[PATCH v1 00/22] powerpc: ftrace optimisation and cleanup and more [v1]

[PATCH v1 00/22] powerpc: ftrace optimisation and cleanup and more [v1]

[Christophe Leroy]

This series provides optimisation and cleanup of ftrace on powerpc.

With this series ftrace activation is about 20% faster on an 8xx.

At the end of the series come additional cleanups around ppc-opcode,
that would likely conflict with this series if posted separately.

Christophe Leroy (22):
  powerpc/ftrace: Refactor prepare_ftrace_return()
  powerpc/ftrace: Remove redundant create_branch() calls
  powerpc/code-patching: Inline is_offset_in_{cond}_branch_range()
  powerpc/ftrace: Use is_offset_in_branch_range()
  powerpc/code-patching: Inline create_branch()
  powerpc/ftrace: Inline ftrace_modify_code()
  powerpc/ftrace: Use patch_instruction() return directly
  powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and
    PPC64
  powerpc/ftrace: Don't include ftrace.o for CONFIG_FTRACE_SYSCALLS
  powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of
    CONFIG_DYNAMIC_FTRACE
  powerpc/ftrace: Remove ftrace_plt_tramps[]
  powerpc/ftrace: Use BRANCH_SET_LINK instead of value 1
  powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding.
  powerpc/ftrace: Use size macro instead of opencoding
  powerpc/ftrace: Simplify expected_nop_sequence()
  powerpc/ftrace: Minimise number of #ifdefs
  powerpc/inst: Add __copy_inst_from_kernel_nofault()
  powerpc/ftrace: Don't use copy_from_kernel_nofault() in
    module_trampoline_target()
  powerpc/inst: Remove PPC_INST_BRANCH
  powerpc/modules: Use PPC_INST_BRANCH_MASK instead of opencoding
  powerpc/inst: Remove PPC_INST_BL
  powerpc/opcodes: Remove unused PPC_INST_XXX macros

 arch/powerpc/include/asm/book3s/32/pgtable.h |   2 +-
 arch/powerpc/include/asm/book3s/64/pgtable.h |   2 +-
 arch/powerpc/include/asm/code-patching.h     |  53 ++-
 arch/powerpc/include/asm/inst.h              |  13 +-
 arch/powerpc/include/asm/module.h            |   6 +-
 arch/powerpc/include/asm/nohash/pgtable.h    |   2 +-
 arch/powerpc/include/asm/ppc-opcode.h        |  20 +-
 arch/powerpc/include/asm/sections.h          |  24 +-
 arch/powerpc/kernel/module_32.c              |  29 +-
 arch/powerpc/kernel/module_64.c              |  10 +-
 arch/powerpc/kernel/trace/Makefile           |   5 +-
 arch/powerpc/kernel/trace/ftrace.c           | 390 ++++++-------------
 arch/powerpc/lib/code-patching.c             |  47 ---
 arch/powerpc/lib/feature-fixups.c            |   2 +-
 arch/powerpc/net/bpf_jit.h                   |   2 +-
 15 files changed, 229 insertions(+), 378 deletions(-)

-- 
2.35.1

[PATCH v1 00/22] powerpc: ftrace optimisation and cleanup and more [v1]

[Christophe Leroy]

This series provides optimisation and cleanup of ftrace on powerpc.

With this series ftrace activation is about 20% faster on an 8xx.

At the end of the series come additional cleanups around ppc-opcode,
that would likely conflict with this series if posted separately.

Christophe Leroy (22):
  powerpc/ftrace: Refactor prepare_ftrace_return()
  powerpc/ftrace: Remove redundant create_branch() calls
  powerpc/code-patching: Inline is_offset_in_{cond}_branch_range()
  powerpc/ftrace: Use is_offset_in_branch_range()
  powerpc/code-patching: Inline create_branch()
  powerpc/ftrace: Inline ftrace_modify_code()
  powerpc/ftrace: Use patch_instruction() return directly
  powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and
    PPC64
  powerpc/ftrace: Don't include ftrace.o for CONFIG_FTRACE_SYSCALLS
  powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of
    CONFIG_DYNAMIC_FTRACE
  powerpc/ftrace: Remove ftrace_plt_tramps[]
  powerpc/ftrace: Use BRANCH_SET_LINK instead of value 1
  powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding.
  powerpc/ftrace: Use size macro instead of opencoding
  powerpc/ftrace: Simplify expected_nop_sequence()
  powerpc/ftrace: Minimise number of #ifdefs
  powerpc/inst: Add __copy_inst_from_kernel_nofault()
  powerpc/ftrace: Don't use copy_from_kernel_nofault() in
    module_trampoline_target()
  powerpc/inst: Remove PPC_INST_BRANCH
  powerpc/modules: Use PPC_INST_BRANCH_MASK instead of opencoding
  powerpc/inst: Remove PPC_INST_BL
  powerpc/opcodes: Remove unused PPC_INST_XXX macros

 arch/powerpc/include/asm/book3s/32/pgtable.h |   2 +-
 arch/powerpc/include/asm/book3s/64/pgtable.h |   2 +-
 arch/powerpc/include/asm/code-patching.h     |  53 ++-
 arch/powerpc/include/asm/inst.h              |  13 +-
 arch/powerpc/include/asm/module.h            |   6 +-
 arch/powerpc/include/asm/nohash/pgtable.h    |   2 +-
 arch/powerpc/include/asm/ppc-opcode.h        |  20 +-
 arch/powerpc/include/asm/sections.h          |  24 +-
 arch/powerpc/kernel/module_32.c              |  29 +-
 arch/powerpc/kernel/module_64.c              |  10 +-
 arch/powerpc/kernel/trace/Makefile           |   5 +-
 arch/powerpc/kernel/trace/ftrace.c           | 390 ++++++-------------
 arch/powerpc/lib/code-patching.c             |  47 ---
 arch/powerpc/lib/feature-fixups.c            |   2 +-
 arch/powerpc/net/bpf_jit.h                   |   2 +-
 15 files changed, 229 insertions(+), 378 deletions(-)

-- 
2.35.1

[PATCH v1 01/22] powerpc/ftrace: Refactor prepare_ftrace_return()

[Christophe Leroy]

When we have CONFIG_DYNAMIC_FTRACE_WITH_ARGS,
prepare_ftrace_return() is called by ftrace_graph_func()
otherwise prepare_ftrace_return() is called from assembly.

Refactor prepare_ftrace_return() into a static
__prepare_ftrace_return() that will be called by both
prepare_ftrace_return() and ftrace_graph_func().

It will allow GCC to fold __prepare_ftrace_return() inside
ftrace_graph_func().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 4ee04aacf9f1..7a266fd469b7 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -939,8 +939,8 @@ int ftrace_disable_ftrace_graph_caller(void)
  * Hook the return address and push it in the stack of return addrs
  * in current thread info. Return the address we want to divert to.
  */
-unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
-						unsigned long sp)
+static unsigned long
+__prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp)
 {
 	unsigned long return_hooker;
 	int bit;
@@ -969,7 +969,13 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
 void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
 		       struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
-	fregs->regs.link = prepare_ftrace_return(parent_ip, ip, fregs->regs.gpr[1]);
+	fregs->regs.link = __prepare_ftrace_return(parent_ip, ip, fregs->regs.gpr[1]);
+}
+#else
+unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
+				    unsigned long sp)
+{
+	return __prepare_ftrace_return(parent, ip, sp);
 }
 #endif
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
-- 
2.35.1

[PATCH v1 01/22] powerpc/ftrace: Refactor prepare_ftrace_return()

[Christophe Leroy]

When we have CONFIG_DYNAMIC_FTRACE_WITH_ARGS,
prepare_ftrace_return() is called by ftrace_graph_func()
otherwise prepare_ftrace_return() is called from assembly.

Refactor prepare_ftrace_return() into a static
__prepare_ftrace_return() that will be called by both
prepare_ftrace_return() and ftrace_graph_func().

It will allow GCC to fold __prepare_ftrace_return() inside
ftrace_graph_func().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 4ee04aacf9f1..7a266fd469b7 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -939,8 +939,8 @@ int ftrace_disable_ftrace_graph_caller(void)
  * Hook the return address and push it in the stack of return addrs
  * in current thread info. Return the address we want to divert to.
  */
-unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
-						unsigned long sp)
+static unsigned long
+__prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp)
 {
 	unsigned long return_hooker;
 	int bit;
@@ -969,7 +969,13 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
 void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
 		       struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
-	fregs->regs.link = prepare_ftrace_return(parent_ip, ip, fregs->regs.gpr[1]);
+	fregs->regs.link = __prepare_ftrace_return(parent_ip, ip, fregs->regs.gpr[1]);
+}
+#else
+unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
+				    unsigned long sp)
+{
+	return __prepare_ftrace_return(parent, ip, sp);
 }
 #endif
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
-- 
2.35.1

[PATCH v1 02/22] powerpc/ftrace: Remove redundant create_branch() calls

[Christophe Leroy]

Since commit d5937db114e4 ("powerpc/code-patching: Fix patch_branch()
return on out-of-range failure") patch_branch() fails with -ERANGE
when trying to branch out of range.

No need to perform the test twice. Remove redundant create_branch()
calls.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 7a266fd469b7..3ce3697e8a7c 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -301,7 +301,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 	int i;
 	ppc_inst_t op;
 	unsigned long ptr;
-	ppc_inst_t instr;
 	static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS];
 
 	/* Is this a known long jump tramp? */
@@ -344,12 +343,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 #else
 	ptr = ppc_global_function_entry((void *)ftrace_caller);
 #endif
-	if (create_branch(&instr, (void *)tramp, ptr, 0)) {
-		pr_debug("%ps is not reachable from existing mcount tramp\n",
-				(void *)ptr);
-		return -1;
-	}
-
 	if (patch_branch((u32 *)tramp, ptr, 0)) {
 		pr_debug("REL24 out of range!\n");
 		return -1;
@@ -490,7 +483,6 @@ static int
 __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 {
 	ppc_inst_t op[2];
-	ppc_inst_t instr;
 	void *ip = (void *)rec->ip;
 	unsigned long entry, ptr, tramp;
 	struct module *mod = rec->arch.mod;
@@ -539,12 +531,6 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 		return -EINVAL;
 	}
 
-	/* Ensure branch is within 24 bits */
-	if (create_branch(&instr, ip, tramp, BRANCH_SET_LINK)) {
-		pr_err("Branch out of range\n");
-		return -EINVAL;
-	}
-
 	if (patch_branch(ip, tramp, BRANCH_SET_LINK)) {
 		pr_err("REL24 out of range!\n");
 		return -EINVAL;
@@ -770,12 +756,6 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 		return -EINVAL;
 	}
 
-	/* Ensure branch is within 24 bits */
-	if (create_branch(&op, (u32 *)ip, tramp, BRANCH_SET_LINK)) {
-		pr_err("Branch out of range\n");
-		return -EINVAL;
-	}
-
 	if (patch_branch((u32 *)ip, tramp, BRANCH_SET_LINK)) {
 		pr_err("REL24 out of range!\n");
 		return -EINVAL;
-- 
2.35.1

[PATCH v1 02/22] powerpc/ftrace: Remove redundant create_branch() calls

[Christophe Leroy]

Since commit d5937db114e4 ("powerpc/code-patching: Fix patch_branch()
return on out-of-range failure") patch_branch() fails with -ERANGE
when trying to branch out of range.

No need to perform the test twice. Remove redundant create_branch()
calls.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 7a266fd469b7..3ce3697e8a7c 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -301,7 +301,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 	int i;
 	ppc_inst_t op;
 	unsigned long ptr;
-	ppc_inst_t instr;
 	static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS];
 
 	/* Is this a known long jump tramp? */
@@ -344,12 +343,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 #else
 	ptr = ppc_global_function_entry((void *)ftrace_caller);
 #endif
-	if (create_branch(&instr, (void *)tramp, ptr, 0)) {
-		pr_debug("%ps is not reachable from existing mcount tramp\n",
-				(void *)ptr);
-		return -1;
-	}
-
 	if (patch_branch((u32 *)tramp, ptr, 0)) {
 		pr_debug("REL24 out of range!\n");
 		return -1;
@@ -490,7 +483,6 @@ static int
 __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 {
 	ppc_inst_t op[2];
-	ppc_inst_t instr;
 	void *ip = (void *)rec->ip;
 	unsigned long entry, ptr, tramp;
 	struct module *mod = rec->arch.mod;
@@ -539,12 +531,6 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 		return -EINVAL;
 	}
 
-	/* Ensure branch is within 24 bits */
-	if (create_branch(&instr, ip, tramp, BRANCH_SET_LINK)) {
-		pr_err("Branch out of range\n");
-		return -EINVAL;
-	}
-
 	if (patch_branch(ip, tramp, BRANCH_SET_LINK)) {
 		pr_err("REL24 out of range!\n");
 		return -EINVAL;
@@ -770,12 +756,6 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 		return -EINVAL;
 	}
 
-	/* Ensure branch is within 24 bits */
-	if (create_branch(&op, (u32 *)ip, tramp, BRANCH_SET_LINK)) {
-		pr_err("Branch out of range\n");
-		return -EINVAL;
-	}
-
 	if (patch_branch((u32 *)ip, tramp, BRANCH_SET_LINK)) {
 		pr_err("REL24 out of range!\n");
 		return -EINVAL;
-- 
2.35.1

[PATCH v1 03/22] powerpc/code-patching: Inline is_offset_in_{cond}_branch_range()

[Christophe Leroy]

Test in is_offset_in_branch_range() and is_offset_in_cond_branch_range()
are simple tests that are worth inlining.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/code-patching.h | 29 ++++++++++++++++++++++--
 arch/powerpc/lib/code-patching.c         | 27 ----------------------
 2 files changed, 27 insertions(+), 29 deletions(-)

diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
index 409483b2d0ce..e7c5df50cb4e 100644
--- a/arch/powerpc/include/asm/code-patching.h
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -22,8 +22,33 @@
 #define BRANCH_SET_LINK	0x1
 #define BRANCH_ABSOLUTE	0x2
 
-bool is_offset_in_branch_range(long offset);
-bool is_offset_in_cond_branch_range(long offset);
+/*
+ * Powerpc branch instruction is :
+ *
+ *  0         6                 30   31
+ *  +---------+----------------+---+---+
+ *  | opcode  |     LI         |AA |LK |
+ *  +---------+----------------+---+---+
+ *  Where AA = 0 and LK = 0
+ *
+ * LI is a signed 24 bits integer. The real branch offset is computed
+ * by: imm32 = SignExtend(LI:'0b00', 32);
+ *
+ * So the maximum forward branch should be:
+ *   (0x007fffff << 2) = 0x01fffffc =  0x1fffffc
+ * The maximum backward branch should be:
+ *   (0xff800000 << 2) = 0xfe000000 = -0x2000000
+ */
+static inline bool is_offset_in_branch_range(long offset)
+{
+	return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3));
+}
+
+static inline bool is_offset_in_cond_branch_range(long offset)
+{
+	return offset >= -0x8000 && offset <= 0x7fff && !(offset & 0x3);
+}
+
 int create_branch(ppc_inst_t *instr, const u32 *addr,
 		  unsigned long target, int flags);
 int create_cond_branch(ppc_inst_t *instr, const u32 *addr,
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 00c68e7fb11e..58262c7e447c 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -208,33 +208,6 @@ int patch_branch(u32 *addr, unsigned long target, int flags)
 	return patch_instruction(addr, instr);
 }
 
-bool is_offset_in_branch_range(long offset)
-{
-	/*
-	 * Powerpc branch instruction is :
-	 *
-	 *  0         6                 30   31
-	 *  +---------+----------------+---+---+
-	 *  | opcode  |     LI         |AA |LK |
-	 *  +---------+----------------+---+---+
-	 *  Where AA = 0 and LK = 0
-	 *
-	 * LI is a signed 24 bits integer. The real branch offset is computed
-	 * by: imm32 = SignExtend(LI:'0b00', 32);
-	 *
-	 * So the maximum forward branch should be:
-	 *   (0x007fffff << 2) = 0x01fffffc =  0x1fffffc
-	 * The maximum backward branch should be:
-	 *   (0xff800000 << 2) = 0xfe000000 = -0x2000000
-	 */
-	return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3));
-}
-
-bool is_offset_in_cond_branch_range(long offset)
-{
-	return offset >= -0x8000 && offset <= 0x7fff && !(offset & 0x3);
-}
-
 /*
  * Helper to check if a given instruction is a conditional branch
  * Derived from the conditional checks in analyse_instr()
-- 
2.35.1

[PATCH v1 03/22] powerpc/code-patching: Inline is_offset_in_{cond}_branch_range()

[Christophe Leroy]

Test in is_offset_in_branch_range() and is_offset_in_cond_branch_range()
are simple tests that are worth inlining.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/code-patching.h | 29 ++++++++++++++++++++++--
 arch/powerpc/lib/code-patching.c         | 27 ----------------------
 2 files changed, 27 insertions(+), 29 deletions(-)

diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
index 409483b2d0ce..e7c5df50cb4e 100644
--- a/arch/powerpc/include/asm/code-patching.h
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -22,8 +22,33 @@
 #define BRANCH_SET_LINK	0x1
 #define BRANCH_ABSOLUTE	0x2
 
-bool is_offset_in_branch_range(long offset);
-bool is_offset_in_cond_branch_range(long offset);
+/*
+ * Powerpc branch instruction is :
+ *
+ *  0         6                 30   31
+ *  +---------+----------------+---+---+
+ *  | opcode  |     LI         |AA |LK |
+ *  +---------+----------------+---+---+
+ *  Where AA = 0 and LK = 0
+ *
+ * LI is a signed 24 bits integer. The real branch offset is computed
+ * by: imm32 = SignExtend(LI:'0b00', 32);
+ *
+ * So the maximum forward branch should be:
+ *   (0x007fffff << 2) = 0x01fffffc =  0x1fffffc
+ * The maximum backward branch should be:
+ *   (0xff800000 << 2) = 0xfe000000 = -0x2000000
+ */
+static inline bool is_offset_in_branch_range(long offset)
+{
+	return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3));
+}
+
+static inline bool is_offset_in_cond_branch_range(long offset)
+{
+	return offset >= -0x8000 && offset <= 0x7fff && !(offset & 0x3);
+}
+
 int create_branch(ppc_inst_t *instr, const u32 *addr,
 		  unsigned long target, int flags);
 int create_cond_branch(ppc_inst_t *instr, const u32 *addr,
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 00c68e7fb11e..58262c7e447c 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -208,33 +208,6 @@ int patch_branch(u32 *addr, unsigned long target, int flags)
 	return patch_instruction(addr, instr);
 }
 
-bool is_offset_in_branch_range(long offset)
-{
-	/*
-	 * Powerpc branch instruction is :
-	 *
-	 *  0         6                 30   31
-	 *  +---------+----------------+---+---+
-	 *  | opcode  |     LI         |AA |LK |
-	 *  +---------+----------------+---+---+
-	 *  Where AA = 0 and LK = 0
-	 *
-	 * LI is a signed 24 bits integer. The real branch offset is computed
-	 * by: imm32 = SignExtend(LI:'0b00', 32);
-	 *
-	 * So the maximum forward branch should be:
-	 *   (0x007fffff << 2) = 0x01fffffc =  0x1fffffc
-	 * The maximum backward branch should be:
-	 *   (0xff800000 << 2) = 0xfe000000 = -0x2000000
-	 */
-	return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3));
-}
-
-bool is_offset_in_cond_branch_range(long offset)
-{
-	return offset >= -0x8000 && offset <= 0x7fff && !(offset & 0x3);
-}
-
 /*
  * Helper to check if a given instruction is a conditional branch
  * Derived from the conditional checks in analyse_instr()
-- 
2.35.1

[PATCH v1 04/22] powerpc/ftrace: Use is_offset_in_branch_range()

[Christophe Leroy]

Use is_offset_in_branch_range() instead of create_branch()
to check if a target is within branch range.

This patch together with the previous one improves
ftrace activation time by 7%

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 3ce3697e8a7c..41c45b9c7f39 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -89,11 +89,9 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
  */
 static int test_24bit_addr(unsigned long ip, unsigned long addr)
 {
-	ppc_inst_t op;
 	addr = ppc_function_entry((void *)addr);
 
-	/* use the create_branch to verify that this offset can be branched */
-	return create_branch(&op, (u32 *)ip, addr, 0) == 0;
+	return is_offset_in_branch_range(addr - ip);
 }
 
 static int is_bl_op(ppc_inst_t op)
@@ -261,7 +259,6 @@ __ftrace_make_nop(struct module *mod,
 static unsigned long find_ftrace_tramp(unsigned long ip)
 {
 	int i;
-	ppc_inst_t instr;
 
 	/*
 	 * We have the compiler generated long_branch tramps at the end
@@ -270,8 +267,7 @@ static unsigned long find_ftrace_tramp(unsigned long ip)
 	for (i = NUM_FTRACE_TRAMPS - 1; i >= 0; i--)
 		if (!ftrace_tramps[i])
 			continue;
-		else if (create_branch(&instr, (void *)ip,
-				       ftrace_tramps[i], 0) == 0)
+		else if (is_offset_in_branch_range(ftrace_tramps[i] - ip))
 			return ftrace_tramps[i];
 
 	return 0;
-- 
2.35.1

[PATCH v1 04/22] powerpc/ftrace: Use is_offset_in_branch_range()

[Christophe Leroy]

Use is_offset_in_branch_range() instead of create_branch()
to check if a target is within branch range.

This patch together with the previous one improves
ftrace activation time by 7%

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 3ce3697e8a7c..41c45b9c7f39 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -89,11 +89,9 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
  */
 static int test_24bit_addr(unsigned long ip, unsigned long addr)
 {
-	ppc_inst_t op;
 	addr = ppc_function_entry((void *)addr);
 
-	/* use the create_branch to verify that this offset can be branched */
-	return create_branch(&op, (u32 *)ip, addr, 0) == 0;
+	return is_offset_in_branch_range(addr - ip);
 }
 
 static int is_bl_op(ppc_inst_t op)
@@ -261,7 +259,6 @@ __ftrace_make_nop(struct module *mod,
 static unsigned long find_ftrace_tramp(unsigned long ip)
 {
 	int i;
-	ppc_inst_t instr;
 
 	/*
 	 * We have the compiler generated long_branch tramps at the end
@@ -270,8 +267,7 @@ static unsigned long find_ftrace_tramp(unsigned long ip)
 	for (i = NUM_FTRACE_TRAMPS - 1; i >= 0; i--)
 		if (!ftrace_tramps[i])
 			continue;
-		else if (create_branch(&instr, (void *)ip,
-				       ftrace_tramps[i], 0) == 0)
+		else if (is_offset_in_branch_range(ftrace_tramps[i] - ip))
 			return ftrace_tramps[i];
 
 	return 0;
-- 
2.35.1

[PATCH v1 05/22] powerpc/code-patching: Inline create_branch()

[Christophe Leroy]

create_branch() is a good candidate for inlining because:
- Flags can be folded in.
- Range tests are likely to be already done.

Hence reducing the create_branch() to only a set of instructions.

So inline it.

It improves ftrace activation by 10%.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/code-patching.h | 22 ++++++++++++++++++++--
 arch/powerpc/lib/code-patching.c         | 20 --------------------
 2 files changed, 20 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
index e7c5df50cb4e..4260e89f62b1 100644
--- a/arch/powerpc/include/asm/code-patching.h
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -49,8 +49,26 @@ static inline bool is_offset_in_cond_branch_range(long offset)
 	return offset >= -0x8000 && offset <= 0x7fff && !(offset & 0x3);
 }
 
-int create_branch(ppc_inst_t *instr, const u32 *addr,
-		  unsigned long target, int flags);
+static inline int create_branch(ppc_inst_t *instr, const u32 *addr,
+				unsigned long target, int flags)
+{
+	long offset;
+
+	*instr = ppc_inst(0);
+	offset = target;
+	if (! (flags & BRANCH_ABSOLUTE))
+		offset = offset - (unsigned long)addr;
+
+	/* Check we can represent the target in the instruction format */
+	if (!is_offset_in_branch_range(offset))
+		return 1;
+
+	/* Mask out the flags and target, so they don't step on each other. */
+	*instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC));
+
+	return 0;
+}
+
 int create_cond_branch(ppc_inst_t *instr, const u32 *addr,
 		       unsigned long target, int flags);
 int patch_branch(u32 *addr, unsigned long target, int flags);
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 58262c7e447c..7adbdb05fee7 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -230,26 +230,6 @@ bool is_conditional_branch(ppc_inst_t instr)
 }
 NOKPROBE_SYMBOL(is_conditional_branch);
 
-int create_branch(ppc_inst_t *instr, const u32 *addr,
-		  unsigned long target, int flags)
-{
-	long offset;
-
-	*instr = ppc_inst(0);
-	offset = target;
-	if (! (flags & BRANCH_ABSOLUTE))
-		offset = offset - (unsigned long)addr;
-
-	/* Check we can represent the target in the instruction format */
-	if (!is_offset_in_branch_range(offset))
-		return 1;
-
-	/* Mask out the flags and target, so they don't step on each other. */
-	*instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC));
-
-	return 0;
-}
-
 int create_cond_branch(ppc_inst_t *instr, const u32 *addr,
 		       unsigned long target, int flags)
 {
-- 
2.35.1

[PATCH v1 05/22] powerpc/code-patching: Inline create_branch()

[Christophe Leroy]

create_branch() is a good candidate for inlining because:
- Flags can be folded in.
- Range tests are likely to be already done.

Hence reducing the create_branch() to only a set of instructions.

So inline it.

It improves ftrace activation by 10%.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/code-patching.h | 22 ++++++++++++++++++++--
 arch/powerpc/lib/code-patching.c         | 20 --------------------
 2 files changed, 20 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
index e7c5df50cb4e..4260e89f62b1 100644
--- a/arch/powerpc/include/asm/code-patching.h
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -49,8 +49,26 @@ static inline bool is_offset_in_cond_branch_range(long offset)
 	return offset >= -0x8000 && offset <= 0x7fff && !(offset & 0x3);
 }
 
-int create_branch(ppc_inst_t *instr, const u32 *addr,
-		  unsigned long target, int flags);
+static inline int create_branch(ppc_inst_t *instr, const u32 *addr,
+				unsigned long target, int flags)
+{
+	long offset;
+
+	*instr = ppc_inst(0);
+	offset = target;
+	if (! (flags & BRANCH_ABSOLUTE))
+		offset = offset - (unsigned long)addr;
+
+	/* Check we can represent the target in the instruction format */
+	if (!is_offset_in_branch_range(offset))
+		return 1;
+
+	/* Mask out the flags and target, so they don't step on each other. */
+	*instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC));
+
+	return 0;
+}
+
 int create_cond_branch(ppc_inst_t *instr, const u32 *addr,
 		       unsigned long target, int flags);
 int patch_branch(u32 *addr, unsigned long target, int flags);
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 58262c7e447c..7adbdb05fee7 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -230,26 +230,6 @@ bool is_conditional_branch(ppc_inst_t instr)
 }
 NOKPROBE_SYMBOL(is_conditional_branch);
 
-int create_branch(ppc_inst_t *instr, const u32 *addr,
-		  unsigned long target, int flags)
-{
-	long offset;
-
-	*instr = ppc_inst(0);
-	offset = target;
-	if (! (flags & BRANCH_ABSOLUTE))
-		offset = offset - (unsigned long)addr;
-
-	/* Check we can represent the target in the instruction format */
-	if (!is_offset_in_branch_range(offset))
-		return 1;
-
-	/* Mask out the flags and target, so they don't step on each other. */
-	*instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC));
-
-	return 0;
-}
-
 int create_cond_branch(ppc_inst_t *instr, const u32 *addr,
 		       unsigned long target, int flags)
 {
-- 
2.35.1

[PATCH v1 06/22] powerpc/ftrace: Inline ftrace_modify_code()

[Christophe Leroy]

Inlining ftrace_modify_code(), it increases a bit the
size of ftrace code but brings 5% improvment on ftrace
activation.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 41c45b9c7f39..98e82fa4980f 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -53,7 +53,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
 	return op;
 }
 
-static int
+static inline int
 ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
 {
 	ppc_inst_t replaced;
-- 
2.35.1

[PATCH v1 06/22] powerpc/ftrace: Inline ftrace_modify_code()

[Christophe Leroy]

Inlining ftrace_modify_code(), it increases a bit the
size of ftrace code but brings 5% improvment on ftrace
activation.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 41c45b9c7f39..98e82fa4980f 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -53,7 +53,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
 	return op;
 }
 
-static int
+static inline int
 ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
 {
 	ppc_inst_t replaced;
-- 
2.35.1

[PATCH v1 07/22] powerpc/ftrace: Use patch_instruction() return directly

[Christophe Leroy]

Instead of returning -EPERM when patch_instruction() fails,
just return what patch_instruction returns.

