignal *ksig,
-		     compat_sigset_t *set, struct pt_regs *regs);
+int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
+int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs);
 #else
 # define user_i387_ia32_struct	user_i387_struct
 # define user32_fxsr_struct	user_fxsr_struct
diff --git a/arch/x86/include/asm/signal.h b/arch/x86/include/asm/signal.h
index 2dfb5fe..4a4043c 100644
--- a/arch/x86/include/asm/signal.h
+++ b/arch/x86/include/asm/signal.h
@@ -28,11 +28,6 @@ typedef struct {
 #define SA_IA32_ABI	0x02000000u
 #define SA_X32_ABI	0x01000000u
 
-#ifndef CONFIG_COMPAT
-#define compat_sigset_t compat_sigset_t
-typedef sigset_t compat_sigset_t;
-#endif
-
 #endif /* __ASSEMBLY__ */
 #include <uapi/asm/signal.h>
 #ifndef __ASSEMBLY__
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 40b1373..489a085 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -324,9 +324,9 @@ static const struct {
 };
 
 static int
-__setup_frame(struct ksignal *ksig, sigset_t *set,
-	      struct pt_regs *regs)
+__setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
+	sigset_t *set = sigmask_to_save();
 	struct sigframe __user *frame;
 	void __user *restorer;
 	void __user *fp = NULL;
@@ -379,9 +379,9 @@ Efault:
 	return -EFAULT;
 }
 
-static int __setup_rt_frame(struct ksignal *ksig,
-			    sigset_t *set, struct pt_regs *regs)
+static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
+	sigset_t *set = sigmask_to_save();
 	struct rt_sigframe __user *frame;
 	void __user *restorer;
 	void __user *fp = NULL;
@@ -458,9 +458,9 @@ static unsigned long frame_uc_flags(struct pt_regs *regs)
 	return flags;
 }
 
-static int __setup_rt_frame(struct ksignal *ksig,
-			    sigset_t *set, struct pt_regs *regs)
+static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
+	sigset_t *set = sigmask_to_save();
 	struct rt_sigframe __user *frame;
 	void __user *fp = NULL;
 	unsigned long uc_flags;
@@ -560,11 +560,10 @@ int copy_siginfo_to_user32(struct compat_siginfo __user *to,
 }
 #endif /* CONFIG_X86_X32_ABI */
 
-static int x32_setup_rt_frame(struct ksignal *ksig,
-			      compat_sigset_t *set,
-			      struct pt_regs *regs)
+static int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
 #ifdef CONFIG_X86_X32_ABI
+	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
 	struct rt_sigframe_x32 __user *frame;
 	unsigned long uc_flags;
 	void __user *restorer;
@@ -763,22 +762,19 @@ static inline int is_x32_frame(struct ksignal *ksig)
 static int
 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
-	sigset_t *set = sigmask_to_save();
-	compat_sigset_t *cset = (compat_sigset_t *) set;
-
 	/* Perform fixup for the pre-signal frame. */
 	rseq_signal_deliver(ksig, regs);
 
 	/* Set up the stack frame */
 	if (is_ia32_frame(ksig)) {
 		if (ksig->ka.sa.sa_flags & SA_SIGINFO)
-			return ia32_setup_rt_frame(ksig, cset, regs);
+			return ia32_setup_rt_frame(ksig, regs);
 		else
-			return ia32_setup_frame(ksig, cset, regs);
+			return ia32_setup_frame(ksig, regs);
 	} else if (is_x32_frame(ksig)) {
-		return x32_setup_rt_frame(ksig, cset, regs);
+		return x32_setup_rt_frame(ksig, regs);
 	} else {
-		return __setup_rt_frame(ksig, set, regs);
+		return __setup_rt_frame(ksig, regs);
 	}
 }
 

[PATCH 3/8] signal/compat: Remove compat_sigset_t override

[Brian Gerst]

x86 no longer uses compat_sigset_t when CONFIG_COMPAT isn't enabled, so
remove the override define.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 include/linux/compat.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 594357881b0b..44b1736c95b5 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -126,11 +126,9 @@ struct compat_tms {
 
 #define _COMPAT_NSIG_WORDS	(_COMPAT_NSIG / _COMPAT_NSIG_BPW)
 
-#ifndef compat_sigset_t
 typedef struct {
 	compat_sigset_word	sig[_COMPAT_NSIG_WORDS];
 } compat_sigset_t;
-#endif
 
 int set_compat_user_sigmask(const compat_sigset_t __user *umask,
 			    size_t sigsetsize);
-- 
2.35.3

[tip: x86/misc] signal/compat: Remove compat_sigset_t override

[tip-bot2 for Brian Gerst]

The following commit has been merged into the x86/misc branch of tip:

Commit-ID:     653714220f88717f239d811222c2dd0e64b181ba
Gitweb:        https://git.kernel.org/tip/653714220f88717f239d811222c2dd0e64b181ba
Author:        Brian Gerst <brgerst@gmail.com>
AuthorDate:    Mon, 06 Jun 2022 16:37:57 -04:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 19 Oct 2022 09:58:49 +02:00

signal/compat: Remove compat_sigset_t override

x86 no longer uses compat_sigset_t when CONFIG_COMPAT isn't enabled, so
remove the override define.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/20220606203802.158958-4-brgerst@gmail.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 include/linux/compat.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 5943578..44b1736 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -126,11 +126,9 @@ struct compat_tms {
 
 #define _COMPAT_NSIG_WORDS	(_COMPAT_NSIG / _COMPAT_NSIG_BPW)
 
-#ifndef compat_sigset_t
 typedef struct {
 	compat_sigset_word	sig[_COMPAT_NSIG_WORDS];
 } compat_sigset_t;
-#endif
 
 int set_compat_user_sigmask(const compat_sigset_t __user *umask,
 			    size_t sigsetsize);

[PATCH 4/8] x86: Remove __USER32_DS

[Brian Gerst]

Replace all users with the equivalent __USER_DS, which will make merging
native and compat code simpler.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/entry/entry_64_compat.S |  4 ++--
 arch/x86/ia32/ia32_signal.c      | 14 +++++++-------
 arch/x86/include/asm/elf.h       |  4 ----
 arch/x86/include/asm/segment.h   |  1 -
 arch/x86/xen/xen-asm.S           |  8 ++++----
 5 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index d1052742ad0c..cd51d1f70382 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -59,7 +59,7 @@ SYM_CODE_START(entry_SYSENTER_compat)
 	movq	PER_CPU_VAR(cpu_current_top_of_stack), %rsp
 
 	/* Construct struct pt_regs on stack */
-	pushq	$__USER32_DS		/* pt_regs->ss */
+	pushq	$__USER_DS		/* pt_regs->ss */
 	pushq	$0			/* pt_regs->sp = 0 (placeholder) */
 
 	/*
@@ -192,7 +192,7 @@ SYM_INNER_LABEL(entry_SYSCALL_compat_safe_stack, SYM_L_GLOBAL)
 	ANNOTATE_NOENDBR
 
 	/* Construct struct pt_regs on stack */
-	pushq	$__USER32_DS		/* pt_regs->ss */
+	pushq	$__USER_DS		/* pt_regs->ss */
 	pushq	%r8			/* pt_regs->sp */
 	pushq	%r11			/* pt_regs->flags */
 	pushq	$__USER32_CS		/* pt_regs->cs */
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index b67e27685d46..a78885e3e85d 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -212,7 +212,7 @@ static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
 	if (ksig->ka.sa.sa_flags & SA_ONSTACK)
 		sp = sigsp(sp, ksig);
 	/* This is the legacy signal stack switching. */
-	else if (regs->ss != __USER32_DS &&
+	else if (regs->ss != __USER_DS &&
 		!(ksig->ka.sa.sa_flags & SA_RESTORER) &&
 		 ksig->ka.sa.sa_restorer)
 		sp = (unsigned long) ksig->ka.sa.sa_restorer;
@@ -284,11 +284,11 @@ int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 	regs->dx = 0;
 	regs->cx = 0;
 
-	loadsegment(ds, __USER32_DS);
-	loadsegment(es, __USER32_DS);
+	loadsegment(ds, __USER_DS);
+	loadsegment(es, __USER_DS);
 
 	regs->cs = __USER32_CS;
-	regs->ss = __USER32_DS;
+	regs->ss = __USER_DS;
 
 	return 0;
 Efault:
@@ -361,11 +361,11 @@ int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	regs->dx = (unsigned long) &frame->info;
 	regs->cx = (unsigned long) &frame->uc;
 
-	loadsegment(ds, __USER32_DS);
-	loadsegment(es, __USER32_DS);
+	loadsegment(ds, __USER_DS);
+	loadsegment(es, __USER_DS);
 
 	regs->cs = __USER32_CS;
-	regs->ss = __USER32_DS;
+	regs->ss = __USER_DS;
 
 	return 0;
 Efault:
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index cb0ff1055ab1..be8b58da63b9 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -152,10 +152,6 @@ do {						\
 	(elf_check_arch_ia32(x) ||					\
 	 (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64))
 
-#if __USER32_DS != __USER_DS
-# error "The following code assumes __USER32_DS == __USER_DS"
-#endif
-
 static inline void elf_common_init(struct thread_struct *t,
 				   struct pt_regs *regs, const u16 ds)
 {
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 2e7890dd58a4..e056c29dfcda 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -210,7 +210,6 @@
 #define __KERNEL_DS			(GDT_ENTRY_KERNEL_DS*8)
 #define __USER32_CS			(GDT_ENTRY_DEFAULT_USER32_CS*8 + 3)
 #define __USER_DS			(GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
-#define __USER32_DS			__USER_DS
 #define __USER_CS			(GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
 #define __CPUNODE_SEG			(GDT_ENTRY_CPUNODE*8 + 3)
 
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index caa9bc2fa100..350174cf9d71 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -262,10 +262,10 @@ SYM_CODE_START(xen_syscall32_target)
 
 	/*
 	 * Neither Xen nor the kernel really knows what the old SS and
-	 * CS were.  The kernel expects __USER32_DS and __USER32_CS, so
+	 * CS were.  The kernel expects __USER_DS and __USER32_CS, so
 	 * report those values even though Xen will guess its own values.
 	 */
-	movq $__USER32_DS, 4*8(%rsp)
+	movq $__USER_DS, 4*8(%rsp)
 	movq $__USER32_CS, 1*8(%rsp)
 
 	jmp entry_SYSCALL_compat_after_hwframe
@@ -284,10 +284,10 @@ SYM_CODE_START(xen_sysenter_target)
 
 	/*
 	 * Neither Xen nor the kernel really knows what the old SS and
-	 * CS were.  The kernel expects __USER32_DS and __USER32_CS, so
+	 * CS were.  The kernel expects __USER_DS and __USER32_CS, so
 	 * report those values even though Xen will guess its own values.
 	 */
-	movq $__USER32_DS, 4*8(%rsp)
+	movq $__USER_DS, 4*8(%rsp)
 	movq $__USER32_CS, 1*8(%rsp)
 
 	jmp entry_SYSENTER_compat_after_hwframe
-- 
2.35.3

[tip: x86/misc] x86: Remove __USER32_DS

[tip-bot2 for Brian Gerst]

The following commit has been merged into the x86/misc branch of tip:

Commit-ID:     695c39bc5b8686a6b27254e60fb830f4989f322d
Gitweb:        https://git.kernel.org/tip/695c39bc5b8686a6b27254e60fb830f4989f322d
Author:        Brian Gerst <brgerst@gmail.com>
AuthorDate:    Mon, 06 Jun 2022 16:37:58 -04:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 19 Oct 2022 09:58:49 +02:00

x86: Remove __USER32_DS

Replace all users with the equivalent __USER_DS, which will make merging
native and compat code simpler.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/20220606203802.158958-5-brgerst@gmail.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/entry/entry_64_compat.S |  4 ++--
 arch/x86/ia32/ia32_signal.c      | 14 +++++++-------
 arch/x86/include/asm/elf.h       |  4 ----
 arch/x86/include/asm/segment.h   |  1 -
 arch/x86/xen/xen-asm.S           |  8 ++++----
 5 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index 4dd1981..59b9390 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -61,7 +61,7 @@ SYM_CODE_START(entry_SYSENTER_compat)
 	movq	PER_CPU_VAR(cpu_current_top_of_stack), %rsp
 
 	/* Construct struct pt_regs on stack */
-	pushq	$__USER32_DS		/* pt_regs->ss */
+	pushq	$__USER_DS		/* pt_regs->ss */
 	pushq	$0			/* pt_regs->sp = 0 (placeholder) */
 
 	/*
@@ -197,7 +197,7 @@ SYM_INNER_LABEL(entry_SYSCALL_compat_safe_stack, SYM_L_GLOBAL)
 	ANNOTATE_NOENDBR
 
 	/* Construct struct pt_regs on stack */
-	pushq	$__USER32_DS		/* pt_regs->ss */
+	pushq	$__USER_DS		/* pt_regs->ss */
 	pushq	%r8			/* pt_regs->sp */
 	pushq	%r11			/* pt_regs->flags */
 	pushq	$__USER32_CS		/* pt_regs->cs */
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index b67e276..a78885e 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -212,7 +212,7 @@ static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
 	if (ksig->ka.sa.sa_flags & SA_ONSTACK)
 		sp = sigsp(sp, ksig);
 	/* This is the legacy signal stack switching. */
-	else if (regs->ss != __USER32_DS &&
+	else if (regs->ss != __USER_DS &&
 		!(ksig->ka.sa.sa_flags & SA_RESTORER) &&
 		 ksig->ka.sa.sa_restorer)
 		sp = (unsigned long) ksig->ka.sa.sa_restorer;
@@ -284,11 +284,11 @@ int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 	regs->dx = 0;
 	regs->cx = 0;
 
-	loadsegment(ds, __USER32_DS);
-	loadsegment(es, __USER32_DS);
+	loadsegment(ds, __USER_DS);
+	loadsegment(es, __USER_DS);
 
 	regs->cs = __USER32_CS;
-	regs->ss = __USER32_DS;
+	regs->ss = __USER_DS;
 
 	return 0;
 Efault:
@@ -361,11 +361,11 @@ int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	regs->dx = (unsigned long) &frame->info;
 	regs->cx = (unsigned long) &frame->uc;
 
-	loadsegment(ds, __USER32_DS);
-	loadsegment(es, __USER32_DS);
+	loadsegment(ds, __USER_DS);
+	loadsegment(es, __USER_DS);
 
 	regs->cs = __USER32_CS;
-	regs->ss = __USER32_DS;
+	regs->ss = __USER_DS;
 
 	return 0;
 Efault:
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index cb0ff10..be8b58d 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -152,10 +152,6 @@ do {						\
 	(elf_check_arch_ia32(x) ||					\
 	 (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64))
 
-#if __USER32_DS != __USER_DS
-# error "The following code assumes __USER32_DS == __USER_DS"
-#endif
-
 static inline void elf_common_init(struct thread_struct *t,
 				   struct pt_regs *regs, const u16 ds)
 {
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 2e7890d..e056c29 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -210,7 +210,6 @@
 #define __KERNEL_DS			(GDT_ENTRY_KERNEL_DS*8)
 #define __USER32_CS			(GDT_ENTRY_DEFAULT_USER32_CS*8 + 3)
 #define __USER_DS			(GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
-#define __USER32_DS			__USER_DS
 #define __USER_CS			(GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
 #define __CPUNODE_SEG			(GDT_ENTRY_CPUNODE*8 + 3)
 
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 6b4fdf6..4a184f6 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -262,10 +262,10 @@ SYM_CODE_START(xen_entry_SYSCALL_compat)
 
 	/*
 	 * Neither Xen nor the kernel really knows what the old SS and
-	 * CS were.  The kernel expects __USER32_DS and __USER32_CS, so
+	 * CS were.  The kernel expects __USER_DS and __USER32_CS, so
 	 * report those values even though Xen will guess its own values.
 	 */
-	movq $__USER32_DS, 4*8(%rsp)
+	movq $__USER_DS, 4*8(%rsp)
 	movq $__USER32_CS, 1*8(%rsp)
 
 	jmp entry_SYSCALL_compat_after_hwframe
@@ -284,10 +284,10 @@ SYM_CODE_START(xen_entry_SYSENTER_compat)
 
 	/*
 	 * Neither Xen nor the kernel really knows what the old SS and
-	 * CS were.  The kernel expects __USER32_DS and __USER32_CS, so
+	 * CS were.  The kernel expects __USER_DS and __USER32_CS, so
 	 * report those values even though Xen will guess its own values.
 	 */
-	movq $__USER32_DS, 4*8(%rsp)
+	movq $__USER_DS, 4*8(%rsp)
 	movq $__USER32_CS, 1*8(%rsp)
 
 	jmp entry_SYSENTER_compat_after_hwframe

[PATCH 5/8] x86/signal: Merge get_sigframe()

[Brian Gerst]

Adapt the native get_sigframe() function so that the compat signal code
can use it.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/ia32/ia32_signal.c        | 34 -------------
 arch/x86/include/asm/sighandling.h |  4 ++
 arch/x86/kernel/signal.c           | 80 ++++++++++++++----------------
 3 files changed, 42 insertions(+), 76 deletions(-)

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index a78885e3e85d..e28421f53d44 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -196,40 +196,6 @@ do {									\
 		goto label;						\
 } while(0)
 
-/*
- * Determine which stack to use..
- */
-static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
-				 size_t frame_size,
-				 void __user **fpstate)
-{
-	unsigned long sp, fx_aligned, math_size;
-
-	/* Default to using normal stack */
-	sp = regs->sp;
-
-	/* This is the X/Open sanctioned signal stack switching.  */
-	if (ksig->ka.sa.sa_flags & SA_ONSTACK)
-		sp = sigsp(sp, ksig);
-	/* This is the legacy signal stack switching. */
-	else if (regs->ss != __USER_DS &&
-		!(ksig->ka.sa.sa_flags & SA_RESTORER) &&
-		 ksig->ka.sa.sa_restorer)
-		sp = (unsigned long) ksig->ka.sa.sa_restorer;
-
-	sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size);
-	*fpstate = (struct _fpstate_32 __user *) sp;
-	if (!copy_fpstate_to_sigframe(*fpstate, (void __user *)fx_aligned,
-				      math_size))
-		return (void __user *) -1L;
-
-	sp -= frame_size;
-	/* Align the stack pointer according to the i386 ABI,
-	 * i.e. so that on function entry ((sp + 4) & 15) == 0. */
-	sp = ((sp + 4) & -16ul) - 4;
-	return (void __user *) sp;
-}
-
 int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
 	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
diff --git a/arch/x86/include/asm/sighandling.h b/arch/x86/include/asm/sighandling.h
index 65e667279e0f..c9e9784efe38 100644
--- a/arch/x86/include/asm/sighandling.h
+++ b/arch/x86/include/asm/sighandling.h
@@ -15,4 +15,8 @@
 
 void signal_fault(struct pt_regs *regs, void __user *frame, char *where);
 
+void __user *
+get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
+	     void __user **fpstate);
+
 #endif /* _ASM_X86_SIGHANDLING_H */
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 489a0859afd2..890ca0523570 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -48,6 +48,23 @@
 #include <asm/sigframe.h>
 #include <asm/signal.h>
 
+static inline int is_ia32_compat_frame(struct ksignal *ksig)
+{
+	return IS_ENABLED(CONFIG_IA32_EMULATION) &&
+		ksig->ka.sa.sa_flags & SA_IA32_ABI;
+}
+
+static inline int is_ia32_frame(struct ksignal *ksig)
+{
+	return IS_ENABLED(CONFIG_X86_32) || is_ia32_compat_frame(ksig);
+}
+
+static inline int is_x32_frame(struct ksignal *ksig)
+{
+	return IS_ENABLED(CONFIG_X86_X32_ABI) &&
+		ksig->ka.sa.sa_flags & SA_X32_ABI;
+}
+
 #ifdef CONFIG_X86_64
 /*
  * If regs->ss will cause an IRET fault, change it.  Otherwise leave it
@@ -223,24 +240,12 @@ do {									\
 /*
  * Determine which stack to use..
  */
-static unsigned long align_sigframe(unsigned long sp)
-{
-#ifdef CONFIG_X86_32
-	/*
-	 * Align the stack pointer according to the i386 ABI,
-	 * i.e. so that on function entry ((sp + 4) & 15) == 0.
-	 */
-	sp = ((sp + 4) & -FRAME_ALIGNMENT) - 4;
-#else /* !CONFIG_X86_32 */
-	sp = round_down(sp, FRAME_ALIGNMENT) - 8;
-#endif
-	return sp;
-}
-
-static void __user *
-get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
+void __user *
+get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
 	     void __user **fpstate)
 {
+	struct k_sigaction *ka = &ksig->ka;
+	int ia32_frame = is_ia32_frame(ksig);
 	/* Default to using normal stack */
 	bool nested_altstack = on_sig_stack(regs->sp);
 	bool entering_altstack = false;
@@ -249,7 +254,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 	unsigned long buf_fx = 0;
 