That simplifies ftrace_modify_code():

	   0:	94 21 ff c0 	stwu    r1,-64(r1)
	   4:	93 e1 00 3c 	stw     r31,60(r1)
	   8:	7c 7f 1b 79 	mr.     r31,r3
	   c:	40 80 00 30 	bge     3c <ftrace_modify_code+0x3c>
	  10:	93 c1 00 38 	stw     r30,56(r1)
	  14:	7c 9e 23 78 	mr      r30,r4
	  18:	7c a4 2b 78 	mr      r4,r5
	  1c:	80 bf 00 00 	lwz     r5,0(r31)
	  20:	7c 1e 28 40 	cmplw   r30,r5
	  24:	40 82 00 34 	bne     58 <ftrace_modify_code+0x58>
	  28:	83 c1 00 38 	lwz     r30,56(r1)
	  2c:	7f e3 fb 78 	mr      r3,r31
	  30:	83 e1 00 3c 	lwz     r31,60(r1)
	  34:	38 21 00 40 	addi    r1,r1,64
	  38:	48 00 00 00 	b       38 <ftrace_modify_code+0x38>
				38: R_PPC_REL24	patch_instruction

Before:

	   0:	94 21 ff c0 	stwu    r1,-64(r1)
	   4:	93 e1 00 3c 	stw     r31,60(r1)
	   8:	7c 7f 1b 79 	mr.     r31,r3
	   c:	40 80 00 4c 	bge     58 <ftrace_modify_code+0x58>
	  10:	93 c1 00 38 	stw     r30,56(r1)
	  14:	7c 9e 23 78 	mr      r30,r4
	  18:	7c a4 2b 78 	mr      r4,r5
	  1c:	80 bf 00 00 	lwz     r5,0(r31)
	  20:	7c 08 02 a6 	mflr    r0
	  24:	90 01 00 44 	stw     r0,68(r1)
	  28:	7c 1e 28 40 	cmplw   r30,r5
	  2c:	40 82 00 48 	bne     74 <ftrace_modify_code+0x74>
	  30:	7f e3 fb 78 	mr      r3,r31
	  34:	48 00 00 01 	bl      34 <ftrace_modify_code+0x34>
				34: R_PPC_REL24	patch_instruction
	  38:	80 01 00 44 	lwz     r0,68(r1)
	  3c:	20 63 00 00 	subfic  r3,r3,0
	  40:	83 c1 00 38 	lwz     r30,56(r1)
	  44:	7c 63 19 10 	subfe   r3,r3,r3
	  48:	7c 08 03 a6 	mtlr    r0
	  4c:	83 e1 00 3c 	lwz     r31,60(r1)
	  50:	38 21 00 40 	addi    r1,r1,64
	  54:	4e 80 00 20 	blr

It improves ftrace activation/deactivation duration by about 3%.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 98e82fa4980f..1b05d33f96c6 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -78,10 +78,7 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
 	}
 
 	/* replace the text with the new text */
-	if (patch_instruction((u32 *)ip, new))
-		return -EPERM;
-
-	return 0;
+	return patch_instruction((u32 *)ip, new);
 }
 
 /*
-- 
2.35.1

[PATCH v1 07/22] powerpc/ftrace: Use patch_instruction() return directly

[Christophe Leroy]

Instead of returning -EPERM when patch_instruction() fails,
just return what patch_instruction returns.

That simplifies ftrace_modify_code():

	   0:	94 21 ff c0 	stwu    r1,-64(r1)
	   4:	93 e1 00 3c 	stw     r31,60(r1)
	   8:	7c 7f 1b 79 	mr.     r31,r3
	   c:	40 80 00 30 	bge     3c <ftrace_modify_code+0x3c>
	  10:	93 c1 00 38 	stw     r30,56(r1)
	  14:	7c 9e 23 78 	mr      r30,r4
	  18:	7c a4 2b 78 	mr      r4,r5
	  1c:	80 bf 00 00 	lwz     r5,0(r31)
	  20:	7c 1e 28 40 	cmplw   r30,r5
	  24:	40 82 00 34 	bne     58 <ftrace_modify_code+0x58>
	  28:	83 c1 00 38 	lwz     r30,56(r1)
	  2c:	7f e3 fb 78 	mr      r3,r31
	  30:	83 e1 00 3c 	lwz     r31,60(r1)
	  34:	38 21 00 40 	addi    r1,r1,64
	  38:	48 00 00 00 	b       38 <ftrace_modify_code+0x38>
				38: R_PPC_REL24	patch_instruction

Before:

	   0:	94 21 ff c0 	stwu    r1,-64(r1)
	   4:	93 e1 00 3c 	stw     r31,60(r1)
	   8:	7c 7f 1b 79 	mr.     r31,r3
	   c:	40 80 00 4c 	bge     58 <ftrace_modify_code+0x58>
	  10:	93 c1 00 38 	stw     r30,56(r1)
	  14:	7c 9e 23 78 	mr      r30,r4
	  18:	7c a4 2b 78 	mr      r4,r5
	  1c:	80 bf 00 00 	lwz     r5,0(r31)
	  20:	7c 08 02 a6 	mflr    r0
	  24:	90 01 00 44 	stw     r0,68(r1)
	  28:	7c 1e 28 40 	cmplw   r30,r5
	  2c:	40 82 00 48 	bne     74 <ftrace_modify_code+0x74>
	  30:	7f e3 fb 78 	mr      r3,r31
	  34:	48 00 00 01 	bl      34 <ftrace_modify_code+0x34>
				34: R_PPC_REL24	patch_instruction
	  38:	80 01 00 44 	lwz     r0,68(r1)
	  3c:	20 63 00 00 	subfic  r3,r3,0
	  40:	83 c1 00 38 	lwz     r30,56(r1)
	  44:	7c 63 19 10 	subfe   r3,r3,r3
	  48:	7c 08 03 a6 	mtlr    r0
	  4c:	83 e1 00 3c 	lwz     r31,60(r1)
	  50:	38 21 00 40 	addi    r1,r1,64
	  54:	4e 80 00 20 	blr

It improves ftrace activation/deactivation duration by about 3%.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 98e82fa4980f..1b05d33f96c6 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -78,10 +78,7 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
 	}
 
 	/* replace the text with the new text */
-	if (patch_instruction((u32 *)ip, new))
-		return -EPERM;
-
-	return 0;
+	return patch_instruction((u32 *)ip, new);
 }
 
 /*
-- 
2.35.1

[PATCH v1 08/22] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64

[Christophe Leroy]

Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target()
for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the
one for PPC64.

Same for __ftrace_make_call().

Make them common.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 108 +++--------------------------
 1 file changed, 8 insertions(+), 100 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 1b05d33f96c6..2c7e42e439bb 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -114,7 +114,6 @@ static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
 }
 
 #ifdef CONFIG_MODULES
-#ifdef CONFIG_PPC64
 static int
 __ftrace_make_nop(struct module *mod,
 		  struct dyn_ftrace *rec, unsigned long addr)
@@ -154,10 +153,11 @@ __ftrace_make_nop(struct module *mod,
 		return -EINVAL;
 	}
 
-#ifdef CONFIG_MPROFILE_KERNEL
-	/* When using -mkernel_profile there is no load to jump over */
+	/* When using -mkernel_profile or PPC32 there is no load to jump over */
 	pop = ppc_inst(PPC_RAW_NOP());
 
+#ifdef CONFIG_PPC64
+#ifdef CONFIG_MPROFILE_KERNEL
 	if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
 		pr_err("Fetching instruction at %lx failed.\n", ip - 4);
 		return -EFAULT;
@@ -201,6 +201,7 @@ __ftrace_make_nop(struct module *mod,
 		return -EINVAL;
 	}
 #endif /* CONFIG_MPROFILE_KERNEL */
+#endif /* PPC64 */
 
 	if (patch_instruction((u32 *)ip, pop)) {
 		pr_err("Patching NOP failed.\n");
@@ -209,48 +210,6 @@ __ftrace_make_nop(struct module *mod,
 
 	return 0;
 }
-
-#else /* !PPC64 */
-static int
-__ftrace_make_nop(struct module *mod,
-		  struct dyn_ftrace *rec, unsigned long addr)
-{
-	ppc_inst_t op;
-	unsigned long ip = rec->ip;
-	unsigned long tramp, ptr;
-
-	if (copy_from_kernel_nofault(&op, (void *)ip, MCOUNT_INSN_SIZE))
-		return -EFAULT;
-
-	/* Make sure that that this is still a 24bit jump */
-	if (!is_bl_op(op)) {
-		pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
-		return -EINVAL;
-	}
-
-	/* lets find where the pointer goes */
-	tramp = find_bl_target(ip, op);
-
-	/* Find where the trampoline jumps to */
-	if (module_trampoline_target(mod, tramp, &ptr)) {
-		pr_err("Failed to get trampoline target\n");
-		return -EFAULT;
-	}
-
-	if (ptr != addr) {
-		pr_err("Trampoline location %08lx does not match addr\n",
-		       tramp);
-		return -EINVAL;
-	}
-
-	op = ppc_inst(PPC_RAW_NOP());
-
-	if (patch_instruction((u32 *)ip, op))
-		return -EPERM;
-
-	return 0;
-}
-#endif /* PPC64 */
 #endif /* CONFIG_MODULES */
 
 static unsigned long find_ftrace_tramp(unsigned long ip)
@@ -437,13 +396,12 @@ int ftrace_make_nop(struct module *mod,
 }
 
 #ifdef CONFIG_MODULES
-#ifdef CONFIG_PPC64
 /*
  * Examine the existing instructions for __ftrace_make_call.
  * They should effectively be a NOP, and follow formal constraints,
  * depending on the ABI. Return false if they don't.
  */
-#ifndef CONFIG_MPROFILE_KERNEL
+#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 static int
 expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 {
@@ -465,7 +423,7 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 static int
 expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 {
-	/* look for patched "NOP" on ppc64 with -mprofile-kernel */
+	/* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
 	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
 		return 0;
 	return 1;
@@ -484,8 +442,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	if (copy_inst_from_kernel_nofault(op, ip))
 		return -EFAULT;
 
+#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
 		return -EFAULT;
+#endif
 
 	if (!expected_nop_sequence(ip, op[0], op[1])) {
 		pr_err("Unexpected call sequence at %p: %s %s\n",
@@ -531,58 +491,6 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 
 	return 0;
 }
-
-#else  /* !CONFIG_PPC64: */
-static int
-__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
-{
-	int err;
-	ppc_inst_t op;
-	u32 *ip = (u32 *)rec->ip;
-	struct module *mod = rec->arch.mod;
-	unsigned long tramp;
-
-	/* read where this goes */
-	if (copy_inst_from_kernel_nofault(&op, ip))
-		return -EFAULT;
-
-	/* It should be pointing to a nop */
-	if (!ppc_inst_equal(op,  ppc_inst(PPC_RAW_NOP()))) {
-		pr_err("Expected NOP but have %s\n", ppc_inst_as_str(op));
-		return -EINVAL;
-	}
-
-	/* If we never set up a trampoline to ftrace_caller, then bail */
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (!mod->arch.tramp || !mod->arch.tramp_regs) {
-#else
-	if (!mod->arch.tramp) {
-#endif
-		pr_err("No ftrace trampoline\n");
-		return -EINVAL;
-	}
-
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (rec->flags & FTRACE_FL_REGS)
-		tramp = mod->arch.tramp_regs;
-	else
-#endif
-		tramp = mod->arch.tramp;
-	/* create the branch to the trampoline */
-	err = create_branch(&op, ip, tramp, BRANCH_SET_LINK);
-	if (err) {
-		pr_err("REL24 out of range!\n");
-		return -EINVAL;
-	}
-
-	pr_devel("write to %lx\n", rec->ip);
-
-	if (patch_instruction(ip, op))
-		return -EPERM;
-
-	return 0;
-}
-#endif /* CONFIG_PPC64 */
 #endif /* CONFIG_MODULES */
 
 static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr)
-- 
2.35.1

[PATCH v1 08/22] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64

[Christophe Leroy]

Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target()
for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the
one for PPC64.

Same for __ftrace_make_call().

Make them common.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 108 +++--------------------------
 1 file changed, 8 insertions(+), 100 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 1b05d33f96c6..2c7e42e439bb 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -114,7 +114,6 @@ static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
 }
 
 #ifdef CONFIG_MODULES
-#ifdef CONFIG_PPC64
 static int
 __ftrace_make_nop(struct module *mod,
 		  struct dyn_ftrace *rec, unsigned long addr)
@@ -154,10 +153,11 @@ __ftrace_make_nop(struct module *mod,
 		return -EINVAL;
 	}
 
-#ifdef CONFIG_MPROFILE_KERNEL
-	/* When using -mkernel_profile there is no load to jump over */
+	/* When using -mkernel_profile or PPC32 there is no load to jump over */
 	pop = ppc_inst(PPC_RAW_NOP());
 
+#ifdef CONFIG_PPC64
+#ifdef CONFIG_MPROFILE_KERNEL
 	if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
 		pr_err("Fetching instruction at %lx failed.\n", ip - 4);
 		return -EFAULT;
@@ -201,6 +201,7 @@ __ftrace_make_nop(struct module *mod,
 		return -EINVAL;
 	}
 #endif /* CONFIG_MPROFILE_KERNEL */
+#endif /* PPC64 */
 
 	if (patch_instruction((u32 *)ip, pop)) {
 		pr_err("Patching NOP failed.\n");
@@ -209,48 +210,6 @@ __ftrace_make_nop(struct module *mod,
 
 	return 0;
 }
-
-#else /* !PPC64 */
-static int
-__ftrace_make_nop(struct module *mod,
-		  struct dyn_ftrace *rec, unsigned long addr)
-{
-	ppc_inst_t op;
-	unsigned long ip = rec->ip;
-	unsigned long tramp, ptr;
-
-	if (copy_from_kernel_nofault(&op, (void *)ip, MCOUNT_INSN_SIZE))
-		return -EFAULT;
-
-	/* Make sure that that this is still a 24bit jump */
-	if (!is_bl_op(op)) {
-		pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
-		return -EINVAL;
-	}
-
-	/* lets find where the pointer goes */
-	tramp = find_bl_target(ip, op);
-
-	/* Find where the trampoline jumps to */
-	if (module_trampoline_target(mod, tramp, &ptr)) {
-		pr_err("Failed to get trampoline target\n");
-		return -EFAULT;
-	}
-
-	if (ptr != addr) {
-		pr_err("Trampoline location %08lx does not match addr\n",
-		       tramp);
-		return -EINVAL;
-	}
-
-	op = ppc_inst(PPC_RAW_NOP());
-
-	if (patch_instruction((u32 *)ip, op))
-		return -EPERM;
-
-	return 0;
-}
-#endif /* PPC64 */
 #endif /* CONFIG_MODULES */
 
 static unsigned long find_ftrace_tramp(unsigned long ip)
@@ -437,13 +396,12 @@ int ftrace_make_nop(struct module *mod,
 }
 
 #ifdef CONFIG_MODULES
-#ifdef CONFIG_PPC64
 /*
  * Examine the existing instructions for __ftrace_make_call.
  * They should effectively be a NOP, and follow formal constraints,
  * depending on the ABI. Return false if they don't.
  */
-#ifndef CONFIG_MPROFILE_KERNEL
+#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 static int
 expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 {
@@ -465,7 +423,7 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 static int
 expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 {
-	/* look for patched "NOP" on ppc64 with -mprofile-kernel */
+	/* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
 	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
 		return 0;
 	return 1;
@@ -484,8 +442,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	if (copy_inst_from_kernel_nofault(op, ip))
 		return -EFAULT;
 
+#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
 		return -EFAULT;
+#endif
 
 	if (!expected_nop_sequence(ip, op[0], op[1])) {
 		pr_err("Unexpected call sequence at %p: %s %s\n",
@@ -531,58 +491,6 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 
 	return 0;
 }
-
-#else  /* !CONFIG_PPC64: */
-static int
-__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
-{
-	int err;
-	ppc_inst_t op;
-	u32 *ip = (u32 *)rec->ip;
-	struct module *mod = rec->arch.mod;
-	unsigned long tramp;
-
-	/* read where this goes */
-	if (copy_inst_from_kernel_nofault(&op, ip))
-		return -EFAULT;
-
-	/* It should be pointing to a nop */
-	if (!ppc_inst_equal(op,  ppc_inst(PPC_RAW_NOP()))) {
-		pr_err("Expected NOP but have %s\n", ppc_inst_as_str(op));
-		return -EINVAL;
-	}
-
-	/* If we never set up a trampoline to ftrace_caller, then bail */
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (!mod->arch.tramp || !mod->arch.tramp_regs) {
-#else
-	if (!mod->arch.tramp) {
-#endif
-		pr_err("No ftrace trampoline\n");
-		return -EINVAL;
-	}
-
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (rec->flags & FTRACE_FL_REGS)
-		tramp = mod->arch.tramp_regs;
-	else
-#endif
-		tramp = mod->arch.tramp;
-	/* create the branch to the trampoline */
-	err = create_branch(&op, ip, tramp, BRANCH_SET_LINK);
-	if (err) {
-		pr_err("REL24 out of range!\n");
-		return -EINVAL;
-	}
-
-	pr_devel("write to %lx\n", rec->ip);
-
-	if (patch_instruction(ip, op))
-		return -EPERM;
-
-	return 0;
-}
-#endif /* CONFIG_PPC64 */
 #endif /* CONFIG_MODULES */
 
 static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr)
-- 
2.35.1

[PATCH v1 09/22] powerpc/ftrace: Don't include ftrace.o for CONFIG_FTRACE_SYSCALLS

[Christophe Leroy]

Since commit 7bea7ac0ca01 ("powerpc/syscalls: Fix syscall tracing")
ftrace.o is not needed anymore for CONFIG_FTRACE_SYSCALLS.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/Makefile | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile
index 542aa7a8b2b4..fc32ec30b297 100644
--- a/arch/powerpc/kernel/trace/Makefile
+++ b/arch/powerpc/kernel/trace/Makefile
@@ -17,7 +17,6 @@ endif
 obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_low.o
 obj-$(CONFIG_DYNAMIC_FTRACE)		+= ftrace.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
-obj-$(CONFIG_FTRACE_SYSCALLS)		+= ftrace.o
 obj-$(CONFIG_TRACING)			+= trace_clock.o
 
 obj-$(CONFIG_PPC64)			+= $(obj64-y)
-- 
2.35.1

[PATCH v1 09/22] powerpc/ftrace: Don't include ftrace.o for CONFIG_FTRACE_SYSCALLS

[Christophe Leroy]

Since commit 7bea7ac0ca01 ("powerpc/syscalls: Fix syscall tracing")
ftrace.o is not needed anymore for CONFIG_FTRACE_SYSCALLS.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/Makefile | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile
index 542aa7a8b2b4..fc32ec30b297 100644
--- a/arch/powerpc/kernel/trace/Makefile
+++ b/arch/powerpc/kernel/trace/Makefile
@@ -17,7 +17,6 @@ endif
 obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_low.o
 obj-$(CONFIG_DYNAMIC_FTRACE)		+= ftrace.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
-obj-$(CONFIG_FTRACE_SYSCALLS)		+= ftrace.o
 obj-$(CONFIG_TRACING)			+= trace_clock.o
 
 obj-$(CONFIG_PPC64)			+= $(obj64-y)
-- 
2.35.1

[PATCH v1 10/22] powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACE

[Christophe Leroy]

Since commit 0c0c52306f47 ("powerpc: Only support DYNAMIC_FTRACE not
static"), CONFIG_DYNAMIC_FTRACE is always selected when
CONFIG_FUNCTION_TRACER is selected.

To avoid confusion and have the reader wonder what's happen when
CONFIG_FUNCTION_TRACER is selected and CONFIG_DYNAMIC_FTRACE is not,
use CONFIG_FUNCTION_TRACER in ifdefs instead of CONFIG_DYNAMIC_FTRACE.

As CONFIG_FUNCTION_GRAPH_TRACER depends on CONFIG_FUNCTION_TRACER,
ftrace.o doesn't need to appear for both symbols in Makefile.

Then as ftrace.o is built only when CONFIG_FUNCTION_TRACER is selected
ifdef CONFIG_FUNCTION_TRACER is not needed in ftrace.c

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/pgtable.h | 2 +-
 arch/powerpc/include/asm/book3s/64/pgtable.h | 2 +-
 arch/powerpc/include/asm/module.h            | 4 ++--
 arch/powerpc/include/asm/nohash/pgtable.h    | 2 +-
 arch/powerpc/kernel/module_32.c              | 4 ++--
 arch/powerpc/kernel/module_64.c              | 6 +++---
 arch/powerpc/kernel/trace/Makefile           | 4 +---
 arch/powerpc/kernel/trace/ftrace.c           | 4 ----
 8 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 772e00dc4ef1..992aed626eb4 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -124,7 +124,7 @@ static inline bool pte_user(pte_t pte)
  * on platforms where such control is possible.
  */
 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
-	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
+	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
 #else
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 875730d5af40..cf01b609572f 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -169,7 +169,7 @@
  * on platforms where such control is possible.
  */
 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) || \
-	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
+	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
 #else
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
index 857d9ff24295..e6f5963fd96e 100644
--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h
@@ -39,7 +39,7 @@ struct mod_arch_specific {
 	unsigned int init_plt_section;
 #endif /* powerpc64 */
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 	unsigned long tramp;
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	unsigned long tramp_regs;
@@ -68,7 +68,7 @@ struct mod_arch_specific {
 #    endif	/* MODULE */
 #endif
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 #    ifdef MODULE
 	asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
 #    endif	/* MODULE */
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index ac75f4ab0dba..2e8cf217a191 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -23,7 +23,7 @@
  * on platforms where such control is possible.
  */
 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
-	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
+	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
 #else
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
index a0432ef46967..2aa368ce21c9 100644
--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c
@@ -39,7 +39,7 @@ static unsigned int count_relocs(const Elf32_Rela *rela, unsigned int num)
 			r_addend = rela[i].r_addend;
 		}
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 	_count_relocs++;	/* add one for ftrace_caller */
 #endif
 	return _count_relocs;
@@ -288,7 +288,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 	return 0;
 }
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 int module_trampoline_target(struct module *mod, unsigned long addr,
 			     unsigned long *target)
 {
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 794720530442..b13a72665eee 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -207,7 +207,7 @@ static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
 		}
 	}
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 	/* make the trampoline to the ftrace_caller */
 	relocs++;
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
@@ -372,7 +372,7 @@ static bool is_mprofile_ftrace_call(const char *name)
 {
 	if (!strcmp("_mcount", name))
 		return true;
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 	if (!strcmp("ftrace_caller", name))
 		return true;
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
@@ -740,7 +740,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 	return 0;
 }
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 int module_trampoline_target(struct module *mod, unsigned long addr,
 			     unsigned long *target)
 {
diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile
index fc32ec30b297..af8527538fe4 100644
--- a/arch/powerpc/kernel/trace/Makefile
+++ b/arch/powerpc/kernel/trace/Makefile
@@ -14,9 +14,7 @@ obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_mprofile.o
 else
 obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_64_pg.o
 endif
-obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_low.o
-obj-$(CONFIG_DYNAMIC_FTRACE)		+= ftrace.o
-obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
+obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_low.o ftrace.o
 obj-$(CONFIG_TRACING)			+= trace_clock.o
 
 obj-$(CONFIG_PPC64)			+= $(obj64-y)
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 2c7e42e439bb..188f59f4ee4a 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -28,9 +28,6 @@
 #include <asm/syscall.h>
 #include <asm/inst.h>
 
-
-#ifdef CONFIG_DYNAMIC_FTRACE
-
 /*
  * We generally only have a single long_branch tramp and at most 2 or 3 plt
  * tramps generated. But, we don't use the plt tramps currently. We also allot
@@ -783,7 +780,6 @@ int __init ftrace_dyn_arch_init(void)
 	return 0;
 }
 #endif
-#endif /* CONFIG_DYNAMIC_FTRACE */
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
-- 
2.35.1

[PATCH v1 10/22] powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACE

[Christophe Leroy]

Since commit 0c0c52306f47 ("powerpc: Only support DYNAMIC_FTRACE not
static"), CONFIG_DYNAMIC_FTRACE is always selected when
CONFIG_FUNCTION_TRACER is selected.

To avoid confusion and have the reader wonder what's happen when
CONFIG_FUNCTION_TRACER is selected and CONFIG_DYNAMIC_FTRACE is not,
use CONFIG_FUNCTION_TRACER in ifdefs instead of CONFIG_DYNAMIC_FTRACE.

As CONFIG_FUNCTION_GRAPH_TRACER depends on CONFIG_FUNCTION_TRACER,
ftrace.o doesn't need to appear for both symbols in Makefile.

Then as ftrace.o is built only when CONFIG_FUNCTION_TRACER is selected
ifdef CONFIG_FUNCTION_TRACER is not needed in ftrace.c

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/pgtable.h | 2 +-
 arch/powerpc/include/asm/book3s/64/pgtable.h | 2 +-
 arch/powerpc/include/asm/module.h            | 4 ++--
 arch/powerpc/include/asm/nohash/pgtable.h    | 2 +-
 arch/powerpc/kernel/module_32.c              | 4 ++--
 arch/powerpc/kernel/module_64.c              | 6 +++---
 arch/powerpc/kernel/trace/Makefile           | 4 +---
 arch/powerpc/kernel/trace/ftrace.c           | 4 ----
 8 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 772e00dc4ef1..992aed626eb4 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -124,7 +124,7 @@ static inline bool pte_user(pte_t pte)
  * on platforms where such control is possible.
  */
 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
-	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
+	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
 #else
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 875730d5af40..cf01b609572f 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -169,7 +169,7 @@
  * on platforms where such control is possible.
  */
 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) || \
-	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
+	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
 #else
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
index 857d9ff24295..e6f5963fd96e 100644
--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h
@@ -39,7 +39,7 @@ struct mod_arch_specific {
 	unsigned int init_plt_section;
 #endif /* powerpc64 */
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 	unsigned long tramp;
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	unsigned long tramp_regs;
@@ -68,7 +68,7 @@ struct mod_arch_specific {
 #    endif	/* MODULE */
 #endif
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 #    ifdef MODULE
 	asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
 #    endif	/* MODULE */
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index ac75f4ab0dba..2e8cf217a191 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -23,7 +23,7 @@
  * on platforms where such control is possible.
  */
 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
-	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
+	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
 #else
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
index a0432ef46967..2aa368ce21c9 100644
--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c
@@ -39,7 +39,7 @@ static unsigned int count_relocs(const Elf32_Rela *rela, unsigned int num)
 			r_addend = rela[i].r_addend;
 		}
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 	_count_relocs++;	/* add one for ftrace_caller */
 #endif
 	return _count_relocs;
@@ -288,7 +288,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 	return 0;
 }
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 int module_trampoline_target(struct module *mod, unsigned long addr,
 			     unsigned long *target)
 {
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 794720530442..b13a72665eee 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -207,7 +207,7 @@ static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
 		}
 	}
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 	/* make the trampoline to the ftrace_caller */
 	relocs++;
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
@@ -372,7 +372,7 @@ static bool is_mprofile_ftrace_call(const char *name)
 {
 	if (!strcmp("_mcount", name))
 		return true;
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 	if (!strcmp("ftrace_caller", name))
 		return true;
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
@@ -740,7 +740,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 	return 0;
 }
 
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 int module_trampoline_target(struct module *mod, unsigned long addr,
 			     unsigned long *target)
 {
diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile
index fc32ec30b297..af8527538fe4 100644
--- a/arch/powerpc/kernel/trace/Makefile
+++ b/arch/powerpc/kernel/trace/Makefile
@@ -14,9 +14,7 @@ obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_mprofile.o
 else
 obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_64_pg.o
 endif
-obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_low.o
-obj-$(CONFIG_DYNAMIC_FTRACE)		+= ftrace.o
-obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
+obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_low.o ftrace.o
 obj-$(CONFIG_TRACING)			+= trace_clock.o
 
 obj-$(CONFIG_PPC64)			+= $(obj64-y)
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 2c7e42e439bb..188f59f4ee4a 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -28,9 +28,6 @@
 #include <asm/syscall.h>
 #include <asm/inst.h>
 
-
-#ifdef CONFIG_DYNAMIC_FTRACE
-
 /*
  * We generally only have a single long_branch tramp and at most 2 or 3 plt
  * tramps generated. But, we don't use the plt tramps currently. We also allot
@@ -783,7 +780,6 @@ int __init ftrace_dyn_arch_init(void)
 	return 0;
 }
 #endif
-#endif /* CONFIG_DYNAMIC_FTRACE */
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
-- 
2.35.1

[PATCH v1 11/22] powerpc/ftrace: Remove ftrace_plt_tramps[]

[Christophe Leroy]

ftrace_plt_tramps table is never filled so it is useless.