 	/* redzone */
-	if (IS_ENABLED(CONFIG_X86_64))
+	if (!ia32_frame)
 		sp -= 128;
 
 	/* This is the X/Open sanctioned signal stack switching.  */
@@ -263,7 +268,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 			sp = current->sas_ss_sp + current->sas_ss_size;
 			entering_altstack = true;
 		}
-	} else if (IS_ENABLED(CONFIG_X86_32) &&
+	} else if (ia32_frame &&
 		   !nested_altstack &&
 		   regs->ss != __USER_DS &&
 		   !(ka->sa.sa_flags & SA_RESTORER) &&
@@ -273,11 +278,19 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 		entering_altstack = true;
 	}
 
-	sp = fpu__alloc_mathframe(sp, IS_ENABLED(CONFIG_X86_32),
-				  &buf_fx, &math_size);
+	sp = fpu__alloc_mathframe(sp, ia32_frame, &buf_fx, &math_size);
 	*fpstate = (void __user *)sp;
 
-	sp = align_sigframe(sp - frame_size);
+	sp -= frame_size;
+
+	if (ia32_frame)
+		/*
+		 * Align the stack pointer according to the i386 ABI,
+		 * i.e. so that on function entry ((sp + 4) & 15) == 0.
+		 */
+		sp = ((sp + 4) & -FRAME_ALIGNMENT) - 4;
+	else
+		sp = round_down(sp, FRAME_ALIGNMENT) - 8;
 
 	/*
 	 * If we are on the alternate signal stack and would overflow it, don't.
@@ -331,7 +344,7 @@ __setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 	void __user *restorer;
 	void __user *fp = NULL;
 
-	frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fp);
+	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
 
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
@@ -386,7 +399,7 @@ static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	void __user *restorer;
 	void __user *fp = NULL;
 
-	frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fp);
+	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
 
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
@@ -469,7 +482,7 @@ static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
 		return -EFAULT;
 
-	frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp);
+	frame = get_sigframe(ksig, regs, sizeof(struct rt_sigframe), &fp);
 	uc_flags = frame_uc_flags(regs);
 
 	if (!user_access_begin(frame, sizeof(*frame)))
@@ -572,7 +585,7 @@ static int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
 		return -EFAULT;
 
-	frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fp);
+	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
 
 	uc_flags = frame_uc_flags(regs);
 
@@ -742,23 +755,6 @@ unsigned long get_sigframe_size(void)
 	return max_frame_size;
 }
 
-static inline int is_ia32_compat_frame(struct ksignal *ksig)
-{
-	return IS_ENABLED(CONFIG_IA32_EMULATION) &&
-		ksig->ka.sa.sa_flags & SA_IA32_ABI;
-}
-
-static inline int is_ia32_frame(struct ksignal *ksig)
-{
-	return IS_ENABLED(CONFIG_X86_32) || is_ia32_compat_frame(ksig);
-}
-
-static inline int is_x32_frame(struct ksignal *ksig)
-{
-	return IS_ENABLED(CONFIG_X86_X32_ABI) &&
-		ksig->ka.sa.sa_flags & SA_X32_ABI;
-}
-
 static int
 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
-- 
2.35.3

[tip: x86/misc] x86/signal: Merge get_sigframe()

[tip-bot2 for Brian Gerst]

The following commit has been merged into the x86/misc branch of tip:

Commit-ID:     9c36e592b3f899c90b9d0d46ae29fcc065051b96
Gitweb:        https://git.kernel.org/tip/9c36e592b3f899c90b9d0d46ae29fcc065051b96
Author:        Brian Gerst <brgerst@gmail.com>
AuthorDate:    Mon, 06 Jun 2022 16:37:59 -04:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 19 Oct 2022 09:58:49 +02:00

x86/signal: Merge get_sigframe()

Adapt the native get_sigframe() function so that the compat signal code
can use it.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/20220606203802.158958-6-brgerst@gmail.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/ia32/ia32_signal.c        | 34 +------------
 arch/x86/include/asm/sighandling.h |  4 +-
 arch/x86/kernel/signal.c           | 80 +++++++++++++----------------
 3 files changed, 42 insertions(+), 76 deletions(-)

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index a78885e..e28421f 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -196,40 +196,6 @@ do {									\
 		goto label;						\
 } while(0)
 
-/*
- * Determine which stack to use..
- */
-static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
-				 size_t frame_size,
-				 void __user **fpstate)
-{
-	unsigned long sp, fx_aligned, math_size;
-
-	/* Default to using normal stack */
-	sp = regs->sp;
-
-	/* This is the X/Open sanctioned signal stack switching.  */
-	if (ksig->ka.sa.sa_flags & SA_ONSTACK)
-		sp = sigsp(sp, ksig);
-	/* This is the legacy signal stack switching. */
-	else if (regs->ss != __USER_DS &&
-		!(ksig->ka.sa.sa_flags & SA_RESTORER) &&
-		 ksig->ka.sa.sa_restorer)
-		sp = (unsigned long) ksig->ka.sa.sa_restorer;
-
-	sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size);
-	*fpstate = (struct _fpstate_32 __user *) sp;
-	if (!copy_fpstate_to_sigframe(*fpstate, (void __user *)fx_aligned,
-				      math_size))
-		return (void __user *) -1L;
-
-	sp -= frame_size;
-	/* Align the stack pointer according to the i386 ABI,
-	 * i.e. so that on function entry ((sp + 4) & 15) == 0. */
-	sp = ((sp + 4) & -16ul) - 4;
-	return (void __user *) sp;
-}
-
 int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
 	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
diff --git a/arch/x86/include/asm/sighandling.h b/arch/x86/include/asm/sighandling.h
index 65e6672..c9e9784 100644
--- a/arch/x86/include/asm/sighandling.h
+++ b/arch/x86/include/asm/sighandling.h
@@ -15,4 +15,8 @@
 
 void signal_fault(struct pt_regs *regs, void __user *frame, char *where);
 
+void __user *
+get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
+	     void __user **fpstate);
+
 #endif /* _ASM_X86_SIGHANDLING_H */
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 489a085..890ca05 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -48,6 +48,23 @@
 #include <asm/sigframe.h>
 #include <asm/signal.h>
 
+static inline int is_ia32_compat_frame(struct ksignal *ksig)
+{
+	return IS_ENABLED(CONFIG_IA32_EMULATION) &&
+		ksig->ka.sa.sa_flags & SA_IA32_ABI;
+}
+
+static inline int is_ia32_frame(struct ksignal *ksig)
+{
+	return IS_ENABLED(CONFIG_X86_32) || is_ia32_compat_frame(ksig);
+}
+
+static inline int is_x32_frame(struct ksignal *ksig)
+{
+	return IS_ENABLED(CONFIG_X86_X32_ABI) &&
+		ksig->ka.sa.sa_flags & SA_X32_ABI;
+}
+
 #ifdef CONFIG_X86_64
 /*
  * If regs->ss will cause an IRET fault, change it.  Otherwise leave it
@@ -223,24 +240,12 @@ do {									\
 /*
  * Determine which stack to use..
  */
-static unsigned long align_sigframe(unsigned long sp)
-{
-#ifdef CONFIG_X86_32
-	/*
-	 * Align the stack pointer according to the i386 ABI,
-	 * i.e. so that on function entry ((sp + 4) & 15) == 0.
-	 */
-	sp = ((sp + 4) & -FRAME_ALIGNMENT) - 4;
-#else /* !CONFIG_X86_32 */
-	sp = round_down(sp, FRAME_ALIGNMENT) - 8;
-#endif
-	return sp;
-}
-
-static void __user *
-get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
+void __user *
+get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
 	     void __user **fpstate)
 {
+	struct k_sigaction *ka = &ksig->ka;
+	int ia32_frame = is_ia32_frame(ksig);
 	/* Default to using normal stack */
 	bool nested_altstack = on_sig_stack(regs->sp);
 	bool entering_altstack = false;
@@ -249,7 +254,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 	unsigned long buf_fx = 0;
 
 	/* redzone */
-	if (IS_ENABLED(CONFIG_X86_64))
+	if (!ia32_frame)
 		sp -= 128;
 
 	/* This is the X/Open sanctioned signal stack switching.  */
@@ -263,7 +268,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 			sp = current->sas_ss_sp + current->sas_ss_size;
 			entering_altstack = true;
 		}
-	} else if (IS_ENABLED(CONFIG_X86_32) &&
+	} else if (ia32_frame &&
 		   !nested_altstack &&
 		   regs->ss != __USER_DS &&
 		   !(ka->sa.sa_flags & SA_RESTORER) &&
@@ -273,11 +278,19 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 		entering_altstack = true;
 	}
 
-	sp = fpu__alloc_mathframe(sp, IS_ENABLED(CONFIG_X86_32),
-				  &buf_fx, &math_size);
+	sp = fpu__alloc_mathframe(sp, ia32_frame, &buf_fx, &math_size);
 	*fpstate = (void __user *)sp;
 
-	sp = align_sigframe(sp - frame_size);
+	sp -= frame_size;
+
+	if (ia32_frame)
+		/*
+		 * Align the stack pointer according to the i386 ABI,
+		 * i.e. so that on function entry ((sp + 4) & 15) == 0.
+		 */
+		sp = ((sp + 4) & -FRAME_ALIGNMENT) - 4;
+	else
+		sp = round_down(sp, FRAME_ALIGNMENT) - 8;
 
 	/*
 	 * If we are on the alternate signal stack and would overflow it, don't.
@@ -331,7 +344,7 @@ __setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 	void __user *restorer;
 	void __user *fp = NULL;
 
-	frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fp);
+	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
 
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
@@ -386,7 +399,7 @@ static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	void __user *restorer;
 	void __user *fp = NULL;
 
-	frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fp);
+	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
 
 	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
@@ -469,7 +482,7 @@ static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
 		return -EFAULT;
 
-	frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp);
+	frame = get_sigframe(ksig, regs, sizeof(struct rt_sigframe), &fp);
 	uc_flags = frame_uc_flags(regs);
 
 	if (!user_access_begin(frame, sizeof(*frame)))
@@ -572,7 +585,7 @@ static int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
 		return -EFAULT;
 
-	frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fp);
+	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
 
 	uc_flags = frame_uc_flags(regs);
 
@@ -742,23 +755,6 @@ unsigned long get_sigframe_size(void)
 	return max_frame_size;
 }
 
-static inline int is_ia32_compat_frame(struct ksignal *ksig)
-{
-	return IS_ENABLED(CONFIG_IA32_EMULATION) &&
-		ksig->ka.sa.sa_flags & SA_IA32_ABI;
-}
-
-static inline int is_ia32_frame(struct ksignal *ksig)
-{
-	return IS_ENABLED(CONFIG_X86_32) || is_ia32_compat_frame(ksig);
-}
-
-static inline int is_x32_frame(struct ksignal *ksig)
-{
-	return IS_ENABLED(CONFIG_X86_X32_ABI) &&
-		ksig->ka.sa.sa_flags & SA_X32_ABI;
-}
-
 static int
 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {

[PATCH 6/8] x86/signal: Add ABI prefixes to frame setup functions

[Brian Gerst]

Add ABI prefixes to the frame setup functions that didn't already have
them.  To avoid compiler warnings and prepare for moving these functions
to separate files, make them non-static.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/include/asm/fpu/signal.h  |  5 -----
 arch/x86/include/asm/sighandling.h |  5 +++++
 arch/x86/kernel/signal.c           | 18 +++++++-----------
 3 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/fpu/signal.h b/arch/x86/include/asm/fpu/signal.h
index 2f255aca5622..611fa41711af 100644
--- a/arch/x86/include/asm/fpu/signal.h
+++ b/arch/x86/include/asm/fpu/signal.h
@@ -13,14 +13,9 @@
 #ifdef CONFIG_X86_64
 # include <uapi/asm/sigcontext.h>
 # include <asm/user32.h>
-struct ksignal;
-int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
-int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs);
 #else
 # define user_i387_ia32_struct	user_i387_struct
 # define user32_fxsr_struct	user_fxsr_struct
-# define ia32_setup_frame	__setup_frame
-# define ia32_setup_rt_frame	__setup_rt_frame
 #endif
 
 extern void convert_from_fxsr(struct user_i387_ia32_struct *env,
diff --git a/arch/x86/include/asm/sighandling.h b/arch/x86/include/asm/sighandling.h
index c9e9784efe38..e770c4fc47f4 100644
--- a/arch/x86/include/asm/sighandling.h
+++ b/arch/x86/include/asm/sighandling.h
@@ -19,4 +19,9 @@ void __user *
 get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
 	     void __user **fpstate);
 
+int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs);
+int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
+int x64_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
+int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
+
 #endif /* _ASM_X86_SIGHANDLING_H */
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 890ca0523570..0511e050d24a 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -336,8 +336,7 @@ static const struct {
 	0
 };
 
-static int
-__setup_frame(struct ksignal *ksig, struct pt_regs *regs)
+int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
 	sigset_t *set = sigmask_to_save();
 	struct sigframe __user *frame;
@@ -392,7 +391,7 @@ __setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 	return -EFAULT;
 }
 
-static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
 	sigset_t *set = sigmask_to_save();
 	struct rt_sigframe __user *frame;
@@ -471,7 +470,7 @@ static unsigned long frame_uc_flags(struct pt_regs *regs)
 	return flags;
 }
 
-static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+int x64_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
 	sigset_t *set = sigmask_to_save();
 	struct rt_sigframe __user *frame;
@@ -571,11 +570,9 @@ int copy_siginfo_to_user32(struct compat_siginfo __user *to,
 		return x32_copy_siginfo_to_user(to, from);
 	return __copy_siginfo_to_user32(to, from);
 }
-#endif /* CONFIG_X86_X32_ABI */
 
-static int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
-#ifdef CONFIG_X86_X32_ABI
 	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
 	struct rt_sigframe_x32 __user *frame;
 	unsigned long uc_flags;
@@ -622,15 +619,14 @@ static int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 
 	regs->cs = __USER_CS;
 	regs->ss = __USER_DS;
-#endif	/* CONFIG_X86_X32_ABI */
 
 	return 0;
-#ifdef CONFIG_X86_X32_ABI
+
 Efault:
 	user_access_end();
 	return -EFAULT;
-#endif
 }
+#endif /* CONFIG_X86_X32_ABI */
 
 /*
  * Do a signal return; undo the signal stack.
@@ -770,7 +766,7 @@ setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	} else if (is_x32_frame(ksig)) {
 		return x32_setup_rt_frame(ksig, regs);
 	} else {
-		return __setup_rt_frame(ksig, regs);
+		return x64_setup_rt_frame(ksig, regs);
 	}
 }
 
-- 
2.35.3

[tip: x86/misc] x86/signal: Add ABI prefixes to frame setup functions

[tip-bot2 for Brian Gerst]

The following commit has been merged into the x86/misc branch of tip:

Commit-ID:     c461ae39373a1ae21952dbb6e2668a693d9f761d
Gitweb:        https://git.kernel.org/tip/c461ae39373a1ae21952dbb6e2668a693d9f761d
Author:        Brian Gerst <brgerst@gmail.com>
AuthorDate:    Mon, 06 Jun 2022 16:38:00 -04:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 19 Oct 2022 09:58:49 +02:00

x86/signal: Add ABI prefixes to frame setup functions

Add ABI prefixes to the frame setup functions that didn't already have
them.  To avoid compiler warnings and prepare for moving these functions
to separate files, make them non-static.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/20220606203802.158958-7-brgerst@gmail.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/include/asm/fpu/signal.h  |  5 -----
 arch/x86/include/asm/sighandling.h |  5 +++++
 arch/x86/kernel/signal.c           | 18 +++++++-----------
 3 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/fpu/signal.h b/arch/x86/include/asm/fpu/signal.h
index 2f255ac..611fa41 100644
--- a/arch/x86/include/asm/fpu/signal.h
+++ b/arch/x86/include/asm/fpu/signal.h
@@ -13,14 +13,9 @@
 #ifdef CONFIG_X86_64
 # include <uapi/asm/sigcontext.h>
 # include <asm/user32.h>
-struct ksignal;
-int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
-int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs);
 #else
 # define user_i387_ia32_struct	user_i387_struct
 # define user32_fxsr_struct	user_fxsr_struct
-# define ia32_setup_frame	__setup_frame
-# define ia32_setup_rt_frame	__setup_rt_frame
 #endif
 
 extern void convert_from_fxsr(struct user_i387_ia32_struct *env,
diff --git a/arch/x86/include/asm/sighandling.h b/arch/x86/include/asm/sighandling.h
index c9e9784..e770c4f 100644
--- a/arch/x86/include/asm/sighandling.h
+++ b/arch/x86/include/asm/sighandling.h
@@ -19,4 +19,9 @@ void __user *
 get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
 	     void __user **fpstate);
 
+int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs);
+int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
+int x64_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
+int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
+
 #endif /* _ASM_X86_SIGHANDLING_H */
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 890ca05..0511e05 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -336,8 +336,7 @@ static const struct {
 	0
 };
 
-static int
-__setup_frame(struct ksignal *ksig, struct pt_regs *regs)
+int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
 	sigset_t *set = sigmask_to_save();
 	struct sigframe __user *frame;
@@ -392,7 +391,7 @@ Efault:
 	return -EFAULT;
 }
 
-static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
 	sigset_t *set = sigmask_to_save();
 	struct rt_sigframe __user *frame;
@@ -471,7 +470,7 @@ static unsigned long frame_uc_flags(struct pt_regs *regs)
 	return flags;
 }
 
-static int __setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+int x64_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
 	sigset_t *set = sigmask_to_save();
 	struct rt_sigframe __user *frame;
@@ -571,11 +570,9 @@ int copy_siginfo_to_user32(struct compat_siginfo __user *to,
 		return x32_copy_siginfo_to_user(to, from);
 	return __copy_siginfo_to_user32(to, from);
 }
-#endif /* CONFIG_X86_X32_ABI */
 
-static int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
-#ifdef CONFIG_X86_X32_ABI
 	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
 	struct rt_sigframe_x32 __user *frame;
 	unsigned long uc_flags;
@@ -622,15 +619,14 @@ static int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 
 	regs->cs = __USER_CS;
 	regs->ss = __USER_DS;
-#endif	/* CONFIG_X86_X32_ABI */
 
 	return 0;
-#ifdef CONFIG_X86_X32_ABI
+
 Efault:
 	user_access_end();
 	return -EFAULT;
-#endif
 }
+#endif /* CONFIG_X86_X32_ABI */
 
 /*
  * Do a signal return; undo the signal stack.
@@ -770,7 +766,7 @@ setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	} else if (is_x32_frame(ksig)) {
 		return x32_setup_rt_frame(ksig, regs);
 	} else {
-		return __setup_rt_frame(ksig, regs);
+		return x64_setup_rt_frame(ksig, regs);
 	}
 }
 

[PATCH 7/8] x86/signal/32: Merge native and compat 32-bit signal code

[Brian Gerst]