Remove it.

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

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 188f59f4ee4a..b6c5223e26b2 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -250,7 +250,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 	int i;
 	ppc_inst_t op;
 	unsigned long ptr;
-	static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS];
 
 	/* Is this a known long jump tramp? */
 	for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
@@ -259,13 +258,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 		else if (ftrace_tramps[i] == tramp)
 			return 0;
 
-	/* Is this a known plt tramp? */
-	for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
-		if (!ftrace_plt_tramps[i])
-			break;
-		else if (ftrace_plt_tramps[i] == tramp)
-			return -1;
-
 	/* New trampoline -- read where this goes */
 	if (copy_inst_from_kernel_nofault(&op, (void *)tramp)) {
 		pr_debug("Fetching opcode failed.\n");
-- 
2.35.1

[PATCH v1 11/22] powerpc/ftrace: Remove ftrace_plt_tramps[]

[Christophe Leroy]

ftrace_plt_tramps table is never filled so it is useless.

Remove it.

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

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 188f59f4ee4a..b6c5223e26b2 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -250,7 +250,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 	int i;
 	ppc_inst_t op;
 	unsigned long ptr;
-	static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS];
 
 	/* Is this a known long jump tramp? */
 	for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
@@ -259,13 +258,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 		else if (ftrace_tramps[i] == tramp)
 			return 0;
 
-	/* Is this a known plt tramp? */
-	for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
-		if (!ftrace_plt_tramps[i])
-			break;
-		else if (ftrace_plt_tramps[i] == tramp)
-			return -1;
-
 	/* New trampoline -- read where this goes */
 	if (copy_inst_from_kernel_nofault(&op, (void *)tramp)) {
 		pr_debug("Fetching opcode failed.\n");
-- 
2.35.1

[PATCH v1 12/22] powerpc/ftrace: Use BRANCH_SET_LINK instead of value 1

[Christophe Leroy]

To make it explicit, use BRANCH_SET_LINK instead of value 1
when calling create_branch().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index b6c5223e26b2..fdc0412c1d8a 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -45,7 +45,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
 	addr = ppc_function_entry((void *)addr);
 
 	/* if (link) set op to 'bl' else 'b' */
-	create_branch(&op, (u32 *)ip, addr, link ? 1 : 0);
+	create_branch(&op, (u32 *)ip, addr, link ? BRANCH_SET_LINK : 0);
 
 	return op;
 }
-- 
2.35.1

[PATCH v1 12/22] powerpc/ftrace: Use BRANCH_SET_LINK instead of value 1

[Christophe Leroy]

To make it explicit, use BRANCH_SET_LINK instead of value 1
when calling create_branch().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index b6c5223e26b2..fdc0412c1d8a 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -45,7 +45,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
 	addr = ppc_function_entry((void *)addr);
 
 	/* if (link) set op to 'bl' else 'b' */
-	create_branch(&op, (u32 *)ip, addr, link ? 1 : 0);
+	create_branch(&op, (u32 *)ip, addr, link ? BRANCH_SET_LINK : 0);
 
 	return op;
 }
-- 
2.35.1

[PATCH v1 13/22] powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding.

[Christophe Leroy]

PPC_RAW_xxx() macros are self explanatory and less error prone
than open coding.

Use them in ftrace.c

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/ppc-opcode.h |  3 +++
 arch/powerpc/kernel/trace/ftrace.c    | 32 +++++++++------------------
 2 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index 82f1f0041c6f..281754aca0a3 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -294,6 +294,8 @@
 #define PPC_INST_BL			0x48000001
 #define PPC_INST_BRANCH_COND		0x40800000
 
+#define PPC_INST_OFFSET24_MASK		0x03fffffc
+
 /* Prefixes */
 #define PPC_INST_LFS			0xc0000000
 #define PPC_INST_STFS			0xd0000000
@@ -572,6 +574,7 @@
 #define PPC_RAW_EIEIO()			(0x7c0006ac)
 
 #define PPC_RAW_BRANCH(addr)		(PPC_INST_BRANCH | ((addr) & 0x03fffffc))
+#define PPC_RAW_BL(offset)		(0x48000001 | ((offset) & PPC_INST_OFFSET24_MASK))
 
 /* Deal with instructions that older assemblers aren't aware of */
 #define	PPC_BCCTR_FLUSH		stringify_in_c(.long PPC_INST_BCCTR_FLUSH)
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index fdc0412c1d8a..afb1d12838c9 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -90,19 +90,19 @@ static int test_24bit_addr(unsigned long ip, unsigned long addr)
 
 static int is_bl_op(ppc_inst_t op)
 {
-	return (ppc_inst_val(op) & 0xfc000003) == 0x48000001;
+	return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == PPC_RAW_BL(0);
 }
 
 static int is_b_op(ppc_inst_t op)
 {
-	return (ppc_inst_val(op) & 0xfc000003) == 0x48000000;
+	return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == PPC_RAW_BRANCH(0);
 }
 
 static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
 {
 	int offset;
 
-	offset = (ppc_inst_val(op) & 0x03fffffc);
+	offset = (ppc_inst_val(op) & PPC_INST_OFFSET24_MASK);
 	/* make it signed */
 	if (offset & 0x02000000)
 		offset |= 0xfe000000;
@@ -182,7 +182,7 @@ __ftrace_make_nop(struct module *mod,
 	 * Use a b +8 to jump over the load.
 	 */
 
-	pop = ppc_inst(PPC_INST_BRANCH | 8);	/* b +8 */
+	pop = ppc_inst(PPC_RAW_BRANCH(8));	/* b +8 */
 
 	/*
 	 * Check what is in the next instruction. We can see ld r2,40(r1), but
@@ -394,17 +394,8 @@ int ftrace_make_nop(struct module *mod,
 static int
 expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 {
-	/*
-	 * We expect to see:
-	 *
-	 * b +8
-	 * ld r2,XX(r1)
-	 *
-	 * The load offset is different depending on the ABI. For simplicity
-	 * just mask it out when doing the compare.
-	 */
-	if (!ppc_inst_equal(op0, ppc_inst(0x48000008)) ||
-	    (ppc_inst_val(op1) & 0xffff0000) != 0xe8410000)
+	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) ||
+	    !ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)))
 		return 0;
 	return 1;
 }
@@ -412,7 +403,6 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 static int
 expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 {
-	/* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
 	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
 		return 0;
 	return 1;
@@ -738,11 +728,11 @@ int __init ftrace_dyn_arch_init(void)
 	int i;
 	unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init };
 	u32 stub_insns[] = {
-		0xe98d0000 | PACATOC,	/* ld      r12,PACATOC(r13)	*/
-		0x3d8c0000,		/* addis   r12,r12,<high>	*/
-		0x398c0000,		/* addi    r12,r12,<low>	*/
-		0x7d8903a6,		/* mtctr   r12			*/
-		0x4e800420,		/* bctr				*/
+		PPC_RAW_LD(_R12, _R13, PACATOC),
+		PPC_RAW_ADDIS(_R12, _R12, 0),
+		PPC_RAW_ADDIS(_R12, _R12, 0),
+		PPC_RAW_MTCTR(_R12),
+		PPC_RAW_BCTR()
 	};
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	unsigned long addr = ppc_global_function_entry((void *)ftrace_regs_caller);
-- 
2.35.1

[PATCH v1 13/22] powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding.

[Christophe Leroy]

PPC_RAW_xxx() macros are self explanatory and less error prone
than open coding.

Use them in ftrace.c

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/ppc-opcode.h |  3 +++
 arch/powerpc/kernel/trace/ftrace.c    | 32 +++++++++------------------
 2 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index 82f1f0041c6f..281754aca0a3 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -294,6 +294,8 @@
 #define PPC_INST_BL			0x48000001
 #define PPC_INST_BRANCH_COND		0x40800000
 
+#define PPC_INST_OFFSET24_MASK		0x03fffffc
+
 /* Prefixes */
 #define PPC_INST_LFS			0xc0000000
 #define PPC_INST_STFS			0xd0000000
@@ -572,6 +574,7 @@
 #define PPC_RAW_EIEIO()			(0x7c0006ac)
 
 #define PPC_RAW_BRANCH(addr)		(PPC_INST_BRANCH | ((addr) & 0x03fffffc))
+#define PPC_RAW_BL(offset)		(0x48000001 | ((offset) & PPC_INST_OFFSET24_MASK))
 
 /* Deal with instructions that older assemblers aren't aware of */
 #define	PPC_BCCTR_FLUSH		stringify_in_c(.long PPC_INST_BCCTR_FLUSH)
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index fdc0412c1d8a..afb1d12838c9 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -90,19 +90,19 @@ static int test_24bit_addr(unsigned long ip, unsigned long addr)
 
 static int is_bl_op(ppc_inst_t op)
 {
-	return (ppc_inst_val(op) & 0xfc000003) == 0x48000001;
+	return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == PPC_RAW_BL(0);
 }
 
 static int is_b_op(ppc_inst_t op)
 {
-	return (ppc_inst_val(op) & 0xfc000003) == 0x48000000;
+	return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == PPC_RAW_BRANCH(0);
 }
 
 static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
 {
 	int offset;
 
-	offset = (ppc_inst_val(op) & 0x03fffffc);
+	offset = (ppc_inst_val(op) & PPC_INST_OFFSET24_MASK);
 	/* make it signed */
 	if (offset & 0x02000000)
 		offset |= 0xfe000000;
@@ -182,7 +182,7 @@ __ftrace_make_nop(struct module *mod,
 	 * Use a b +8 to jump over the load.
 	 */
 
-	pop = ppc_inst(PPC_INST_BRANCH | 8);	/* b +8 */
+	pop = ppc_inst(PPC_RAW_BRANCH(8));	/* b +8 */
 
 	/*
 	 * Check what is in the next instruction. We can see ld r2,40(r1), but
@@ -394,17 +394,8 @@ int ftrace_make_nop(struct module *mod,
 static int
 expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 {
-	/*
-	 * We expect to see:
-	 *
-	 * b +8
-	 * ld r2,XX(r1)
-	 *
-	 * The load offset is different depending on the ABI. For simplicity
-	 * just mask it out when doing the compare.
-	 */
-	if (!ppc_inst_equal(op0, ppc_inst(0x48000008)) ||
-	    (ppc_inst_val(op1) & 0xffff0000) != 0xe8410000)
+	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) ||
+	    !ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)))
 		return 0;
 	return 1;
 }
@@ -412,7 +403,6 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 static int
 expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 {
-	/* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
 	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
 		return 0;
 	return 1;
@@ -738,11 +728,11 @@ int __init ftrace_dyn_arch_init(void)
 	int i;
 	unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init };
 	u32 stub_insns[] = {
-		0xe98d0000 | PACATOC,	/* ld      r12,PACATOC(r13)	*/
-		0x3d8c0000,		/* addis   r12,r12,<high>	*/
-		0x398c0000,		/* addi    r12,r12,<low>	*/
-		0x7d8903a6,		/* mtctr   r12			*/
-		0x4e800420,		/* bctr				*/
+		PPC_RAW_LD(_R12, _R13, PACATOC),
+		PPC_RAW_ADDIS(_R12, _R12, 0),
+		PPC_RAW_ADDIS(_R12, _R12, 0),
+		PPC_RAW_MTCTR(_R12),
+		PPC_RAW_BCTR()
 	};
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	unsigned long addr = ppc_global_function_entry((void *)ftrace_regs_caller);
-- 
2.35.1

[PATCH v1 14/22] powerpc/ftrace: Use size macro instead of opencoding

[Christophe Leroy]

0x80000000 is SZ_2G. Use it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index afb1d12838c9..15e0746806f8 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -741,7 +741,7 @@ int __init ftrace_dyn_arch_init(void)
 #endif
 	long reladdr = addr - kernel_toc_addr();
 
-	if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
+	if (reladdr >= SZ_2G || reladdr < -SZ_2G) {
 		pr_err("Address of %ps out of range of kernel_toc.\n",
 				(void *)addr);
 		return -1;
-- 
2.35.1

[PATCH v1 14/22] powerpc/ftrace: Use size macro instead of opencoding

[Christophe Leroy]

0x80000000 is SZ_2G. Use it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index afb1d12838c9..15e0746806f8 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -741,7 +741,7 @@ int __init ftrace_dyn_arch_init(void)
 #endif
 	long reladdr = addr - kernel_toc_addr();
 
-	if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
+	if (reladdr >= SZ_2G || reladdr < -SZ_2G) {
 		pr_err("Address of %ps out of range of kernel_toc.\n",
 				(void *)addr);
 		return -1;
-- 
2.35.1

[PATCH v1 15/22] powerpc/ftrace: Simplify expected_nop_sequence()

[Christophe Leroy]

Avoid ifdefs around expected_nop_sequence().

While at it make it a bool.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 22 ++++++----------------
 1 file changed, 6 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 15e0746806f8..ffedf8c82ea8 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -390,24 +390,14 @@ int ftrace_make_nop(struct module *mod,
  * They should effectively be a NOP, and follow formal constraints,
  * depending on the ABI. Return false if they don't.
  */
-#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-static int
-expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
-{
-	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) ||
-	    !ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)))
-		return 0;
-	return 1;
-}
-#else
-static int
-expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
+static bool expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 {
-	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
-		return 0;
-	return 1;
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
+		return ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP()));
+	else
+		return ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) &&
+		       ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC));
 }
-#endif
 
 static int
 __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
-- 
2.35.1

[PATCH v1 15/22] powerpc/ftrace: Simplify expected_nop_sequence()

[Christophe Leroy]

Avoid ifdefs around expected_nop_sequence().

While at it make it a bool.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 22 ++++++----------------
 1 file changed, 6 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 15e0746806f8..ffedf8c82ea8 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -390,24 +390,14 @@ int ftrace_make_nop(struct module *mod,
  * They should effectively be a NOP, and follow formal constraints,
  * depending on the ABI. Return false if they don't.
  */
-#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-static int
-expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
-{
-	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) ||
-	    !ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)))
-		return 0;
-	return 1;
-}
-#else
-static int
-expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
+static bool expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 {
-	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
-		return 0;
-	return 1;
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
+		return ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP()));
+	else
+		return ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) &&
+		       ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC));
 }
-#endif
 
 static int
 __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
-- 
2.35.1

[PATCH v1 16/22] powerpc/ftrace: Minimise number of #ifdefs

[Christophe Leroy]

A lot of #ifdefs can be replaced by IS_ENABLED()

Do so.

This requires to have kernel_toc_addr() defined at all time
and PPC_INST_LD_TOC as well.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/code-patching.h |   2 -
 arch/powerpc/include/asm/module.h        |   2 -
 arch/powerpc/include/asm/sections.h      |  24 +--
 arch/powerpc/kernel/trace/ftrace.c       | 201 ++++++++++++-----------
 4 files changed, 113 insertions(+), 116 deletions(-)

diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
index 4260e89f62b1..071fcbec31c5 100644
--- a/arch/powerpc/include/asm/code-patching.h
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -217,7 +217,6 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
 	return addr;
 }
 
-#ifdef CONFIG_PPC64
 /*
  * Some instruction encodings commonly used in dynamic ftracing
  * and function live patching.
@@ -234,6 +233,5 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
 
 /* usually preceded by a mflr r0 */
 #define PPC_INST_STD_LR		PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF)
-#endif /* CONFIG_PPC64 */
 
 #endif /* _ASM_POWERPC_CODE_PATCHING_H */
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
index e6f5963fd96e..700d7ecd9012 100644
--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h
@@ -41,9 +41,7 @@ struct mod_arch_specific {
 
 #ifdef CONFIG_FUNCTION_TRACER
 	unsigned long tramp;
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	unsigned long tramp_regs;
-#endif
 #endif
 
 	/* List of BUG addresses, source line numbers and filenames */
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index 8be2c491c733..6980eaeb16fe 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -29,18 +29,6 @@ extern char start_virt_trampolines[];
 extern char end_virt_trampolines[];
 #endif
 
-/*
- * This assumes the kernel is never compiled -mcmodel=small or
- * the total .toc is always less than 64k.
- */
-static inline unsigned long kernel_toc_addr(void)
-{
-	unsigned long toc_ptr;
-
-	asm volatile("mr %0, 2" : "=r" (toc_ptr));
-	return toc_ptr;
-}
-
 static inline int overlaps_interrupt_vector_text(unsigned long start,
 							unsigned long end)
 {
@@ -60,5 +48,17 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
 
 #endif
 
+/*
+ * This assumes the kernel is never compiled -mcmodel=small or
+ * the total .toc is always less than 64k.
+ */
+static inline unsigned long kernel_toc_addr(void)
+{
+	unsigned long toc_ptr;
+
+	asm volatile("mr %0, 2" : "=r" (toc_ptr));
+	return toc_ptr;
+}
+
 #endif /* __KERNEL__ */
 #endif	/* _ASM_POWERPC_SECTIONS_H */
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index ffedf8c82ea8..4dd30e396026 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -150,55 +150,55 @@ __ftrace_make_nop(struct module *mod,
 		return -EINVAL;
 	}
 
-	/* When using -mkernel_profile or PPC32 there is no load to jump over */
-	pop = ppc_inst(PPC_RAW_NOP());
+	if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) {
+		/* When using -mkernel_profile or PPC32 there is no load to jump over */
+		pop = ppc_inst(PPC_RAW_NOP());
 
-#ifdef CONFIG_PPC64
-#ifdef CONFIG_MPROFILE_KERNEL
-	if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
-		pr_err("Fetching instruction at %lx failed.\n", ip - 4);
-		return -EFAULT;
-	}
+		if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
+			pr_err("Fetching instruction at %lx failed.\n", ip - 4);
+			return -EFAULT;
+		}
 
-	/* We expect either a mflr r0, or a std r0, LRSAVE(r1) */
-	if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_MFLR(_R0))) &&
-	    !ppc_inst_equal(op, ppc_inst(PPC_INST_STD_LR))) {
-		pr_err("Unexpected instruction %s around bl _mcount\n",
-		       ppc_inst_as_str(op));
-		return -EINVAL;
-	}
-#else
-	/*
-	 * Our original call site looks like:
-	 *
-	 * bl <tramp>
-	 * ld r2,XX(r1)
-	 *
-	 * Milton Miller pointed out that we can not simply nop the branch.
-	 * If a task was preempted when calling a trace function, the nops
-	 * will remove the way to restore the TOC in r2 and the r2 TOC will
-	 * get corrupted.
-	 *
-	 * Use a b +8 to jump over the load.
-	 */
+		/* We expect either a mflr r0, or a std r0, LRSAVE(r1) */
+		if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_MFLR(_R0))) &&
+		    !ppc_inst_equal(op, ppc_inst(PPC_INST_STD_LR))) {
+			pr_err("Unexpected instruction %s around bl _mcount\n",
+			       ppc_inst_as_str(op));
+			return -EINVAL;
+		}
+	} else if (IS_ENABLED(CONFIG_PPC64)) {
+		/*
+		 * Our original call site looks like:
+		 *
+		 * bl <tramp>
+		 * ld r2,XX(r1)
+		 *
+		 * Milton Miller pointed out that we can not simply nop the branch.
+		 * If a task was preempted when calling a trace function, the nops
+		 * will remove the way to restore the TOC in r2 and the r2 TOC will
+		 * get corrupted.
+		 *
+		 * Use a b +8 to jump over the load.
+		 */
 
-	pop = ppc_inst(PPC_RAW_BRANCH(8));	/* b +8 */
+		pop = ppc_inst(PPC_RAW_BRANCH(8));	/* b +8 */
 
-	/*
-	 * Check what is in the next instruction. We can see ld r2,40(r1), but
-	 * on first pass after boot we will see mflr r0.
-	 */
-	if (copy_inst_from_kernel_nofault(&op, (void *)(ip + 4))) {
-		pr_err("Fetching op failed.\n");
-		return -EFAULT;
-	}
+		/*
+		 * Check what is in the next instruction. We can see ld r2,40(r1), but
+		 * on first pass after boot we will see mflr r0.
+		 */
+		if (copy_inst_from_kernel_nofault(&op, (void *)(ip + 4))) {
+			pr_err("Fetching op failed.\n");
+			return -EFAULT;
+		}
 
-	if (!ppc_inst_equal(op,  ppc_inst(PPC_INST_LD_TOC))) {
-		pr_err("Expected %08lx found %s\n", PPC_INST_LD_TOC, ppc_inst_as_str(op));
-		return -EINVAL;
+		if (!ppc_inst_equal(op,  ppc_inst(PPC_INST_LD_TOC))) {
+			pr_err("Expected %08lx found %s\n", PPC_INST_LD_TOC, ppc_inst_as_str(op));
+			return -EINVAL;
+		}
+	} else {
+		pop = ppc_inst(PPC_RAW_NOP());
 	}
-#endif /* CONFIG_MPROFILE_KERNEL */
-#endif /* PPC64 */
 
 	if (patch_instruction((u32 *)ip, pop)) {
 		pr_err("Patching NOP failed.\n");
@@ -207,6 +207,11 @@ __ftrace_make_nop(struct module *mod,
 
 	return 0;
 }
+#else
+static int __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
+{
+	return 0;
+}
 #endif /* CONFIG_MODULES */
 
 static unsigned long find_ftrace_tramp(unsigned long ip)
@@ -279,11 +284,11 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 	}
 
 	/* Let's re-write the tramp to go to ftrace_[regs_]caller */
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	ptr = ppc_global_function_entry((void *)ftrace_regs_caller);
-#else
-	ptr = ppc_global_function_entry((void *)ftrace_caller);
-#endif
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
+		ptr = ppc_global_function_entry((void *)ftrace_regs_caller);
+	else
+		ptr = ppc_global_function_entry((void *)ftrace_caller);
+
 	if (patch_branch((u32 *)tramp, ptr, 0)) {
 		pr_debug("REL24 out of range!\n");
 		return -1;
@@ -352,10 +357,12 @@ int ftrace_make_nop(struct module *mod,
 		old = ftrace_call_replace(ip, addr, 1);
 		new = ppc_inst(PPC_RAW_NOP());
 		return ftrace_modify_code(ip, old, new);
-	} else if (core_kernel_text(ip))
+	} else if (core_kernel_text(ip)) {
 		return __ftrace_make_nop_kernel(rec, addr);
+	} else if (!IS_ENABLED(CONFIG_MODULES)) {
+		return -EINVAL;
+	}
 
-#ifdef CONFIG_MODULES
 	/*
 	 * Out of range jumps are called from modules.
 	 * We should either already have a pointer to the module
@@ -378,10 +385,6 @@ int ftrace_make_nop(struct module *mod,
 		mod = rec->arch.mod;
 
 	return __ftrace_make_nop(mod, rec, addr);
-#else
-	/* We should not get here without modules */
-	return -EINVAL;
-#endif /* CONFIG_MODULES */
 }
 
 #ifdef CONFIG_MODULES
@@ -411,10 +414,9 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	if (copy_inst_from_kernel_nofault(op, ip))
 		return -EFAULT;
 
-#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
+	if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) &&
+	    copy_inst_from_kernel_nofault(op + 1, ip + 4))
 		return -EFAULT;
-#endif
 
 	if (!expected_nop_sequence(ip, op[0], op[1])) {
 		pr_err("Unexpected call sequence at %p: %s %s\n",
@@ -423,20 +425,15 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	}
 
 	/* If we never set up ftrace trampoline(s), then bail */
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (!mod->arch.tramp || !mod->arch.tramp_regs) {
-#else
-	if (!mod->arch.tramp) {
-#endif
+	if (!mod->arch.tramp ||
+	    (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !mod->arch.tramp_regs)) {
 		pr_err("No ftrace trampoline\n");
 		return -EINVAL;
 	}
 
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (rec->flags & FTRACE_FL_REGS)
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && rec->flags & FTRACE_FL_REGS)
 		tramp = mod->arch.tramp_regs;
 	else
-#endif
 		tramp = mod->arch.tramp;
 
 	if (module_trampoline_target(mod, tramp, &ptr)) {
@@ -460,6 +457,11 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 
 	return 0;
 }
+#else
+static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+	return 0;
+}
 #endif /* CONFIG_MODULES */
 
 static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr)
@@ -472,16 +474,12 @@ static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr)
 	entry = ppc_global_function_entry((void *)ftrace_caller);
 	ptr = ppc_global_function_entry((void *)addr);
 
-	if (ptr != entry) {
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+	if (ptr != entry && IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
 		entry = ppc_global_function_entry((void *)ftrace_regs_caller);
-		if (ptr != entry) {
-#endif
-			pr_err("Unknown ftrace addr to patch: %ps\n", (void *)ptr);
-			return -EINVAL;
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-		}
-#endif
+
+	if (ptr != entry) {
+		pr_err("Unknown ftrace addr to patch: %ps\n", (void *)ptr);
+		return -EINVAL;
 	}
 
 	/* Make sure we have a nop */
@@ -524,10 +522,13 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 		old = ppc_inst(PPC_RAW_NOP());
 		new = ftrace_call_replace(ip, addr, 1);
 		return ftrace_modify_code(ip, old, new);
-	} else if (core_kernel_text(ip))
+	} else if (core_kernel_text(ip)) {
 		return __ftrace_make_call_kernel(rec, addr);
+	} else if (!IS_ENABLED(CONFIG_MODULES)) {
+		/* We should not get here without modules */
+		return -EINVAL;
+	}
 
-#ifdef CONFIG_MODULES
 	/*
 	 * Out of range jumps are called from modules.
 	 * Being that we are converting from nop, it had better
@@ -539,10 +540,6 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	}
 
 	return __ftrace_make_call(rec, addr);
-#else
-	/* We should not get here without modules */
-	return -EINVAL;
-#endif /* CONFIG_MODULES */
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
@@ -633,6 +630,11 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 
 	return 0;
 }
+#else
+static int __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr)
+{
+	return 0;
+}
 #endif
 
 int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
@@ -657,9 +659,11 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 		 * variant, so there is nothing to do here
 		 */
 		return 0;
+	} else if (!IS_ENABLED(CONFIG_MODULES)) {
+		/* We should not get here without modules */
+		return -EINVAL;
 	}
 
-#ifdef CONFIG_MODULES
 	/*
 	 * Out of range jumps are called from modules.
 	 */
@@ -669,10 +673,6 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 	}
 
 	return __ftrace_modify_call(rec, old_addr, addr);
-#else
-	/* We should not get here without modules */
-	return -EINVAL;
-#endif /* CONFIG_MODULES */
 }
 #endif
 
@@ -686,15 +686,13 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
 	new = ftrace_call_replace(ip, (unsigned long)func, 1);
 	ret = ftrace_modify_code(ip, old, new);
 
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	/* Also update the regs callback function */
-	if (!ret) {
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !ret) {
 		ip = (unsigned long)(&ftrace_regs_call);
 		old = ppc_inst_read((u32 *)&ftrace_regs_call);
 		new = ftrace_call_replace(ip, (unsigned long)func, 1);
 		ret = ftrace_modify_code(ip, old, new);
 	}
-#endif
 
 	return ret;
 }
@@ -710,6 +708,9 @@ void arch_ftrace_update_code(int command)
 
 #ifdef CONFIG_PPC64
 #define PACATOC offsetof(struct paca_struct, kernel_toc)
+#else
+#define PACATOC 0
+#endif
 
 extern unsigned int ftrace_tramp_text[], ftrace_tramp_init[];
 
@@ -724,12 +725,18 @@ int __init ftrace_dyn_arch_init(void)
 		PPC_RAW_MTCTR(_R12),
 		PPC_RAW_BCTR()
 	};
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	unsigned long addr = ppc_global_function_entry((void *)ftrace_regs_caller);
-#else
-	unsigned long addr = ppc_global_function_entry((void *)ftrace_caller);
-#endif
-	long reladdr = addr - kernel_toc_addr();
+	unsigned long addr;
+	long reladdr;
+
+	if (IS_ENABLED(CONFIG_PPC32))
+		return 0;
+
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
+		addr = ppc_global_function_entry((void *)ftrace_regs_caller);
+	else
+		addr = ppc_global_function_entry((void *)ftrace_caller);
+
+	reladdr = addr - kernel_toc_addr();
 
 	if (reladdr >= SZ_2G || reladdr < -SZ_2G) {
 		pr_err("Address of %ps out of range of kernel_toc.\n",
@@ -746,12 +753,6 @@ int __init ftrace_dyn_arch_init(void)
 
 	return 0;
 }
-#else
-int __init ftrace_dyn_arch_init(void)
-{
-	return 0;
-}
-#endif
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
-- 
2.35.1

[PATCH v1 16/22] powerpc/ftrace: Minimise number of #ifdefs

[Christophe Leroy]

A lot of #ifdefs can be replaced by IS_ENABLED()

Do so.