There are significant differences between signal handling on 32-bit vs.
64-bit, like different structure layouts and legacy syscalls.  Instead
of duplicating that code for native and compat, merge both versions
into one file.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/ia32/Makefile                        |   2 -
 arch/x86/include/asm/segment.h                |   1 +
 arch/x86/kernel/Makefile                      |   4 +-
 arch/x86/kernel/signal.c                      | 219 +-----------------
 .../ia32_signal.c => kernel/signal_32.c}      |  59 ++++-
 include/linux/syscalls.h                      |   2 +
 6 files changed, 60 insertions(+), 227 deletions(-)
 rename arch/x86/{ia32/ia32_signal.c => kernel/signal_32.c} (86%)

diff --git a/arch/x86/ia32/Makefile b/arch/x86/ia32/Makefile
index e481056698de..333556a86b2a 100644
--- a/arch/x86/ia32/Makefile
+++ b/arch/x86/ia32/Makefile
@@ -3,7 +3,5 @@
 # Makefile for the ia32 kernel emulation subsystem.
 #
 
-obj-$(CONFIG_IA32_EMULATION) := ia32_signal.o
-
 audit-class-$(CONFIG_AUDIT) := audit.o
 obj-$(CONFIG_IA32_EMULATION) += $(audit-class-y)
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index e056c29dfcda..c390a672d560 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -135,6 +135,7 @@
 #define __KERNEL_DS			(GDT_ENTRY_KERNEL_DS*8)
 #define __USER_DS			(GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
 #define __USER_CS			(GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
+#define __USER32_CS			__USER_CS
 #define __ESPFIX_SS			(GDT_ENTRY_ESPFIX_SS*8)
 
 /* segment for calling fn: */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 03364dc40d8d..4aa1bd55a362 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -57,8 +57,8 @@ obj-y			+= setup.o x86_init.o i8259.o irqinit.o
 obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o
 obj-$(CONFIG_IRQ_WORK)  += irq_work.o
 obj-y			+= probe_roms.o
-obj-$(CONFIG_X86_32)	+= sys_ia32.o
-obj-$(CONFIG_IA32_EMULATION)	+= sys_ia32.o
+obj-$(CONFIG_X86_32)	+= sys_ia32.o signal_32.o
+obj-$(CONFIG_IA32_EMULATION)	+= sys_ia32.o signal_32.o
 obj-$(CONFIG_X86_64)	+= sys_x86_64.o
 obj-$(CONFIG_X86_ESPFIX64)	+= espfix_64.o
 obj-$(CONFIG_SYSFS)	+= ksysfs.o
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 0511e050d24a..962cfd835c90 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -92,10 +92,6 @@ static void force_valid_ss(struct pt_regs *regs)
 	    ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA_EXPDOWN))
 		regs->ss = __USER_DS;
 }
-# define CONTEXT_COPY_SIZE	offsetof(struct sigcontext, reserved1)
-#else
-# define CONTEXT_COPY_SIZE	sizeof(struct sigcontext)
-#endif
 
 static bool restore_sigcontext(struct pt_regs *regs,
 			       struct sigcontext __user *usc,
@@ -106,16 +102,9 @@ static bool restore_sigcontext(struct pt_regs *regs,
 	/* Always make any pending restarted system calls return -EINTR */
 	current->restart_block.fn = do_no_restart_syscall;
 
-	if (copy_from_user(&sc, usc, CONTEXT_COPY_SIZE))
+	if (copy_from_user(&sc, usc, offsetof(struct sigcontext, reserved1)))
 		return false;
 
-#ifdef CONFIG_X86_32
-	loadsegment(gs, sc.gs);
-	regs->fs = sc.fs;
-	regs->es = sc.es;
-	regs->ds = sc.ds;
-#endif /* CONFIG_X86_32 */
-
 	regs->bx = sc.bx;
 	regs->cx = sc.cx;
 	regs->dx = sc.dx;
@@ -125,8 +114,6 @@ static bool restore_sigcontext(struct pt_regs *regs,
 	regs->ax = sc.ax;
 	regs->sp = sc.sp;
 	regs->ip = sc.ip;
-
-#ifdef CONFIG_X86_64
 	regs->r8 = sc.r8;
 	regs->r9 = sc.r9;
 	regs->r10 = sc.r10;
@@ -135,7 +122,6 @@ static bool restore_sigcontext(struct pt_regs *regs,
 	regs->r13 = sc.r13;
 	regs->r14 = sc.r14;
 	regs->r15 = sc.r15;
-#endif /* CONFIG_X86_64 */
 
 	/* Get CS/SS and force CPL3 */
 	regs->cs = sc.cs | 0x03;
@@ -145,33 +131,20 @@ static bool restore_sigcontext(struct pt_regs *regs,
 	/* disable syscall checks */
 	regs->orig_ax = -1;
 
-#ifdef CONFIG_X86_64
 	/*
 	 * Fix up SS if needed for the benefit of old DOSEMU and
 	 * CRIU.
 	 */
 	if (unlikely(!(uc_flags & UC_STRICT_RESTORE_SS) && user_64bit_mode(regs)))
 		force_valid_ss(regs);
-#endif
 
-	return fpu__restore_sig((void __user *)sc.fpstate,
-			       IS_ENABLED(CONFIG_X86_32));
+	return fpu__restore_sig((void __user *)sc.fpstate, 0);
 }
 
 static __always_inline int
 __unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 		     struct pt_regs *regs, unsigned long mask)
 {
-#ifdef CONFIG_X86_32
-	unsigned int gs;
-	savesegment(gs, gs);
-
-	unsafe_put_user(gs,	  (unsigned int __user *)&sc->gs, Efault);
-	unsafe_put_user(regs->fs, (unsigned int __user *)&sc->fs, Efault);
-	unsafe_put_user(regs->es, (unsigned int __user *)&sc->es, Efault);
-	unsafe_put_user(regs->ds, (unsigned int __user *)&sc->ds, Efault);
-#endif /* CONFIG_X86_32 */
-
 	unsafe_put_user(regs->di, &sc->di, Efault);
 	unsafe_put_user(regs->si, &sc->si, Efault);
 	unsafe_put_user(regs->bp, &sc->bp, Efault);
@@ -180,7 +153,6 @@ __unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 	unsafe_put_user(regs->dx, &sc->dx, Efault);
 	unsafe_put_user(regs->cx, &sc->cx, Efault);
 	unsafe_put_user(regs->ax, &sc->ax, Efault);
-#ifdef CONFIG_X86_64
 	unsafe_put_user(regs->r8, &sc->r8, Efault);
 	unsafe_put_user(regs->r9, &sc->r9, Efault);
 	unsafe_put_user(regs->r10, &sc->r10, Efault);
@@ -189,23 +161,15 @@ __unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 	unsafe_put_user(regs->r13, &sc->r13, Efault);
 	unsafe_put_user(regs->r14, &sc->r14, Efault);
 	unsafe_put_user(regs->r15, &sc->r15, Efault);
-#endif /* CONFIG_X86_64 */
 
 	unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
 	unsafe_put_user(current->thread.error_code, &sc->err, Efault);
 	unsafe_put_user(regs->ip, &sc->ip, Efault);
-#ifdef CONFIG_X86_32
-	unsafe_put_user(regs->cs, (unsigned int __user *)&sc->cs, Efault);
-	unsafe_put_user(regs->flags, &sc->flags, Efault);
-	unsafe_put_user(regs->sp, &sc->sp_at_signal, Efault);
-	unsafe_put_user(regs->ss, (unsigned int __user *)&sc->ss, Efault);
-#else /* !CONFIG_X86_32 */
 	unsafe_put_user(regs->flags, &sc->flags, Efault);
 	unsafe_put_user(regs->cs, &sc->cs, Efault);
 	unsafe_put_user(0, &sc->gs, Efault);
 	unsafe_put_user(0, &sc->fs, Efault);
 	unsafe_put_user(regs->ss, &sc->ss, Efault);
-#endif /* CONFIG_X86_32 */
 
 	unsafe_put_user(fpstate, (unsigned long __user *)&sc->fpstate, Efault);
 
@@ -228,6 +192,8 @@ do {									\
 			(__u64 __user *)&(frame)->uc.uc_sigmask, \
 			label)
 
+#endif /* CONFIG_X86_64 */
+
 /*
  * Set up a signal frame.
  */
@@ -313,148 +279,7 @@ get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
 	return (void __user *)sp;
 }
 
-#ifdef CONFIG_X86_32
-static const struct {
-	u16 poplmovl;
-	u32 val;
-	u16 int80;
-} __attribute__((packed)) retcode = {
-	0xb858,		/* popl %eax; movl $..., %eax */
-	__NR_sigreturn,
-	0x80cd,		/* int $0x80 */
-};
-
-static const struct {
-	u8  movl;
-	u32 val;
-	u16 int80;
-	u8  pad;
-} __attribute__((packed)) rt_retcode = {
-	0xb8,		/* movl $..., %eax */
-	__NR_rt_sigreturn,
-	0x80cd,		/* int $0x80 */
-	0
-};
-
-int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	sigset_t *set = sigmask_to_save();
-	struct sigframe __user *frame;
-	void __user *restorer;
-	void __user *fp = NULL;
-
-	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	unsafe_put_user(ksig->sig, &frame->sig, Efault);
-	unsafe_put_sigcontext(&frame->sc, fp, regs, set, Efault);
-	unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
-	if (current->mm->context.vdso)
-		restorer = current->mm->context.vdso +
-			vdso_image_32.sym___kernel_sigreturn;
-	else
-		restorer = &frame->retcode;
-	if (ksig->ka.sa.sa_flags & SA_RESTORER)
-		restorer = ksig->ka.sa.sa_restorer;
-
-	/* Set up to return from userspace.  */
-	unsafe_put_user(restorer, &frame->pretcode, Efault);
-
-	/*
-	 * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
-	 *
-	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
-	 * reasons and because gdb uses it as a signature to notice
-	 * signal handler stack frames.
-	 */
-	unsafe_put_user(*((u64 *)&retcode), (u64 *)frame->retcode, Efault);
-	user_access_end();
-
-	/* Set up registers for signal handler */
-	regs->sp = (unsigned long)frame;
-	regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
-	regs->ax = (unsigned long)ksig->sig;
-	regs->dx = 0;
-	regs->cx = 0;
-
-	regs->ds = __USER_DS;
-	regs->es = __USER_DS;
-	regs->ss = __USER_DS;
-	regs->cs = __USER_CS;
-
-	return 0;
-
-Efault:
-	user_access_end();
-	return -EFAULT;
-}
-
-int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	sigset_t *set = sigmask_to_save();
-	struct rt_sigframe __user *frame;
-	void __user *restorer;
-	void __user *fp = NULL;
-
-	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	unsafe_put_user(ksig->sig, &frame->sig, Efault);
-	unsafe_put_user(&frame->info, &frame->pinfo, Efault);
-	unsafe_put_user(&frame->uc, &frame->puc, Efault);
-
-	/* Create the ucontext.  */
-	if (static_cpu_has(X86_FEATURE_XSAVE))
-		unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault);
-	else
-		unsafe_put_user(0, &frame->uc.uc_flags, Efault);
-	unsafe_put_user(0, &frame->uc.uc_link, Efault);
-	unsafe_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
-
-	/* Set up to return from userspace.  */
-	restorer = current->mm->context.vdso +
-		vdso_image_32.sym___kernel_rt_sigreturn;
-	if (ksig->ka.sa.sa_flags & SA_RESTORER)
-		restorer = ksig->ka.sa.sa_restorer;
-	unsafe_put_user(restorer, &frame->pretcode, Efault);
-
-	/*
-	 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
-	 *
-	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
-	 * reasons and because gdb uses it as a signature to notice
-	 * signal handler stack frames.
-	 */
-	unsafe_put_user(*((u64 *)&rt_retcode), (u64 *)frame->retcode, Efault);
-	unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
-	unsafe_put_sigmask(set, frame, Efault);
-	user_access_end();
-	
-	if (copy_siginfo_to_user(&frame->info, &ksig->info))
-		return -EFAULT;
-
-	/* Set up registers for signal handler */
-	regs->sp = (unsigned long)frame;
-	regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
-	regs->ax = (unsigned long)ksig->sig;
-	regs->dx = (unsigned long)&frame->info;
-	regs->cx = (unsigned long)&frame->uc;
-
-	regs->ds = __USER_DS;
-	regs->es = __USER_DS;
-	regs->ss = __USER_DS;
-	regs->cs = __USER_CS;
-
-	return 0;
-Efault:
-	user_access_end();
-	return -EFAULT;
-}
-#else /* !CONFIG_X86_32 */
+#ifdef CONFIG_X86_64
 static unsigned long frame_uc_flags(struct pt_regs *regs)
 {
 	unsigned long flags;
@@ -545,7 +370,6 @@ int x64_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	user_access_end();
 	return -EFAULT;
 }
-#endif /* CONFIG_X86_32 */
 
 #ifdef CONFIG_X86_X32_ABI
 static int x32_copy_siginfo_to_user(struct compat_siginfo __user *to,
@@ -631,38 +455,6 @@ int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 /*
  * Do a signal return; undo the signal stack.
  */
-#ifdef CONFIG_X86_32
-SYSCALL_DEFINE0(sigreturn)
-{
-	struct pt_regs *regs = current_pt_regs();
-	struct sigframe __user *frame;
-	sigset_t set;
-
-	frame = (struct sigframe __user *)(regs->sp - 8);
-
-	if (!access_ok(frame, sizeof(*frame)))
-		goto badframe;
-	if (__get_user(set.sig[0], &frame->sc.oldmask) ||
-	    __get_user(set.sig[1], &frame->extramask[0]))
-		goto badframe;
-
-	set_current_blocked(&set);
-
-	/*
-	 * x86_32 has no uc_flags bits relevant to restore_sigcontext.
-	 * Save a few cycles by skipping the __get_user.
-	 */
-	if (!restore_sigcontext(regs, &frame->sc, 0))
-		goto badframe;
-	return regs->ax;
-
-badframe:
-	signal_fault(regs, frame, "sigreturn");
-
-	return 0;
-}
-#endif /* CONFIG_X86_32 */
-
 SYSCALL_DEFINE0(rt_sigreturn)
 {
 	struct pt_regs *regs = current_pt_regs();
@@ -692,6 +484,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
 	signal_fault(regs, frame, "rt_sigreturn");
 	return 0;
 }
+#endif /* CONFIG_X86_64 */
 
 /*
  * There are four different struct types for signal frame: sigframe_ia32,
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/kernel/signal_32.c
similarity index 86%
rename from arch/x86/ia32/ia32_signal.c
rename to arch/x86/kernel/signal_32.c
index e28421f53d44..2553136cf39b 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/kernel/signal_32.c
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- *  linux/arch/x86_64/ia32/ia32_signal.c
- *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
  *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
@@ -26,7 +24,6 @@
 #include <linux/uaccess.h>
 #include <asm/fpu/signal.h>
 #include <asm/ptrace.h>
-#include <asm/ia32_unistd.h>
 #include <asm/user32.h>
 #include <uapi/asm/sigcontext.h>
 #include <asm/proto.h>
@@ -35,6 +32,9 @@
 #include <asm/sighandling.h>
 #include <asm/smap.h>
 
+#ifdef CONFIG_IA32_EMULATION
+#include <asm/ia32_unistd.h>
+
 static inline void reload_segments(struct sigcontext_32 *sc)
 {
 	unsigned int cur;
@@ -53,6 +53,21 @@ static inline void reload_segments(struct sigcontext_32 *sc)
 		loadsegment(es, sc->es | 0x03);
 }
 
+#define sigset32_t			compat_sigset_t
+#define restore_altstack32		compat_restore_altstack
+#define unsafe_save_altstack32		unsafe_compat_save_altstack
+
+#else
+
+#define sigset32_t			sigset_t
+#define __NR_ia32_sigreturn		__NR_sigreturn
+#define __NR_ia32_rt_sigreturn		__NR_rt_sigreturn
+#define restore_altstack32		restore_altstack
+#define unsafe_save_altstack32		unsafe_save_altstack
+#define __copy_siginfo_to_user32	copy_siginfo_to_user
+
+#endif
+
 /*
  * Do a signal return; undo the signal stack.
  */
@@ -86,6 +101,7 @@ static bool ia32_restore_sigcontext(struct pt_regs *regs,
 	/* disable syscall checks */
 	regs->orig_ax = -1;
 
+#ifdef CONFIG_IA32_EMULATION
 	/*
 	 * Reload fs and gs if they have changed in the signal
 	 * handler.  This does not handle long fs/gs base changes in
@@ -93,10 +109,17 @@ static bool ia32_restore_sigcontext(struct pt_regs *regs,
 	 * normal case.
 	 */
 	reload_segments(&sc);
+#else
+	loadsegment(gs, sc.gs);
+	regs->fs = sc.fs;
+	regs->es = sc.es;
+	regs->ds = sc.ds;
+#endif
+
 	return fpu__restore_sig(compat_ptr(sc.fpstate), 1);
 }
 
-COMPAT_SYSCALL_DEFINE0(sigreturn)
+SYSCALL32_DEFINE0(sigreturn)
 {
 	struct pt_regs *regs = current_pt_regs();
 	struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
@@ -119,7 +142,7 @@ COMPAT_SYSCALL_DEFINE0(sigreturn)
 	return 0;
 }
 
-COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
+SYSCALL32_DEFINE0(rt_sigreturn)
 {
 	struct pt_regs *regs = current_pt_regs();
 	struct rt_sigframe_ia32 __user *frame;
@@ -129,7 +152,7 @@ COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
 
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
-	if (__get_user(set.sig[0], (__u64 __user *)&frame->uc.uc_sigmask))
+	if (__get_user(*(__u64 *)&set, (__u64 __user *)&frame->uc.uc_sigmask))
 		goto badframe;
 
 	set_current_blocked(&set);
@@ -137,7 +160,7 @@ COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
 	if (!ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
 		goto badframe;
 
-	if (compat_restore_altstack(&frame->uc.uc_stack))
+	if (restore_altstack32(&frame->uc.uc_stack))
 		goto badframe;
 
 	return regs->ax;
@@ -159,9 +182,15 @@ __unsafe_setup_sigcontext32(struct sigcontext_32 __user *sc,
 			    struct pt_regs *regs, unsigned int mask)
 {
 	unsafe_put_user(get_user_seg(gs), (unsigned int __user *)&sc->gs, Efault);
+#ifdef CONFIG_IA32_EMULATION
 	unsafe_put_user(get_user_seg(fs), (unsigned int __user *)&sc->fs, Efault);
 	unsafe_put_user(get_user_seg(ds), (unsigned int __user *)&sc->ds, Efault);
 	unsafe_put_user(get_user_seg(es), (unsigned int __user *)&sc->es, Efault);
+#else
+	unsafe_put_user(regs->fs, (unsigned int __user *)&sc->fs, Efault);
+	unsafe_put_user(regs->es, (unsigned int __user *)&sc->es, Efault);
+	unsafe_put_user(regs->ds, (unsigned int __user *)&sc->ds, Efault);
+#endif
 
 	unsafe_put_user(regs->di, &sc->di, Efault);
 	unsafe_put_user(regs->si, &sc->si, Efault);
@@ -198,7 +227,7 @@ do {									\
 
 int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
-	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
+	sigset32_t *set = (sigset32_t *) sigmask_to_save();
 	struct sigframe_ia32 __user *frame;
 	void __user *restorer;
 	void __user *fp = NULL;
@@ -250,8 +279,13 @@ int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 	regs->dx = 0;
 	regs->cx = 0;
 
+#ifdef CONFIG_IA32_EMULATION
 	loadsegment(ds, __USER_DS);
 	loadsegment(es, __USER_DS);
+#else
+	regs->ds = __USER_DS;
+	regs->es = __USER_DS;
+#endif
 
 	regs->cs = __USER32_CS;
 	regs->ss = __USER_DS;
@@ -264,7 +298,7 @@ int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
 
 int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 {
-	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
+	sigset32_t *set = (sigset32_t *) sigmask_to_save();
 	struct rt_sigframe_ia32 __user *frame;
 	void __user *restorer;
 	void __user *fp = NULL;
@@ -297,7 +331,7 @@ int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	else
 		unsafe_put_user(0, &frame->uc.uc_flags, Efault);
 	unsafe_put_user(0, &frame->uc.uc_link, Efault);
-	unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
+	unsafe_save_altstack32(&frame->uc.uc_stack, regs->sp, Efault);
 
 	if (ksig->ka.sa.sa_flags & SA_RESTORER)
 		restorer = ksig->ka.sa.sa_restorer;
@@ -327,8 +361,13 @@ int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 	regs->dx = (unsigned long) &frame->info;
 	regs->cx = (unsigned long) &frame->uc;
 