This requires to have kernel_toc_addr() defined at all time
and PPC_INST_LD_TOC as well.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/code-patching.h |   2 -
 arch/powerpc/include/asm/module.h        |   2 -
 arch/powerpc/include/asm/sections.h      |  24 +--
 arch/powerpc/kernel/trace/ftrace.c       | 201 ++++++++++++-----------
 4 files changed, 113 insertions(+), 116 deletions(-)

diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
index 4260e89f62b1..071fcbec31c5 100644
--- a/arch/powerpc/include/asm/code-patching.h
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -217,7 +217,6 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
 	return addr;
 }
 
-#ifdef CONFIG_PPC64
 /*
  * Some instruction encodings commonly used in dynamic ftracing
  * and function live patching.
@@ -234,6 +233,5 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
 
 /* usually preceded by a mflr r0 */
 #define PPC_INST_STD_LR		PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF)
-#endif /* CONFIG_PPC64 */
 
 #endif /* _ASM_POWERPC_CODE_PATCHING_H */
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
index e6f5963fd96e..700d7ecd9012 100644
--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h
@@ -41,9 +41,7 @@ struct mod_arch_specific {
 
 #ifdef CONFIG_FUNCTION_TRACER
 	unsigned long tramp;
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	unsigned long tramp_regs;
-#endif
 #endif
 
 	/* List of BUG addresses, source line numbers and filenames */
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index 8be2c491c733..6980eaeb16fe 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -29,18 +29,6 @@ extern char start_virt_trampolines[];
 extern char end_virt_trampolines[];
 #endif
 
-/*
- * This assumes the kernel is never compiled -mcmodel=small or
- * the total .toc is always less than 64k.
- */
-static inline unsigned long kernel_toc_addr(void)
-{
-	unsigned long toc_ptr;
-
-	asm volatile("mr %0, 2" : "=r" (toc_ptr));
-	return toc_ptr;
-}
-
 static inline int overlaps_interrupt_vector_text(unsigned long start,
 							unsigned long end)
 {
@@ -60,5 +48,17 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
 
 #endif
 
+/*
+ * This assumes the kernel is never compiled -mcmodel=small or
+ * the total .toc is always less than 64k.
+ */
+static inline unsigned long kernel_toc_addr(void)
+{
+	unsigned long toc_ptr;
+
+	asm volatile("mr %0, 2" : "=r" (toc_ptr));
+	return toc_ptr;
+}
+
 #endif /* __KERNEL__ */
 #endif	/* _ASM_POWERPC_SECTIONS_H */
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index ffedf8c82ea8..4dd30e396026 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -150,55 +150,55 @@ __ftrace_make_nop(struct module *mod,
 		return -EINVAL;
 	}
 
-	/* When using -mkernel_profile or PPC32 there is no load to jump over */
-	pop = ppc_inst(PPC_RAW_NOP());
+	if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) {
+		/* When using -mkernel_profile or PPC32 there is no load to jump over */
+		pop = ppc_inst(PPC_RAW_NOP());
 
-#ifdef CONFIG_PPC64
-#ifdef CONFIG_MPROFILE_KERNEL
-	if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
-		pr_err("Fetching instruction at %lx failed.\n", ip - 4);
-		return -EFAULT;
-	}
+		if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
+			pr_err("Fetching instruction at %lx failed.\n", ip - 4);
+			return -EFAULT;
+		}
 
-	/* We expect either a mflr r0, or a std r0, LRSAVE(r1) */
-	if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_MFLR(_R0))) &&
-	    !ppc_inst_equal(op, ppc_inst(PPC_INST_STD_LR))) {
-		pr_err("Unexpected instruction %s around bl _mcount\n",
-		       ppc_inst_as_str(op));
-		return -EINVAL;
-	}
-#else
-	/*
-	 * Our original call site looks like:
-	 *
-	 * bl <tramp>
-	 * ld r2,XX(r1)
-	 *
-	 * Milton Miller pointed out that we can not simply nop the branch.
-	 * If a task was preempted when calling a trace function, the nops
-	 * will remove the way to restore the TOC in r2 and the r2 TOC will
-	 * get corrupted.
-	 *
-	 * Use a b +8 to jump over the load.
-	 */
+		/* We expect either a mflr r0, or a std r0, LRSAVE(r1) */
+		if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_MFLR(_R0))) &&
+		    !ppc_inst_equal(op, ppc_inst(PPC_INST_STD_LR))) {
+			pr_err("Unexpected instruction %s around bl _mcount\n",
+			       ppc_inst_as_str(op));
+			return -EINVAL;
+		}
+	} else if (IS_ENABLED(CONFIG_PPC64)) {
+		/*
+		 * Our original call site looks like:
+		 *
+		 * bl <tramp>
+		 * ld r2,XX(r1)
+		 *
+		 * Milton Miller pointed out that we can not simply nop the branch.
+		 * If a task was preempted when calling a trace function, the nops
+		 * will remove the way to restore the TOC in r2 and the r2 TOC will
+		 * get corrupted.
+		 *
+		 * Use a b +8 to jump over the load.
+		 */
 
-	pop = ppc_inst(PPC_RAW_BRANCH(8));	/* b +8 */
+		pop = ppc_inst(PPC_RAW_BRANCH(8));	/* b +8 */
 
-	/*
-	 * Check what is in the next instruction. We can see ld r2,40(r1), but
-	 * on first pass after boot we will see mflr r0.
-	 */
-	if (copy_inst_from_kernel_nofault(&op, (void *)(ip + 4))) {
-		pr_err("Fetching op failed.\n");
-		return -EFAULT;
-	}
+		/*
+		 * Check what is in the next instruction. We can see ld r2,40(r1), but
+		 * on first pass after boot we will see mflr r0.
+		 */
+		if (copy_inst_from_kernel_nofault(&op, (void *)(ip + 4))) {
+			pr_err("Fetching op failed.\n");
+			return -EFAULT;
+		}
 
-	if (!ppc_inst_equal(op,  ppc_inst(PPC_INST_LD_TOC))) {
-		pr_err("Expected %08lx found %s\n", PPC_INST_LD_TOC, ppc_inst_as_str(op));
-		return -EINVAL;
+		if (!ppc_inst_equal(op,  ppc_inst(PPC_INST_LD_TOC))) {
+			pr_err("Expected %08lx found %s\n", PPC_INST_LD_TOC, ppc_inst_as_str(op));
+			return -EINVAL;
+		}
+	} else {
+		pop = ppc_inst(PPC_RAW_NOP());
 	}
-#endif /* CONFIG_MPROFILE_KERNEL */
-#endif /* PPC64 */
 
 	if (patch_instruction((u32 *)ip, pop)) {
 		pr_err("Patching NOP failed.\n");
@@ -207,6 +207,11 @@ __ftrace_make_nop(struct module *mod,
 
 	return 0;
 }
+#else
+static int __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
+{
+	return 0;
+}
 #endif /* CONFIG_MODULES */
 
 static unsigned long find_ftrace_tramp(unsigned long ip)
@@ -279,11 +284,11 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 	}
 
 	/* Let's re-write the tramp to go to ftrace_[regs_]caller */
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	ptr = ppc_global_function_entry((void *)ftrace_regs_caller);
-#else
-	ptr = ppc_global_function_entry((void *)ftrace_caller);
-#endif
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
+		ptr = ppc_global_function_entry((void *)ftrace_regs_caller);
+	else
+		ptr = ppc_global_function_entry((void *)ftrace_caller);
+
 	if (patch_branch((u32 *)tramp, ptr, 0)) {
 		pr_debug("REL24 out of range!\n");
 		return -1;
@@ -352,10 +357,12 @@ int ftrace_make_nop(struct module *mod,
 		old = ftrace_call_replace(ip, addr, 1);
 		new = ppc_inst(PPC_RAW_NOP());
 		return ftrace_modify_code(ip, old, new);
-	} else if (core_kernel_text(ip))
+	} else if (core_kernel_text(ip)) {
 		return __ftrace_make_nop_kernel(rec, addr);
+	} else if (!IS_ENABLED(CONFIG_MODULES)) {
+		return -EINVAL;
+	}
 
-#ifdef CONFIG_MODULES
 	/*
 	 * Out of range jumps are called from modules.
 	 * We should either already have a pointer to the module
@@ -378,10 +385,6 @@ int ftrace_make_nop(struct module *mod,
 		mod = rec->arch.mod;
 
 	return __ftrace_make_nop(mod, rec, addr);
-#else
-	/* We should not get here without modules */
-	return -EINVAL;
-#endif /* CONFIG_MODULES */
 }
 
 #ifdef CONFIG_MODULES
@@ -411,10 +414,9 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	if (copy_inst_from_kernel_nofault(op, ip))
 		return -EFAULT;
 
-#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
+	if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) &&
+	    copy_inst_from_kernel_nofault(op + 1, ip + 4))
 		return -EFAULT;
-#endif
 
 	if (!expected_nop_sequence(ip, op[0], op[1])) {
 		pr_err("Unexpected call sequence at %p: %s %s\n",
@@ -423,20 +425,15 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	}
 
 	/* If we never set up ftrace trampoline(s), then bail */
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (!mod->arch.tramp || !mod->arch.tramp_regs) {
-#else
-	if (!mod->arch.tramp) {
-#endif
+	if (!mod->arch.tramp ||
+	    (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !mod->arch.tramp_regs)) {
 		pr_err("No ftrace trampoline\n");
 		return -EINVAL;
 	}
 
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (rec->flags & FTRACE_FL_REGS)
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && rec->flags & FTRACE_FL_REGS)
 		tramp = mod->arch.tramp_regs;
 	else
-#endif
 		tramp = mod->arch.tramp;
 
 	if (module_trampoline_target(mod, tramp, &ptr)) {
@@ -460,6 +457,11 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 
 	return 0;
 }
+#else
+static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+	return 0;
+}
 #endif /* CONFIG_MODULES */
 
 static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr)
@@ -472,16 +474,12 @@ static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr)
 	entry = ppc_global_function_entry((void *)ftrace_caller);
 	ptr = ppc_global_function_entry((void *)addr);
 
-	if (ptr != entry) {
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+	if (ptr != entry && IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
 		entry = ppc_global_function_entry((void *)ftrace_regs_caller);
-		if (ptr != entry) {
-#endif
-			pr_err("Unknown ftrace addr to patch: %ps\n", (void *)ptr);
-			return -EINVAL;
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-		}
-#endif
+
+	if (ptr != entry) {
+		pr_err("Unknown ftrace addr to patch: %ps\n", (void *)ptr);
+		return -EINVAL;
 	}
 
 	/* Make sure we have a nop */
@@ -524,10 +522,13 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 		old = ppc_inst(PPC_RAW_NOP());
 		new = ftrace_call_replace(ip, addr, 1);
 		return ftrace_modify_code(ip, old, new);
-	} else if (core_kernel_text(ip))
+	} else if (core_kernel_text(ip)) {
 		return __ftrace_make_call_kernel(rec, addr);
+	} else if (!IS_ENABLED(CONFIG_MODULES)) {
+		/* We should not get here without modules */
+		return -EINVAL;
+	}
 
-#ifdef CONFIG_MODULES
 	/*
 	 * Out of range jumps are called from modules.
 	 * Being that we are converting from nop, it had better
@@ -539,10 +540,6 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	}
 
 	return __ftrace_make_call(rec, addr);
-#else
-	/* We should not get here without modules */
-	return -EINVAL;
-#endif /* CONFIG_MODULES */
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
@@ -633,6 +630,11 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 
 	return 0;
 }
+#else
+static int __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr)
+{
+	return 0;
+}
 #endif
 
 int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
@@ -657,9 +659,11 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 		 * variant, so there is nothing to do here
 		 */
 		return 0;
+	} else if (!IS_ENABLED(CONFIG_MODULES)) {
+		/* We should not get here without modules */
+		return -EINVAL;
 	}
 
-#ifdef CONFIG_MODULES
 	/*
 	 * Out of range jumps are called from modules.
 	 */
@@ -669,10 +673,6 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 	}
 
 	return __ftrace_modify_call(rec, old_addr, addr);
-#else
-	/* We should not get here without modules */
-	return -EINVAL;
-#endif /* CONFIG_MODULES */
 }
 #endif
 
@@ -686,15 +686,13 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
 	new = ftrace_call_replace(ip, (unsigned long)func, 1);
 	ret = ftrace_modify_code(ip, old, new);
 
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	/* Also update the regs callback function */
-	if (!ret) {
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !ret) {
 		ip = (unsigned long)(&ftrace_regs_call);
 		old = ppc_inst_read((u32 *)&ftrace_regs_call);
 		new = ftrace_call_replace(ip, (unsigned long)func, 1);
 		ret = ftrace_modify_code(ip, old, new);
 	}
-#endif
 
 	return ret;
 }
@@ -710,6 +708,9 @@ void arch_ftrace_update_code(int command)
 
 #ifdef CONFIG_PPC64
 #define PACATOC offsetof(struct paca_struct, kernel_toc)
+#else
+#define PACATOC 0
+#endif
 
 extern unsigned int ftrace_tramp_text[], ftrace_tramp_init[];
 
@@ -724,12 +725,18 @@ int __init ftrace_dyn_arch_init(void)
 		PPC_RAW_MTCTR(_R12),
 		PPC_RAW_BCTR()
 	};
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	unsigned long addr = ppc_global_function_entry((void *)ftrace_regs_caller);
-#else
-	unsigned long addr = ppc_global_function_entry((void *)ftrace_caller);
-#endif
-	long reladdr = addr - kernel_toc_addr();
+	unsigned long addr;
+	long reladdr;
+
+	if (IS_ENABLED(CONFIG_PPC32))
+		return 0;
+
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
+		addr = ppc_global_function_entry((void *)ftrace_regs_caller);
+	else
+		addr = ppc_global_function_entry((void *)ftrace_caller);
+
+	reladdr = addr - kernel_toc_addr();
 
 	if (reladdr >= SZ_2G || reladdr < -SZ_2G) {
 		pr_err("Address of %ps out of range of kernel_toc.\n",
@@ -746,12 +753,6 @@ int __init ftrace_dyn_arch_init(void)
 
 	return 0;
 }
-#else
-int __init ftrace_dyn_arch_init(void)
-{
-	return 0;
-}
-#endif
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
-- 
2.35.1

[PATCH v1 17/22] powerpc/inst: Add __copy_inst_from_kernel_nofault()

[Christophe Leroy]

On the same model as get_user() versus __get_user(),
introduce __copy_inst_from_kernel_nofault() which doesn't
check address.

To be used by callers that have already checked that the adress
is a kernel address.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/inst.h | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h
index 80b6d74146c6..b49aae9f6f27 100644
--- a/arch/powerpc/include/asm/inst.h
+++ b/arch/powerpc/include/asm/inst.h
@@ -158,13 +158,10 @@ static inline char *__ppc_inst_as_str(char str[PPC_INST_STR_LEN], ppc_inst_t x)
 	__str;				\
 })
 
-static inline int copy_inst_from_kernel_nofault(ppc_inst_t *inst, u32 *src)
+static inline int __copy_inst_from_kernel_nofault(ppc_inst_t *inst, u32 *src)
 {
 	unsigned int val, suffix;
 
-	if (unlikely(!is_kernel_addr((unsigned long)src)))
-		return -ERANGE;
-
 /* See https://github.com/ClangBuiltLinux/linux/issues/1521 */
 #if defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 140000
 	val = suffix = 0;
@@ -181,4 +178,12 @@ static inline int copy_inst_from_kernel_nofault(ppc_inst_t *inst, u32 *src)
 	return -EFAULT;
 }
 
+static inline int copy_inst_from_kernel_nofault(ppc_inst_t *inst, u32 *src)
+{
+	if (unlikely(!is_kernel_addr((unsigned long)src)))
+		return -ERANGE;
+
+	return __copy_inst_from_kernel_nofault(inst, src);
+}
+
 #endif /* _ASM_POWERPC_INST_H */
-- 
2.35.1

[PATCH v1 17/22] powerpc/inst: Add __copy_inst_from_kernel_nofault()

[Christophe Leroy]

On the same model as get_user() versus __get_user(),
introduce __copy_inst_from_kernel_nofault() which doesn't
check address.

To be used by callers that have already checked that the adress
is a kernel address.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/inst.h | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h
index 80b6d74146c6..b49aae9f6f27 100644
--- a/arch/powerpc/include/asm/inst.h
+++ b/arch/powerpc/include/asm/inst.h
@@ -158,13 +158,10 @@ static inline char *__ppc_inst_as_str(char str[PPC_INST_STR_LEN], ppc_inst_t x)
 	__str;				\
 })
 
-static inline int copy_inst_from_kernel_nofault(ppc_inst_t *inst, u32 *src)
+static inline int __copy_inst_from_kernel_nofault(ppc_inst_t *inst, u32 *src)
 {
 	unsigned int val, suffix;
 
-	if (unlikely(!is_kernel_addr((unsigned long)src)))
-		return -ERANGE;
-
 /* See https://github.com/ClangBuiltLinux/linux/issues/1521 */
 #if defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 140000
 	val = suffix = 0;
@@ -181,4 +178,12 @@ static inline int copy_inst_from_kernel_nofault(ppc_inst_t *inst, u32 *src)
 	return -EFAULT;
 }
 
+static inline int copy_inst_from_kernel_nofault(ppc_inst_t *inst, u32 *src)
+{
+	if (unlikely(!is_kernel_addr((unsigned long)src)))
+		return -ERANGE;
+
+	return __copy_inst_from_kernel_nofault(inst, src);
+}
+
 #endif /* _ASM_POWERPC_INST_H */
-- 
2.35.1

[PATCH v1 18/22] powerpc/ftrace: Don't use copy_from_kernel_nofault() in module_trampoline_target()

[Christophe Leroy]

module_trampoline_target() is quite a hot path used when
activating/deactivating function tracer.

Avoid the heavy copy_from_kernel_nofault() by doing four calls
to copy_inst_from_kernel_nofault().

Use __copy_inst_from_kernel_nofault() for the 3 last calls. First call
is done to copy_from_kernel_nofault() to check address is within
kernel space. No risk to wrap out the top of kernel space because the
last page is never mapped so if address is in last page the first copy
will fails and the other ones will never be performed.

And also make it notrace just like all functions that call it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/module_32.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
index 2aa368ce21c9..1282cfd672f2 100644
--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c
@@ -289,13 +289,19 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 }
 
 #ifdef CONFIG_FUNCTION_TRACER
-int module_trampoline_target(struct module *mod, unsigned long addr,
-			     unsigned long *target)
+notrace int module_trampoline_target(struct module *mod, unsigned long addr,
+				     unsigned long *target)
 {
 	unsigned int jmp[4];
 
 	/* Find where the trampoline jumps to */
-	if (copy_from_kernel_nofault(jmp, (void *)addr, sizeof(jmp)))
+	if (copy_inst_from_kernel_nofault(jmp, (void *)addr))
+		return -EFAULT;
+	if (__copy_inst_from_kernel_nofault(jmp + 1, (void *)addr + 4))
+		return -EFAULT;
+	if (__copy_inst_from_kernel_nofault(jmp + 2, (void *)addr + 8))
+		return -EFAULT;
+	if (__copy_inst_from_kernel_nofault(jmp + 3, (void *)addr + 12))
 		return -EFAULT;
 
 	/* verify that this is what we expect it to be */
-- 
2.35.1

[PATCH v1 18/22] powerpc/ftrace: Don't use copy_from_kernel_nofault() in module_trampoline_target()

[Christophe Leroy]

module_trampoline_target() is quite a hot path used when
activating/deactivating function tracer.

Avoid the heavy copy_from_kernel_nofault() by doing four calls
to copy_inst_from_kernel_nofault().

Use __copy_inst_from_kernel_nofault() for the 3 last calls. First call
is done to copy_from_kernel_nofault() to check address is within
kernel space. No risk to wrap out the top of kernel space because the
last page is never mapped so if address is in last page the first copy
will fails and the other ones will never be performed.

And also make it notrace just like all functions that call it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/module_32.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
index 2aa368ce21c9..1282cfd672f2 100644
--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c
@@ -289,13 +289,19 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 }
 
 #ifdef CONFIG_FUNCTION_TRACER
-int module_trampoline_target(struct module *mod, unsigned long addr,
-			     unsigned long *target)
+notrace int module_trampoline_target(struct module *mod, unsigned long addr,
+				     unsigned long *target)
 {
 	unsigned int jmp[4];
 
 	/* Find where the trampoline jumps to */
-	if (copy_from_kernel_nofault(jmp, (void *)addr, sizeof(jmp)))
+	if (copy_inst_from_kernel_nofault(jmp, (void *)addr))
+		return -EFAULT;
+	if (__copy_inst_from_kernel_nofault(jmp + 1, (void *)addr + 4))
+		return -EFAULT;
+	if (__copy_inst_from_kernel_nofault(jmp + 2, (void *)addr + 8))
+		return -EFAULT;
+	if (__copy_inst_from_kernel_nofault(jmp + 3, (void *)addr + 12))
 		return -EFAULT;
 
 	/* verify that this is what we expect it to be */
-- 
2.35.1

[PATCH v1 19/22] powerpc/inst: Remove PPC_INST_BRANCH

[Christophe Leroy]

Convert last users of PPC_INST_BRANCH to PPC_RAW_BRANCH()

And remove PPC_INST_BRANCH.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/ppc-opcode.h | 3 +--
 arch/powerpc/lib/feature-fixups.c     | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index 281754aca0a3..ada8fe17b199 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -290,7 +290,6 @@
 #define PPC_INST_ADDIS			0x3c000000
 #define PPC_INST_ADD			0x7c000214
 #define PPC_INST_DIVD			0x7c0003d2
-#define PPC_INST_BRANCH			0x48000000
 #define PPC_INST_BL			0x48000001
 #define PPC_INST_BRANCH_COND		0x40800000
 
@@ -573,7 +572,7 @@
 #define PPC_RAW_MTSPR(spr, d)		(0x7c0003a6 | ___PPC_RS(d) | __PPC_SPR(spr))
 #define PPC_RAW_EIEIO()			(0x7c0006ac)
 
-#define PPC_RAW_BRANCH(addr)		(PPC_INST_BRANCH | ((addr) & 0x03fffffc))
+#define PPC_RAW_BRANCH(offset)		(0x48000000 | ((offset) & PPC_INST_OFFSET24_MASK))
 #define PPC_RAW_BL(offset)		(0x48000001 | ((offset) & PPC_INST_OFFSET24_MASK))
 
 /* Deal with instructions that older assemblers aren't aware of */
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 343a78826035..993d3f31832a 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -451,7 +451,7 @@ static int __do_rfi_flush_fixups(void *data)
 
 	if (types & L1D_FLUSH_FALLBACK)
 		/* b .+16 to fallback flush */
-		instrs[0] = PPC_INST_BRANCH | 16;
+		instrs[0] = PPC_RAW_BRANCH(16);
 
 	i = 0;
 	if (types & L1D_FLUSH_ORI) {
-- 
2.35.1

[PATCH v1 19/22] powerpc/inst: Remove PPC_INST_BRANCH

[Christophe Leroy]

Convert last users of PPC_INST_BRANCH to PPC_RAW_BRANCH()

And remove PPC_INST_BRANCH.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/ppc-opcode.h | 3 +--
 arch/powerpc/lib/feature-fixups.c     | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index 281754aca0a3..ada8fe17b199 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -290,7 +290,6 @@
 #define PPC_INST_ADDIS			0x3c000000
 #define PPC_INST_ADD			0x7c000214
 #define PPC_INST_DIVD			0x7c0003d2
-#define PPC_INST_BRANCH			0x48000000
 #define PPC_INST_BL			0x48000001
 #define PPC_INST_BRANCH_COND		0x40800000
 
@@ -573,7 +572,7 @@
 #define PPC_RAW_MTSPR(spr, d)		(0x7c0003a6 | ___PPC_RS(d) | __PPC_SPR(spr))
 #define PPC_RAW_EIEIO()			(0x7c0006ac)
 
-#define PPC_RAW_BRANCH(addr)		(PPC_INST_BRANCH | ((addr) & 0x03fffffc))
+#define PPC_RAW_BRANCH(offset)		(0x48000000 | ((offset) & PPC_INST_OFFSET24_MASK))
 #define PPC_RAW_BL(offset)		(0x48000001 | ((offset) & PPC_INST_OFFSET24_MASK))
 
 /* Deal with instructions that older assemblers aren't aware of */
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 343a78826035..993d3f31832a 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -451,7 +451,7 @@ static int __do_rfi_flush_fixups(void *data)
 
 	if (types & L1D_FLUSH_FALLBACK)
 		/* b .+16 to fallback flush */
-		instrs[0] = PPC_INST_BRANCH | 16;
+		instrs[0] = PPC_RAW_BRANCH(16);
 
 	i = 0;
 	if (types & L1D_FLUSH_ORI) {
-- 
2.35.1

[PATCH v1 20/22] powerpc/modules: Use PPC_INST_BRANCH_MASK instead of opencoding

[Christophe Leroy]

Use PPC_INST_BRANCH_MASK instead of opencoding.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/module_32.c | 13 ++++++-------
 arch/powerpc/kernel/module_64.c |  4 ++--
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
index 1282cfd672f2..344941855e9e 100644
--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c
@@ -256,9 +256,8 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 			       value, (uint32_t)location);
 			pr_debug("Location before: %08X.\n",
 			       *(uint32_t *)location);
-			value = (*(uint32_t *)location & ~0x03fffffc)
-				| ((value - (uint32_t)location)
-				   & 0x03fffffc);
+			value = (*(uint32_t *)location & ~PPC_INST_OFFSET24_MASK) |
+				((value - (uint32_t)location) & PPC_INST_OFFSET24_MASK);
 
 			if (patch_instruction(location, ppc_inst(value)))
 				return -EFAULT;
@@ -266,10 +265,10 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 			pr_debug("Location after: %08X.\n",
 			       *(uint32_t *)location);
 			pr_debug("ie. jump to %08X+%08X = %08X\n",
-			       *(uint32_t *)location & 0x03fffffc,
-			       (uint32_t)location,
-			       (*(uint32_t *)location & 0x03fffffc)
-			       + (uint32_t)location);
+				 *(uint32_t *)location & PPC_INST_OFFSET24_MASK,
+				 (uint32_t)location,
+				 (*(uint32_t *)location & PPC_INST_OFFSET24_MASK) +
+				 (uint32_t)location);
 			break;
 
 		case R_PPC_REL32:
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index b13a72665eee..8f70a04aac6c 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -653,8 +653,8 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 			}
 
 			/* Only replace bits 2 through 26 */
-			value = (*(uint32_t *)location & ~0x03fffffc)
-				| (value & 0x03fffffc);
+			value = (*(uint32_t *)location & ~PPC_INST_OFFSET24_MASK) |
+				(value & PPC_INST_OFFSET24_MASK);
 
 			if (patch_instruction((u32 *)location, ppc_inst(value)))
 				return -EFAULT;
-- 
2.35.1

[PATCH v1 20/22] powerpc/modules: Use PPC_INST_BRANCH_MASK instead of opencoding

[Christophe Leroy]

Use PPC_INST_BRANCH_MASK instead of opencoding.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/module_32.c | 13 ++++++-------
 arch/powerpc/kernel/module_64.c |  4 ++--
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
index 1282cfd672f2..344941855e9e 100644
--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c
@@ -256,9 +256,8 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 			       value, (uint32_t)location);
 			pr_debug("Location before: %08X.\n",
 			       *(uint32_t *)location);
-			value = (*(uint32_t *)location & ~0x03fffffc)
-				| ((value - (uint32_t)location)
-				   & 0x03fffffc);
+			value = (*(uint32_t *)location & ~PPC_INST_OFFSET24_MASK) |
+				((value - (uint32_t)location) & PPC_INST_OFFSET24_MASK);
 
 			if (patch_instruction(location, ppc_inst(value)))
 				return -EFAULT;
@@ -266,10 +265,10 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 			pr_debug("Location after: %08X.\n",
 			       *(uint32_t *)location);
 			pr_debug("ie. jump to %08X+%08X = %08X\n",
-			       *(uint32_t *)location & 0x03fffffc,
-			       (uint32_t)location,
-			       (*(uint32_t *)location & 0x03fffffc)
-			       + (uint32_t)location);
+				 *(uint32_t *)location & PPC_INST_OFFSET24_MASK,
+				 (uint32_t)location,
+				 (*(uint32_t *)location & PPC_INST_OFFSET24_MASK) +
+				 (uint32_t)location);
 			break;
 
 		case R_PPC_REL32:
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index b13a72665eee..8f70a04aac6c 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -653,8 +653,8 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 			}
 