+#ifdef CONFIG_IA32_EMULATION
 	loadsegment(ds, __USER_DS);
 	loadsegment(es, __USER_DS);
+#else
+	regs->ds = __USER_DS;
+	regs->es = __USER_DS;
+#endif
 
 	regs->cs = __USER32_CS;
 	regs->ss = __USER_DS;
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index a34b0f9a9972..33a0ee3bcb2e 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -264,6 +264,7 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 #define SC_VAL64(type, name) ((type) name##_hi << 32 | name##_lo)
 
 #ifdef CONFIG_COMPAT
+#define SYSCALL32_DEFINE0 COMPAT_SYSCALL_DEFINE0
 #define SYSCALL32_DEFINE1 COMPAT_SYSCALL_DEFINE1
 #define SYSCALL32_DEFINE2 COMPAT_SYSCALL_DEFINE2
 #define SYSCALL32_DEFINE3 COMPAT_SYSCALL_DEFINE3
@@ -271,6 +272,7 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 #define SYSCALL32_DEFINE5 COMPAT_SYSCALL_DEFINE5
 #define SYSCALL32_DEFINE6 COMPAT_SYSCALL_DEFINE6
 #else
+#define SYSCALL32_DEFINE0 SYSCALL_DEFINE0
 #define SYSCALL32_DEFINE1 SYSCALL_DEFINE1
 #define SYSCALL32_DEFINE2 SYSCALL_DEFINE2
 #define SYSCALL32_DEFINE3 SYSCALL_DEFINE3
-- 
2.35.3

[tip: x86/misc] x86/signal/32: Merge native and compat 32-bit signal code

[tip-bot2 for Brian Gerst]

The following commit has been merged into the x86/misc branch of tip:

Commit-ID:     24e6dc35ccd825de7c71751610ff8f3295347e5b
Gitweb:        https://git.kernel.org/tip/24e6dc35ccd825de7c71751610ff8f3295347e5b
Author:        Brian Gerst <brgerst@gmail.com>
AuthorDate:    Mon, 06 Jun 2022 16:38:01 -04:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 19 Oct 2022 09:58:49 +02:00

x86/signal/32: Merge native and compat 32-bit signal code

There are significant differences between signal handling on 32-bit vs.
64-bit, like different structure layouts and legacy syscalls.  Instead
of duplicating that code for native and compat, merge both versions
into one file.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/20220606203802.158958-8-brgerst@gmail.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/ia32/Makefile         |   2 +-
 arch/x86/ia32/ia32_signal.c    | 340 +-----------------------------
 arch/x86/include/asm/segment.h |   1 +-
 arch/x86/kernel/Makefile       |   4 +-
 arch/x86/kernel/signal.c       | 219 +------------------
 arch/x86/kernel/signal_32.c    | 379 ++++++++++++++++++++++++++++++++-
 include/linux/syscalls.h       |   2 +-
 7 files changed, 390 insertions(+), 557 deletions(-)
 delete mode 100644 arch/x86/ia32/ia32_signal.c
 create mode 100644 arch/x86/kernel/signal_32.c

diff --git a/arch/x86/ia32/Makefile b/arch/x86/ia32/Makefile
index e481056..333556a 100644
--- a/arch/x86/ia32/Makefile
+++ b/arch/x86/ia32/Makefile
@@ -3,7 +3,5 @@
 # Makefile for the ia32 kernel emulation subsystem.
 #
 
-obj-$(CONFIG_IA32_EMULATION) := ia32_signal.o
-
 audit-class-$(CONFIG_AUDIT) := audit.o
 obj-$(CONFIG_IA32_EMULATION) += $(audit-class-y)
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
deleted file mode 100644
index e28421f..0000000
--- a/arch/x86/ia32/ia32_signal.c
+++ /dev/null
@@ -1,340 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- *  linux/arch/x86_64/ia32/ia32_signal.c
- *
- *  Copyright (C) 1991, 1992  Linus Torvalds
- *
- *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
- *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
- *  2000-12-*   x86-64 compatibility mode signal handling by Andi Kleen
- */
-
-#include <linux/sched.h>
-#include <linux/sched/task_stack.h>
-#include <linux/mm.h>
-#include <linux/smp.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/wait.h>
-#include <linux/unistd.h>
-#include <linux/stddef.h>
-#include <linux/personality.h>
-#include <linux/compat.h>
-#include <linux/binfmts.h>
-#include <linux/syscalls.h>
-#include <asm/ucontext.h>
-#include <linux/uaccess.h>
-#include <asm/fpu/signal.h>
-#include <asm/ptrace.h>
-#include <asm/ia32_unistd.h>
-#include <asm/user32.h>
-#include <uapi/asm/sigcontext.h>
-#include <asm/proto.h>
-#include <asm/vdso.h>
-#include <asm/sigframe.h>
-#include <asm/sighandling.h>
-#include <asm/smap.h>
-
-static inline void reload_segments(struct sigcontext_32 *sc)
-{
-	unsigned int cur;
-
-	savesegment(gs, cur);
-	if ((sc->gs | 0x03) != cur)
-		load_gs_index(sc->gs | 0x03);
-	savesegment(fs, cur);
-	if ((sc->fs | 0x03) != cur)
-		loadsegment(fs, sc->fs | 0x03);
-	savesegment(ds, cur);
-	if ((sc->ds | 0x03) != cur)
-		loadsegment(ds, sc->ds | 0x03);
-	savesegment(es, cur);
-	if ((sc->es | 0x03) != cur)
-		loadsegment(es, sc->es | 0x03);
-}
-
-/*
- * Do a signal return; undo the signal stack.
- */
-static bool ia32_restore_sigcontext(struct pt_regs *regs,
-				    struct sigcontext_32 __user *usc)
-{
-	struct sigcontext_32 sc;
-
-	/* Always make any pending restarted system calls return -EINTR */
-	current->restart_block.fn = do_no_restart_syscall;
-
-	if (unlikely(copy_from_user(&sc, usc, sizeof(sc))))
-		return false;
-
-	/* Get only the ia32 registers. */
-	regs->bx = sc.bx;
-	regs->cx = sc.cx;
-	regs->dx = sc.dx;
-	regs->si = sc.si;
-	regs->di = sc.di;
-	regs->bp = sc.bp;
-	regs->ax = sc.ax;
-	regs->sp = sc.sp;
-	regs->ip = sc.ip;
-
-	/* Get CS/SS and force CPL3 */
-	regs->cs = sc.cs | 0x03;
-	regs->ss = sc.ss | 0x03;
-
-	regs->flags = (regs->flags & ~FIX_EFLAGS) | (sc.flags & FIX_EFLAGS);
-	/* disable syscall checks */
-	regs->orig_ax = -1;
-
-	/*
-	 * Reload fs and gs if they have changed in the signal
-	 * handler.  This does not handle long fs/gs base changes in
-	 * the handler, but does not clobber them at least in the
-	 * normal case.
-	 */
-	reload_segments(&sc);
-	return fpu__restore_sig(compat_ptr(sc.fpstate), 1);
-}
-
-COMPAT_SYSCALL_DEFINE0(sigreturn)
-{
-	struct pt_regs *regs = current_pt_regs();
-	struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
-	sigset_t set;
-
-	if (!access_ok(frame, sizeof(*frame)))
-		goto badframe;
-	if (__get_user(set.sig[0], &frame->sc.oldmask)
-	    || __get_user(((__u32 *)&set)[1], &frame->extramask[0]))
-		goto badframe;
-
-	set_current_blocked(&set);
-
-	if (!ia32_restore_sigcontext(regs, &frame->sc))
-		goto badframe;
-	return regs->ax;
-
-badframe:
-	signal_fault(regs, frame, "32bit sigreturn");
-	return 0;
-}
-
-COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
-{
-	struct pt_regs *regs = current_pt_regs();
-	struct rt_sigframe_ia32 __user *frame;
-	sigset_t set;
-
-	frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
-
-	if (!access_ok(frame, sizeof(*frame)))
-		goto badframe;
-	if (__get_user(set.sig[0], (__u64 __user *)&frame->uc.uc_sigmask))
-		goto badframe;
-
-	set_current_blocked(&set);
-
-	if (!ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
-		goto badframe;
-
-	if (compat_restore_altstack(&frame->uc.uc_stack))
-		goto badframe;
-
-	return regs->ax;
-
-badframe:
-	signal_fault(regs, frame, "32bit rt sigreturn");
-	return 0;
-}
-
-/*
- * Set up a signal frame.
- */
-
-#define get_user_seg(seg)	({ unsigned int v; savesegment(seg, v); v; })
-
-static __always_inline int
-__unsafe_setup_sigcontext32(struct sigcontext_32 __user *sc,
-			    void __user *fpstate,
-			    struct pt_regs *regs, unsigned int mask)
-{
-	unsafe_put_user(get_user_seg(gs), (unsigned int __user *)&sc->gs, Efault);
-	unsafe_put_user(get_user_seg(fs), (unsigned int __user *)&sc->fs, Efault);
-	unsafe_put_user(get_user_seg(ds), (unsigned int __user *)&sc->ds, Efault);
-	unsafe_put_user(get_user_seg(es), (unsigned int __user *)&sc->es, Efault);
-
-	unsafe_put_user(regs->di, &sc->di, Efault);
-	unsafe_put_user(regs->si, &sc->si, Efault);
-	unsafe_put_user(regs->bp, &sc->bp, Efault);
-	unsafe_put_user(regs->sp, &sc->sp, Efault);
-	unsafe_put_user(regs->bx, &sc->bx, Efault);
-	unsafe_put_user(regs->dx, &sc->dx, Efault);
-	unsafe_put_user(regs->cx, &sc->cx, Efault);
-	unsafe_put_user(regs->ax, &sc->ax, Efault);
-	unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
-	unsafe_put_user(current->thread.error_code, &sc->err, Efault);
-	unsafe_put_user(regs->ip, &sc->ip, Efault);
-	unsafe_put_user(regs->cs, (unsigned int __user *)&sc->cs, Efault);
-	unsafe_put_user(regs->flags, &sc->flags, Efault);
-	unsafe_put_user(regs->sp, &sc->sp_at_signal, Efault);
-	unsafe_put_user(regs->ss, (unsigned int __user *)&sc->ss, Efault);
-
-	unsafe_put_user(ptr_to_compat(fpstate), &sc->fpstate, Efault);
-
-	/* non-iBCS2 extensions.. */
-	unsafe_put_user(mask, &sc->oldmask, Efault);
-	unsafe_put_user(current->thread.cr2, &sc->cr2, Efault);
-	return 0;
-
-Efault:
-	return -EFAULT;
-}
-
-#define unsafe_put_sigcontext32(sc, fp, regs, set, label)		\
-do {									\
-	if (__unsafe_setup_sigcontext32(sc, fp, regs, set->sig[0]))	\
-		goto label;						\
-} while(0)
-
-int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
-	struct sigframe_ia32 __user *frame;
-	void __user *restorer;
-	void __user *fp = NULL;
-
-	/* copy_to_user optimizes that into a single 8 byte store */
-	static const struct {
-		u16 poplmovl;
-		u32 val;
-		u16 int80;
-	} __attribute__((packed)) code = {
-		0xb858,		 /* popl %eax ; movl $...,%eax */
-		__NR_ia32_sigreturn,
-		0x80cd,		/* int $0x80 */
-	};
-
-	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
-	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
-		restorer = ksig->ka.sa.sa_restorer;
-	} else {
-		/* Return stub is in 32bit vsyscall page */
-		if (current->mm->context.vdso)
-			restorer = current->mm->context.vdso +
-				vdso_image_32.sym___kernel_sigreturn;
-		else
-			restorer = &frame->retcode;
-	}
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	unsafe_put_user(ksig->sig, &frame->sig, Efault);
-	unsafe_put_sigcontext32(&frame->sc, fp, regs, set, Efault);
-	unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
-	unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
-	/*
-	 * These are actually not used anymore, but left because some
-	 * gdb versions depend on them as a marker.
-	 */
-	unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
-	user_access_end();
-
-	/* Set up registers for signal handler */
-	regs->sp = (unsigned long) frame;
-	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
-
-	/* Make -mregparm=3 work */
-	regs->ax = ksig->sig;
-	regs->dx = 0;
-	regs->cx = 0;
-
-	loadsegment(ds, __USER_DS);
-	loadsegment(es, __USER_DS);
-
-	regs->cs = __USER32_CS;
-	regs->ss = __USER_DS;
-
-	return 0;
-Efault:
-	user_access_end();
-	return -EFAULT;
-}
-
-int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
-	struct rt_sigframe_ia32 __user *frame;
-	void __user *restorer;
-	void __user *fp = NULL;
-
-	/* unsafe_put_user optimizes that into a single 8 byte store */
-	static const struct {
-		u8 movl;
-		u32 val;
-		u16 int80;
-		u8  pad;
-	} __attribute__((packed)) code = {
-		0xb8,
-		__NR_ia32_rt_sigreturn,
-		0x80cd,
-		0,
-	};
-
-	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	unsafe_put_user(ksig->sig, &frame->sig, Efault);
-	unsafe_put_user(ptr_to_compat(&frame->info), &frame->pinfo, Efault);
-	unsafe_put_user(ptr_to_compat(&frame->uc), &frame->puc, Efault);
-
-	/* Create the ucontext.  */
-	if (static_cpu_has(X86_FEATURE_XSAVE))
-		unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault);
-	else
-		unsafe_put_user(0, &frame->uc.uc_flags, Efault);
-	unsafe_put_user(0, &frame->uc.uc_link, Efault);
-	unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
-
-	if (ksig->ka.sa.sa_flags & SA_RESTORER)
-		restorer = ksig->ka.sa.sa_restorer;
-	else
-		restorer = current->mm->context.vdso +
-			vdso_image_32.sym___kernel_rt_sigreturn;
-	unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
-
-	/*
-	 * Not actually used anymore, but left because some gdb
-	 * versions need it.
-	 */
-	unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
-	unsafe_put_sigcontext32(&frame->uc.uc_mcontext, fp, regs, set, Efault);
-	unsafe_put_user(*(__u64 *)set, (__u64 __user *)&frame->uc.uc_sigmask, Efault);
-	user_access_end();
-
-	if (__copy_siginfo_to_user32(&frame->info, &ksig->info))
-		return -EFAULT;
-
-	/* Set up registers for signal handler */
-	regs->sp = (unsigned long) frame;
-	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
-
-	/* Make -mregparm=3 work */
-	regs->ax = ksig->sig;
-	regs->dx = (unsigned long) &frame->info;
-	regs->cx = (unsigned long) &frame->uc;
-
-	loadsegment(ds, __USER_DS);
-	loadsegment(es, __USER_DS);
-
-	regs->cs = __USER32_CS;
-	regs->ss = __USER_DS;
-
-	return 0;
-Efault:
-	user_access_end();
-	return -EFAULT;
-}
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index e056c29..c390a67 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -135,6 +135,7 @@
 #define __KERNEL_DS			(GDT_ENTRY_KERNEL_DS*8)
 #define __USER_DS			(GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
 #define __USER_CS			(GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
+#define __USER32_CS			__USER_CS
 #define __ESPFIX_SS			(GDT_ENTRY_ESPFIX_SS*8)
 
 /* segment for calling fn: */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index f901658..72e1371 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -53,8 +53,8 @@ obj-y			+= setup.o x86_init.o i8259.o irqinit.o
 obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o
 obj-$(CONFIG_IRQ_WORK)  += irq_work.o
 obj-y			+= probe_roms.o
-obj-$(CONFIG_X86_32)	+= sys_ia32.o
-obj-$(CONFIG_IA32_EMULATION)	+= sys_ia32.o
+obj-$(CONFIG_X86_32)	+= sys_ia32.o signal_32.o
+obj-$(CONFIG_IA32_EMULATION)	+= sys_ia32.o signal_32.o
 obj-$(CONFIG_X86_64)	+= sys_x86_64.o
 obj-$(CONFIG_X86_ESPFIX64)	+= espfix_64.o
 obj-$(CONFIG_SYSFS)	+= ksysfs.o
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 0511e05..962cfd8 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -92,10 +92,6 @@ static void force_valid_ss(struct pt_regs *regs)
 	    ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA_EXPDOWN))
 		regs->ss = __USER_DS;
 }
-# define CONTEXT_COPY_SIZE	offsetof(struct sigcontext, reserved1)
-#else
-# define CONTEXT_COPY_SIZE	sizeof(struct sigcontext)
-#endif
 
 static bool restore_sigcontext(struct pt_regs *regs,
 			       struct sigcontext __user *usc,
@@ -106,16 +102,9 @@ static bool restore_sigcontext(struct pt_regs *regs,
 	/* Always make any pending restarted system calls return -EINTR */
 	current->restart_block.fn = do_no_restart_syscall;
 
-	if (copy_from_user(&sc, usc, CONTEXT_COPY_SIZE))
+	if (copy_from_user(&sc, usc, offsetof(struct sigcontext, reserved1)))
 		return false;
 
-#ifdef CONFIG_X86_32
-	loadsegment(gs, sc.gs);
-	regs->fs = sc.fs;
-	regs->es = sc.es;
-	regs->ds = sc.ds;
-#endif /* CONFIG_X86_32 */
-
 	regs->bx = sc.bx;
 	regs->cx = sc.cx;
 	regs->dx = sc.dx;
@@ -125,8 +114,6 @@ static bool restore_sigcontext(struct pt_regs *regs,
 	regs->ax = sc.ax;
 	regs->sp = sc.sp;
 	regs->ip = sc.ip;
-
-#ifdef CONFIG_X86_64
 	regs->r8 = sc.r8;
 	regs->r9 = sc.r9;
 	regs->r10 = sc.r10;
@@ -135,7 +122,6 @@ static bool restore_sigcontext(struct pt_regs *regs,
 	regs->r13 = sc.r13;
 	regs->r14 = sc.r14;
 	regs->r15 = sc.r15;
-#endif /* CONFIG_X86_64 */
 
 	/* Get CS/SS and force CPL3 */
 	regs->cs = sc.cs | 0x03;
@@ -145,33 +131,20 @@ static bool restore_sigcontext(struct pt_regs *regs,
 	/* disable syscall checks */
 	regs->orig_ax = -1;
 
-#ifdef CONFIG_X86_64
 	/*
 	 * Fix up SS if needed for the benefit of old DOSEMU and
 	 * CRIU.
 	 */
 	if (unlikely(!(uc_flags & UC_STRICT_RESTORE_SS) && user_64bit_mode(regs)))
 		force_valid_ss(regs);
-#endif
 
-	return fpu__restore_sig((void __user *)sc.fpstate,
-			       IS_ENABLED(CONFIG_X86_32));
+	return fpu__restore_sig((void __user *)sc.fpstate, 0);
 }
 
 static __always_inline int
 __unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 		     struct pt_regs *regs, unsigned long mask)
 {
-#ifdef CONFIG_X86_32
-	unsigned int gs;
-	savesegment(gs, gs);
-
-	unsafe_put_user(gs,	  (unsigned int __user *)&sc->gs, Efault);
-	unsafe_put_user(regs->fs, (unsigned int __user *)&sc->fs, Efault);
-	unsafe_put_user(regs->es, (unsigned int __user *)&sc->es, Efault);
-	unsafe_put_user(regs->ds, (unsigned int __user *)&sc->ds, Efault);
-#endif /* CONFIG_X86_32 */
-
 	unsafe_put_user(regs->di, &sc->di, Efault);
 	unsafe_put_user(regs->si, &sc->si, Efault);
 	unsafe_put_user(regs->bp, &sc->bp, Efault);
@@ -180,7 +153,6 @@ __unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 	unsafe_put_user(regs->dx, &sc->dx, Efault);
 	unsafe_put_user(regs->cx, &sc->cx, Efault);
 	unsafe_put_user(regs->ax, &sc->ax, Efault);
-#ifdef CONFIG_X86_64
 	unsafe_put_user(regs->r8, &sc->r8, Efault);
 	unsafe_put_user(regs->r9, &sc->r9, Efault);
 	unsafe_put_user(regs->r10, &sc->r10, Efault);
@@ -189,23 +161,15 @@ __unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 	unsafe_put_user(regs->r13, &sc->r13, Efault);
 	unsafe_put_user(regs->r14, &sc->r14, Efault);
 	unsafe_put_user(regs->r15, &sc->r15, Efault);
-#endif /* CONFIG_X86_64 */
 
 	unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
 	unsafe_put_user(current->thread.error_code, &sc->err, Efault);
 	unsafe_put_user(regs->ip, &sc->ip, Efault);
-#ifdef CONFIG_X86_32
-	unsafe_put_user(regs->cs, (unsigned int __user *)&sc->cs, Efault);
-	unsafe_put_user(regs->flags, &sc->flags, Efault);
-	unsafe_put_user(regs->sp, &sc->sp_at_signal, Efault);
-	unsafe_put_user(regs->ss, (unsigned int __user *)&sc->ss, Efault);
-#else /* !CONFIG_X86_32 */
 	unsafe_put_user(regs->flags, &sc->flags, Efault);
 	unsafe_put_user(regs->cs, &sc->cs, Efault);
 	unsafe_put_user(0, &sc->gs, Efault);
 	unsafe_put_user(0, &sc->fs, Efault);
 	unsafe_put_user(regs->ss, &sc->ss, Efault);
-#endif /* CONFIG_X86_32 */
 
 	unsafe_put_user(fpstate, (unsigned long __user *)&sc->fpstate, Efault);
 