 			/* Only replace bits 2 through 26 */
-			value = (*(uint32_t *)location & ~0x03fffffc)
-				| (value & 0x03fffffc);
+			value = (*(uint32_t *)location & ~PPC_INST_OFFSET24_MASK) |
+				(value & PPC_INST_OFFSET24_MASK);
 
 			if (patch_instruction((u32 *)location, ppc_inst(value)))
 				return -EFAULT;
-- 
2.35.1

[PATCH v1 21/22] powerpc/inst: Remove PPC_INST_BL

[Christophe Leroy]

Convert last users of PPC_INST_BL to PPC_RAW_BL()

And remove PPC_INST_BL.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/ppc-opcode.h | 1 -
 arch/powerpc/net/bpf_jit.h            | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index ada8fe17b199..810a28af9dce 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -290,7 +290,6 @@
 #define PPC_INST_ADDIS			0x3c000000
 #define PPC_INST_ADD			0x7c000214
 #define PPC_INST_DIVD			0x7c0003d2
-#define PPC_INST_BL			0x48000001
 #define PPC_INST_BRANCH_COND		0x40800000
 
 #define PPC_INST_OFFSET24_MASK		0x03fffffc
diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h
index 979701d360da..c63324ff9f04 100644
--- a/arch/powerpc/net/bpf_jit.h
+++ b/arch/powerpc/net/bpf_jit.h
@@ -35,7 +35,7 @@
 	} while (0)
 
 /* bl (unconditional 'branch' with link) */
-#define PPC_BL(dest)	EMIT(PPC_INST_BL | (((dest) - (unsigned long)(image + ctx->idx)) & 0x03fffffc))
+#define PPC_BL(dest)	EMIT(PPC_RAW_BL((dest) - (unsigned long)(image + ctx->idx)))
 
 /* "cond" here covers BO:BI fields. */
 #define PPC_BCC_SHORT(cond, dest)					      \
-- 
2.35.1

[PATCH v1 21/22] powerpc/inst: Remove PPC_INST_BL

[Christophe Leroy]

Convert last users of PPC_INST_BL to PPC_RAW_BL()

And remove PPC_INST_BL.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/ppc-opcode.h | 1 -
 arch/powerpc/net/bpf_jit.h            | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index ada8fe17b199..810a28af9dce 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -290,7 +290,6 @@
 #define PPC_INST_ADDIS			0x3c000000
 #define PPC_INST_ADD			0x7c000214
 #define PPC_INST_DIVD			0x7c0003d2
-#define PPC_INST_BL			0x48000001
 #define PPC_INST_BRANCH_COND		0x40800000
 
 #define PPC_INST_OFFSET24_MASK		0x03fffffc
diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h
index 979701d360da..c63324ff9f04 100644
--- a/arch/powerpc/net/bpf_jit.h
+++ b/arch/powerpc/net/bpf_jit.h
@@ -35,7 +35,7 @@
 	} while (0)
 
 /* bl (unconditional 'branch' with link) */
-#define PPC_BL(dest)	EMIT(PPC_INST_BL | (((dest) - (unsigned long)(image + ctx->idx)) & 0x03fffffc))
+#define PPC_BL(dest)	EMIT(PPC_RAW_BL((dest) - (unsigned long)(image + ctx->idx)))
 
 /* "cond" here covers BO:BI fields. */
 #define PPC_BCC_SHORT(cond, dest)					      \
-- 
2.35.1

[PATCH v1 22/22] powerpc/opcodes: Remove unused PPC_INST_XXX macros

[Christophe Leroy]

The following PPC_INST_XXX macros are not used anymore
outside ppc-opcode.h:
	- PPC_INST_LD
	- PPC_INST_STD
	- PPC_INST_ADDIS
	- PPC_INST_ADD
	- PPC_INST_DIVD

Remove them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/ppc-opcode.h | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index 810a28af9dce..4cdda507e816 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -285,11 +285,6 @@
 #define PPC_INST_TRECHKPT		0x7c0007dd
 #define PPC_INST_TRECLAIM		0x7c00075d
 #define PPC_INST_TSR			0x7c0005dd
-#define PPC_INST_LD			0xe8000000
-#define PPC_INST_STD			0xf8000000
-#define PPC_INST_ADDIS			0x3c000000
-#define PPC_INST_ADD			0x7c000214
-#define PPC_INST_DIVD			0x7c0003d2
 #define PPC_INST_BRANCH_COND		0x40800000
 
 #define PPC_INST_OFFSET24_MASK		0x03fffffc
@@ -460,10 +455,10 @@
 	(0x100000c7 | ___PPC_RT(vrt) | ___PPC_RA(vra) | ___PPC_RB(vrb) | __PPC_RC21)
 #define PPC_RAW_VCMPEQUB_RC(vrt, vra, vrb) \
 	(0x10000006 | ___PPC_RT(vrt) | ___PPC_RA(vra) | ___PPC_RB(vrb) | __PPC_RC21)
-#define PPC_RAW_LD(r, base, i)		(PPC_INST_LD | ___PPC_RT(r) | ___PPC_RA(base) | IMM_DS(i))
+#define PPC_RAW_LD(r, base, i)		(0xe8000000 | ___PPC_RT(r) | ___PPC_RA(base) | IMM_DS(i))
 #define PPC_RAW_LWZ(r, base, i)		(0x80000000 | ___PPC_RT(r) | ___PPC_RA(base) | IMM_L(i))
 #define PPC_RAW_LWZX(t, a, b)		(0x7c00002e | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
-#define PPC_RAW_STD(r, base, i)		(PPC_INST_STD | ___PPC_RS(r) | ___PPC_RA(base) | IMM_DS(i))
+#define PPC_RAW_STD(r, base, i)		(0xf8000000 | ___PPC_RS(r) | ___PPC_RA(base) | IMM_DS(i))
 #define PPC_RAW_STDCX(s, a, b)		(0x7c0001ad | ___PPC_RS(s) | ___PPC_RA(a) | ___PPC_RB(b))
 #define PPC_RAW_LFSX(t, a, b)		(0x7c00042e | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
 #define PPC_RAW_STFSX(s, a, b)		(0x7c00052e | ___PPC_RS(s) | ___PPC_RA(a) | ___PPC_RB(b))
@@ -474,8 +469,8 @@
 #define PPC_RAW_ADDE(t, a, b)		(0x7c000114 | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
 #define PPC_RAW_ADDZE(t, a)		(0x7c000194 | ___PPC_RT(t) | ___PPC_RA(a))
 #define PPC_RAW_ADDME(t, a)		(0x7c0001d4 | ___PPC_RT(t) | ___PPC_RA(a))
-#define PPC_RAW_ADD(t, a, b)		(PPC_INST_ADD | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
-#define PPC_RAW_ADD_DOT(t, a, b)	(PPC_INST_ADD | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b) | 0x1)
+#define PPC_RAW_ADD(t, a, b)		(0x7c000214 | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
+#define PPC_RAW_ADD_DOT(t, a, b)	(0x7c000214 | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b) | 0x1)
 #define PPC_RAW_ADDC(t, a, b)		(0x7c000014 | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
 #define PPC_RAW_ADDC_DOT(t, a, b)	(0x7c000014 | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b) | 0x1)
 #define PPC_RAW_NOP()			PPC_RAW_ORI(0, 0, 0)
-- 
2.35.1

[PATCH v1 22/22] powerpc/opcodes: Remove unused PPC_INST_XXX macros

[Christophe Leroy]

The following PPC_INST_XXX macros are not used anymore
outside ppc-opcode.h:
	- PPC_INST_LD
	- PPC_INST_STD
	- PPC_INST_ADDIS
	- PPC_INST_ADD
	- PPC_INST_DIVD

Remove them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/ppc-opcode.h | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index 810a28af9dce..4cdda507e816 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -285,11 +285,6 @@
 #define PPC_INST_TRECHKPT		0x7c0007dd
 #define PPC_INST_TRECLAIM		0x7c00075d
 #define PPC_INST_TSR			0x7c0005dd
-#define PPC_INST_LD			0xe8000000
-#define PPC_INST_STD			0xf8000000
-#define PPC_INST_ADDIS			0x3c000000
-#define PPC_INST_ADD			0x7c000214
-#define PPC_INST_DIVD			0x7c0003d2
 #define PPC_INST_BRANCH_COND		0x40800000
 
 #define PPC_INST_OFFSET24_MASK		0x03fffffc
@@ -460,10 +455,10 @@
 	(0x100000c7 | ___PPC_RT(vrt) | ___PPC_RA(vra) | ___PPC_RB(vrb) | __PPC_RC21)
 #define PPC_RAW_VCMPEQUB_RC(vrt, vra, vrb) \
 	(0x10000006 | ___PPC_RT(vrt) | ___PPC_RA(vra) | ___PPC_RB(vrb) | __PPC_RC21)
-#define PPC_RAW_LD(r, base, i)		(PPC_INST_LD | ___PPC_RT(r) | ___PPC_RA(base) | IMM_DS(i))
+#define PPC_RAW_LD(r, base, i)		(0xe8000000 | ___PPC_RT(r) | ___PPC_RA(base) | IMM_DS(i))
 #define PPC_RAW_LWZ(r, base, i)		(0x80000000 | ___PPC_RT(r) | ___PPC_RA(base) | IMM_L(i))
 #define PPC_RAW_LWZX(t, a, b)		(0x7c00002e | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
-#define PPC_RAW_STD(r, base, i)		(PPC_INST_STD | ___PPC_RS(r) | ___PPC_RA(base) | IMM_DS(i))
+#define PPC_RAW_STD(r, base, i)		(0xf8000000 | ___PPC_RS(r) | ___PPC_RA(base) | IMM_DS(i))
 #define PPC_RAW_STDCX(s, a, b)		(0x7c0001ad | ___PPC_RS(s) | ___PPC_RA(a) | ___PPC_RB(b))
 #define PPC_RAW_LFSX(t, a, b)		(0x7c00042e | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
 #define PPC_RAW_STFSX(s, a, b)		(0x7c00052e | ___PPC_RS(s) | ___PPC_RA(a) | ___PPC_RB(b))
@@ -474,8 +469,8 @@
 #define PPC_RAW_ADDE(t, a, b)		(0x7c000114 | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
 #define PPC_RAW_ADDZE(t, a)		(0x7c000194 | ___PPC_RT(t) | ___PPC_RA(a))
 #define PPC_RAW_ADDME(t, a)		(0x7c0001d4 | ___PPC_RT(t) | ___PPC_RA(a))
-#define PPC_RAW_ADD(t, a, b)		(PPC_INST_ADD | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
-#define PPC_RAW_ADD_DOT(t, a, b)	(PPC_INST_ADD | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b) | 0x1)
+#define PPC_RAW_ADD(t, a, b)		(0x7c000214 | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
+#define PPC_RAW_ADD_DOT(t, a, b)	(0x7c000214 | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b) | 0x1)
 #define PPC_RAW_ADDC(t, a, b)		(0x7c000014 | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b))
 #define PPC_RAW_ADDC_DOT(t, a, b)	(0x7c000014 | ___PPC_RT(t) | ___PPC_RA(a) | ___PPC_RB(b) | 0x1)
 #define PPC_RAW_NOP()			PPC_RAW_ORI(0, 0, 0)
-- 
2.35.1

Re: [PATCH v1 06/22] powerpc/ftrace: Inline ftrace_modify_code()

[Naveen N. Rao]

Christophe Leroy wrote:
> Inlining ftrace_modify_code(), it increases a bit the
> size of ftrace code but brings 5% improvment on ftrace
> activation.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/kernel/trace/ftrace.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index 41c45b9c7f39..98e82fa4980f 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -53,7 +53,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
>  	return op;
>  }
> 
> -static int
> +static inline int
>  ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
>  {
>  	ppc_inst_t replaced;

I thought gcc was free to inline functions without the need for 
'inline'. Don't you see this being inlined otherwise?

On the flip side, don't we need __always_inline if we want to force 
inlining?


- Naveen

Re: [PATCH v1 06/22] powerpc/ftrace: Inline ftrace_modify_code()

[Naveen N. Rao]

Christophe Leroy wrote:
> Inlining ftrace_modify_code(), it increases a bit the
> size of ftrace code but brings 5% improvment on ftrace
> activation.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/kernel/trace/ftrace.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index 41c45b9c7f39..98e82fa4980f 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -53,7 +53,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
>  	return op;
>  }
> 
> -static int
> +static inline int
>  ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
>  {
>  	ppc_inst_t replaced;

I thought gcc was free to inline functions without the need for 
'inline'. Don't you see this being inlined otherwise?

On the flip side, don't we need __always_inline if we want to force 
inlining?


- Naveen

Re: [PATCH v1 07/22] powerpc/ftrace: Use patch_instruction() return directly

[Naveen N. Rao]

Christophe Leroy wrote:
> Instead of returning -EPERM when patch_instruction() fails,
> just return what patch_instruction returns.
> 
> That simplifies ftrace_modify_code():
> 
> 	   0:	94 21 ff c0 	stwu    r1,-64(r1)
> 	   4:	93 e1 00 3c 	stw     r31,60(r1)
> 	   8:	7c 7f 1b 79 	mr.     r31,r3
> 	   c:	40 80 00 30 	bge     3c <ftrace_modify_code+0x3c>
> 	  10:	93 c1 00 38 	stw     r30,56(r1)
> 	  14:	7c 9e 23 78 	mr      r30,r4
> 	  18:	7c a4 2b 78 	mr      r4,r5
> 	  1c:	80 bf 00 00 	lwz     r5,0(r31)
> 	  20:	7c 1e 28 40 	cmplw   r30,r5
> 	  24:	40 82 00 34 	bne     58 <ftrace_modify_code+0x58>
> 	  28:	83 c1 00 38 	lwz     r30,56(r1)
> 	  2c:	7f e3 fb 78 	mr      r3,r31
> 	  30:	83 e1 00 3c 	lwz     r31,60(r1)
> 	  34:	38 21 00 40 	addi    r1,r1,64
> 	  38:	48 00 00 00 	b       38 <ftrace_modify_code+0x38>
> 				38: R_PPC_REL24	patch_instruction
> 
> Before:
> 
> 	   0:	94 21 ff c0 	stwu    r1,-64(r1)
> 	   4:	93 e1 00 3c 	stw     r31,60(r1)
> 	   8:	7c 7f 1b 79 	mr.     r31,r3
> 	   c:	40 80 00 4c 	bge     58 <ftrace_modify_code+0x58>
> 	  10:	93 c1 00 38 	stw     r30,56(r1)
> 	  14:	7c 9e 23 78 	mr      r30,r4
> 	  18:	7c a4 2b 78 	mr      r4,r5
> 	  1c:	80 bf 00 00 	lwz     r5,0(r31)
> 	  20:	7c 08 02 a6 	mflr    r0
> 	  24:	90 01 00 44 	stw     r0,68(r1)
> 	  28:	7c 1e 28 40 	cmplw   r30,r5
> 	  2c:	40 82 00 48 	bne     74 <ftrace_modify_code+0x74>
> 	  30:	7f e3 fb 78 	mr      r3,r31
> 	  34:	48 00 00 01 	bl      34 <ftrace_modify_code+0x34>
> 				34: R_PPC_REL24	patch_instruction
> 	  38:	80 01 00 44 	lwz     r0,68(r1)
> 	  3c:	20 63 00 00 	subfic  r3,r3,0
> 	  40:	83 c1 00 38 	lwz     r30,56(r1)
> 	  44:	7c 63 19 10 	subfe   r3,r3,r3
> 	  48:	7c 08 03 a6 	mtlr    r0
> 	  4c:	83 e1 00 3c 	lwz     r31,60(r1)
> 	  50:	38 21 00 40 	addi    r1,r1,64
> 	  54:	4e 80 00 20 	blr
> 
> It improves ftrace activation/deactivation duration by about 3%.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/kernel/trace/ftrace.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index 98e82fa4980f..1b05d33f96c6 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -78,10 +78,7 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
>  	}
> 
>  	/* replace the text with the new text */
> -	if (patch_instruction((u32 *)ip, new))
> -		return -EPERM;
> -
> -	return 0;
> +	return patch_instruction((u32 *)ip, new);

I think the reason we were returning -EPERM is so that ftrace_bug() can 
throw the right error message. That will change due to this patch, 
though I'm not sure how much it matters. -EFAULT and -EPERM seem to 
print almost the same error message.

- Naveen

Re: [PATCH v1 07/22] powerpc/ftrace: Use patch_instruction() return directly

[Naveen N. Rao]

Christophe Leroy wrote:
> Instead of returning -EPERM when patch_instruction() fails,
> just return what patch_instruction returns.
> 
> That simplifies ftrace_modify_code():
> 
> 	   0:	94 21 ff c0 	stwu    r1,-64(r1)
> 	   4:	93 e1 00 3c 	stw     r31,60(r1)
> 	   8:	7c 7f 1b 79 	mr.     r31,r3
> 	   c:	40 80 00 30 	bge     3c <ftrace_modify_code+0x3c>
> 	  10:	93 c1 00 38 	stw     r30,56(r1)
> 	  14:	7c 9e 23 78 	mr      r30,r4
> 	  18:	7c a4 2b 78 	mr      r4,r5
> 	  1c:	80 bf 00 00 	lwz     r5,0(r31)
> 	  20:	7c 1e 28 40 	cmplw   r30,r5
> 	  24:	40 82 00 34 	bne     58 <ftrace_modify_code+0x58>
> 	  28:	83 c1 00 38 	lwz     r30,56(r1)
> 	  2c:	7f e3 fb 78 	mr      r3,r31
> 	  30:	83 e1 00 3c 	lwz     r31,60(r1)
> 	  34:	38 21 00 40 	addi    r1,r1,64
> 	  38:	48 00 00 00 	b       38 <ftrace_modify_code+0x38>
> 				38: R_PPC_REL24	patch_instruction
> 
> Before:
> 
> 	   0:	94 21 ff c0 	stwu    r1,-64(r1)
> 	   4:	93 e1 00 3c 	stw     r31,60(r1)
> 	   8:	7c 7f 1b 79 	mr.     r31,r3
> 	   c:	40 80 00 4c 	bge     58 <ftrace_modify_code+0x58>
> 	  10:	93 c1 00 38 	stw     r30,56(r1)
> 	  14:	7c 9e 23 78 	mr      r30,r4
> 	  18:	7c a4 2b 78 	mr      r4,r5
> 	  1c:	80 bf 00 00 	lwz     r5,0(r31)
> 	  20:	7c 08 02 a6 	mflr    r0
> 	  24:	90 01 00 44 	stw     r0,68(r1)
> 	  28:	7c 1e 28 40 	cmplw   r30,r5
> 	  2c:	40 82 00 48 	bne     74 <ftrace_modify_code+0x74>
> 	  30:	7f e3 fb 78 	mr      r3,r31
> 	  34:	48 00 00 01 	bl      34 <ftrace_modify_code+0x34>
> 				34: R_PPC_REL24	patch_instruction
> 	  38:	80 01 00 44 	lwz     r0,68(r1)
> 	  3c:	20 63 00 00 	subfic  r3,r3,0
> 	  40:	83 c1 00 38 	lwz     r30,56(r1)
> 	  44:	7c 63 19 10 	subfe   r3,r3,r3
> 	  48:	7c 08 03 a6 	mtlr    r0
> 	  4c:	83 e1 00 3c 	lwz     r31,60(r1)
> 	  50:	38 21 00 40 	addi    r1,r1,64
> 	  54:	4e 80 00 20 	blr
> 
> It improves ftrace activation/deactivation duration by about 3%.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/kernel/trace/ftrace.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index 98e82fa4980f..1b05d33f96c6 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -78,10 +78,7 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
>  	}
> 
>  	/* replace the text with the new text */
> -	if (patch_instruction((u32 *)ip, new))
> -		return -EPERM;
> -
> -	return 0;
> +	return patch_instruction((u32 *)ip, new);

I think the reason we were returning -EPERM is so that ftrace_bug() can 
throw the right error message. That will change due to this patch, 
though I'm not sure how much it matters. -EFAULT and -EPERM seem to 
print almost the same error message.

- Naveen

Re: [PATCH v1 08/22] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64

[Naveen N. Rao]

Christophe Leroy wrote:
> Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target()
> for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the
> one for PPC64.
> 
> Same for __ftrace_make_call().
> 
> Make them common.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/kernel/trace/ftrace.c | 108 +++--------------------------
>  1 file changed, 8 insertions(+), 100 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index 1b05d33f96c6..2c7e42e439bb 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -114,7 +114,6 @@ static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
>  }
> 
>  #ifdef CONFIG_MODULES
> -#ifdef CONFIG_PPC64
>  static int
>  __ftrace_make_nop(struct module *mod,
>  		  struct dyn_ftrace *rec, unsigned long addr)
> @@ -154,10 +153,11 @@ __ftrace_make_nop(struct module *mod,
>  		return -EINVAL;
>  	}
> 
> -#ifdef CONFIG_MPROFILE_KERNEL
> -	/* When using -mkernel_profile there is no load to jump over */
> +	/* When using -mkernel_profile or PPC32 there is no load to jump over */
                      -mprofile-kernel

Since you are modifying that line anyway ^^


>  	pop = ppc_inst(PPC_RAW_NOP());
> 
> +#ifdef CONFIG_PPC64
> +#ifdef CONFIG_MPROFILE_KERNEL
>  	if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
>  		pr_err("Fetching instruction at %lx failed.\n", ip - 4);
>  		return -EFAULT;
> @@ -201,6 +201,7 @@ __ftrace_make_nop(struct module *mod,
>  		return -EINVAL;
>  	}
>  #endif /* CONFIG_MPROFILE_KERNEL */
> +#endif /* PPC64 */
> 
>  	if (patch_instruction((u32 *)ip, pop)) {
>  		pr_err("Patching NOP failed.\n");
> @@ -209,48 +210,6 @@ __ftrace_make_nop(struct module *mod,
> 
>  	return 0;
>  }
> -
> -#else /* !PPC64 */
> -static int
> -__ftrace_make_nop(struct module *mod,
> -		  struct dyn_ftrace *rec, unsigned long addr)
> -{
> -	ppc_inst_t op;
> -	unsigned long ip = rec->ip;
> -	unsigned long tramp, ptr;
> -
> -	if (copy_from_kernel_nofault(&op, (void *)ip, MCOUNT_INSN_SIZE))
> -		return -EFAULT;
> -
> -	/* Make sure that that this is still a 24bit jump */
> -	if (!is_bl_op(op)) {
> -		pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
> -		return -EINVAL;
> -	}
> -
> -	/* lets find where the pointer goes */
> -	tramp = find_bl_target(ip, op);
> -
> -	/* Find where the trampoline jumps to */
> -	if (module_trampoline_target(mod, tramp, &ptr)) {
> -		pr_err("Failed to get trampoline target\n");
> -		return -EFAULT;
> -	}
> -
> -	if (ptr != addr) {
> -		pr_err("Trampoline location %08lx does not match addr\n",
> -		       tramp);
> -		return -EINVAL;
> -	}
> -
> -	op = ppc_inst(PPC_RAW_NOP());
> -
> -	if (patch_instruction((u32 *)ip, op))
> -		return -EPERM;
> -
> -	return 0;
> -}
> -#endif /* PPC64 */
>  #endif /* CONFIG_MODULES */
> 
>  static unsigned long find_ftrace_tramp(unsigned long ip)
> @@ -437,13 +396,12 @@ int ftrace_make_nop(struct module *mod,
>  }
> 
>  #ifdef CONFIG_MODULES
> -#ifdef CONFIG_PPC64
>  /*
>   * Examine the existing instructions for __ftrace_make_call.
>   * They should effectively be a NOP, and follow formal constraints,
>   * depending on the ABI. Return false if they don't.
>   */
> -#ifndef CONFIG_MPROFILE_KERNEL
> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS

It is better to gate this on PPC64_ELF_ABI_v1

>  static int
>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  {
> @@ -465,7 +423,7 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  static int
>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  {
> -	/* look for patched "NOP" on ppc64 with -mprofile-kernel */
> +	/* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
>  	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
>  		return 0;
>  	return 1;
> @@ -484,8 +442,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
>  	if (copy_inst_from_kernel_nofault(op, ip))
>  		return -EFAULT;
> 
> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>  	if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
>  		return -EFAULT;
> +#endif

Here too...


- Naveen

Re: [PATCH v1 08/22] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64

[Naveen N. Rao]

Christophe Leroy wrote:
> Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target()
> for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the
> one for PPC64.
> 
> Same for __ftrace_make_call().
> 
> Make them common.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/kernel/trace/ftrace.c | 108 +++--------------------------
>  1 file changed, 8 insertions(+), 100 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index 1b05d33f96c6..2c7e42e439bb 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -114,7 +114,6 @@ static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
>  }
> 
>  #ifdef CONFIG_MODULES
> -#ifdef CONFIG_PPC64
>  static int
>  __ftrace_make_nop(struct module *mod,
>  		  struct dyn_ftrace *rec, unsigned long addr)
> @@ -154,10 +153,11 @@ __ftrace_make_nop(struct module *mod,
>  		return -EINVAL;
>  	}
> 
> -#ifdef CONFIG_MPROFILE_KERNEL
> -	/* When using -mkernel_profile there is no load to jump over */
> +	/* When using -mkernel_profile or PPC32 there is no load to jump over */
                      -mprofile-kernel

Since you are modifying that line anyway ^^


>  	pop = ppc_inst(PPC_RAW_NOP());
> 
> +#ifdef CONFIG_PPC64
> +#ifdef CONFIG_MPROFILE_KERNEL
>  	if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
>  		pr_err("Fetching instruction at %lx failed.\n", ip - 4);
>  		return -EFAULT;
> @@ -201,6 +201,7 @@ __ftrace_make_nop(struct module *mod,
>  		return -EINVAL;
>  	}
>  #endif /* CONFIG_MPROFILE_KERNEL */
> +#endif /* PPC64 */
> 
>  	if (patch_instruction((u32 *)ip, pop)) {
>  		pr_err("Patching NOP failed.\n");
> @@ -209,48 +210,6 @@ __ftrace_make_nop(struct module *mod,
> 
>  	return 0;
>  }
> -
> -#else /* !PPC64 */
> -static int
> -__ftrace_make_nop(struct module *mod,
> -		  struct dyn_ftrace *rec, unsigned long addr)
> -{
> -	ppc_inst_t op;
> -	unsigned long ip = rec->ip;
> -	unsigned long tramp, ptr;
> -
> -	if (copy_from_kernel_nofault(&op, (void *)ip, MCOUNT_INSN_SIZE))
> -		return -EFAULT;
> -
> -	/* Make sure that that this is still a 24bit jump */
> -	if (!is_bl_op(op)) {
> -		pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
> -		return -EINVAL;
> -	}
> -
> -	/* lets find where the pointer goes */
> -	tramp = find_bl_target(ip, op);
> -
> -	/* Find where the trampoline jumps to */
> -	if (module_trampoline_target(mod, tramp, &ptr)) {
> -		pr_err("Failed to get trampoline target\n");
> -		return -EFAULT;
> -	}
> -
> -	if (ptr != addr) {
> -		pr_err("Trampoline location %08lx does not match addr\n",
> -		       tramp);
> -		return -EINVAL;
> -	}
> -
> -	op = ppc_inst(PPC_RAW_NOP());
> -
> -	if (patch_instruction((u32 *)ip, op))
> -		return -EPERM;
> -
> -	return 0;
> -}
> -#endif /* PPC64 */
>  #endif /* CONFIG_MODULES */
> 
>  static unsigned long find_ftrace_tramp(unsigned long ip)
> @@ -437,13 +396,12 @@ int ftrace_make_nop(struct module *mod,
>  }
> 
>  #ifdef CONFIG_MODULES
> -#ifdef CONFIG_PPC64
>  /*
>   * Examine the existing instructions for __ftrace_make_call.
>   * They should effectively be a NOP, and follow formal constraints,
>   * depending on the ABI. Return false if they don't.
>   */
> -#ifndef CONFIG_MPROFILE_KERNEL
> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS

It is better to gate this on PPC64_ELF_ABI_v1

>  static int
>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  {
> @@ -465,7 +423,7 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  static int
>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  {
> -	/* look for patched "NOP" on ppc64 with -mprofile-kernel */
> +	/* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
>  	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
>  		return 0;
>  	return 1;
> @@ -484,8 +442,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
>  	if (copy_inst_from_kernel_nofault(op, ip))
>  		return -EFAULT;
> 
> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>  	if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
>  		return -EFAULT;
> +#endif

Here too...


- Naveen

Re: [PATCH v1 10/22] powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACE

[Naveen N. Rao]

Christophe Leroy wrote:
> Since commit 0c0c52306f47 ("powerpc: Only support DYNAMIC_FTRACE not
> static"), CONFIG_DYNAMIC_FTRACE is always selected when
> CONFIG_FUNCTION_TRACER is selected.
> 
> To avoid confusion and have the reader wonder what's happen when
> CONFIG_FUNCTION_TRACER is selected and CONFIG_DYNAMIC_FTRACE is not,
> use CONFIG_FUNCTION_TRACER in ifdefs instead of CONFIG_DYNAMIC_FTRACE.
> 
> As CONFIG_FUNCTION_GRAPH_TRACER depends on CONFIG_FUNCTION_TRACER,
> ftrace.o doesn't need to appear for both symbols in Makefile.
> 
> Then as ftrace.o is built only when CONFIG_FUNCTION_TRACER is selected

and since it implies CONFIG_DYNAMIC_FTRACE, CONFIG_DYNAMIC_FTRACE is not 
needed in ftrace.c

> ifdef CONFIG_FUNCTION_TRACER is not needed in ftrace.c
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/include/asm/book3s/32/pgtable.h | 2 +-
>  arch/powerpc/include/asm/book3s/64/pgtable.h | 2 +-
>  arch/powerpc/include/asm/module.h            | 4 ++--
>  arch/powerpc/include/asm/nohash/pgtable.h    | 2 +-
>  arch/powerpc/kernel/module_32.c              | 4 ++--
>  arch/powerpc/kernel/module_64.c              | 6 +++---
>  arch/powerpc/kernel/trace/Makefile           | 4 +---
>  arch/powerpc/kernel/trace/ftrace.c           | 4 ----
>  8 files changed, 11 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
> index 772e00dc4ef1..992aed626eb4 100644
> --- a/arch/powerpc/include/asm/book3s/32/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
> @@ -124,7 +124,7 @@ static inline bool pte_user(pte_t pte)
>   * on platforms where such control is possible.
>   */
>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
> -	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
> +	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
>  #else
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
> index 875730d5af40..cf01b609572f 100644
> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
> @@ -169,7 +169,7 @@
>   * on platforms where such control is possible.
>   */
>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) || \
> -	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
> +	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
>  #else
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
> diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
> index 857d9ff24295..e6f5963fd96e 100644
> --- a/arch/powerpc/include/asm/module.h
> +++ b/arch/powerpc/include/asm/module.h
> @@ -39,7 +39,7 @@ struct mod_arch_specific {
>  	unsigned int init_plt_section;
>  #endif /* powerpc64 */
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  	unsigned long tramp;
>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>  	unsigned long tramp_regs;
> @@ -68,7 +68,7 @@ struct mod_arch_specific {
>  #    endif	/* MODULE */
>  #endif
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  #    ifdef MODULE
>  	asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
>  #    endif	/* MODULE */
> diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
> index ac75f4ab0dba..2e8cf217a191 100644
> --- a/arch/powerpc/include/asm/nohash/pgtable.h
> +++ b/arch/powerpc/include/asm/nohash/pgtable.h
> @@ -23,7 +23,7 @@
>   * on platforms where such control is possible.
>   */
>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
> -	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
> +	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
>  #else
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
> diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
> index a0432ef46967..2aa368ce21c9 100644
> --- a/arch/powerpc/kernel/module_32.c
> +++ b/arch/powerpc/kernel/module_32.c
> @@ -39,7 +39,7 @@ static unsigned int count_relocs(const Elf32_Rela *rela, unsigned int num)
>  			r_addend = rela[i].r_addend;
>  		}
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  	_count_relocs++;	/* add one for ftrace_caller */
>  #endif
>  	return _count_relocs;
> @@ -288,7 +288,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
>  	return 0;
>  }
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  int module_trampoline_target(struct module *mod, unsigned long addr,
>  			     unsigned long *target)
>  {
> diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
> index 794720530442..b13a72665eee 100644
> --- a/arch/powerpc/kernel/module_64.c
> +++ b/arch/powerpc/kernel/module_64.c
> @@ -207,7 +207,7 @@ static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
>  		}
>  	}
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  	/* make the trampoline to the ftrace_caller */
>  	relocs++;
>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> @@ -372,7 +372,7 @@ static bool is_mprofile_ftrace_call(const char *name)
>  {
>  	if (!strcmp("_mcount", name))
>  		return true;
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  	if (!strcmp("ftrace_caller", name))
>  		return true;
>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> @@ -740,7 +740,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
>  	return 0;
>  }
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  int module_trampoline_target(struct module *mod, unsigned long addr,
>  			     unsigned long *target)
>  {

The below two changes to trace/Makefile and trace/ftrace.c make 
sense, but I'm not sure the above changes are necessary.

For generic code (outside arch/powerpc/kernel/trace), I think it is good 
to retain the actual dependency which is DYNAMIC_FTRACE. In my view, 
gating some of the above code on FUNCTION_TRACER is also confusing. The 
primary implication of always selecting DYNAMIC_FTRACE is within the 
powerpc trace code, and it is good to keep it that way.

> diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile
> index fc32ec30b297..af8527538fe4 100644
> --- a/arch/powerpc/kernel/trace/Makefile
> +++ b/arch/powerpc/kernel/trace/Makefile
> @@ -14,9 +14,7 @@ obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_mprofile.o
>  else
>  obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_64_pg.o
>  endif
> -obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_low.o
> -obj-$(CONFIG_DYNAMIC_FTRACE)		+= ftrace.o
> -obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
> +obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_low.o ftrace.o
>  obj-$(CONFIG_TRACING)			+= trace_clock.o
> 
>  obj-$(CONFIG_PPC64)			+= $(obj64-y)
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index 2c7e42e439bb..188f59f4ee4a 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -28,9 +28,6 @@
>  #include <asm/syscall.h>
>  #include <asm/inst.h>
> 
> -
> -#ifdef CONFIG_DYNAMIC_FTRACE
> -
>  /*
>   * We generally only have a single long_branch tramp and at most 2 or 3 plt
>   * tramps generated. But, we don't use the plt tramps currently. We also allot
> @@ -783,7 +780,6 @@ int __init ftrace_dyn_arch_init(void)
>  	return 0;
>  }
>  #endif
> -#endif /* CONFIG_DYNAMIC_FTRACE */
> 
>  #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> 
> -- 
> 2.35.1
> 

- Naveen

Re: [PATCH v1 10/22] powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACE

[Naveen N. Rao]

Christophe Leroy wrote:
> Since commit 0c0c52306f47 ("powerpc: Only support DYNAMIC_FTRACE not
> static"), CONFIG_DYNAMIC_FTRACE is always selected when
> CONFIG_FUNCTION_TRACER is selected.
> 
> To avoid confusion and have the reader wonder what's happen when
> CONFIG_FUNCTION_TRACER is selected and CONFIG_DYNAMIC_FTRACE is not,
> use CONFIG_FUNCTION_TRACER in ifdefs instead of CONFIG_DYNAMIC_FTRACE.
> 
> As CONFIG_FUNCTION_GRAPH_TRACER depends on CONFIG_FUNCTION_TRACER,
> ftrace.o doesn't need to appear for both symbols in Makefile.
> 
> Then as ftrace.o is built only when CONFIG_FUNCTION_TRACER is selected

and since it implies CONFIG_DYNAMIC_FTRACE, CONFIG_DYNAMIC_FTRACE is not 
needed in ftrace.c

> ifdef CONFIG_FUNCTION_TRACER is not needed in ftrace.c
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/include/asm/book3s/32/pgtable.h | 2 +-
>  arch/powerpc/include/asm/book3s/64/pgtable.h | 2 +-
>  arch/powerpc/include/asm/module.h            | 4 ++--
>  arch/powerpc/include/asm/nohash/pgtable.h    | 2 +-
>  arch/powerpc/kernel/module_32.c              | 4 ++--
>  arch/powerpc/kernel/module_64.c              | 6 +++---
>  arch/powerpc/kernel/trace/Makefile           | 4 +---
>  arch/powerpc/kernel/trace/ftrace.c           | 4 ----
>  8 files changed, 11 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
> index 772e00dc4ef1..992aed626eb4 100644
> --- a/arch/powerpc/include/asm/book3s/32/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
> @@ -124,7 +124,7 @@ static inline bool pte_user(pte_t pte)
>   * on platforms where such control is possible.
>   */
>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
> -	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
> +	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
>  #else
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
> index 875730d5af40..cf01b609572f 100644
> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
> @@ -169,7 +169,7 @@
>   * on platforms where such control is possible.
>   */
>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) || \
> -	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
> +	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
>  #else
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
> diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
> index 857d9ff24295..e6f5963fd96e 100644
> --- a/arch/powerpc/include/asm/module.h
> +++ b/arch/powerpc/include/asm/module.h
> @@ -39,7 +39,7 @@ struct mod_arch_specific {
>  	unsigned int init_plt_section;
>  #endif /* powerpc64 */
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  	unsigned long tramp;
>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>  	unsigned long tramp_regs;
> @@ -68,7 +68,7 @@ struct mod_arch_specific {
>  #    endif	/* MODULE */
>  #endif
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  #    ifdef MODULE
>  	asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
>  #    endif	/* MODULE */
> diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
> index ac75f4ab0dba..2e8cf217a191 100644
> --- a/arch/powerpc/include/asm/nohash/pgtable.h
> +++ b/arch/powerpc/include/asm/nohash/pgtable.h
> @@ -23,7 +23,7 @@
>   * on platforms where such control is possible.
>   */
>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
> -	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
> +	defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
>  #else
>  #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
> diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
> index a0432ef46967..2aa368ce21c9 100644
> --- a/arch/powerpc/kernel/module_32.c
> +++ b/arch/powerpc/kernel/module_32.c
> @@ -39,7 +39,7 @@ static unsigned int count_relocs(const Elf32_Rela *rela, unsigned int num)
>  			r_addend = rela[i].r_addend;
>  		}
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  	_count_relocs++;	/* add one for ftrace_caller */
>  #endif
>  	return _count_relocs;
> @@ -288,7 +288,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
>  	return 0;
>  }
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  int module_trampoline_target(struct module *mod, unsigned long addr,
>  			     unsigned long *target)
>  {
> diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
> index 794720530442..b13a72665eee 100644
> --- a/arch/powerpc/kernel/module_64.c
> +++ b/arch/powerpc/kernel/module_64.c
> @@ -207,7 +207,7 @@ static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
>  		}
>  	}
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  	/* make the trampoline to the ftrace_caller */
>  	relocs++;
>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> @@ -372,7 +372,7 @@ static bool is_mprofile_ftrace_call(const char *name)
>  {
>  	if (!strcmp("_mcount", name))
>  		return true;
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  	if (!strcmp("ftrace_caller", name))
>  		return true;
>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> @@ -740,7 +740,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
>  	return 0;
>  }
> 
> -#ifdef CONFIG_DYNAMIC_FTRACE
> +#ifdef CONFIG_FUNCTION_TRACER
>  int module_trampoline_target(struct module *mod, unsigned long addr,
>  			     unsigned long *target)
>  {

The below two changes to trace/Makefile and trace/ftrace.c make 
sense, but I'm not sure the above changes are necessary.

For generic code (outside arch/powerpc/kernel/trace), I think it is good 
to retain the actual dependency which is DYNAMIC_FTRACE. In my view, 
gating some of the above code on FUNCTION_TRACER is also confusing. The 
primary implication of always selecting DYNAMIC_FTRACE is within the 
powerpc trace code, and it is good to keep it that way.

> diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile
> index fc32ec30b297..af8527538fe4 100644
> --- a/arch/powerpc/kernel/trace/Makefile
> +++ b/arch/powerpc/kernel/trace/Makefile
> @@ -14,9 +14,7 @@ obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_mprofile.o
>  else
>  obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_64_pg.o
>  endif
> -obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_low.o
> -obj-$(CONFIG_DYNAMIC_FTRACE)		+= ftrace.o
> -obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
> +obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_low.o ftrace.o
>  obj-$(CONFIG_TRACING)			+= trace_clock.o
> 
>  obj-$(CONFIG_PPC64)			+= $(obj64-y)
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index 2c7e42e439bb..188f59f4ee4a 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -28,9 +28,6 @@
>  #include <asm/syscall.h>
>  #include <asm/inst.h>
> 
> -
> -#ifdef CONFIG_DYNAMIC_FTRACE
> -
>  /*
>   * We generally only have a single long_branch tramp and at most 2 or 3 plt
>   * tramps generated. But, we don't use the plt tramps currently. We also allot
> @@ -783,7 +780,6 @@ int __init ftrace_dyn_arch_init(void)
>  	return 0;
>  }
>  #endif
> -#endif /* CONFIG_DYNAMIC_FTRACE */
> 
>  #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> 
> -- 
> 2.35.1
> 

- Naveen

Re: [PATCH v1 13/22] powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding.

[Naveen N. Rao]

Christophe Leroy wrote:
> PPC_RAW_xxx() macros are self explanatory and less error prone
> than open coding.
> 
> Use them in ftrace.c
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/include/asm/ppc-opcode.h |  3 +++
>  arch/powerpc/kernel/trace/ftrace.c    | 32 +++++++++------------------
>  2 files changed, 14 insertions(+), 21 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
> index 82f1f0041c6f..281754aca0a3 100644
> --- a/arch/powerpc/include/asm/ppc-opcode.h
> +++ b/arch/powerpc/include/asm/ppc-opcode.h
> @@ -294,6 +294,8 @@
>  #define PPC_INST_BL			0x48000001
>  #define PPC_INST_BRANCH_COND		0x40800000
> 
> +#define PPC_INST_OFFSET24_MASK		0x03fffffc

This corresponds to the LI field, per the ISA. See section 8.1.2/1.7: 
'Instruction Fields'. Would it be better to name it PPC_INST_LI_MASK?

> +
>  /* Prefixes */
>  #define PPC_INST_LFS			0xc0000000
>  #define PPC_INST_STFS			0xd0000000
> @@ -572,6 +574,7 @@
>  #define PPC_RAW_EIEIO()			(0x7c0006ac)
> 
>  #define PPC_RAW_BRANCH(addr)		(PPC_INST_BRANCH | ((addr) & 0x03fffffc))
> +#define PPC_RAW_BL(offset)		(0x48000001 | ((offset) & PPC_INST_OFFSET24_MASK))
> 
>  /* Deal with instructions that older assemblers aren't aware of */
>  #define	PPC_BCCTR_FLUSH		stringify_in_c(.long PPC_INST_BCCTR_FLUSH)
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index fdc0412c1d8a..afb1d12838c9 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -90,19 +90,19 @@ static int test_24bit_addr(unsigned long ip, unsigned long addr)
> 
>  static int is_bl_op(ppc_inst_t op)
>  {
> -	return (ppc_inst_val(op) & 0xfc000003) == 0x48000001;
> +	return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == PPC_RAW_BL(0);
>  }
> 
>  static int is_b_op(ppc_inst_t op)
>  {
> -	return (ppc_inst_val(op) & 0xfc000003) == 0x48000000;
> +	return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == PPC_RAW_BRANCH(0);
>  }
> 
>  static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
>  {
>  	int offset;
> 
> -	offset = (ppc_inst_val(op) & 0x03fffffc);
> +	offset = (ppc_inst_val(op) & PPC_INST_OFFSET24_MASK);
>  	/* make it signed */
>  	if (offset & 0x02000000)
>  		offset |= 0xfe000000;
> @@ -182,7 +182,7 @@ __ftrace_make_nop(struct module *mod,
>  	 * Use a b +8 to jump over the load.
>  	 */
> 
> -	pop = ppc_inst(PPC_INST_BRANCH | 8);	/* b +8 */
> +	pop = ppc_inst(PPC_RAW_BRANCH(8));	/* b +8 */
> 
>  	/*
>  	 * Check what is in the next instruction. We can see ld r2,40(r1), but
> @@ -394,17 +394,8 @@ int ftrace_make_nop(struct module *mod,
>  static int
>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  {
> -	/*
> -	 * We expect to see:
> -	 *
> -	 * b +8
> -	 * ld r2,XX(r1)
> -	 *
> -	 * The load offset is different depending on the ABI. For simplicity
> -	 * just mask it out when doing the compare.
> -	 */
> -	if (!ppc_inst_equal(op0, ppc_inst(0x48000008)) ||
> -	    (ppc_inst_val(op1) & 0xffff0000) != 0xe8410000)
> +	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) ||
> +	    !ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)))

It would be good to move PPC_INST_LD_TOC to ppc-opcode.h

>  		return 0;
>  	return 1;
>  }
> @@ -412,7 +403,6 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  static int
>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  {
> -	/* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
>  	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
>  		return 0;
>  	return 1;
> @@ -738,11 +728,11 @@ int __init ftrace_dyn_arch_init(void)
>  	int i;
>  	unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init };
>  	u32 stub_insns[] = {
> -		0xe98d0000 | PACATOC,	/* ld      r12,PACATOC(r13)	*/
> -		0x3d8c0000,		/* addis   r12,r12,<high>	*/
> -		0x398c0000,		/* addi    r12,r12,<low>	*/
> -		0x7d8903a6,		/* mtctr   r12			*/
> -		0x4e800420,		/* bctr				*/
> +		PPC_RAW_LD(_R12, _R13, PACATOC),
> +		PPC_RAW_ADDIS(_R12, _R12, 0),
> +		PPC_RAW_ADDIS(_R12, _R12, 0),

This should be PPC_RAW_ADDI.


- Naveen

Re: [PATCH v1 13/22] powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding.

[Naveen N. Rao]

Christophe Leroy wrote:
> PPC_RAW_xxx() macros are self explanatory and less error prone
> than open coding.
> 
> Use them in ftrace.c
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/include/asm/ppc-opcode.h |  3 +++
>  arch/powerpc/kernel/trace/ftrace.c    | 32 +++++++++------------------
>  2 files changed, 14 insertions(+), 21 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
> index 82f1f0041c6f..281754aca0a3 100644
> --- a/arch/powerpc/include/asm/ppc-opcode.h
> +++ b/arch/powerpc/include/asm/ppc-opcode.h
> @@ -294,6 +294,8 @@
>  #define PPC_INST_BL			0x48000001
>  #define PPC_INST_BRANCH_COND		0x40800000
> 
> +#define PPC_INST_OFFSET24_MASK		0x03fffffc

This corresponds to the LI field, per the ISA. See section 8.1.2/1.7: 
'Instruction Fields'. Would it be better to name it PPC_INST_LI_MASK?

> +
>  /* Prefixes */
>  #define PPC_INST_LFS			0xc0000000
>  #define PPC_INST_STFS			0xd0000000
> @@ -572,6 +574,7 @@
>  #define PPC_RAW_EIEIO()			(0x7c0006ac)
> 
>  #define PPC_RAW_BRANCH(addr)		(PPC_INST_BRANCH | ((addr) & 0x03fffffc))
> +#define PPC_RAW_BL(offset)		(0x48000001 | ((offset) & PPC_INST_OFFSET24_MASK))
> 
>  /* Deal with instructions that older assemblers aren't aware of */
>  #define	PPC_BCCTR_FLUSH		stringify_in_c(.long PPC_INST_BCCTR_FLUSH)
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index fdc0412c1d8a..afb1d12838c9 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -90,19 +90,19 @@ static int test_24bit_addr(unsigned long ip, unsigned long addr)
> 
>  static int is_bl_op(ppc_inst_t op)
>  {
> -	return (ppc_inst_val(op) & 0xfc000003) == 0x48000001;
> +	return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == PPC_RAW_BL(0);
>  }
> 
>  static int is_b_op(ppc_inst_t op)
>  {
> -	return (ppc_inst_val(op) & 0xfc000003) == 0x48000000;
> +	return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == PPC_RAW_BRANCH(0);
>  }
> 
>  static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
>  {
>  	int offset;
> 
> -	offset = (ppc_inst_val(op) & 0x03fffffc);
> +	offset = (ppc_inst_val(op) & PPC_INST_OFFSET24_MASK);
>  	/* make it signed */
>  	if (offset & 0x02000000)
>  		offset |= 0xfe000000;
> @@ -182,7 +182,7 @@ __ftrace_make_nop(struct module *mod,
>  	 * Use a b +8 to jump over the load.
>  	 */
> 
> -	pop = ppc_inst(PPC_INST_BRANCH | 8);	/* b +8 */
> +	pop = ppc_inst(PPC_RAW_BRANCH(8));	/* b +8 */
> 
>  	/*
>  	 * Check what is in the next instruction. We can see ld r2,40(r1), but
> @@ -394,17 +394,8 @@ int ftrace_make_nop(struct module *mod,
>  static int
>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  {
> -	/*
> -	 * We expect to see:
> -	 *
> -	 * b +8
> -	 * ld r2,XX(r1)
> -	 *
> -	 * The load offset is different depending on the ABI. For simplicity
> -	 * just mask it out when doing the compare.
> -	 */
> -	if (!ppc_inst_equal(op0, ppc_inst(0x48000008)) ||
> -	    (ppc_inst_val(op1) & 0xffff0000) != 0xe8410000)
> +	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) ||
> +	    !ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)))

It would be good to move PPC_INST_LD_TOC to ppc-opcode.h

>  		return 0;
>  	return 1;
>  }
> @@ -412,7 +403,6 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  static int
>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>  {
> -	/* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
>  	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
>  		return 0;
>  	return 1;
> @@ -738,11 +728,11 @@ int __init ftrace_dyn_arch_init(void)
>  	int i;
>  	unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init };
>  	u32 stub_insns[] = {
> -		0xe98d0000 | PACATOC,	/* ld      r12,PACATOC(r13)	*/
> -		0x3d8c0000,		/* addis   r12,r12,<high>	*/
> -		0x398c0000,		/* addi    r12,r12,<low>	*/
> -		0x7d8903a6,		/* mtctr   r12			*/
> -		0x4e800420,		/* bctr				*/
> +		PPC_RAW_LD(_R12, _R13, PACATOC),
> +		PPC_RAW_ADDIS(_R12, _R12, 0),
> +		PPC_RAW_ADDIS(_R12, _R12, 0),

This should be PPC_RAW_ADDI.


- Naveen

Re: [PATCH v1 16/22] powerpc/ftrace: Minimise number of #ifdefs

[Naveen N. Rao]

Christophe Leroy wrote:
> A lot of #ifdefs can be replaced by IS_ENABLED()
> 
> Do so.
> 
> This requires to have kernel_toc_addr() defined at all time
> and PPC_INST_LD_TOC as well.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/include/asm/code-patching.h |   2 -
>  arch/powerpc/include/asm/module.h        |   2 -
>  arch/powerpc/include/asm/sections.h      |  24 +--
>  arch/powerpc/kernel/trace/ftrace.c       | 201 ++++++++++++-----------
>  4 files changed, 113 insertions(+), 116 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
> index 4260e89f62b1..071fcbec31c5 100644
> --- a/arch/powerpc/include/asm/code-patching.h
> +++ b/arch/powerpc/include/asm/code-patching.h
> @@ -217,7 +217,6 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
>  	return addr;
>  }
> 
> -#ifdef CONFIG_PPC64
>  /*
>   * Some instruction encodings commonly used in dynamic ftracing
>   * and function live patching.
> @@ -234,6 +233,5 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
> 
>  /* usually preceded by a mflr r0 */
>  #define PPC_INST_STD_LR		PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF)
> -#endif /* CONFIG_PPC64 */
> 
>  #endif /* _ASM_POWERPC_CODE_PATCHING_H */
> diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
> index e6f5963fd96e..700d7ecd9012 100644
> --- a/arch/powerpc/include/asm/module.h
> +++ b/arch/powerpc/include/asm/module.h
> @@ -41,9 +41,7 @@ struct mod_arch_specific {
> 
>  #ifdef CONFIG_FUNCTION_TRACER
>  	unsigned long tramp;
> -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>  	unsigned long tramp_regs;
> -#endif
>  #endif
> 
>  	/* List of BUG addresses, source line numbers and filenames */
> diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
> index 8be2c491c733..6980eaeb16fe 100644
> --- a/arch/powerpc/include/asm/sections.h
> +++ b/arch/powerpc/include/asm/sections.h
> @@ -29,18 +29,6 @@ extern char start_virt_trampolines[];
>  extern char end_virt_trampolines[];
>  #endif
> 
> -/*
> - * This assumes the kernel is never compiled -mcmodel=small or
> - * the total .toc is always less than 64k.
> - */
> -static inline unsigned long kernel_toc_addr(void)
> -{
> -	unsigned long toc_ptr;
> -
> -	asm volatile("mr %0, 2" : "=r" (toc_ptr));
> -	return toc_ptr;
> -}
> -
>  static inline int overlaps_interrupt_vector_text(unsigned long start,
>  							unsigned long end)
>  {
> @@ -60,5 +48,17 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
> 
>  #endif
> 
> +/*
> + * This assumes the kernel is never compiled -mcmodel=small or
> + * the total .toc is always less than 64k.
> + */
> +static inline unsigned long kernel_toc_addr(void)
> +{
> +	unsigned long toc_ptr;
> +
> +	asm volatile("mr %0, 2" : "=r" (toc_ptr));
> +	return toc_ptr;
> +}
> +
>  #endif /* __KERNEL__ */
>  #endif	/* _ASM_POWERPC_SECTIONS_H */
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index ffedf8c82ea8..4dd30e396026 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -150,55 +150,55 @@ __ftrace_make_nop(struct module *mod,
>  		return -EINVAL;
>  	}
> 
> -	/* When using -mkernel_profile or PPC32 there is no load to jump over */
> -	pop = ppc_inst(PPC_RAW_NOP());
> +	if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) {
> +		/* When using -mkernel_profile or PPC32 there is no load to jump over */
> +		pop = ppc_inst(PPC_RAW_NOP());

Why move this inside the if() statement? You can keep this out and drop 
the else clause.

- Naveen

Re: [PATCH v1 16/22] powerpc/ftrace: Minimise number of #ifdefs

[Naveen N. Rao]

Christophe Leroy wrote:
> A lot of #ifdefs can be replaced by IS_ENABLED()
> 
> Do so.
> 
> This requires to have kernel_toc_addr() defined at all time
> and PPC_INST_LD_TOC as well.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/include/asm/code-patching.h |   2 -
>  arch/powerpc/include/asm/module.h        |   2 -
>  arch/powerpc/include/asm/sections.h      |  24 +--
>  arch/powerpc/kernel/trace/ftrace.c       | 201 ++++++++++++-----------
>  4 files changed, 113 insertions(+), 116 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
> index 4260e89f62b1..071fcbec31c5 100644
> --- a/arch/powerpc/include/asm/code-patching.h
> +++ b/arch/powerpc/include/asm/code-patching.h
> @@ -217,7 +217,6 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
>  	return addr;
>  }
> 
> -#ifdef CONFIG_PPC64
>  /*
>   * Some instruction encodings commonly used in dynamic ftracing
>   * and function live patching.
> @@ -234,6 +233,5 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
> 
>  /* usually preceded by a mflr r0 */
>  #define PPC_INST_STD_LR		PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF)
> -#endif /* CONFIG_PPC64 */
> 
>  #endif /* _ASM_POWERPC_CODE_PATCHING_H */
> diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
> index e6f5963fd96e..700d7ecd9012 100644
> --- a/arch/powerpc/include/asm/module.h
> +++ b/arch/powerpc/include/asm/module.h
> @@ -41,9 +41,7 @@ struct mod_arch_specific {
> 
>  #ifdef CONFIG_FUNCTION_TRACER
>  	unsigned long tramp;
> -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>  	unsigned long tramp_regs;
> -#endif
>  #endif
> 
>  	/* List of BUG addresses, source line numbers and filenames */
> diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
> index 8be2c491c733..6980eaeb16fe 100644
> --- a/arch/powerpc/include/asm/sections.h
> +++ b/arch/powerpc/include/asm/sections.h
> @@ -29,18 +29,6 @@ extern char start_virt_trampolines[];
>  extern char end_virt_trampolines[];
>  #endif
> 
> -/*
> - * This assumes the kernel is never compiled -mcmodel=small or
> - * the total .toc is always less than 64k.
> - */
> -static inline unsigned long kernel_toc_addr(void)
> -{
> -	unsigned long toc_ptr;
> -
> -	asm volatile("mr %0, 2" : "=r" (toc_ptr));
> -	return toc_ptr;
> -}
> -
>  static inline int overlaps_interrupt_vector_text(unsigned long start,
>  							unsigned long end)
>  {
> @@ -60,5 +48,17 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
> 
>  #endif
> 
> +/*
> + * This assumes the kernel is never compiled -mcmodel=small or
> + * the total .toc is always less than 64k.
> + */
> +static inline unsigned long kernel_toc_addr(void)
> +{
> +	unsigned long toc_ptr;
> +
> +	asm volatile("mr %0, 2" : "=r" (toc_ptr));
> +	return toc_ptr;
> +}
> +
>  #endif /* __KERNEL__ */
>  #endif	/* _ASM_POWERPC_SECTIONS_H */
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index ffedf8c82ea8..4dd30e396026 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -150,55 +150,55 @@ __ftrace_make_nop(struct module *mod,
>  		return -EINVAL;
>  	}
> 
> -	/* When using -mkernel_profile or PPC32 there is no load to jump over */
> -	pop = ppc_inst(PPC_RAW_NOP());
> +	if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) {
> +		/* When using -mkernel_profile or PPC32 there is no load to jump over */
> +		pop = ppc_inst(PPC_RAW_NOP());

Why move this inside the if() statement? You can keep this out and drop 
the else clause.