@@ -228,6 +192,8 @@ do {									\
 			(__u64 __user *)&(frame)->uc.uc_sigmask, \
 			label)
 
+#endif /* CONFIG_X86_64 */
+
 /*
  * Set up a signal frame.
  */
@@ -313,148 +279,7 @@ get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
 	return (void __user *)sp;
 }
 
-#ifdef CONFIG_X86_32
-static const struct {
-	u16 poplmovl;
-	u32 val;
-	u16 int80;
-} __attribute__((packed)) retcode = {
-	0xb858,		/* popl %eax; movl $..., %eax */
-	__NR_sigreturn,
-	0x80cd,		/* int $0x80 */
-};
-
-static const struct {
-	u8  movl;
-	u32 val;
-	u16 int80;
-	u8  pad;
-} __attribute__((packed)) rt_retcode = {
-	0xb8,		/* movl $..., %eax */
-	__NR_rt_sigreturn,
-	0x80cd,		/* int $0x80 */
-	0
-};
-
-int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	sigset_t *set = sigmask_to_save();
-	struct sigframe __user *frame;
-	void __user *restorer;
-	void __user *fp = NULL;
-
-	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	unsafe_put_user(ksig->sig, &frame->sig, Efault);
-	unsafe_put_sigcontext(&frame->sc, fp, regs, set, Efault);
-	unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
-	if (current->mm->context.vdso)
-		restorer = current->mm->context.vdso +
-			vdso_image_32.sym___kernel_sigreturn;
-	else
-		restorer = &frame->retcode;
-	if (ksig->ka.sa.sa_flags & SA_RESTORER)
-		restorer = ksig->ka.sa.sa_restorer;
-
-	/* Set up to return from userspace.  */
-	unsafe_put_user(restorer, &frame->pretcode, Efault);
-
-	/*
-	 * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
-	 *
-	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
-	 * reasons and because gdb uses it as a signature to notice
-	 * signal handler stack frames.
-	 */
-	unsafe_put_user(*((u64 *)&retcode), (u64 *)frame->retcode, Efault);
-	user_access_end();
-
-	/* Set up registers for signal handler */
-	regs->sp = (unsigned long)frame;
-	regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
-	regs->ax = (unsigned long)ksig->sig;
-	regs->dx = 0;
-	regs->cx = 0;
-
-	regs->ds = __USER_DS;
-	regs->es = __USER_DS;
-	regs->ss = __USER_DS;
-	regs->cs = __USER_CS;
-
-	return 0;
-
-Efault:
-	user_access_end();
-	return -EFAULT;
-}
-
-int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	sigset_t *set = sigmask_to_save();
-	struct rt_sigframe __user *frame;
-	void __user *restorer;
-	void __user *fp = NULL;
-
-	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	unsafe_put_user(ksig->sig, &frame->sig, Efault);
-	unsafe_put_user(&frame->info, &frame->pinfo, Efault);
-	unsafe_put_user(&frame->uc, &frame->puc, Efault);
-
-	/* Create the ucontext.  */
-	if (static_cpu_has(X86_FEATURE_XSAVE))
-		unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault);
-	else
-		unsafe_put_user(0, &frame->uc.uc_flags, Efault);
-	unsafe_put_user(0, &frame->uc.uc_link, Efault);
-	unsafe_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
-
-	/* Set up to return from userspace.  */
-	restorer = current->mm->context.vdso +
-		vdso_image_32.sym___kernel_rt_sigreturn;
-	if (ksig->ka.sa.sa_flags & SA_RESTORER)
-		restorer = ksig->ka.sa.sa_restorer;
-	unsafe_put_user(restorer, &frame->pretcode, Efault);
-
-	/*
-	 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
-	 *
-	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
-	 * reasons and because gdb uses it as a signature to notice
-	 * signal handler stack frames.
-	 */
-	unsafe_put_user(*((u64 *)&rt_retcode), (u64 *)frame->retcode, Efault);
-	unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
-	unsafe_put_sigmask(set, frame, Efault);
-	user_access_end();
-	
-	if (copy_siginfo_to_user(&frame->info, &ksig->info))
-		return -EFAULT;
-
-	/* Set up registers for signal handler */
-	regs->sp = (unsigned long)frame;
-	regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
-	regs->ax = (unsigned long)ksig->sig;
-	regs->dx = (unsigned long)&frame->info;
-	regs->cx = (unsigned long)&frame->uc;
-
-	regs->ds = __USER_DS;
-	regs->es = __USER_DS;
-	regs->ss = __USER_DS;
-	regs->cs = __USER_CS;
-
-	return 0;
-Efault:
-	user_access_end();
-	return -EFAULT;
-}
-#else /* !CONFIG_X86_32 */
+#ifdef CONFIG_X86_64
 static unsigned long frame_uc_flags(struct pt_regs *regs)
 {
 	unsigned long flags;
@@ -545,7 +370,6 @@ Efault:
 	user_access_end();
 	return -EFAULT;
 }
-#endif /* CONFIG_X86_32 */
 
 #ifdef CONFIG_X86_X32_ABI
 static int x32_copy_siginfo_to_user(struct compat_siginfo __user *to,
@@ -631,38 +455,6 @@ Efault:
 /*
  * Do a signal return; undo the signal stack.
  */
-#ifdef CONFIG_X86_32
-SYSCALL_DEFINE0(sigreturn)
-{
-	struct pt_regs *regs = current_pt_regs();
-	struct sigframe __user *frame;
-	sigset_t set;
-
-	frame = (struct sigframe __user *)(regs->sp - 8);
-
-	if (!access_ok(frame, sizeof(*frame)))
-		goto badframe;
-	if (__get_user(set.sig[0], &frame->sc.oldmask) ||
-	    __get_user(set.sig[1], &frame->extramask[0]))
-		goto badframe;
-
-	set_current_blocked(&set);
-
-	/*
-	 * x86_32 has no uc_flags bits relevant to restore_sigcontext.
-	 * Save a few cycles by skipping the __get_user.
-	 */
-	if (!restore_sigcontext(regs, &frame->sc, 0))
-		goto badframe;
-	return regs->ax;
-
-badframe:
-	signal_fault(regs, frame, "sigreturn");
-
-	return 0;
-}
-#endif /* CONFIG_X86_32 */
-
 SYSCALL_DEFINE0(rt_sigreturn)
 {
 	struct pt_regs *regs = current_pt_regs();
@@ -692,6 +484,7 @@ badframe:
 	signal_fault(regs, frame, "rt_sigreturn");
 	return 0;
 }
+#endif /* CONFIG_X86_64 */
 
 /*
  * There are four different struct types for signal frame: sigframe_ia32,
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
new file mode 100644
index 0000000..2553136
--- /dev/null
+++ b/arch/x86/kernel/signal_32.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
+ *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
+ *  2000-12-*   x86-64 compatibility mode signal handling by Andi Kleen
+ */
+
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/personality.h>
+#include <linux/compat.h>
+#include <linux/binfmts.h>
+#include <linux/syscalls.h>
+#include <asm/ucontext.h>
+#include <linux/uaccess.h>
+#include <asm/fpu/signal.h>
+#include <asm/ptrace.h>
+#include <asm/user32.h>
+#include <uapi/asm/sigcontext.h>
+#include <asm/proto.h>
+#include <asm/vdso.h>
+#include <asm/sigframe.h>
+#include <asm/sighandling.h>
+#include <asm/smap.h>
+
+#ifdef CONFIG_IA32_EMULATION
+#include <asm/ia32_unistd.h>
+
+static inline void reload_segments(struct sigcontext_32 *sc)
+{
+	unsigned int cur;
+
+	savesegment(gs, cur);
+	if ((sc->gs | 0x03) != cur)
+		load_gs_index(sc->gs | 0x03);
+	savesegment(fs, cur);
+	if ((sc->fs | 0x03) != cur)
+		loadsegment(fs, sc->fs | 0x03);
+	savesegment(ds, cur);
+	if ((sc->ds | 0x03) != cur)
+		loadsegment(ds, sc->ds | 0x03);
+	savesegment(es, cur);
+	if ((sc->es | 0x03) != cur)
+		loadsegment(es, sc->es | 0x03);
+}
+
+#define sigset32_t			compat_sigset_t
+#define restore_altstack32		compat_restore_altstack
+#define unsafe_save_altstack32		unsafe_compat_save_altstack
+
+#else
+
+#define sigset32_t			sigset_t
+#define __NR_ia32_sigreturn		__NR_sigreturn
+#define __NR_ia32_rt_sigreturn		__NR_rt_sigreturn
+#define restore_altstack32		restore_altstack
+#define unsafe_save_altstack32		unsafe_save_altstack
+#define __copy_siginfo_to_user32	copy_siginfo_to_user
+
+#endif
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+static bool ia32_restore_sigcontext(struct pt_regs *regs,
+				    struct sigcontext_32 __user *usc)
+{
+	struct sigcontext_32 sc;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	if (unlikely(copy_from_user(&sc, usc, sizeof(sc))))
+		return false;
+
+	/* Get only the ia32 registers. */
+	regs->bx = sc.bx;
+	regs->cx = sc.cx;
+	regs->dx = sc.dx;
+	regs->si = sc.si;
+	regs->di = sc.di;
+	regs->bp = sc.bp;
+	regs->ax = sc.ax;
+	regs->sp = sc.sp;
+	regs->ip = sc.ip;
+
+	/* Get CS/SS and force CPL3 */
+	regs->cs = sc.cs | 0x03;
+	regs->ss = sc.ss | 0x03;
+
+	regs->flags = (regs->flags & ~FIX_EFLAGS) | (sc.flags & FIX_EFLAGS);
+	/* disable syscall checks */
+	regs->orig_ax = -1;
+
+#ifdef CONFIG_IA32_EMULATION
+	/*
+	 * Reload fs and gs if they have changed in the signal
+	 * handler.  This does not handle long fs/gs base changes in
+	 * the handler, but does not clobber them at least in the
+	 * normal case.
+	 */
+	reload_segments(&sc);
+#else
+	loadsegment(gs, sc.gs);
+	regs->fs = sc.fs;
+	regs->es = sc.es;
+	regs->ds = sc.ds;
+#endif
+
+	return fpu__restore_sig(compat_ptr(sc.fpstate), 1);
+}
+
+SYSCALL32_DEFINE0(sigreturn)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
+	sigset_t set;
+
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+	if (__get_user(set.sig[0], &frame->sc.oldmask)
+	    || __get_user(((__u32 *)&set)[1], &frame->extramask[0]))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (!ia32_restore_sigcontext(regs, &frame->sc))
+		goto badframe;
+	return regs->ax;
+
+badframe:
+	signal_fault(regs, frame, "32bit sigreturn");
+	return 0;
+}
+
+SYSCALL32_DEFINE0(rt_sigreturn)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct rt_sigframe_ia32 __user *frame;
+	sigset_t set;
+
+	frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
+
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+	if (__get_user(*(__u64 *)&set, (__u64 __user *)&frame->uc.uc_sigmask))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (!ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
+		goto badframe;
+
+	if (restore_altstack32(&frame->uc.uc_stack))
+		goto badframe;
+
+	return regs->ax;
+
+badframe:
+	signal_fault(regs, frame, "32bit rt sigreturn");
+	return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+#define get_user_seg(seg)	({ unsigned int v; savesegment(seg, v); v; })
+
+static __always_inline int
+__unsafe_setup_sigcontext32(struct sigcontext_32 __user *sc,
+			    void __user *fpstate,
+			    struct pt_regs *regs, unsigned int mask)
+{
+	unsafe_put_user(get_user_seg(gs), (unsigned int __user *)&sc->gs, Efault);
+#ifdef CONFIG_IA32_EMULATION
+	unsafe_put_user(get_user_seg(fs), (unsigned int __user *)&sc->fs, Efault);
+	unsafe_put_user(get_user_seg(ds), (unsigned int __user *)&sc->ds, Efault);
+	unsafe_put_user(get_user_seg(es), (unsigned int __user *)&sc->es, Efault);
+#else
+	unsafe_put_user(regs->fs, (unsigned int __user *)&sc->fs, Efault);
+	unsafe_put_user(regs->es, (unsigned int __user *)&sc->es, Efault);
+	unsafe_put_user(regs->ds, (unsigned int __user *)&sc->ds, Efault);
+#endif
+
+	unsafe_put_user(regs->di, &sc->di, Efault);
+	unsafe_put_user(regs->si, &sc->si, Efault);
+	unsafe_put_user(regs->bp, &sc->bp, Efault);
+	unsafe_put_user(regs->sp, &sc->sp, Efault);
+	unsafe_put_user(regs->bx, &sc->bx, Efault);
+	unsafe_put_user(regs->dx, &sc->dx, Efault);
+	unsafe_put_user(regs->cx, &sc->cx, Efault);
+	unsafe_put_user(regs->ax, &sc->ax, Efault);
+	unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
+	unsafe_put_user(current->thread.error_code, &sc->err, Efault);
+	unsafe_put_user(regs->ip, &sc->ip, Efault);
+	unsafe_put_user(regs->cs, (unsigned int __user *)&sc->cs, Efault);
+	unsafe_put_user(regs->flags, &sc->flags, Efault);
+	unsafe_put_user(regs->sp, &sc->sp_at_signal, Efault);
+	unsafe_put_user(regs->ss, (unsigned int __user *)&sc->ss, Efault);
+
+	unsafe_put_user(ptr_to_compat(fpstate), &sc->fpstate, Efault);
+
+	/* non-iBCS2 extensions.. */
+	unsafe_put_user(mask, &sc->oldmask, Efault);
+	unsafe_put_user(current->thread.cr2, &sc->cr2, Efault);
+	return 0;
+
+Efault:
+	return -EFAULT;
+}
+
+#define unsafe_put_sigcontext32(sc, fp, regs, set, label)		\
+do {									\
+	if (__unsafe_setup_sigcontext32(sc, fp, regs, set->sig[0]))	\
+		goto label;						\
+} while(0)
+
+int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
+{
+	sigset32_t *set = (sigset32_t *) sigmask_to_save();
+	struct sigframe_ia32 __user *frame;
+	void __user *restorer;
+	void __user *fp = NULL;
+
+	/* copy_to_user optimizes that into a single 8 byte store */
+	static const struct {
+		u16 poplmovl;
+		u32 val;
+		u16 int80;
+	} __attribute__((packed)) code = {
+		0xb858,		 /* popl %eax ; movl $...,%eax */
+		__NR_ia32_sigreturn,
+		0x80cd,		/* int $0x80 */
+	};
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
+
+	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+		restorer = ksig->ka.sa.sa_restorer;
+	} else {
+		/* Return stub is in 32bit vsyscall page */
+		if (current->mm->context.vdso)
+			restorer = current->mm->context.vdso +
+				vdso_image_32.sym___kernel_sigreturn;
+		else
+			restorer = &frame->retcode;
+	}
+
+	if (!user_access_begin(frame, sizeof(*frame)))
+		return -EFAULT;
+
+	unsafe_put_user(ksig->sig, &frame->sig, Efault);
+	unsafe_put_sigcontext32(&frame->sc, fp, regs, set, Efault);
+	unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
+	unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
+	/*
+	 * These are actually not used anymore, but left because some
+	 * gdb versions depend on them as a marker.
+	 */
+	unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
+	user_access_end();
+
+	/* Set up registers for signal handler */
+	regs->sp = (unsigned long) frame;
+	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
+
+	/* Make -mregparm=3 work */
+	regs->ax = ksig->sig;
+	regs->dx = 0;
+	regs->cx = 0;
+
+#ifdef CONFIG_IA32_EMULATION
+	loadsegment(ds, __USER_DS);
+	loadsegment(es, __USER_DS);
+#else
+	regs->ds = __USER_DS;
+	regs->es = __USER_DS;
+#endif
+
+	regs->cs = __USER32_CS;
+	regs->ss = __USER_DS;
+
+	return 0;
+Efault:
+	user_access_end();
+	return -EFAULT;
+}
+
+int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+{
+	sigset32_t *set = (sigset32_t *) sigmask_to_save();
+	struct rt_sigframe_ia32 __user *frame;
+	void __user *restorer;
+	void __user *fp = NULL;
+
+	/* unsafe_put_user optimizes that into a single 8 byte store */
+	static const struct {
+		u8 movl;
+		u32 val;
+		u16 int80;
+		u8  pad;
+	} __attribute__((packed)) code = {
+		0xb8,
+		__NR_ia32_rt_sigreturn,
+		0x80cd,
+		0,
+	};
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
+
+	if (!user_access_begin(frame, sizeof(*frame)))
+		return -EFAULT;
+
+	unsafe_put_user(ksig->sig, &frame->sig, Efault);
+	unsafe_put_user(ptr_to_compat(&frame->info), &frame->pinfo, Efault);
+	unsafe_put_user(ptr_to_compat(&frame->uc), &frame->puc, Efault);
+
+	/* Create the ucontext.  */
+	if (static_cpu_has(X86_FEATURE_XSAVE))
+		unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault);
+	else
+		unsafe_put_user(0, &frame->uc.uc_flags, Efault);
+	unsafe_put_user(0, &frame->uc.uc_link, Efault);
+	unsafe_save_altstack32(&frame->uc.uc_stack, regs->sp, Efault);
+
+	if (ksig->ka.sa.sa_flags & SA_RESTORER)
+		restorer = ksig->ka.sa.sa_restorer;
+	else
+		restorer = current->mm->context.vdso +
+			vdso_image_32.sym___kernel_rt_sigreturn;
+	unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
+
+	/*
+	 * Not actually used anymore, but left because some gdb
+	 * versions need it.
+	 */
+	unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
+	unsafe_put_sigcontext32(&frame->uc.uc_mcontext, fp, regs, set, Efault);
+	unsafe_put_user(*(__u64 *)set, (__u64 __user *)&frame->uc.uc_sigmask, Efault);
+	user_access_end();
+
+	if (__copy_siginfo_to_user32(&frame->info, &ksig->info))
+		return -EFAULT;
+
+	/* Set up registers for signal handler */
+	regs->sp = (unsigned long) frame;
+	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
+
+	/* Make -mregparm=3 work */
+	regs->ax = ksig->sig;
+	regs->dx = (unsigned long) &frame->info;
+	regs->cx = (unsigned long) &frame->uc;
+
+#ifdef CONFIG_IA32_EMULATION
+	loadsegment(ds, __USER_DS);
+	loadsegment(es, __USER_DS);
+#else
+	regs->ds = __USER_DS;
+	regs->es = __USER_DS;
+#endif
+
+	regs->cs = __USER32_CS;
+	regs->ss = __USER_DS;
+
+	return 0;
+Efault:
+	user_access_end();
+	return -EFAULT;
+}
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index a34b0f9..33a0ee3 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -264,6 +264,7 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 #define SC_VAL64(type, name) ((type) name##_hi << 32 | name##_lo)
 
 #ifdef CONFIG_COMPAT
+#define SYSCALL32_DEFINE0 COMPAT_SYSCALL_DEFINE0
 #define SYSCALL32_DEFINE1 COMPAT_SYSCALL_DEFINE1
 #define SYSCALL32_DEFINE2 COMPAT_SYSCALL_DEFINE2
 #define SYSCALL32_DEFINE3 COMPAT_SYSCALL_DEFINE3
@@ -271,6 +272,7 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 #define SYSCALL32_DEFINE5 COMPAT_SYSCALL_DEFINE5
 #define SYSCALL32_DEFINE6 COMPAT_SYSCALL_DEFINE6
 #else
+#define SYSCALL32_DEFINE0 SYSCALL_DEFINE0
 #define SYSCALL32_DEFINE1 SYSCALL_DEFINE1
 #define SYSCALL32_DEFINE2 SYSCALL_DEFINE2
 #define SYSCALL32_DEFINE3 SYSCALL_DEFINE3

[PATCH 8/8] x86/signal/64: Move 64-bit signal code to its own file

[Brian Gerst]

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/kernel/Makefile    |   4 +-
 arch/x86/kernel/signal.c    | 376 -----------------------------------
 arch/x86/kernel/signal_64.c | 383 ++++++++++++++++++++++++++++++++++++
 3 files changed, 385 insertions(+), 378 deletions(-)
 create mode 100644 arch/x86/kernel/signal_64.c

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 4aa1bd55a362..a1bb527a02f5 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -48,7 +48,7 @@ KCOV_INSTRUMENT		:= n
 
 CFLAGS_irq.o := -I $(srctree)/$(src)/../include/asm/trace
 
-obj-y			:= process_$(BITS).o signal.o
+obj-y			:= process_$(BITS).o signal.o signal_$(BITS).o
 obj-$(CONFIG_COMPAT)	+= signal_compat.o
 obj-y			+= traps.o idt.o irq.o irq_$(BITS).o dumpstack_$(BITS).o
 obj-y			+= time.o ioport.o dumpstack.o nmi.o
@@ -57,7 +57,7 @@ obj-y			+= setup.o x86_init.o i8259.o irqinit.o
 obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o
 obj-$(CONFIG_IRQ_WORK)  += irq_work.o
 obj-y			+= probe_roms.o
-obj-$(CONFIG_X86_32)	+= sys_ia32.o signal_32.o
+obj-$(CONFIG_X86_32)	+= sys_ia32.o
 obj-$(CONFIG_IA32_EMULATION)	+= sys_ia32.o signal_32.o
 obj-$(CONFIG_X86_64)	+= sys_x86_64.o
 obj-$(CONFIG_X86_ESPFIX64)	+= espfix_64.o
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 962cfd835c90..1504eb8d25aa 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -37,13 +37,6 @@
 #include <asm/sighandling.h>
 #include <asm/vm86.h>
 
-#ifdef CONFIG_X86_64
-#include <linux/compat.h>
-#include <asm/proto.h>
-#include <asm/ia32_unistd.h>
-#include <asm/fpu/xstate.h>
-#endif /* CONFIG_X86_64 */
-
 #include <asm/syscall.h>
 #include <asm/sigframe.h>
 #include <asm/signal.h>
@@ -65,135 +58,6 @@ static inline int is_x32_frame(struct ksignal *ksig)
 		ksig->ka.sa.sa_flags & SA_X32_ABI;
 }
 
-#ifdef CONFIG_X86_64
-/*
- * If regs->ss will cause an IRET fault, change it.  Otherwise leave it
- * alone.  Using this generally makes no sense unless
- * user_64bit_mode(regs) would return true.
- */
-static void force_valid_ss(struct pt_regs *regs)
-{
-	u32 ar;
-	asm volatile ("lar %[old_ss], %[ar]\n\t"
-		      "jz 1f\n\t"		/* If invalid: */
-		      "xorl %[ar], %[ar]\n\t"	/* set ar = 0 */
-		      "1:"
-		      : [ar] "=r" (ar)
-		      : [old_ss] "rm" ((u16)regs->ss));
-
-	/*
-	 * For a valid 64-bit user context, we need DPL 3, type
-	 * read-write data or read-write exp-down data, and S and P
-	 * set.  We can't use VERW because VERW doesn't check the
-	 * P bit.
-	 */
-	ar &= AR_DPL_MASK | AR_S | AR_P | AR_TYPE_MASK;
-	if (ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA) &&
-	    ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA_EXPDOWN))
-		regs->ss = __USER_DS;
-}
-
-static bool restore_sigcontext(struct pt_regs *regs,
-			       struct sigcontext __user *usc,
-			       unsigned long uc_flags)
-{
-	struct sigcontext sc;
-
-	/* Always make any pending restarted system calls return -EINTR */
-	current->restart_block.fn = do_no_restart_syscall;
-
-	if (copy_from_user(&sc, usc, offsetof(struct sigcontext, reserved1)))
-		return false;
-
-	regs->bx = sc.bx;
-	regs->cx = sc.cx;
-	regs->dx = sc.dx;
-	regs->si = sc.si;
-	regs->di = sc.di;
-	regs->bp = sc.bp;
-	regs->ax = sc.ax;
-	regs->sp = sc.sp;
-	regs->ip = sc.ip;
-	regs->r8 = sc.r8;
-	regs->r9 = sc.r9;
-	regs->r10 = sc.r10;
-	regs->r11 = sc.r11;
-	regs->r12 = sc.r12;
-	regs->r13 = sc.r13;
-	regs->r14 = sc.r14;
-	regs->r15 = sc.r15;
-
-	/* Get CS/SS and force CPL3 */
-	regs->cs = sc.cs | 0x03;
-	regs->ss = sc.ss | 0x03;
-
-	regs->flags = (regs->flags & ~FIX_EFLAGS) | (sc.flags & FIX_EFLAGS);
-	/* disable syscall checks */
-	regs->orig_ax = -1;
-
-	/*
-	 * Fix up SS if needed for the benefit of old DOSEMU and
-	 * CRIU.
-	 */
-	if (unlikely(!(uc_flags & UC_STRICT_RESTORE_SS) && user_64bit_mode(regs)))
-		force_valid_ss(regs);
-
-	return fpu__restore_sig((void __user *)sc.fpstate, 0);
-}
-
-static __always_inline int
-__unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
-		     struct pt_regs *regs, unsigned long mask)
-{
-	unsafe_put_user(regs->di, &sc->di, Efault);
-	unsafe_put_user(regs->si, &sc->si, Efault);
-	unsafe_put_user(regs->bp, &sc->bp, Efault);
-	unsafe_put_user(regs->sp, &sc->sp, Efault);
-	unsafe_put_user(regs->bx, &sc->bx, Efault);
-	unsafe_put_user(regs->dx, &sc->dx, Efault);
-	unsafe_put_user(regs->cx, &sc->cx, Efault);
-	unsafe_put_user(regs->ax, &sc->ax, Efault);
-	unsafe_put_user(regs->r8, &sc->r8, Efault);
-	unsafe_put_user(regs->r9, &sc->r9, Efault);
-	unsafe_put_user(regs->r10, &sc->r10, Efault);
-	unsafe_put_user(regs->r11, &sc->r11, Efault);
-	unsafe_put_user(regs->r12, &sc->r12, Efault);
-	unsafe_put_user(regs->r13, &sc->r13, Efault);
-	unsafe_put_user(regs->r14, &sc->r14, Efault);
-	unsafe_put_user(regs->r15, &sc->r15, Efault);
-
-	unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
-	unsafe_put_user(current->thread.error_code, &sc->err, Efault);
-	unsafe_put_user(regs->ip, &sc->ip, Efault);
-	unsafe_put_user(regs->flags, &sc->flags, Efault);
-	unsafe_put_user(regs->cs, &sc->cs, Efault);
-	unsafe_put_user(0, &sc->gs, Efault);
-	unsafe_put_user(0, &sc->fs, Efault);
-	unsafe_put_user(regs->ss, &sc->ss, Efault);
-
-	unsafe_put_user(fpstate, (unsigned long __user *)&sc->fpstate, Efault);
-
-	/* non-iBCS2 extensions.. */
-	unsafe_put_user(mask, &sc->oldmask, Efault);
-	unsafe_put_user(current->thread.cr2, &sc->cr2, Efault);
-	return 0;
-Efault:
-	return -EFAULT;
-}
-
-#define unsafe_put_sigcontext(sc, fp, regs, set, label)			\
-do {									\
-	if (__unsafe_setup_sigcontext(sc, fp, regs, set->sig[0]))	\
-		goto label;						\
-} while(0);
-
-#define unsafe_put_sigmask(set, frame, label) \
-	unsafe_put_user(*(__u64 *)(set), \
-			(__u64 __user *)&(frame)->uc.uc_sigmask, \
-			label)
-
-#endif /* CONFIG_X86_64 */
-
 /*
  * Set up a signal frame.
  */
@@ -279,213 +143,6 @@ get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
 	return (void __user *)sp;
 }
 
-#ifdef CONFIG_X86_64
-static unsigned long frame_uc_flags(struct pt_regs *regs)
-{
-	unsigned long flags;
-
-	if (boot_cpu_has(X86_FEATURE_XSAVE))
-		flags = UC_FP_XSTATE | UC_SIGCONTEXT_SS;
-	else
-		flags = UC_SIGCONTEXT_SS;
-
-	if (likely(user_64bit_mode(regs)))
-		flags |= UC_STRICT_RESTORE_SS;
-
-	return flags;
-}
-
-int x64_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	sigset_t *set = sigmask_to_save();
-	struct rt_sigframe __user *frame;
-	void __user *fp = NULL;
-	unsigned long uc_flags;
-
-	/* x86-64 should always use SA_RESTORER. */
-	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
-		return -EFAULT;
-
-	frame = get_sigframe(ksig, regs, sizeof(struct rt_sigframe), &fp);
-	uc_flags = frame_uc_flags(regs);
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	/* Create the ucontext.  */
-	unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault);
-	unsafe_put_user(0, &frame->uc.uc_link, Efault);
-	unsafe_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
-
-	/* Set up to return from userspace.  If provided, use a stub
-	   already in userspace.  */
-	unsafe_put_user(ksig->ka.sa.sa_restorer, &frame->pretcode, Efault);
-	unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
-	unsafe_put_sigmask(set, frame, Efault);
-	user_access_end();
-
-	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
-		if (copy_siginfo_to_user(&frame->info, &ksig->info))
-			return -EFAULT;
-	}
-
-	/* Set up registers for signal handler */
-	regs->di = ksig->sig;
-	/* In case the signal handler was declared without prototypes */
-	regs->ax = 0;
-
-	/* This also works for non SA_SIGINFO handlers because they expect the
-	   next argument after the signal number on the stack. */
-	regs->si = (unsigned long)&frame->info;
-	regs->dx = (unsigned long)&frame->uc;
-	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
-
-	regs->sp = (unsigned long)frame;
-
-	/*
-	 * Set up the CS and SS registers to run signal handlers in
-	 * 64-bit mode, even if the handler happens to be interrupting
-	 * 32-bit or 16-bit code.
-	 *
-	 * SS is subtle.  In 64-bit mode, we don't need any particular
-	 * SS descriptor, but we do need SS to be valid.  It's possible
-	 * that the old SS is entirely bogus -- this can happen if the
-	 * signal we're trying to deliver is #GP or #SS caused by a bad
-	 * SS value.  We also have a compatibility issue here: DOSEMU
-	 * relies on the contents of the SS register indicating the
-	 * SS value at the time of the signal, even though that code in
-	 * DOSEMU predates sigreturn's ability to restore SS.  (DOSEMU
-	 * avoids relying on sigreturn to restore SS; instead it uses
-	 * a trampoline.)  So we do our best: if the old SS was valid,
-	 * we keep it.  Otherwise we replace it.
-	 */
-	regs->cs = __USER_CS;
-
-	if (unlikely(regs->ss != __USER_DS))
-		force_valid_ss(regs);
-
-	return 0;
-
-Efault:
-	user_access_end();
-	return -EFAULT;
-}
-
-#ifdef CONFIG_X86_X32_ABI
-static int x32_copy_siginfo_to_user(struct compat_siginfo __user *to,
-		const struct kernel_siginfo *from)
-{
-	struct compat_siginfo new;
-
-	copy_siginfo_to_external32(&new, from);
-	if (from->si_signo == SIGCHLD) {
-		new._sifields._sigchld_x32._utime = from->si_utime;
-		new._sifields._sigchld_x32._stime = from->si_stime;
-	}
-	if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
-		return -EFAULT;
-	return 0;
-}
-
-int copy_siginfo_to_user32(struct compat_siginfo __user *to,
-			   const struct kernel_siginfo *from)
-{
-	if (in_x32_syscall())
-		return x32_copy_siginfo_to_user(to, from);
-	return __copy_siginfo_to_user32(to, from);
-}
-
-int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
-	struct rt_sigframe_x32 __user *frame;
-	unsigned long uc_flags;
-	void __user *restorer;
-	void __user *fp = NULL;
-
-	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
-		return -EFAULT;
-
-	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
-	uc_flags = frame_uc_flags(regs);
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	/* Create the ucontext.  */
-	unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault);
-	unsafe_put_user(0, &frame->uc.uc_link, Efault);
-	unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
-	unsafe_put_user(0, &frame->uc.uc__pad0, Efault);
-	restorer = ksig->ka.sa.sa_restorer;
-	unsafe_put_user(restorer, (unsigned long __user *)&frame->pretcode, Efault);
-	unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
-	unsafe_put_sigmask(set, frame, Efault);
-	user_access_end();
-
-	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
-		if (x32_copy_siginfo_to_user(&frame->info, &ksig->info))
-			return -EFAULT;
-	}
-
-	/* Set up registers for signal handler */
-	regs->sp = (unsigned long) frame;
-	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
-
-	/* We use the x32 calling convention here... */
-	regs->di = ksig->sig;
-	regs->si = (unsigned long) &frame->info;
-	regs->dx = (unsigned long) &frame->uc;
-
-	loadsegment(ds, __USER_DS);
-	loadsegment(es, __USER_DS);
-
-	regs->cs = __USER_CS;
-	regs->ss = __USER_DS;
-
-	return 0;
-
-Efault:
-	user_access_end();
-	return -EFAULT;
-}
-#endif /* CONFIG_X86_X32_ABI */
-
-/*
- * Do a signal return; undo the signal stack.
- */
-SYSCALL_DEFINE0(rt_sigreturn)
-{
-	struct pt_regs *regs = current_pt_regs();
-	struct rt_sigframe __user *frame;
-	sigset_t set;
-	unsigned long uc_flags;
-
-	frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
-	if (!access_ok(frame, sizeof(*frame)))
-		goto badframe;
-	if (__get_user(*(__u64 *)&set, (__u64 __user *)&frame->uc.uc_sigmask))
-		goto badframe;
-	if (__get_user(uc_flags, &frame->uc.uc_flags))
-		goto badframe;
-
-	set_current_blocked(&set);
-
-	if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
-		goto badframe;
-
-	if (restore_altstack(&frame->uc.uc_stack))
-		goto badframe;
-
-	return regs->ax;
-
-badframe:
-	signal_fault(regs, frame, "rt_sigreturn");
-	return 0;
-}
-#endif /* CONFIG_X86_64 */
-
 /*
  * There are four different struct types for signal frame: sigframe_ia32,
  * rt_sigframe_ia32, rt_sigframe_x32, and rt_sigframe. Use the worst case
@@ -749,36 +406,3 @@ bool sigaltstack_size_valid(size_t ss_size)
 	return true;
 }
 #endif /* CONFIG_DYNAMIC_SIGFRAME */
-
-#ifdef CONFIG_X86_X32_ABI
-COMPAT_SYSCALL_DEFINE0(x32_rt_sigreturn)
-{
-	struct pt_regs *regs = current_pt_regs();
-	struct rt_sigframe_x32 __user *frame;
-	sigset_t set;
-	unsigned long uc_flags;
-
-	frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
-
-	if (!access_ok(frame, sizeof(*frame)))
-		goto badframe;
-	if (__get_user(set.sig[0], (__u64 __user *)&frame->uc.uc_sigmask))
-		goto badframe;
-	if (__get_user(uc_flags, &frame->uc.uc_flags))
-		goto badframe;
-
-	set_current_blocked(&set);
-
-	if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
-		goto badframe;
-
-	if (compat_restore_altstack(&frame->uc.uc_stack))
-		goto badframe;
-
-	return regs->ax;
-
-badframe:
-	signal_fault(regs, frame, "x32 rt_sigreturn");
-	return 0;
-}
-#endif
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
new file mode 100644
index 000000000000..ff9c55064223
--- /dev/null
+++ b/arch/x86/kernel/signal_64.c
@@ -0,0 +1,383 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+
+#include <asm/ucontext.h>
+#include <asm/fpu/signal.h>
+#include <asm/sighandling.h>
+
+#include <asm/syscall.h>
+#include <asm/sigframe.h>
+#include <asm/signal.h>
+
+/*
+ * If regs->ss will cause an IRET fault, change it.  Otherwise leave it
+ * alone.  Using this generally makes no sense unless
+ * user_64bit_mode(regs) would return true.
+ */
+static void force_valid_ss(struct pt_regs *regs)
+{
+	u32 ar;
+	asm volatile ("lar %[old_ss], %[ar]\n\t"
+		      "jz 1f\n\t"		/* If invalid: */
+		      "xorl %[ar], %[ar]\n\t"	/* set ar = 0 */
+		      "1:"
+		      : [ar] "=r" (ar)
+		      : [old_ss] "rm" ((u16)regs->ss));
+
+	/*
+	 * For a valid 64-bit user context, we need DPL 3, type
+	 * read-write data or read-write exp-down data, and S and P
+	 * set.  We can't use VERW because VERW doesn't check the
+	 * P bit.
+	 */
+	ar &= AR_DPL_MASK | AR_S | AR_P | AR_TYPE_MASK;
+	if (ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA) &&
+	    ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA_EXPDOWN))
+		regs->ss = __USER_DS;
+}
+
+static bool restore_sigcontext(struct pt_regs *regs,
+			       struct sigcontext __user *usc,
+			       unsigned long uc_flags)
+{
+	struct sigcontext sc;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	if (copy_from_user(&sc, usc, offsetof(struct sigcontext, reserved1)))
+		return false;
+
+	regs->bx = sc.bx;
+	regs->cx = sc.cx;
+	regs->dx = sc.dx;
+	regs->si = sc.si;
+	regs->di = sc.di;
+	regs->bp = sc.bp;
+	regs->ax = sc.ax;
+	regs->sp = sc.sp;
+	regs->ip = sc.ip;
+	regs->r8 = sc.r8;
+	regs->r9 = sc.r9;
+	regs->r10 = sc.r10;
+	regs->r11 = sc.r11;
+	regs->r12 = sc.r12;
+	regs->r13 = sc.r13;
+	regs->r14 = sc.r14;
+	regs->r15 = sc.r15;
+
+	/* Get CS/SS and force CPL3 */
+	regs->cs = sc.cs | 0x03;
+	regs->ss = sc.ss | 0x03;
+
+	regs->flags = (regs->flags & ~FIX_EFLAGS) | (sc.flags & FIX_EFLAGS);
+	/* disable syscall checks */
+	regs->orig_ax = -1;
+
+	/*
+	 * Fix up SS if needed for the benefit of old DOSEMU and
+	 * CRIU.
+	 */
+	if (unlikely(!(uc_flags & UC_STRICT_RESTORE_SS) && user_64bit_mode(regs)))
+		force_valid_ss(regs);
+
+	return fpu__restore_sig((void __user *)sc.fpstate, 0);
+}
+
+static __always_inline int
+__unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
+		     struct pt_regs *regs, unsigned long mask)
+{
+	unsafe_put_user(regs->di, &sc->di, Efault);
+	unsafe_put_user(regs->si, &sc->si, Efault);
+	unsafe_put_user(regs->bp, &sc->bp, Efault);
+	unsafe_put_user(regs->sp, &sc->sp, Efault);
+	unsafe_put_user(regs->bx, &sc->bx, Efault);
+	unsafe_put_user(regs->dx, &sc->dx, Efault);
+	unsafe_put_user(regs->cx, &sc->cx, Efault);
+	unsafe_put_user(regs->ax, &sc->ax, Efault);
+	unsafe_put_user(regs->r8, &sc->r8, Efault);
+	unsafe_put_user(regs->r9, &sc->r9, Efault);
+	unsafe_put_user(regs->r10, &sc->r10, Efault);
+	unsafe_put_user(regs->r11, &sc->r11, Efault);
+	unsafe_put_user(regs->r12, &sc->r12, Efault);
+	unsafe_put_user(regs->r13, &sc->r13, Efault);
+	unsafe_put_user(regs->r14, &sc->r14, Efault);
+	unsafe_put_user(regs->r15, &sc->r15, Efault);
+
+	unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
+	unsafe_put_user(current->thread.error_code, &sc->err, Efault);
+	unsafe_put_user(regs->ip, &sc->ip, Efault);
+	unsafe_put_user(regs->flags, &sc->flags, Efault);
+	unsafe_put_user(regs->cs, &sc->cs, Efault);
+	unsafe_put_user(0, &sc->gs, Efault);
+	unsafe_put_user(0, &sc->fs, Efault);
+	unsafe_put_user(regs->ss, &sc->ss, Efault);
+
+	unsafe_put_user(fpstate, (unsigned long __user *)&sc->fpstate, Efault);
+
+	/* non-iBCS2 extensions.. */
+	unsafe_put_user(mask, &sc->oldmask, Efault);
+	unsafe_put_user(current->thread.cr2, &sc->cr2, Efault);
+	return 0;
+Efault:
+	return -EFAULT;
+}
+
+#define unsafe_put_sigcontext(sc, fp, regs, set, label)			\
+do {									\
+	if (__unsafe_setup_sigcontext(sc, fp, regs, set->sig[0]))	\
+		goto label;						\
+} while(0);
+
+#define unsafe_put_sigmask(set, frame, label) \
+	unsafe_put_user(*(__u64 *)(set), \
+			(__u64 __user *)&(frame)->uc.uc_sigmask, \
+			label)
+
+static unsigned long frame_uc_flags(struct pt_regs *regs)
+{
+	unsigned long flags;
+
+	if (boot_cpu_has(X86_FEATURE_XSAVE))
+		flags = UC_FP_XSTATE | UC_SIGCONTEXT_SS;
+	else
+		flags = UC_SIGCONTEXT_SS;
+
+	if (likely(user_64bit_mode(regs)))
+		flags |= UC_STRICT_RESTORE_SS;
+
+	return flags;
+}
+
+int x64_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+{
+	sigset_t *set = sigmask_to_save();
+	struct rt_sigframe __user *frame;
+	void __user *fp = NULL;
+	unsigned long uc_flags;
+
+	/* x86-64 should always use SA_RESTORER. */
+	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
+		return -EFAULT;
+
+	frame = get_sigframe(ksig, regs, sizeof(struct rt_sigframe), &fp);
+	uc_flags = frame_uc_flags(regs);
+
+	if (!user_access_begin(frame, sizeof(*frame)))
+		return -EFAULT;
+
+	/* Create the ucontext.  */
+	unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault);
+	unsafe_put_user(0, &frame->uc.uc_link, Efault);
+	unsafe_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	unsafe_put_user(ksig->ka.sa.sa_restorer, &frame->pretcode, Efault);
+	unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
+	unsafe_put_sigmask(set, frame, Efault);
+	user_access_end();
+
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
+		if (copy_siginfo_to_user(&frame->info, &ksig->info))
+			return -EFAULT;
+	}
+
+	/* Set up registers for signal handler */
+	regs->di = ksig->sig;
+	/* In case the signal handler was declared without prototypes */
+	regs->ax = 0;
+
+	/* This also works for non SA_SIGINFO handlers because they expect the
+	   next argument after the signal number on the stack. */
+	regs->si = (unsigned long)&frame->info;
+	regs->dx = (unsigned long)&frame->uc;
+	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
+
+	regs->sp = (unsigned long)frame;
+
+	/*
+	 * Set up the CS and SS registers to run signal handlers in
+	 * 64-bit mode, even if the handler happens to be interrupting
+	 * 32-bit or 16-bit code.
+	 *
+	 * SS is subtle.  In 64-bit mode, we don't need any particular
+	 * SS descriptor, but we do need SS to be valid.  It's possible
+	 * that the old SS is entirely bogus -- this can happen if the
+	 * signal we're trying to deliver is #GP or #SS caused by a bad
+	 * SS value.  We also have a compatibility issue here: DOSEMU
+	 * relies on the contents of the SS register indicating the
+	 * SS value at the time of the signal, even though that code in
+	 * DOSEMU predates sigreturn's ability to restore SS.  (DOSEMU
+	 * avoids relying on sigreturn to restore SS; instead it uses
+	 * a trampoline.)  So we do our best: if the old SS was valid,
+	 * we keep it.  Otherwise we replace it.
+	 */
+	regs->cs = __USER_CS;
+
+	if (unlikely(regs->ss != __USER_DS))
+		force_valid_ss(regs);
+
+	return 0;
+
+Efault:
+	user_access_end();
+	return -EFAULT;
+}
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+SYSCALL_DEFINE0(rt_sigreturn)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct rt_sigframe __user *frame;
+	sigset_t set;
+	unsigned long uc_flags;
+
+	frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+	if (__get_user(*(__u64 *)&set, (__u64 __user *)&frame->uc.uc_sigmask))
+		goto badframe;
+	if (__get_user(uc_flags, &frame->uc.uc_flags))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
+		goto badframe;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return regs->ax;
+
+badframe:
+	signal_fault(regs, frame, "rt_sigreturn");
+	return 0;
+}
+
+#ifdef CONFIG_X86_X32_ABI
+static int x32_copy_siginfo_to_user(struct compat_siginfo __user *to,
+		const struct kernel_siginfo *from)
+{
+	struct compat_siginfo new;
+
+	copy_siginfo_to_external32(&new, from);
+	if (from->si_signo == SIGCHLD) {
+		new._sifields._sigchld_x32._utime = from->si_utime;
+		new._sifields._sigchld_x32._stime = from->si_stime;
+	}
+	if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
+		return -EFAULT;
+	return 0;
+}
+
+int copy_siginfo_to_user32(struct compat_siginfo __user *to,
+			   const struct kernel_siginfo *from)
+{
+	if (in_x32_syscall())
+		return x32_copy_siginfo_to_user(to, from);
+	return __copy_siginfo_to_user32(to, from);
+}
+
+int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+{
+	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
+	struct rt_sigframe_x32 __user *frame;
+	unsigned long uc_flags;
+	void __user *restorer;
+	void __user *fp = NULL;
+
+	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
+		return -EFAULT;
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
+
+	uc_flags = frame_uc_flags(regs);
+
+	if (!user_access_begin(frame, sizeof(*frame)))
+		return -EFAULT;
+
+	/* Create the ucontext.  */
+	unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault);
+	unsafe_put_user(0, &frame->uc.uc_link, Efault);
+	unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
+	unsafe_put_user(0, &frame->uc.uc__pad0, Efault);
+	restorer = ksig->ka.sa.sa_restorer;
+	unsafe_put_user(restorer, (unsigned long __user *)&frame->pretcode, Efault);
+	unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
+	unsafe_put_sigmask(set, frame, Efault);
+	user_access_end();
+
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
+		if (x32_copy_siginfo_to_user(&frame->info, &ksig->info))
+			return -EFAULT;
+	}
+
+	/* Set up registers for signal handler */
+	regs->sp = (unsigned long) frame;
+	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
+
+	/* We use the x32 calling convention here... */
+	regs->di = ksig->sig;
+	regs->si = (unsigned long) &frame->info;
+	regs->dx = (unsigned long) &frame->uc;
+
+	loadsegment(ds, __USER_DS);
+	loadsegment(es, __USER_DS);
+
+	regs->cs = __USER_CS;
+	regs->ss = __USER_DS;
+
+	return 0;
+
+Efault:
+	user_access_end();
+	return -EFAULT;
+}
+
+COMPAT_SYSCALL_DEFINE0(x32_rt_sigreturn)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct rt_sigframe_x32 __user *frame;
+	sigset_t set;
+	unsigned long uc_flags;
+
+	frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
+
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+	if (__get_user(set.sig[0], (__u64 __user *)&frame->uc.uc_sigmask))
+		goto badframe;
+	if (__get_user(uc_flags, &frame->uc.uc_flags))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
+		goto badframe;
+
+	if (compat_restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return regs->ax;
+
+badframe:
+	signal_fault(regs, frame, "x32 rt_sigreturn");
+	return 0;
+}
+#endif /* CONFIG_X86_X32_ABI */
-- 
2.35.3