- Naveen

Re: [PATCH v1 07/22] powerpc/ftrace: Use patch_instruction() return directly

[Steven Rostedt]

On Mon, 18 Apr 2022 11:51:16 +0530
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote:

> > --- a/arch/powerpc/kernel/trace/ftrace.c
> > +++ b/arch/powerpc/kernel/trace/ftrace.c
> > @@ -78,10 +78,7 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
> >  	}
> > 
> >  	/* replace the text with the new text */
> > -	if (patch_instruction((u32 *)ip, new))
> > -		return -EPERM;
> > -
> > -	return 0;
> > +	return patch_instruction((u32 *)ip, new);  
> 
> I think the reason we were returning -EPERM is so that ftrace_bug() can 

That is correct.

> throw the right error message. That will change due to this patch, 
> though I'm not sure how much it matters. -EFAULT and -EPERM seem to 
> print almost the same error message.

In these cases it helps to know the type of failure, as the way to debug it
is different.

-EFAULT: It failed to read it the location. This means that the memory is
likely not even mapped in, or the pointer is way off.

-EINVAL: Means that what was read did not match what was expected (the code
was already updated, pointing to the wrong location, or simply the
calculation of what to expect is incorrect).

-EPERM: Means the write failed. What was read was expected, but the
permissions to write have not been updated properly.

Differentiating the three is crucial to looking at where the issue lies
when an ftrace_bug() triggers.

-- Steve

Re: [PATCH v1 07/22] powerpc/ftrace: Use patch_instruction() return directly

[Steven Rostedt]

On Mon, 18 Apr 2022 11:51:16 +0530
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote:

> > --- a/arch/powerpc/kernel/trace/ftrace.c
> > +++ b/arch/powerpc/kernel/trace/ftrace.c
> > @@ -78,10 +78,7 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
> >  	}
> > 
> >  	/* replace the text with the new text */
> > -	if (patch_instruction((u32 *)ip, new))
> > -		return -EPERM;
> > -
> > -	return 0;
> > +	return patch_instruction((u32 *)ip, new);  
> 
> I think the reason we were returning -EPERM is so that ftrace_bug() can 

That is correct.

> throw the right error message. That will change due to this patch, 
> though I'm not sure how much it matters. -EFAULT and -EPERM seem to 
> print almost the same error message.

In these cases it helps to know the type of failure, as the way to debug it
is different.

-EFAULT: It failed to read it the location. This means that the memory is
likely not even mapped in, or the pointer is way off.

-EINVAL: Means that what was read did not match what was expected (the code
was already updated, pointing to the wrong location, or simply the
calculation of what to expect is incorrect).

-EPERM: Means the write failed. What was read was expected, but the
permissions to write have not been updated properly.

Differentiating the three is crucial to looking at where the issue lies
when an ftrace_bug() triggers.

-- Steve

Re: [PATCH v1 06/22] powerpc/ftrace: Inline ftrace_modify_code()

[Michael Ellerman]

"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> writes:
> Christophe Leroy wrote:
>> Inlining ftrace_modify_code(), it increases a bit the
>> size of ftrace code but brings 5% improvment on ftrace
>> activation.
>> 
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/kernel/trace/ftrace.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
>> index 41c45b9c7f39..98e82fa4980f 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -53,7 +53,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
>>  	return op;
>>  }
>> 
>> -static int
>> +static inline int
>>  ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
>>  {
>>  	ppc_inst_t replaced;
>
> I thought gcc was free to inline functions without the need for 
> 'inline'.

Yes it is.

> On the flip side, don't we need __always_inline if we want to force 
> inlining?

Yes. Since ac7c3e4ff401 ("compiler: enable CONFIG_OPTIMIZE_INLINING forcibly").

cheers

Re: [PATCH v1 06/22] powerpc/ftrace: Inline ftrace_modify_code()

[Michael Ellerman]

"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> writes:
> Christophe Leroy wrote:
>> Inlining ftrace_modify_code(), it increases a bit the
>> size of ftrace code but brings 5% improvment on ftrace
>> activation.
>> 
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/kernel/trace/ftrace.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
>> index 41c45b9c7f39..98e82fa4980f 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -53,7 +53,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
>>  	return op;
>>  }
>> 
>> -static int
>> +static inline int
>>  ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
>>  {
>>  	ppc_inst_t replaced;
>
> I thought gcc was free to inline functions without the need for 
> 'inline'.

Yes it is.

> On the flip side, don't we need __always_inline if we want to force 
> inlining?

Yes. Since ac7c3e4ff401 ("compiler: enable CONFIG_OPTIMIZE_INLINING forcibly").

cheers

Re: [PATCH v1 06/22] powerpc/ftrace: Inline ftrace_modify_code()

[Christophe Leroy]

Le 18/04/2022 à 08:07, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> Inlining ftrace_modify_code(), it increases a bit the
>> size of ftrace code but brings 5% improvment on ftrace
>> activation.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/kernel/trace/ftrace.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index 41c45b9c7f39..98e82fa4980f 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -53,7 +53,7 @@ ftrace_call_replace(unsigned long ip, unsigned long 
>> addr, int link)
>>      return op;
>>  }
>>
>> -static int
>> +static inline int
>>  ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
>>  {
>>      ppc_inst_t replaced;
> 
> I thought gcc was free to inline functions without the need for 
> 'inline'. Don't you see this being inlined otherwise?

Yep, gcc is free to inline, but in that case it doesn't inline unless 
you suggest it to do so.

> 
> On the flip side, don't we need __always_inline if we want to force 
> inlining?

The question is, do we want to force inlining, even with 
CONFIG_CC_OPTIMIZE_FOR_SIZE ?

With 'inline', gcc seems to now inline it with 
CONFIG_CC_OPTIMIZE_FOR_SPEED and still keep it out of line with 
CONFIG_CC_OPTIMIZE_FOR_SIZE.

Christophe

Re: [PATCH v1 06/22] powerpc/ftrace: Inline ftrace_modify_code()

[Christophe Leroy]

Le 18/04/2022 à 08:07, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> Inlining ftrace_modify_code(), it increases a bit the
>> size of ftrace code but brings 5% improvment on ftrace
>> activation.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/kernel/trace/ftrace.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index 41c45b9c7f39..98e82fa4980f 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -53,7 +53,7 @@ ftrace_call_replace(unsigned long ip, unsigned long 
>> addr, int link)
>>      return op;
>>  }
>>
>> -static int
>> +static inline int
>>  ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
>>  {
>>      ppc_inst_t replaced;
> 
> I thought gcc was free to inline functions without the need for 
> 'inline'. Don't you see this being inlined otherwise?

Yep, gcc is free to inline, but in that case it doesn't inline unless 
you suggest it to do so.

> 
> On the flip side, don't we need __always_inline if we want to force 
> inlining?

The question is, do we want to force inlining, even with 
CONFIG_CC_OPTIMIZE_FOR_SIZE ?

With 'inline', gcc seems to now inline it with 
CONFIG_CC_OPTIMIZE_FOR_SPEED and still keep it out of line with 
CONFIG_CC_OPTIMIZE_FOR_SIZE.

Christophe

Re: [PATCH v1 07/22] powerpc/ftrace: Use patch_instruction() return directly

[Christophe Leroy]

Le 18/04/2022 à 21:44, Steven Rostedt a écrit :
> On Mon, 18 Apr 2022 11:51:16 +0530
> "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote:
> 
>>> --- a/arch/powerpc/kernel/trace/ftrace.c
>>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>>> @@ -78,10 +78,7 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
>>>   	}
>>>
>>>   	/* replace the text with the new text */
>>> -	if (patch_instruction((u32 *)ip, new))
>>> -		return -EPERM;
>>> -
>>> -	return 0;
>>> +	return patch_instruction((u32 *)ip, new);
>>
>> I think the reason we were returning -EPERM is so that ftrace_bug() can
> 
> That is correct.
> 
>> throw the right error message. That will change due to this patch,
>> though I'm not sure how much it matters. -EFAULT and -EPERM seem to
>> print almost the same error message.
> 
> In these cases it helps to know the type of failure, as the way to debug it
> is different.
> 
> -EFAULT: It failed to read it the location. This means that the memory is
> likely not even mapped in, or the pointer is way off.
> 
> -EINVAL: Means that what was read did not match what was expected (the code
> was already updated, pointing to the wrong location, or simply the
> calculation of what to expect is incorrect).
> 
> -EPERM: Means the write failed. What was read was expected, but the
> permissions to write have not been updated properly.
> 
> Differentiating the three is crucial to looking at where the issue lies
> when an ftrace_bug() triggers.
> 


Apparently no caller really care about the value returned by 
patch_instruction(), the ones who check the return value just check that 
it's not 0.

So the most performant would be to have patch_instruction() return 
-EPERM instead of -EFAULT in case of failure.

Christophe

Re: [PATCH v1 07/22] powerpc/ftrace: Use patch_instruction() return directly

[Christophe Leroy]

Le 18/04/2022 à 21:44, Steven Rostedt a écrit :
> On Mon, 18 Apr 2022 11:51:16 +0530
> "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote:
> 
>>> --- a/arch/powerpc/kernel/trace/ftrace.c
>>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>>> @@ -78,10 +78,7 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
>>>   	}
>>>
>>>   	/* replace the text with the new text */
>>> -	if (patch_instruction((u32 *)ip, new))
>>> -		return -EPERM;
>>> -
>>> -	return 0;
>>> +	return patch_instruction((u32 *)ip, new);
>>
>> I think the reason we were returning -EPERM is so that ftrace_bug() can
> 
> That is correct.
> 
>> throw the right error message. That will change due to this patch,
>> though I'm not sure how much it matters. -EFAULT and -EPERM seem to
>> print almost the same error message.
> 
> In these cases it helps to know the type of failure, as the way to debug it
> is different.
> 
> -EFAULT: It failed to read it the location. This means that the memory is
> likely not even mapped in, or the pointer is way off.
> 
> -EINVAL: Means that what was read did not match what was expected (the code
> was already updated, pointing to the wrong location, or simply the
> calculation of what to expect is incorrect).
> 
> -EPERM: Means the write failed. What was read was expected, but the
> permissions to write have not been updated properly.
> 
> Differentiating the three is crucial to looking at where the issue lies
> when an ftrace_bug() triggers.
> 


Apparently no caller really care about the value returned by 
patch_instruction(), the ones who check the return value just check that 
it's not 0.

So the most performant would be to have patch_instruction() return 
-EPERM instead of -EFAULT in case of failure.

Christophe

Re: [PATCH v1 08/22] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64

[Christophe Leroy]

Le 18/04/2022 à 08:40, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target()
>> for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the
>> one for PPC64.
>>
>> Same for __ftrace_make_call().
>>
>> Make them common.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/kernel/trace/ftrace.c | 108 +++--------------------------
>>  1 file changed, 8 insertions(+), 100 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index 1b05d33f96c6..2c7e42e439bb 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -114,7 +114,6 @@ static unsigned long find_bl_target(unsigned long 
>> ip, ppc_inst_t op)
>>  }
>>
>>  #ifdef CONFIG_MODULES
>> -#ifdef CONFIG_PPC64
>>  static int
>>  __ftrace_make_nop(struct module *mod,
>>            struct dyn_ftrace *rec, unsigned long addr)
>> @@ -154,10 +153,11 @@ __ftrace_make_nop(struct module *mod,
>>          return -EINVAL;
>>      }
>>
>> -#ifdef CONFIG_MPROFILE_KERNEL
>> -    /* When using -mkernel_profile there is no load to jump over */
>> +    /* When using -mkernel_profile or PPC32 there is no load to jump 
>> over */
>                       -mprofile-kernel
> 
> Since you are modifying that line anyway ^^

ok


> 
> 
>>      pop = ppc_inst(PPC_RAW_NOP());
>>
>> +#ifdef CONFIG_PPC64
>> +#ifdef CONFIG_MPROFILE_KERNEL
>>      if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
>>          pr_err("Fetching instruction at %lx failed.\n", ip - 4);
>>          return -EFAULT;
>> @@ -201,6 +201,7 @@ __ftrace_make_nop(struct module *mod,
>>          return -EINVAL;
>>      }
>>  #endif /* CONFIG_MPROFILE_KERNEL */
>> +#endif /* PPC64 */
>>
>>      if (patch_instruction((u32 *)ip, pop)) {
>>          pr_err("Patching NOP failed.\n");
>> @@ -209,48 +210,6 @@ __ftrace_make_nop(struct module *mod,
>>
>>      return 0;
>>  }
>> -
>> -#else /* !PPC64 */
>> -static int
>> -__ftrace_make_nop(struct module *mod,
>> -          struct dyn_ftrace *rec, unsigned long addr)
>> -{
>> -    ppc_inst_t op;
>> -    unsigned long ip = rec->ip;
>> -    unsigned long tramp, ptr;
>> -
>> -    if (copy_from_kernel_nofault(&op, (void *)ip, MCOUNT_INSN_SIZE))
>> -        return -EFAULT;
>> -
>> -    /* Make sure that that this is still a 24bit jump */
>> -    if (!is_bl_op(op)) {
>> -        pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
>> -        return -EINVAL;
>> -    }
>> -
>> -    /* lets find where the pointer goes */
>> -    tramp = find_bl_target(ip, op);
>> -
>> -    /* Find where the trampoline jumps to */
>> -    if (module_trampoline_target(mod, tramp, &ptr)) {
>> -        pr_err("Failed to get trampoline target\n");
>> -        return -EFAULT;
>> -    }
>> -
>> -    if (ptr != addr) {
>> -        pr_err("Trampoline location %08lx does not match addr\n",
>> -               tramp);
>> -        return -EINVAL;
>> -    }
>> -
>> -    op = ppc_inst(PPC_RAW_NOP());
>> -
>> -    if (patch_instruction((u32 *)ip, op))
>> -        return -EPERM;
>> -
>> -    return 0;
>> -}
>> -#endif /* PPC64 */
>>  #endif /* CONFIG_MODULES */
>>
>>  static unsigned long find_ftrace_tramp(unsigned long ip)
>> @@ -437,13 +396,12 @@ int ftrace_make_nop(struct module *mod,
>>  }
>>
>>  #ifdef CONFIG_MODULES
>> -#ifdef CONFIG_PPC64
>>  /*
>>   * Examine the existing instructions for __ftrace_make_call.
>>   * They should effectively be a NOP, and follow formal constraints,
>>   * depending on the ABI. Return false if they don't.
>>   */
>> -#ifndef CONFIG_MPROFILE_KERNEL
>> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> 
> It is better to gate this on PPC64_ELF_ABI_v1

Well ... let then first change this to a CONFIG_ item, it should 
simplify some stuff here and there.

> 
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> @@ -465,7 +423,7 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, 
>> ppc_inst_t op1)
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> -    /* look for patched "NOP" on ppc64 with -mprofile-kernel */
>> +    /* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
>>      if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
>>          return 0;
>>      return 1;
>> @@ -484,8 +442,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, 
>> unsigned long addr)
>>      if (copy_inst_from_kernel_nofault(op, ip))
>>          return -EFAULT;
>>
>> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>      if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
>>          return -EFAULT;
>> +#endif
> 
> Here too...
> 

Ok

Christophe

Re: [PATCH v1 08/22] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64

[Christophe Leroy]

Le 18/04/2022 à 08:40, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target()
>> for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the
>> one for PPC64.
>>
>> Same for __ftrace_make_call().
>>
>> Make them common.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/kernel/trace/ftrace.c | 108 +++--------------------------
>>  1 file changed, 8 insertions(+), 100 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index 1b05d33f96c6..2c7e42e439bb 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -114,7 +114,6 @@ static unsigned long find_bl_target(unsigned long 
>> ip, ppc_inst_t op)
>>  }
>>
>>  #ifdef CONFIG_MODULES
>> -#ifdef CONFIG_PPC64
>>  static int
>>  __ftrace_make_nop(struct module *mod,
>>            struct dyn_ftrace *rec, unsigned long addr)
>> @@ -154,10 +153,11 @@ __ftrace_make_nop(struct module *mod,
>>          return -EINVAL;
>>      }
>>
>> -#ifdef CONFIG_MPROFILE_KERNEL
>> -    /* When using -mkernel_profile there is no load to jump over */
>> +    /* When using -mkernel_profile or PPC32 there is no load to jump 
>> over */
>                       -mprofile-kernel
> 
> Since you are modifying that line anyway ^^

ok


> 
> 
>>      pop = ppc_inst(PPC_RAW_NOP());
>>
>> +#ifdef CONFIG_PPC64
>> +#ifdef CONFIG_MPROFILE_KERNEL
>>      if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
>>          pr_err("Fetching instruction at %lx failed.\n", ip - 4);
>>          return -EFAULT;
>> @@ -201,6 +201,7 @@ __ftrace_make_nop(struct module *mod,
>>          return -EINVAL;
>>      }
>>  #endif /* CONFIG_MPROFILE_KERNEL */
>> +#endif /* PPC64 */
>>
>>      if (patch_instruction((u32 *)ip, pop)) {
>>          pr_err("Patching NOP failed.\n");
>> @@ -209,48 +210,6 @@ __ftrace_make_nop(struct module *mod,
>>
>>      return 0;
>>  }
>> -
>> -#else /* !PPC64 */
>> -static int
>> -__ftrace_make_nop(struct module *mod,
>> -          struct dyn_ftrace *rec, unsigned long addr)
>> -{
>> -    ppc_inst_t op;
>> -    unsigned long ip = rec->ip;
>> -    unsigned long tramp, ptr;
>> -
>> -    if (copy_from_kernel_nofault(&op, (void *)ip, MCOUNT_INSN_SIZE))
>> -        return -EFAULT;
>> -
>> -    /* Make sure that that this is still a 24bit jump */
>> -    if (!is_bl_op(op)) {
>> -        pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
>> -        return -EINVAL;
>> -    }
>> -
>> -    /* lets find where the pointer goes */
>> -    tramp = find_bl_target(ip, op);
>> -
>> -    /* Find where the trampoline jumps to */
>> -    if (module_trampoline_target(mod, tramp, &ptr)) {
>> -        pr_err("Failed to get trampoline target\n");
>> -        return -EFAULT;
>> -    }
>> -
>> -    if (ptr != addr) {
>> -        pr_err("Trampoline location %08lx does not match addr\n",
>> -               tramp);
>> -        return -EINVAL;
>> -    }
>> -
>> -    op = ppc_inst(PPC_RAW_NOP());
>> -
>> -    if (patch_instruction((u32 *)ip, op))
>> -        return -EPERM;
>> -
>> -    return 0;
>> -}
>> -#endif /* PPC64 */
>>  #endif /* CONFIG_MODULES */
>>
>>  static unsigned long find_ftrace_tramp(unsigned long ip)
>> @@ -437,13 +396,12 @@ int ftrace_make_nop(struct module *mod,
>>  }
>>
>>  #ifdef CONFIG_MODULES
>> -#ifdef CONFIG_PPC64
>>  /*
>>   * Examine the existing instructions for __ftrace_make_call.
>>   * They should effectively be a NOP, and follow formal constraints,
>>   * depending on the ABI. Return false if they don't.
>>   */
>> -#ifndef CONFIG_MPROFILE_KERNEL
>> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> 
> It is better to gate this on PPC64_ELF_ABI_v1

Well ... let then first change this to a CONFIG_ item, it should 
simplify some stuff here and there.

> 
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> @@ -465,7 +423,7 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, 
>> ppc_inst_t op1)
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> -    /* look for patched "NOP" on ppc64 with -mprofile-kernel */
>> +    /* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
>>      if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
>>          return 0;
>>      return 1;
>> @@ -484,8 +442,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, 
>> unsigned long addr)
>>      if (copy_inst_from_kernel_nofault(op, ip))
>>          return -EFAULT;
>>
>> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>      if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
>>          return -EFAULT;
>> +#endif
> 
> Here too...
> 

Ok

Christophe

Re: [PATCH v1 13/22] powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding.

[Christophe Leroy]

Le 18/04/2022 à 09:38, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> PPC_RAW_xxx() macros are self explanatory and less error prone
>> than open coding.
>>
>> Use them in ftrace.c
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/include/asm/ppc-opcode.h |  3 +++
>>  arch/powerpc/kernel/trace/ftrace.c    | 32 +++++++++------------------
>>  2 files changed, 14 insertions(+), 21 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/ppc-opcode.h 
>> b/arch/powerpc/include/asm/ppc-opcode.h
>> index 82f1f0041c6f..281754aca0a3 100644
>> --- a/arch/powerpc/include/asm/ppc-opcode.h
>> +++ b/arch/powerpc/include/asm/ppc-opcode.h
>> @@ -294,6 +294,8 @@
>>  #define PPC_INST_BL            0x48000001
>>  #define PPC_INST_BRANCH_COND        0x40800000
>>
>> +#define PPC_INST_OFFSET24_MASK        0x03fffffc
> 
> This corresponds to the LI field, per the ISA. See section 8.1.2/1.7: 
> 'Instruction Fields'. Would it be better to name it PPC_INST_LI_MASK?

Isn't there a risk of confusing with the 'li' instruction ? Like we 
could have PPC_INST_LI just like we have PPC_INST_ADD ?



> 
>> +
>>  /* Prefixes */
>>  #define PPC_INST_LFS            0xc0000000
>>  #define PPC_INST_STFS            0xd0000000
>> @@ -572,6 +574,7 @@
>>  #define PPC_RAW_EIEIO()            (0x7c0006ac)
>>
>>  #define PPC_RAW_BRANCH(addr)        (PPC_INST_BRANCH | ((addr) & 
>> 0x03fffffc))
>> +#define PPC_RAW_BL(offset)        (0x48000001 | ((offset) & 
>> PPC_INST_OFFSET24_MASK))
>>
>>  /* Deal with instructions that older assemblers aren't aware of */
>>  #define    PPC_BCCTR_FLUSH        stringify_in_c(.long 
>> PPC_INST_BCCTR_FLUSH)
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index fdc0412c1d8a..afb1d12838c9 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -90,19 +90,19 @@ static int test_24bit_addr(unsigned long ip, 
>> unsigned long addr)
>>
>>  static int is_bl_op(ppc_inst_t op)
>>  {
>> -    return (ppc_inst_val(op) & 0xfc000003) == 0x48000001;
>> +    return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == 
>> PPC_RAW_BL(0);
>>  }
>>
>>  static int is_b_op(ppc_inst_t op)
>>  {
>> -    return (ppc_inst_val(op) & 0xfc000003) == 0x48000000;
>> +    return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == 
>> PPC_RAW_BRANCH(0);
>>  }
>>
>>  static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
>>  {
>>      int offset;
>>
>> -    offset = (ppc_inst_val(op) & 0x03fffffc);
>> +    offset = (ppc_inst_val(op) & PPC_INST_OFFSET24_MASK);
>>      /* make it signed */
>>      if (offset & 0x02000000)
>>          offset |= 0xfe000000;
>> @@ -182,7 +182,7 @@ __ftrace_make_nop(struct module *mod,
>>       * Use a b +8 to jump over the load.
>>       */
>>
>> -    pop = ppc_inst(PPC_INST_BRANCH | 8);    /* b +8 */
>> +    pop = ppc_inst(PPC_RAW_BRANCH(8));    /* b +8 */
>>
>>      /*
>>       * Check what is in the next instruction. We can see ld 
>> r2,40(r1), but
>> @@ -394,17 +394,8 @@ int ftrace_make_nop(struct module *mod,
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> -    /*
>> -     * We expect to see:
>> -     *
>> -     * b +8
>> -     * ld r2,XX(r1)
>> -     *
>> -     * The load offset is different depending on the ABI. For simplicity
>> -     * just mask it out when doing the compare.
>> -     */
>> -    if (!ppc_inst_equal(op0, ppc_inst(0x48000008)) ||
>> -        (ppc_inst_val(op1) & 0xffff0000) != 0xe8410000)
>> +    if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) ||
>> +        !ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)))
> 
> It would be good to move PPC_INST_LD_TOC to ppc-opcode.h

It's not really just an instruction, it's closely linked to the ABI, so 
does it really belong to ppc-opcode.h ? Maybe it could be better to have 
it in ppc_asm.h instead, which already contains ABI related definitions ?

If we move it into ppc-opcode.h, then we also have to move 
R2_STACK_OFFSET. Or should we use STK_GOT defined in ppc_asm.h and drop 
R2_STACK_OFFSET ?

> 
>>          return 0;
>>      return 1;
>>  }
>> @@ -412,7 +403,6 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, 
>> ppc_inst_t op1)
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> -    /* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
>>      if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
>>          return 0;
>>      return 1;
>> @@ -738,11 +728,11 @@ int __init ftrace_dyn_arch_init(void)
>>      int i;
>>      unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init };
>>      u32 stub_insns[] = {
>> -        0xe98d0000 | PACATOC,    /* ld      r12,PACATOC(r13)    */
>> -        0x3d8c0000,        /* addis   r12,r12,<high>    */
>> -        0x398c0000,        /* addi    r12,r12,<low>    */
>> -        0x7d8903a6,        /* mtctr   r12            */
>> -        0x4e800420,        /* bctr                */
>> +        PPC_RAW_LD(_R12, _R13, PACATOC),
>> +        PPC_RAW_ADDIS(_R12, _R12, 0),
>> +        PPC_RAW_ADDIS(_R12, _R12, 0),
> 
> This should be PPC_RAW_ADDI.
> 

Oops.

Christophe

Re: [PATCH v1 13/22] powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding.

[Christophe Leroy]

Le 18/04/2022 à 09:38, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> PPC_RAW_xxx() macros are self explanatory and less error prone
>> than open coding.
>>
>> Use them in ftrace.c
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/include/asm/ppc-opcode.h |  3 +++
>>  arch/powerpc/kernel/trace/ftrace.c    | 32 +++++++++------------------
>>  2 files changed, 14 insertions(+), 21 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/ppc-opcode.h 
>> b/arch/powerpc/include/asm/ppc-opcode.h
>> index 82f1f0041c6f..281754aca0a3 100644
>> --- a/arch/powerpc/include/asm/ppc-opcode.h
>> +++ b/arch/powerpc/include/asm/ppc-opcode.h
>> @@ -294,6 +294,8 @@
>>  #define PPC_INST_BL            0x48000001
>>  #define PPC_INST_BRANCH_COND        0x40800000
>>
>> +#define PPC_INST_OFFSET24_MASK        0x03fffffc
> 
> This corresponds to the LI field, per the ISA. See section 8.1.2/1.7: 
> 'Instruction Fields'. Would it be better to name it PPC_INST_LI_MASK?

Isn't there a risk of confusing with the 'li' instruction ? Like we 
could have PPC_INST_LI just like we have PPC_INST_ADD ?