[tip: x86/misc] x86/signal/64: Move 64-bit signal code to its own file

[tip-bot2 for Brian Gerst]

The following commit has been merged into the x86/misc branch of tip:

Commit-ID:     a545b48c2d907d6096e7bcf65d9b0681cc850e69
Gitweb:        https://git.kernel.org/tip/a545b48c2d907d6096e7bcf65d9b0681cc850e69
Author:        Brian Gerst <brgerst@gmail.com>
AuthorDate:    Mon, 06 Jun 2022 16:38:02 -04:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 19 Oct 2022 09:58:49 +02:00

x86/signal/64: Move 64-bit signal code to its own file

  [ bp: Fixup merge conflict caused by changes coming from the kbuild tree. ]

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/20220606203802.158958-9-brgerst@gmail.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/kernel/Makefile    |   4 +-
 arch/x86/kernel/signal.c    | 376 +----------------------------------
 arch/x86/kernel/signal_64.c | 383 +++++++++++++++++++++++++++++++++++-
 3 files changed, 385 insertions(+), 378 deletions(-)
 create mode 100644 arch/x86/kernel/signal_64.c

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 72e1371..cceaafd 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -44,7 +44,7 @@ obj-y			+= head_$(BITS).o
 obj-y			+= head$(BITS).o
 obj-y			+= ebda.o
 obj-y			+= platform-quirks.o
-obj-y			+= process_$(BITS).o signal.o
+obj-y			+= process_$(BITS).o signal.o signal_$(BITS).o
 obj-$(CONFIG_COMPAT)	+= signal_compat.o
 obj-y			+= traps.o idt.o irq.o irq_$(BITS).o dumpstack_$(BITS).o
 obj-y			+= time.o ioport.o dumpstack.o nmi.o
@@ -53,7 +53,7 @@ obj-y			+= setup.o x86_init.o i8259.o irqinit.o
 obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o
 obj-$(CONFIG_IRQ_WORK)  += irq_work.o
 obj-y			+= probe_roms.o
-obj-$(CONFIG_X86_32)	+= sys_ia32.o signal_32.o
+obj-$(CONFIG_X86_32)	+= sys_ia32.o
 obj-$(CONFIG_IA32_EMULATION)	+= sys_ia32.o signal_32.o
 obj-$(CONFIG_X86_64)	+= sys_x86_64.o
 obj-$(CONFIG_X86_ESPFIX64)	+= espfix_64.o
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 962cfd8..1504eb8 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -37,13 +37,6 @@
 #include <asm/sighandling.h>
 #include <asm/vm86.h>
 
-#ifdef CONFIG_X86_64
-#include <linux/compat.h>
-#include <asm/proto.h>
-#include <asm/ia32_unistd.h>
-#include <asm/fpu/xstate.h>
-#endif /* CONFIG_X86_64 */
-
 #include <asm/syscall.h>
 #include <asm/sigframe.h>
 #include <asm/signal.h>
@@ -65,135 +58,6 @@ static inline int is_x32_frame(struct ksignal *ksig)
 		ksig->ka.sa.sa_flags & SA_X32_ABI;
 }
 
-#ifdef CONFIG_X86_64
-/*
- * If regs->ss will cause an IRET fault, change it.  Otherwise leave it
- * alone.  Using this generally makes no sense unless
- * user_64bit_mode(regs) would return true.
- */
-static void force_valid_ss(struct pt_regs *regs)
-{
-	u32 ar;
-	asm volatile ("lar %[old_ss], %[ar]\n\t"
-		      "jz 1f\n\t"		/* If invalid: */
-		      "xorl %[ar], %[ar]\n\t"	/* set ar = 0 */
-		      "1:"
-		      : [ar] "=r" (ar)
-		      : [old_ss] "rm" ((u16)regs->ss));
-
-	/*
-	 * For a valid 64-bit user context, we need DPL 3, type
-	 * read-write data or read-write exp-down data, and S and P
-	 * set.  We can't use VERW because VERW doesn't check the
-	 * P bit.
-	 */
-	ar &= AR_DPL_MASK | AR_S | AR_P | AR_TYPE_MASK;
-	if (ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA) &&
-	    ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA_EXPDOWN))
-		regs->ss = __USER_DS;
-}
-
-static bool restore_sigcontext(struct pt_regs *regs,
-			       struct sigcontext __user *usc,
-			       unsigned long uc_flags)
-{
-	struct sigcontext sc;
-
-	/* Always make any pending restarted system calls return -EINTR */
-	current->restart_block.fn = do_no_restart_syscall;
-
-	if (copy_from_user(&sc, usc, offsetof(struct sigcontext, reserved1)))
-		return false;
-
-	regs->bx = sc.bx;
-	regs->cx = sc.cx;
-	regs->dx = sc.dx;
-	regs->si = sc.si;
-	regs->di = sc.di;
-	regs->bp = sc.bp;
-	regs->ax = sc.ax;
-	regs->sp = sc.sp;
-	regs->ip = sc.ip;
-	regs->r8 = sc.r8;
-	regs->r9 = sc.r9;
-	regs->r10 = sc.r10;
-	regs->r11 = sc.r11;
-	regs->r12 = sc.r12;
-	regs->r13 = sc.r13;
-	regs->r14 = sc.r14;
-	regs->r15 = sc.r15;
-
-	/* Get CS/SS and force CPL3 */
-	regs->cs = sc.cs | 0x03;
-	regs->ss = sc.ss | 0x03;
-
-	regs->flags = (regs->flags & ~FIX_EFLAGS) | (sc.flags & FIX_EFLAGS);
-	/* disable syscall checks */
-	regs->orig_ax = -1;
-
-	/*
-	 * Fix up SS if needed for the benefit of old DOSEMU and
-	 * CRIU.
-	 */
-	if (unlikely(!(uc_flags & UC_STRICT_RESTORE_SS) && user_64bit_mode(regs)))
-		force_valid_ss(regs);
-
-	return fpu__restore_sig((void __user *)sc.fpstate, 0);
-}
-
-static __always_inline int
-__unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
-		     struct pt_regs *regs, unsigned long mask)
-{
-	unsafe_put_user(regs->di, &sc->di, Efault);
-	unsafe_put_user(regs->si, &sc->si, Efault);
-	unsafe_put_user(regs->bp, &sc->bp, Efault);
-	unsafe_put_user(regs->sp, &sc->sp, Efault);
-	unsafe_put_user(regs->bx, &sc->bx, Efault);
-	unsafe_put_user(regs->dx, &sc->dx, Efault);
-	unsafe_put_user(regs->cx, &sc->cx, Efault);
-	unsafe_put_user(regs->ax, &sc->ax, Efault);
-	unsafe_put_user(regs->r8, &sc->r8, Efault);
-	unsafe_put_user(regs->r9, &sc->r9, Efault);
-	unsafe_put_user(regs->r10, &sc->r10, Efault);
-	unsafe_put_user(regs->r11, &sc->r11, Efault);
-	unsafe_put_user(regs->r12, &sc->r12, Efault);
-	unsafe_put_user(regs->r13, &sc->r13, Efault);
-	unsafe_put_user(regs->r14, &sc->r14, Efault);
-	unsafe_put_user(regs->r15, &sc->r15, Efault);
-
-	unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
-	unsafe_put_user(current->thread.error_code, &sc->err, Efault);
-	unsafe_put_user(regs->ip, &sc->ip, Efault);
-	unsafe_put_user(regs->flags, &sc->flags, Efault);
-	unsafe_put_user(regs->cs, &sc->cs, Efault);
-	unsafe_put_user(0, &sc->gs, Efault);
-	unsafe_put_user(0, &sc->fs, Efault);
-	unsafe_put_user(regs->ss, &sc->ss, Efault);
-
-	unsafe_put_user(fpstate, (unsigned long __user *)&sc->fpstate, Efault);
-
-	/* non-iBCS2 extensions.. */
-	unsafe_put_user(mask, &sc->oldmask, Efault);
-	unsafe_put_user(current->thread.cr2, &sc->cr2, Efault);
-	return 0;
-Efault:
-	return -EFAULT;
-}
-
-#define unsafe_put_sigcontext(sc, fp, regs, set, label)			\
-do {									\
-	if (__unsafe_setup_sigcontext(sc, fp, regs, set->sig[0]))	\
-		goto label;						\
-} while(0);
-
-#define unsafe_put_sigmask(set, frame, label) \
-	unsafe_put_user(*(__u64 *)(set), \
-			(__u64 __user *)&(frame)->uc.uc_sigmask, \
-			label)
-
-#endif /* CONFIG_X86_64 */
-
 /*
  * Set up a signal frame.
  */
@@ -279,213 +143,6 @@ get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
 	return (void __user *)sp;
 }
 
-#ifdef CONFIG_X86_64
-static unsigned long frame_uc_flags(struct pt_regs *regs)
-{
-	unsigned long flags;
-
-	if (boot_cpu_has(X86_FEATURE_XSAVE))
-		flags = UC_FP_XSTATE | UC_SIGCONTEXT_SS;
-	else
-		flags = UC_SIGCONTEXT_SS;
-
-	if (likely(user_64bit_mode(regs)))
-		flags |= UC_STRICT_RESTORE_SS;
-
-	return flags;
-}
-
-int x64_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	sigset_t *set = sigmask_to_save();
-	struct rt_sigframe __user *frame;
-	void __user *fp = NULL;
-	unsigned long uc_flags;
-
-	/* x86-64 should always use SA_RESTORER. */
-	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
-		return -EFAULT;
-
-	frame = get_sigframe(ksig, regs, sizeof(struct rt_sigframe), &fp);
-	uc_flags = frame_uc_flags(regs);
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	/* Create the ucontext.  */
-	unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault);
-	unsafe_put_user(0, &frame->uc.uc_link, Efault);
-	unsafe_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
-
-	/* Set up to return from userspace.  If provided, use a stub
-	   already in userspace.  */
-	unsafe_put_user(ksig->ka.sa.sa_restorer, &frame->pretcode, Efault);
-	unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
-	unsafe_put_sigmask(set, frame, Efault);
-	user_access_end();
-
-	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
-		if (copy_siginfo_to_user(&frame->info, &ksig->info))
-			return -EFAULT;
-	}
-
-	/* Set up registers for signal handler */
-	regs->di = ksig->sig;
-	/* In case the signal handler was declared without prototypes */
-	regs->ax = 0;
-
-	/* This also works for non SA_SIGINFO handlers because they expect the
-	   next argument after the signal number on the stack. */
-	regs->si = (unsigned long)&frame->info;
-	regs->dx = (unsigned long)&frame->uc;
-	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
-
-	regs->sp = (unsigned long)frame;
-
-	/*
-	 * Set up the CS and SS registers to run signal handlers in
-	 * 64-bit mode, even if the handler happens to be interrupting
-	 * 32-bit or 16-bit code.
-	 *
-	 * SS is subtle.  In 64-bit mode, we don't need any particular
-	 * SS descriptor, but we do need SS to be valid.  It's possible
-	 * that the old SS is entirely bogus -- this can happen if the
-	 * signal we're trying to deliver is #GP or #SS caused by a bad
-	 * SS value.  We also have a compatibility issue here: DOSEMU
-	 * relies on the contents of the SS register indicating the
-	 * SS value at the time of the signal, even though that code in
-	 * DOSEMU predates sigreturn's ability to restore SS.  (DOSEMU
-	 * avoids relying on sigreturn to restore SS; instead it uses
-	 * a trampoline.)  So we do our best: if the old SS was valid,
-	 * we keep it.  Otherwise we replace it.
-	 */
-	regs->cs = __USER_CS;
-
-	if (unlikely(regs->ss != __USER_DS))
-		force_valid_ss(regs);
-
-	return 0;
-
-Efault:
-	user_access_end();
-	return -EFAULT;
-}
-
-#ifdef CONFIG_X86_X32_ABI
-static int x32_copy_siginfo_to_user(struct compat_siginfo __user *to,
-		const struct kernel_siginfo *from)
-{
-	struct compat_siginfo new;
-
-	copy_siginfo_to_external32(&new, from);
-	if (from->si_signo == SIGCHLD) {
-		new._sifields._sigchld_x32._utime = from->si_utime;
-		new._sifields._sigchld_x32._stime = from->si_stime;
-	}
-	if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
-		return -EFAULT;
-	return 0;
-}
-
-int copy_siginfo_to_user32(struct compat_siginfo __user *to,
-			   const struct kernel_siginfo *from)
-{
-	if (in_x32_syscall())
-		return x32_copy_siginfo_to_user(to, from);
-	return __copy_siginfo_to_user32(to, from);
-}
-
-int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
-	struct rt_sigframe_x32 __user *frame;
-	unsigned long uc_flags;
-	void __user *restorer;
-	void __user *fp = NULL;
-
-	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
-		return -EFAULT;
-
-	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
-	uc_flags = frame_uc_flags(regs);
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	/* Create the ucontext.  */
-	unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault);
-	unsafe_put_user(0, &frame->uc.uc_link, Efault);
-	unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
-	unsafe_put_user(0, &frame->uc.uc__pad0, Efault);
-	restorer = ksig->ka.sa.sa_restorer;
-	unsafe_put_user(restorer, (unsigned long __user *)&frame->pretcode, Efault);
-	unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
-	unsafe_put_sigmask(set, frame, Efault);
-	user_access_end();
-
-	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
-		if (x32_copy_siginfo_to_user(&frame->info, &ksig->info))
-			return -EFAULT;
-	}
-
-	/* Set up registers for signal handler */
-	regs->sp = (unsigned long) frame;
-	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
-
-	/* We use the x32 calling convention here... */
-	regs->di = ksig->sig;
-	regs->si = (unsigned long) &frame->info;
-	regs->dx = (unsigned long) &frame->uc;
-
-	loadsegment(ds, __USER_DS);
-	loadsegment(es, __USER_DS);
-
-	regs->cs = __USER_CS;
-	regs->ss = __USER_DS;
-
-	return 0;
-
-Efault:
-	user_access_end();
-	return -EFAULT;
-}
-#endif /* CONFIG_X86_X32_ABI */
-
-/*
- * Do a signal return; undo the signal stack.
- */
-SYSCALL_DEFINE0(rt_sigreturn)
-{
-	struct pt_regs *regs = current_pt_regs();
-	struct rt_sigframe __user *frame;
-	sigset_t set;
-	unsigned long uc_flags;
-
-	frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
-	if (!access_ok(frame, sizeof(*frame)))
-		goto badframe;
-	if (__get_user(*(__u64 *)&set, (__u64 __user *)&frame->uc.uc_sigmask))
-		goto badframe;
-	if (__get_user(uc_flags, &frame->uc.uc_flags))
-		goto badframe;
-
-	set_current_blocked(&set);
-
-	if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
-		goto badframe;
-
-	if (restore_altstack(&frame->uc.uc_stack))
-		goto badframe;
-
-	return regs->ax;
-
-badframe:
-	signal_fault(regs, frame, "rt_sigreturn");
-	return 0;
-}
-#endif /* CONFIG_X86_64 */
-
 /*
  * There are four different struct types for signal frame: sigframe_ia32,
  * rt_sigframe_ia32, rt_sigframe_x32, and rt_sigframe. Use the worst case
@@ -749,36 +406,3 @@ bool sigaltstack_size_valid(size_t ss_size)
 	return true;
 }
 #endif /* CONFIG_DYNAMIC_SIGFRAME */
-
-#ifdef CONFIG_X86_X32_ABI
-COMPAT_SYSCALL_DEFINE0(x32_rt_sigreturn)
-{
-	struct pt_regs *regs = current_pt_regs();
-	struct rt_sigframe_x32 __user *frame;
-	sigset_t set;
-	unsigned long uc_flags;
-
-	frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
-
-	if (!access_ok(frame, sizeof(*frame)))
-		goto badframe;
-	if (__get_user(set.sig[0], (__u64 __user *)&frame->uc.uc_sigmask))
-		goto badframe;
-	if (__get_user(uc_flags, &frame->uc.uc_flags))
-		goto badframe;
-
-	set_current_blocked(&set);
-
-	if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
-		goto badframe;
-
-	if (compat_restore_altstack(&frame->uc.uc_stack))
-		goto badframe;
-
-	return regs->ax;
-
-badframe:
-	signal_fault(regs, frame, "x32 rt_sigreturn");
-	return 0;
-}
-#endif
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
new file mode 100644
index 0000000..ff9c550
--- /dev/null
+++ b/arch/x86/kernel/signal_64.c
@@ -0,0 +1,383 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+
+#include <asm/ucontext.h>
+#include <asm/fpu/signal.h>
+#include <asm/sighandling.h>
+
+#include <asm/syscall.h>
+#include <asm/sigframe.h>
+#include <asm/signal.h>
+
+/*
+ * If regs->ss will cause an IRET fault, change it.  Otherwise leave it
+ * alone.  Using this generally makes no sense unless
+ * user_64bit_mode(regs) would return true.
+ */
+static void force_valid_ss(struct pt_regs *regs)
+{
+	u32 ar;
+	asm volatile ("lar %[old_ss], %[ar]\n\t"
+		      "jz 1f\n\t"		/* If invalid: */
+		      "xorl %[ar], %[ar]\n\t"	/* set ar = 0 */
+		      "1:"
+		      : [ar] "=r" (ar)
+		      : [old_ss] "rm" ((u16)regs->ss));
+
+	/*
+	 * For a valid 64-bit user context, we need DPL 3, type
+	 * read-write data or read-write exp-down data, and S and P
+	 * set.  We can't use VERW because VERW doesn't check the
+	 * P bit.
+	 */
+	ar &= AR_DPL_MASK | AR_S | AR_P | AR_TYPE_MASK;
+	if (ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA) &&
+	    ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA_EXPDOWN))
+		regs->ss = __USER_DS;
+}
+
+static bool restore_sigcontext(struct pt_regs *regs,
+			       struct sigcontext __user *usc,
+			       unsigned long uc_flags)
+{
+	struct sigcontext sc;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	if (copy_from_user(&sc, usc, offsetof(struct sigcontext, reserved1)))
+		return false;
+
+	regs->bx = sc.bx;
+	regs->cx = sc.cx;
+	regs->dx = sc.dx;
+	regs->si = sc.si;
+	regs->di = sc.di;
+	regs->bp = sc.bp;
+	regs->ax = sc.ax;
+	regs->sp = sc.sp;
+	regs->ip = sc.ip;
+	regs->r8 = sc.r8;
+	regs->r9 = sc.r9;
+	regs->r10 = sc.r10;
+	regs->r11 = sc.r11;
+	regs->r12 = sc.r12;
+	regs->r13 = sc.r13;
+	regs->r14 = sc.r14;
+	regs->r15 = sc.r15;
+
+	/* Get CS/SS and force CPL3 */
+	regs->cs = sc.cs | 0x03;
+	regs->ss = sc.ss | 0x03;
+
+	regs->flags = (regs->flags & ~FIX_EFLAGS) | (sc.flags & FIX_EFLAGS);
+	/* disable syscall checks */
+	regs->orig_ax = -1;
+
+	/*
+	 * Fix up SS if needed for the benefit of old DOSEMU and
+	 * CRIU.
+	 */
+	if (unlikely(!(uc_flags & UC_STRICT_RESTORE_SS) && user_64bit_mode(regs)))
+		force_valid_ss(regs);
+
+	return fpu__restore_sig((void __user *)sc.fpstate, 0);
+}
+
+static __always_inline int
+__unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
+		     struct pt_regs *regs, unsigned long mask)
+{
+	unsafe_put_user(regs->di, &sc->di, Efault);
+	unsafe_put_user(regs->si, &sc->si, Efault);
+	unsafe_put_user(regs->bp, &sc->bp, Efault);
+	unsafe_put_user(regs->sp, &sc->sp, Efault);
+	unsafe_put_user(regs->bx, &sc->bx, Efault);
+	unsafe_put_user(regs->dx, &sc->dx, Efault);
+	unsafe_put_user(regs->cx, &sc->cx, Efault);
+	unsafe_put_user(regs->ax, &sc->ax, Efault);
+	unsafe_put_user(regs->r8, &sc->r8, Efault);
+	unsafe_put_user(regs->r9, &sc->r9, Efault);
+	unsafe_put_user(regs->r10, &sc->r10, Efault);
+	unsafe_put_user(regs->r11, &sc->r11, Efault);
+	unsafe_put_user(regs->r12, &sc->r12, Efault);
+	unsafe_put_user(regs->r13, &sc->r13, Efault);
+	unsafe_put_user(regs->r14, &sc->r14, Efault);
+	unsafe_put_user(regs->r15, &sc->r15, Efault);
+
+	unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
+	unsafe_put_user(current->thread.error_code, &sc->err, Efault);
+	unsafe_put_user(regs->ip, &sc->ip, Efault);
+	unsafe_put_user(regs->flags, &sc->flags, Efault);
+	unsafe_put_user(regs->cs, &sc->cs, Efault);
+	unsafe_put_user(0, &sc->gs, Efault);
+	unsafe_put_user(0, &sc->fs, Efault);
+	unsafe_put_user(regs->ss, &sc->ss, Efault);
+
+	unsafe_put_user(fpstate, (unsigned long __user *)&sc->fpstate, Efault);
+
+	/* non-iBCS2 extensions.. */
+	unsafe_put_user(mask, &sc->oldmask, Efault);
+	unsafe_put_user(current->thread.cr2, &sc->cr2, Efault);
+	return 0;
+Efault:
+	return -EFAULT;
+}
+
+#define unsafe_put_sigcontext(sc, fp, regs, set, label)			\
+do {									\
+	if (__unsafe_setup_sigcontext(sc, fp, regs, set->sig[0]))	\
+		goto label;						\
+} while(0);
+
+#define unsafe_put_sigmask(set, frame, label) \
+	unsafe_put_user(*(__u64 *)(set), \
+			(__u64 __user *)&(frame)->uc.uc_sigmask, \
+			label)
+
+static unsigned long frame_uc_flags(struct pt_regs *regs)
+{
+	unsigned long flags;
+
+	if (boot_cpu_has(X86_FEATURE_XSAVE))
+		flags = UC_FP_XSTATE | UC_SIGCONTEXT_SS;
+	else
+		flags = UC_SIGCONTEXT_SS;
+
+	if (likely(user_64bit_mode(regs)))
+		flags |= UC_STRICT_RESTORE_SS;
+
+	return flags;
+}
+
+int x64_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+{
+	sigset_t *set = sigmask_to_save();
+	struct rt_sigframe __user *frame;
+	void __user *fp = NULL;
+	unsigned long uc_flags;
+
+	/* x86-64 should always use SA_RESTORER. */
+	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
+		return -EFAULT;
+
+	frame = get_sigframe(ksig, regs, sizeof(struct rt_sigframe), &fp);
+	uc_flags = frame_uc_flags(regs);
+
+	if (!user_access_begin(frame, sizeof(*frame)))
+		return -EFAULT;
+
+	/* Create the ucontext.  */
+	unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault);
+	unsafe_put_user(0, &frame->uc.uc_link, Efault);
+	unsafe_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	unsafe_put_user(ksig->ka.sa.sa_restorer, &frame->pretcode, Efault);
+	unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
+	unsafe_put_sigmask(set, frame, Efault);
+	user_access_end();
+
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
+		if (copy_siginfo_to_user(&frame->info, &ksig->info))
+			return -EFAULT;
+	}
+
+	/* Set up registers for signal handler */
+	regs->di = ksig->sig;
+	/* In case the signal handler was declared without prototypes */
+	regs->ax = 0;
+
+	/* This also works for non SA_SIGINFO handlers because they expect the
+	   next argument after the signal number on the stack. */
+	regs->si = (unsigned long)&frame->info;
+	regs->dx = (unsigned long)&frame->uc;
+	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
+
+	regs->sp = (unsigned long)frame;
+
+	/*
+	 * Set up the CS and SS registers to run signal handlers in
+	 * 64-bit mode, even if the handler happens to be interrupting
+	 * 32-bit or 16-bit code.
+	 *
+	 * SS is subtle.  In 64-bit mode, we don't need any particular
+	 * SS descriptor, but we do need SS to be valid.  It's possible
+	 * that the old SS is entirely bogus -- this can happen if the
+	 * signal we're trying to deliver is #GP or #SS caused by a bad
+	 * SS value.  We also have a compatibility issue here: DOSEMU
+	 * relies on the contents of the SS register indicating the
+	 * SS value at the time of the signal, even though that code in
+	 * DOSEMU predates sigreturn's ability to restore SS.  (DOSEMU
+	 * avoids relying on sigreturn to restore SS; instead it uses
+	 * a trampoline.)  So we do our best: if the old SS was valid,
+	 * we keep it.  Otherwise we replace it.
+	 */
+	regs->cs = __USER_CS;
+
+	if (unlikely(regs->ss != __USER_DS))
+		force_valid_ss(regs);
+
+	return 0;
+
+Efault:
+	user_access_end();
+	return -EFAULT;
+}
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+SYSCALL_DEFINE0(rt_sigreturn)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct rt_sigframe __user *frame;
+	sigset_t set;
+	unsigned long uc_flags;
+
+	frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+	if (__get_user(*(__u64 *)&set, (__u64 __user *)&frame->uc.uc_sigmask))
+		goto badframe;
+	if (__get_user(uc_flags, &frame->uc.uc_flags))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
+		goto badframe;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return regs->ax;
+
+badframe:
+	signal_fault(regs, frame, "rt_sigreturn");
+	return 0;
+}
+
+#ifdef CONFIG_X86_X32_ABI
+static int x32_copy_siginfo_to_user(struct compat_siginfo __user *to,
+		const struct kernel_siginfo *from)
+{
+	struct compat_siginfo new;
+
+	copy_siginfo_to_external32(&new, from);
+	if (from->si_signo == SIGCHLD) {
+		new._sifields._sigchld_x32._utime = from->si_utime;
+		new._sifields._sigchld_x32._stime = from->si_stime;
+	}
+	if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
+		return -EFAULT;
+	return 0;
+}
+
+int copy_siginfo_to_user32(struct compat_siginfo __user *to,
+			   const struct kernel_siginfo *from)
+{
+	if (in_x32_syscall())
+		return x32_copy_siginfo_to_user(to, from);
+	return __copy_siginfo_to_user32(to, from);
+}
+
+int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+{
+	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
+	struct rt_sigframe_x32 __user *frame;
+	unsigned long uc_flags;
+	void __user *restorer;
+	void __user *fp = NULL;
+
+	if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
+		return -EFAULT;
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
+
+	uc_flags = frame_uc_flags(regs);
+
+	if (!user_access_begin(frame, sizeof(*frame)))
+		return -EFAULT;
+
+	/* Create the ucontext.  */
+	unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault);
+	unsafe_put_user(0, &frame->uc.uc_link, Efault);
+	unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
+	unsafe_put_user(0, &frame->uc.uc__pad0, Efault);
+	restorer = ksig->ka.sa.sa_restorer;
+	unsafe_put_user(restorer, (unsigned long __user *)&frame->pretcode, Efault);
+	unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
+	unsafe_put_sigmask(set, frame, Efault);
+	user_access_end();
+
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
+		if (x32_copy_siginfo_to_user(&frame->info, &ksig->info))
+			return -EFAULT;
+	}
+
+	/* Set up registers for signal handler */
+	regs->sp = (unsigned long) frame;
+	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
+
+	/* We use the x32 calling convention here... */
+	regs->di = ksig->sig;
+	regs->si = (unsigned long) &frame->info;
+	regs->dx = (unsigned long) &frame->uc;
+
+	loadsegment(ds, __USER_DS);
+	loadsegment(es, __USER_DS);
+
+	regs->cs = __USER_CS;
+	regs->ss = __USER_DS;
+
+	return 0;
+
+Efault:
+	user_access_end();
+	return -EFAULT;
+}
+
+COMPAT_SYSCALL_DEFINE0(x32_rt_sigreturn)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct rt_sigframe_x32 __user *frame;
+	sigset_t set;
+	unsigned long uc_flags;
+
+	frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
+
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+	if (__get_user(set.sig[0], (__u64 __user *)&frame->uc.uc_sigmask))
+		goto badframe;
+	if (__get_user(uc_flags, &frame->uc.uc_flags))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
+		goto badframe;
+
+	if (compat_restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return regs->ax;
+
+badframe:
+	signal_fault(regs, frame, "x32 rt_sigreturn");
+	return 0;
+}
+#endif /* CONFIG_X86_X32_ABI */

Re: [PATCH 0/8] x86 signal code cleanups

[Eric W. Biederman]

Brian Gerst <brgerst@gmail.com> writes:

> The 32-bit signal code has significant differences from 64-bit, and
> those are duplicated for native and compat modes.  This patch series
> merges the 32-bit code into one file, and does some general cleanups
> in the x86 signal code.  There should be no functional changes.

At a quick skim I don't see anything scary in there.

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>

> Brian Gerst (8):
>   x86/signal: Remove sig parameter from frame setup functions
>   x86/signal: Remove sigset_t parameter from frame setup functions
>   signal/compat: Remove compat_sigset_t override
>   x86: Remove __USER32_DS
>   x86/signal: Merge get_sigframe()
>   x86/signal: Add ABI prefixes to frame setup functions
>   x86/signal/32: Merge native and compat 32-bit signal code
>   x86/signal/64: Move 64-bit signal code to its own file
>
>  arch/x86/entry/entry_64_compat.S              |   4 +-
>  arch/x86/ia32/Makefile                        |   2 -
>  arch/x86/include/asm/elf.h                    |   4 -
>  arch/x86/include/asm/fpu/signal.h             |   7 -
>  arch/x86/include/asm/segment.h                |   2 +-
>  arch/x86/include/asm/sighandling.h            |   9 +
>  arch/x86/include/asm/signal.h                 |   5 -
>  arch/x86/kernel/Makefile                      |   4 +-
>  arch/x86/kernel/signal.c                      | 654 +-----------------
>  .../ia32_signal.c => kernel/signal_32.c}      | 117 ++--
>  arch/x86/kernel/signal_64.c                   | 383 ++++++++++
>  arch/x86/xen/xen-asm.S                        |   8 +-
>  include/linux/compat.h                        |   2 -
>  include/linux/syscalls.h                      |   2 +
>  14 files changed, 493 insertions(+), 710 deletions(-)
>  rename arch/x86/{ia32/ia32_signal.c => kernel/signal_32.c} (82%)
>  create mode 100644 arch/x86/kernel/signal_64.c

Eric

Re: [PATCH 0/8] x86 signal code cleanups

[Andy Lutomirski]

On 6/6/22 13:37, Brian Gerst wrote:
> The 32-bit signal code has significant differences from 64-bit, and
> those are duplicated for native and compat modes.  This patch series
> merges the 32-bit code into one file, and does some general cleanups
> in the x86 signal code.  There should be no functional changes.
> 

This looks generally sane.  What kind of testing have you done?

--Andy

Re: [PATCH 0/8] x86 signal code cleanups

[Brian Gerst]

On Tue, Jun 28, 2022 at 7:23 PM Andy Lutomirski <luto@kernel.org> wrote:
>
> On 6/6/22 13:37, Brian Gerst wrote:
> > The 32-bit signal code has significant differences from 64-bit, and
> > those are duplicated for native and compat modes.  This patch series
> > merges the 32-bit code into one file, and does some general cleanups
> > in the x86 signal code.  There should be no functional changes.
> >
>
> This looks generally sane.  What kind of testing have you done?

I ran all of the self tests, did a parallel kernel build, and general
usage like web browsing.  Do you have any suggestions for other tests?

--
Brian Gerst