> 
>> +
>>  /* Prefixes */
>>  #define PPC_INST_LFS            0xc0000000
>>  #define PPC_INST_STFS            0xd0000000
>> @@ -572,6 +574,7 @@
>>  #define PPC_RAW_EIEIO()            (0x7c0006ac)
>>
>>  #define PPC_RAW_BRANCH(addr)        (PPC_INST_BRANCH | ((addr) & 
>> 0x03fffffc))
>> +#define PPC_RAW_BL(offset)        (0x48000001 | ((offset) & 
>> PPC_INST_OFFSET24_MASK))
>>
>>  /* Deal with instructions that older assemblers aren't aware of */
>>  #define    PPC_BCCTR_FLUSH        stringify_in_c(.long 
>> PPC_INST_BCCTR_FLUSH)
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index fdc0412c1d8a..afb1d12838c9 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -90,19 +90,19 @@ static int test_24bit_addr(unsigned long ip, 
>> unsigned long addr)
>>
>>  static int is_bl_op(ppc_inst_t op)
>>  {
>> -    return (ppc_inst_val(op) & 0xfc000003) == 0x48000001;
>> +    return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == 
>> PPC_RAW_BL(0);
>>  }
>>
>>  static int is_b_op(ppc_inst_t op)
>>  {
>> -    return (ppc_inst_val(op) & 0xfc000003) == 0x48000000;
>> +    return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == 
>> PPC_RAW_BRANCH(0);
>>  }
>>
>>  static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
>>  {
>>      int offset;
>>
>> -    offset = (ppc_inst_val(op) & 0x03fffffc);
>> +    offset = (ppc_inst_val(op) & PPC_INST_OFFSET24_MASK);
>>      /* make it signed */
>>      if (offset & 0x02000000)
>>          offset |= 0xfe000000;
>> @@ -182,7 +182,7 @@ __ftrace_make_nop(struct module *mod,
>>       * Use a b +8 to jump over the load.
>>       */
>>
>> -    pop = ppc_inst(PPC_INST_BRANCH | 8);    /* b +8 */
>> +    pop = ppc_inst(PPC_RAW_BRANCH(8));    /* b +8 */
>>
>>      /*
>>       * Check what is in the next instruction. We can see ld 
>> r2,40(r1), but
>> @@ -394,17 +394,8 @@ int ftrace_make_nop(struct module *mod,
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> -    /*
>> -     * We expect to see:
>> -     *
>> -     * b +8
>> -     * ld r2,XX(r1)
>> -     *
>> -     * The load offset is different depending on the ABI. For simplicity
>> -     * just mask it out when doing the compare.
>> -     */
>> -    if (!ppc_inst_equal(op0, ppc_inst(0x48000008)) ||
>> -        (ppc_inst_val(op1) & 0xffff0000) != 0xe8410000)
>> +    if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) ||
>> +        !ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)))
> 
> It would be good to move PPC_INST_LD_TOC to ppc-opcode.h

It's not really just an instruction, it's closely linked to the ABI, so 
does it really belong to ppc-opcode.h ? Maybe it could be better to have 
it in ppc_asm.h instead, which already contains ABI related definitions ?

If we move it into ppc-opcode.h, then we also have to move 
R2_STACK_OFFSET. Or should we use STK_GOT defined in ppc_asm.h and drop 
R2_STACK_OFFSET ?

> 
>>          return 0;
>>      return 1;
>>  }
>> @@ -412,7 +403,6 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, 
>> ppc_inst_t op1)
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> -    /* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
>>      if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
>>          return 0;
>>      return 1;
>> @@ -738,11 +728,11 @@ int __init ftrace_dyn_arch_init(void)
>>      int i;
>>      unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init };
>>      u32 stub_insns[] = {
>> -        0xe98d0000 | PACATOC,    /* ld      r12,PACATOC(r13)    */
>> -        0x3d8c0000,        /* addis   r12,r12,<high>    */
>> -        0x398c0000,        /* addi    r12,r12,<low>    */
>> -        0x7d8903a6,        /* mtctr   r12            */
>> -        0x4e800420,        /* bctr                */
>> +        PPC_RAW_LD(_R12, _R13, PACATOC),
>> +        PPC_RAW_ADDIS(_R12, _R12, 0),
>> +        PPC_RAW_ADDIS(_R12, _R12, 0),
> 
> This should be PPC_RAW_ADDI.
> 

Oops.

Christophe

Re: [PATCH v1 16/22] powerpc/ftrace: Minimise number of #ifdefs

[Christophe Leroy]

Le 18/04/2022 à 09:59, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> A lot of #ifdefs can be replaced by IS_ENABLED()
>>
>> Do so.
>>
>> This requires to have kernel_toc_addr() defined at all time
>> and PPC_INST_LD_TOC as well.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/include/asm/code-patching.h |   2 -
>>  arch/powerpc/include/asm/module.h        |   2 -
>>  arch/powerpc/include/asm/sections.h      |  24 +--
>>  arch/powerpc/kernel/trace/ftrace.c       | 201 ++++++++++++-----------
>>  4 files changed, 113 insertions(+), 116 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/code-patching.h 
>> b/arch/powerpc/include/asm/code-patching.h
>> index 4260e89f62b1..071fcbec31c5 100644
>> --- a/arch/powerpc/include/asm/code-patching.h
>> +++ b/arch/powerpc/include/asm/code-patching.h
>> @@ -217,7 +217,6 @@ static inline unsigned long 
>> ppc_kallsyms_lookup_name(const char *name)
>>      return addr;
>>  }
>>
>> -#ifdef CONFIG_PPC64
>>  /*
>>   * Some instruction encodings commonly used in dynamic ftracing
>>   * and function live patching.
>> @@ -234,6 +233,5 @@ static inline unsigned long 
>> ppc_kallsyms_lookup_name(const char *name)
>>
>>  /* usually preceded by a mflr r0 */
>>  #define PPC_INST_STD_LR        PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF)
>> -#endif /* CONFIG_PPC64 */
>>
>>  #endif /* _ASM_POWERPC_CODE_PATCHING_H */
>> diff --git a/arch/powerpc/include/asm/module.h 
>> b/arch/powerpc/include/asm/module.h
>> index e6f5963fd96e..700d7ecd9012 100644
>> --- a/arch/powerpc/include/asm/module.h
>> +++ b/arch/powerpc/include/asm/module.h
>> @@ -41,9 +41,7 @@ struct mod_arch_specific {
>>
>>  #ifdef CONFIG_FUNCTION_TRACER
>>      unsigned long tramp;
>> -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>      unsigned long tramp_regs;
>> -#endif
>>  #endif
>>
>>      /* List of BUG addresses, source line numbers and filenames */
>> diff --git a/arch/powerpc/include/asm/sections.h 
>> b/arch/powerpc/include/asm/sections.h
>> index 8be2c491c733..6980eaeb16fe 100644
>> --- a/arch/powerpc/include/asm/sections.h
>> +++ b/arch/powerpc/include/asm/sections.h
>> @@ -29,18 +29,6 @@ extern char start_virt_trampolines[];
>>  extern char end_virt_trampolines[];
>>  #endif
>>
>> -/*
>> - * This assumes the kernel is never compiled -mcmodel=small or
>> - * the total .toc is always less than 64k.
>> - */
>> -static inline unsigned long kernel_toc_addr(void)
>> -{
>> -    unsigned long toc_ptr;
>> -
>> -    asm volatile("mr %0, 2" : "=r" (toc_ptr));
>> -    return toc_ptr;
>> -}
>> -
>>  static inline int overlaps_interrupt_vector_text(unsigned long start,
>>                              unsigned long end)
>>  {
>> @@ -60,5 +48,17 @@ static inline int overlaps_kernel_text(unsigned 
>> long start, unsigned long end)
>>
>>  #endif
>>
>> +/*
>> + * This assumes the kernel is never compiled -mcmodel=small or
>> + * the total .toc is always less than 64k.
>> + */
>> +static inline unsigned long kernel_toc_addr(void)
>> +{
>> +    unsigned long toc_ptr;
>> +
>> +    asm volatile("mr %0, 2" : "=r" (toc_ptr));
>> +    return toc_ptr;
>> +}
>> +
>>  #endif /* __KERNEL__ */
>>  #endif    /* _ASM_POWERPC_SECTIONS_H */
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index ffedf8c82ea8..4dd30e396026 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -150,55 +150,55 @@ __ftrace_make_nop(struct module *mod,
>>          return -EINVAL;
>>      }
>>
>> -    /* When using -mkernel_profile or PPC32 there is no load to jump 
>> over */
>> -    pop = ppc_inst(PPC_RAW_NOP());
>> +    if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) {
>> +        /* When using -mkernel_profile or PPC32 there is no load to 
>> jump over */
>> +        pop = ppc_inst(PPC_RAW_NOP());
> 
> Why move this inside the if() statement? You can keep this out and drop 
> the else clause.

I find it less error prone that way.

Putting a bad value and then replace it later with the good one can be 
misleading, and if some day someone removes that second set by error, it 
will go unnoticed. When you set it only once, GCC will complain in case 
that setting disappear by error.

Christophe

Re: [PATCH v1 16/22] powerpc/ftrace: Minimise number of #ifdefs

[Christophe Leroy]

Le 18/04/2022 à 09:59, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> A lot of #ifdefs can be replaced by IS_ENABLED()
>>
>> Do so.
>>
>> This requires to have kernel_toc_addr() defined at all time
>> and PPC_INST_LD_TOC as well.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/include/asm/code-patching.h |   2 -
>>  arch/powerpc/include/asm/module.h        |   2 -
>>  arch/powerpc/include/asm/sections.h      |  24 +--
>>  arch/powerpc/kernel/trace/ftrace.c       | 201 ++++++++++++-----------
>>  4 files changed, 113 insertions(+), 116 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/code-patching.h 
>> b/arch/powerpc/include/asm/code-patching.h
>> index 4260e89f62b1..071fcbec31c5 100644
>> --- a/arch/powerpc/include/asm/code-patching.h
>> +++ b/arch/powerpc/include/asm/code-patching.h
>> @@ -217,7 +217,6 @@ static inline unsigned long 
>> ppc_kallsyms_lookup_name(const char *name)
>>      return addr;
>>  }
>>
>> -#ifdef CONFIG_PPC64
>>  /*
>>   * Some instruction encodings commonly used in dynamic ftracing
>>   * and function live patching.
>> @@ -234,6 +233,5 @@ static inline unsigned long 
>> ppc_kallsyms_lookup_name(const char *name)
>>
>>  /* usually preceded by a mflr r0 */
>>  #define PPC_INST_STD_LR        PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF)
>> -#endif /* CONFIG_PPC64 */
>>
>>  #endif /* _ASM_POWERPC_CODE_PATCHING_H */
>> diff --git a/arch/powerpc/include/asm/module.h 
>> b/arch/powerpc/include/asm/module.h
>> index e6f5963fd96e..700d7ecd9012 100644
>> --- a/arch/powerpc/include/asm/module.h
>> +++ b/arch/powerpc/include/asm/module.h
>> @@ -41,9 +41,7 @@ struct mod_arch_specific {
>>
>>  #ifdef CONFIG_FUNCTION_TRACER
>>      unsigned long tramp;
>> -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>      unsigned long tramp_regs;
>> -#endif
>>  #endif
>>
>>      /* List of BUG addresses, source line numbers and filenames */
>> diff --git a/arch/powerpc/include/asm/sections.h 
>> b/arch/powerpc/include/asm/sections.h
>> index 8be2c491c733..6980eaeb16fe 100644
>> --- a/arch/powerpc/include/asm/sections.h
>> +++ b/arch/powerpc/include/asm/sections.h
>> @@ -29,18 +29,6 @@ extern char start_virt_trampolines[];
>>  extern char end_virt_trampolines[];
>>  #endif
>>
>> -/*
>> - * This assumes the kernel is never compiled -mcmodel=small or
>> - * the total .toc is always less than 64k.
>> - */
>> -static inline unsigned long kernel_toc_addr(void)
>> -{
>> -    unsigned long toc_ptr;
>> -
>> -    asm volatile("mr %0, 2" : "=r" (toc_ptr));
>> -    return toc_ptr;
>> -}
>> -
>>  static inline int overlaps_interrupt_vector_text(unsigned long start,
>>                              unsigned long end)
>>  {
>> @@ -60,5 +48,17 @@ static inline int overlaps_kernel_text(unsigned 
>> long start, unsigned long end)
>>
>>  #endif
>>
>> +/*
>> + * This assumes the kernel is never compiled -mcmodel=small or
>> + * the total .toc is always less than 64k.
>> + */
>> +static inline unsigned long kernel_toc_addr(void)
>> +{
>> +    unsigned long toc_ptr;
>> +
>> +    asm volatile("mr %0, 2" : "=r" (toc_ptr));
>> +    return toc_ptr;
>> +}
>> +
>>  #endif /* __KERNEL__ */
>>  #endif    /* _ASM_POWERPC_SECTIONS_H */
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index ffedf8c82ea8..4dd30e396026 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -150,55 +150,55 @@ __ftrace_make_nop(struct module *mod,
>>          return -EINVAL;
>>      }
>>
>> -    /* When using -mkernel_profile or PPC32 there is no load to jump 
>> over */
>> -    pop = ppc_inst(PPC_RAW_NOP());
>> +    if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) {
>> +        /* When using -mkernel_profile or PPC32 there is no load to 
>> jump over */
>> +        pop = ppc_inst(PPC_RAW_NOP());
> 
> Why move this inside the if() statement? You can keep this out and drop 
> the else clause.

I find it less error prone that way.

Putting a bad value and then replace it later with the good one can be 
misleading, and if some day someone removes that second set by error, it 
will go unnoticed. When you set it only once, GCC will complain in case 
that setting disappear by error.

Christophe

Re: [PATCH v1 13/22] powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding.

[Christophe Leroy]

Le 04/05/2022 à 14:39, Christophe Leroy a écrit :
> 
> 
> Le 18/04/2022 à 09:38, Naveen N. Rao a écrit :
>> Christophe Leroy wrote:
>>> PPC_RAW_xxx() macros are self explanatory and less error prone
>>> than open coding.
>>>
>>> Use them in ftrace.c
>>>
>>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>>> ---
>>>   arch/powerpc/include/asm/ppc-opcode.h |  3 +++
>>>   arch/powerpc/kernel/trace/ftrace.c    | 32 +++++++++------------------
>>>   2 files changed, 14 insertions(+), 21 deletions(-)
>>>
>>> diff --git a/arch/powerpc/include/asm/ppc-opcode.h
>>> b/arch/powerpc/include/asm/ppc-opcode.h
>>> index 82f1f0041c6f..281754aca0a3 100644
>>> --- a/arch/powerpc/include/asm/ppc-opcode.h
>>> +++ b/arch/powerpc/include/asm/ppc-opcode.h
>>> @@ -294,6 +294,8 @@
>>>   #define PPC_INST_BL            0x48000001
>>>   #define PPC_INST_BRANCH_COND        0x40800000
>>>
>>> +#define PPC_INST_OFFSET24_MASK        0x03fffffc
>>
>> This corresponds to the LI field, per the ISA. See section 8.1.2/1.7:
>> 'Instruction Fields'. Would it be better to name it PPC_INST_LI_MASK?
> 
> Isn't there a risk of confusing with the 'li' instruction ? Like we
> could have PPC_INST_LI just like we have PPC_INST_ADD ?

I called it PPC_LI() and PPC_LI_MASK, similar to PPC_LO, PPC_HI etc ...

> 
> 
> 
>>
>>> +
>>>   /* Prefixes */
>>>   #define PPC_INST_LFS            0xc0000000
>>>   #define PPC_INST_STFS            0xd0000000
>>> @@ -572,6 +574,7 @@
>>>   #define PPC_RAW_EIEIO()            (0x7c0006ac)
>>>
>>>   #define PPC_RAW_BRANCH(addr)        (PPC_INST_BRANCH | ((addr) &
>>> 0x03fffffc))
>>> +#define PPC_RAW_BL(offset)        (0x48000001 | ((offset) &
>>> PPC_INST_OFFSET24_MASK))
>>>
>>>   /* Deal with instructions that older assemblers aren't aware of */
>>>   #define    PPC_BCCTR_FLUSH        stringify_in_c(.long
>>> PPC_INST_BCCTR_FLUSH)
>>> diff --git a/arch/powerpc/kernel/trace/ftrace.c
>>> b/arch/powerpc/kernel/trace/ftrace.c
>>> index fdc0412c1d8a..afb1d12838c9 100644
>>> --- a/arch/powerpc/kernel/trace/ftrace.c
>>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>>> @@ -90,19 +90,19 @@ static int test_24bit_addr(unsigned long ip,
>>> unsigned long addr)
>>>
>>>   static int is_bl_op(ppc_inst_t op)
>>>   {
>>> -    return (ppc_inst_val(op) & 0xfc000003) == 0x48000001;
>>> +    return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) ==
>>> PPC_RAW_BL(0);
>>>   }
>>>
>>>   static int is_b_op(ppc_inst_t op)
>>>   {
>>> -    return (ppc_inst_val(op) & 0xfc000003) == 0x48000000;
>>> +    return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) ==
>>> PPC_RAW_BRANCH(0);
>>>   }
>>>
>>>   static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
>>>   {
>>>       int offset;
>>>
>>> -    offset = (ppc_inst_val(op) & 0x03fffffc);
>>> +    offset = (ppc_inst_val(op) & PPC_INST_OFFSET24_MASK);
>>>       /* make it signed */
>>>       if (offset & 0x02000000)
>>>           offset |= 0xfe000000;
>>> @@ -182,7 +182,7 @@ __ftrace_make_nop(struct module *mod,
>>>        * Use a b +8 to jump over the load.
>>>        */
>>>
>>> -    pop = ppc_inst(PPC_INST_BRANCH | 8);    /* b +8 */
>>> +    pop = ppc_inst(PPC_RAW_BRANCH(8));    /* b +8 */
>>>
>>>       /*
>>>        * Check what is in the next instruction. We can see ld
>>> r2,40(r1), but
>>> @@ -394,17 +394,8 @@ int ftrace_make_nop(struct module *mod,
>>>   static int
>>>   expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>>   {
>>> -    /*
>>> -     * We expect to see:
>>> -     *
>>> -     * b +8
>>> -     * ld r2,XX(r1)
>>> -     *
>>> -     * The load offset is different depending on the ABI. For simplicity
>>> -     * just mask it out when doing the compare.
>>> -     */
>>> -    if (!ppc_inst_equal(op0, ppc_inst(0x48000008)) ||
>>> -        (ppc_inst_val(op1) & 0xffff0000) != 0xe8410000)
>>> +    if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) ||
>>> +        !ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)))
>>
>> It would be good to move PPC_INST_LD_TOC to ppc-opcode.h
> 
> It's not really just an instruction, it's closely linked to the ABI, so
> does it really belong to ppc-opcode.h ? Maybe it could be better to have
> it in ppc_asm.h instead, which already contains ABI related definitions ?
> 
> If we move it into ppc-opcode.h, then we also have to move
> R2_STACK_OFFSET. Or should we use STK_GOT defined in ppc_asm.h and drop
> R2_STACK_OFFSET ?

Looked at it in more details, looks like STK_GOT is an assembly only 
symbol, and ppc_asm.h is dedicated to ASM allthough it has recently 
leaked a bit into C.

So I propose to leave it as is and do the change in a followup patch.


> 
>>
>>>           return 0;
>>>       return 1;
>>>   }
>>> @@ -412,7 +403,6 @@ expected_nop_sequence(void *ip, ppc_inst_t op0,
>>> ppc_inst_t op1)
>>>   static int
>>>   expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>>   {
>>> -    /* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
>>>       if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
>>>           return 0;
>>>       return 1;
>>> @@ -738,11 +728,11 @@ int __init ftrace_dyn_arch_init(void)
>>>       int i;
>>>       unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init };
>>>       u32 stub_insns[] = {
>>> -        0xe98d0000 | PACATOC,    /* ld      r12,PACATOC(r13)    */
>>> -        0x3d8c0000,        /* addis   r12,r12,<high>    */
>>> -        0x398c0000,        /* addi    r12,r12,<low>    */
>>> -        0x7d8903a6,        /* mtctr   r12            */
>>> -        0x4e800420,        /* bctr                */
>>> +        PPC_RAW_LD(_R12, _R13, PACATOC),
>>> +        PPC_RAW_ADDIS(_R12, _R12, 0),
>>> +        PPC_RAW_ADDIS(_R12, _R12, 0),
>>
>> This should be PPC_RAW_ADDI.
>>
> 
> Oops.
> 
> Christophe

Re: [PATCH v1 10/22] powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACE

[Christophe Leroy]

Le 18/04/2022 à 09:00, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> Since commit 0c0c52306f47 ("powerpc: Only support DYNAMIC_FTRACE not
>> static"), CONFIG_DYNAMIC_FTRACE is always selected when
>> CONFIG_FUNCTION_TRACER is selected.
>>
>> To avoid confusion and have the reader wonder what's happen when
>> CONFIG_FUNCTION_TRACER is selected and CONFIG_DYNAMIC_FTRACE is not,
>> use CONFIG_FUNCTION_TRACER in ifdefs instead of CONFIG_DYNAMIC_FTRACE.
>>
>> As CONFIG_FUNCTION_GRAPH_TRACER depends on CONFIG_FUNCTION_TRACER,
>> ftrace.o doesn't need to appear for both symbols in Makefile.
>>
>> Then as ftrace.o is built only when CONFIG_FUNCTION_TRACER is selected
> 
> and since it implies CONFIG_DYNAMIC_FTRACE, CONFIG_DYNAMIC_FTRACE is not 
> needed in ftrace.c

Ok, added to the commit message

> 
>> ifdef CONFIG_FUNCTION_TRACER is not needed in ftrace.c
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/include/asm/book3s/32/pgtable.h | 2 +-
>>  arch/powerpc/include/asm/book3s/64/pgtable.h | 2 +-
>>  arch/powerpc/include/asm/module.h            | 4 ++--
>>  arch/powerpc/include/asm/nohash/pgtable.h    | 2 +-
>>  arch/powerpc/kernel/module_32.c              | 4 ++--
>>  arch/powerpc/kernel/module_64.c              | 6 +++---
>>  arch/powerpc/kernel/trace/Makefile           | 4 +---
>>  arch/powerpc/kernel/trace/ftrace.c           | 4 ----
>>  8 files changed, 11 insertions(+), 17 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h 
>> b/arch/powerpc/include/asm/book3s/32/pgtable.h
>> index 772e00dc4ef1..992aed626eb4 100644
>> --- a/arch/powerpc/include/asm/book3s/32/pgtable.h
>> +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
>> @@ -124,7 +124,7 @@ static inline bool pte_user(pte_t pte)
>>   * on platforms where such control is possible.
>>   */
>>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || 
>> defined(CONFIG_BDI_SWITCH) ||\
>> -    defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
>> +    defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_X
>>  #else
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_ROX
>> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h 
>> b/arch/powerpc/include/asm/book3s/64/pgtable.h
>> index 875730d5af40..cf01b609572f 100644
>> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
>> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
>> @@ -169,7 +169,7 @@
>>   * on platforms where such control is possible.
>>   */
>>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || 
>> defined(CONFIG_BDI_SWITCH) || \
>> -    defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
>> +    defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_X
>>  #else
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_ROX
>> diff --git a/arch/powerpc/include/asm/module.h 
>> b/arch/powerpc/include/asm/module.h
>> index 857d9ff24295..e6f5963fd96e 100644
>> --- a/arch/powerpc/include/asm/module.h
>> +++ b/arch/powerpc/include/asm/module.h
>> @@ -39,7 +39,7 @@ struct mod_arch_specific {
>>      unsigned int init_plt_section;
>>  #endif /* powerpc64 */
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>      unsigned long tramp;
>>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>      unsigned long tramp_regs;
>> @@ -68,7 +68,7 @@ struct mod_arch_specific {
>>  #    endif    /* MODULE */
>>  #endif
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>  #    ifdef MODULE
>>      asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
>>  #    endif    /* MODULE */
>> diff --git a/arch/powerpc/include/asm/nohash/pgtable.h 
>> b/arch/powerpc/include/asm/nohash/pgtable.h
>> index ac75f4ab0dba..2e8cf217a191 100644
>> --- a/arch/powerpc/include/asm/nohash/pgtable.h
>> +++ b/arch/powerpc/include/asm/nohash/pgtable.h
>> @@ -23,7 +23,7 @@
>>   * on platforms where such control is possible.
>>   */
>>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || 
>> defined(CONFIG_BDI_SWITCH) ||\
>> -    defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
>> +    defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_X
>>  #else
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_ROX
>> diff --git a/arch/powerpc/kernel/module_32.c 
>> b/arch/powerpc/kernel/module_32.c
>> index a0432ef46967..2aa368ce21c9 100644
>> --- a/arch/powerpc/kernel/module_32.c
>> +++ b/arch/powerpc/kernel/module_32.c
>> @@ -39,7 +39,7 @@ static unsigned int count_relocs(const Elf32_Rela 
>> *rela, unsigned int num)
>>              r_addend = rela[i].r_addend;
>>          }
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>      _count_relocs++;    /* add one for ftrace_caller */
>>  #endif
>>      return _count_relocs;
>> @@ -288,7 +288,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
>>      return 0;
>>  }
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>  int module_trampoline_target(struct module *mod, unsigned long addr,
>>                   unsigned long *target)
>>  {
>> diff --git a/arch/powerpc/kernel/module_64.c 
>> b/arch/powerpc/kernel/module_64.c
>> index 794720530442..b13a72665eee 100644
>> --- a/arch/powerpc/kernel/module_64.c
>> +++ b/arch/powerpc/kernel/module_64.c
>> @@ -207,7 +207,7 @@ static unsigned long get_stubs_size(const 
>> Elf64_Ehdr *hdr,
>>          }
>>      }
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>      /* make the trampoline to the ftrace_caller */
>>      relocs++;
>>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>> @@ -372,7 +372,7 @@ static bool is_mprofile_ftrace_call(const char *name)
>>  {
>>      if (!strcmp("_mcount", name))
>>          return true;
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>      if (!strcmp("ftrace_caller", name))
>>          return true;
>>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>> @@ -740,7 +740,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
>>      return 0;
>>  }
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>  int module_trampoline_target(struct module *mod, unsigned long addr,
>>                   unsigned long *target)
>>  {
> 
> The below two changes to trace/Makefile and trace/ftrace.c make sense, 
> but I'm not sure the above changes are necessary.
> 
> For generic code (outside arch/powerpc/kernel/trace), I think it is good 
> to retain the actual dependency which is DYNAMIC_FTRACE. In my view, 
> gating some of the above code on FUNCTION_TRACER is also confusing. The 
> primary implication of always selecting DYNAMIC_FTRACE is within the 
> powerpc trace code, and it is good to keep it that way.

Ok I keep only the changes to trace directory for now.

> 
>> diff --git a/arch/powerpc/kernel/trace/Makefile 
>> b/arch/powerpc/kernel/trace/Makefile
>> index fc32ec30b297..af8527538fe4 100644
>> --- a/arch/powerpc/kernel/trace/Makefile
>> +++ b/arch/powerpc/kernel/trace/Makefile
>> @@ -14,9 +14,7 @@ obj64-$(CONFIG_FUNCTION_TRACER)        += 
>> ftrace_mprofile.o
>>  else
>>  obj64-$(CONFIG_FUNCTION_TRACER)        += ftrace_64_pg.o
>>  endif
>> -obj-$(CONFIG_FUNCTION_TRACER)        += ftrace_low.o
>> -obj-$(CONFIG_DYNAMIC_FTRACE)        += ftrace.o
>> -obj-$(CONFIG_FUNCTION_GRAPH_TRACER)    += ftrace.o
>> +obj-$(CONFIG_FUNCTION_TRACER)        += ftrace_low.o ftrace.o
>>  obj-$(CONFIG_TRACING)            += trace_clock.o
>>
>>  obj-$(CONFIG_PPC64)            += $(obj64-y)
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index 2c7e42e439bb..188f59f4ee4a 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -28,9 +28,6 @@
>>  #include <asm/syscall.h>
>>  #include <asm/inst.h>
>>
>> -
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> -
>>  /*
>>   * We generally only have a single long_branch tramp and at most 2 or 
>> 3 plt
>>   * tramps generated. But, we don't use the plt tramps currently. We 
>> also allot
>> @@ -783,7 +780,6 @@ int __init ftrace_dyn_arch_init(void)
>>      return 0;
>>  }
>>  #endif
>> -#endif /* CONFIG_DYNAMIC_FTRACE */
>>
>>  #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>>
>> -- 
>> 2.35.1
>>
> 
> - Naveen

Re: [PATCH v1 10/22] powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACE

[Christophe Leroy]

Le 18/04/2022 à 09:00, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> Since commit 0c0c52306f47 ("powerpc: Only support DYNAMIC_FTRACE not
>> static"), CONFIG_DYNAMIC_FTRACE is always selected when
>> CONFIG_FUNCTION_TRACER is selected.
>>
>> To avoid confusion and have the reader wonder what's happen when
>> CONFIG_FUNCTION_TRACER is selected and CONFIG_DYNAMIC_FTRACE is not,
>> use CONFIG_FUNCTION_TRACER in ifdefs instead of CONFIG_DYNAMIC_FTRACE.
>>
>> As CONFIG_FUNCTION_GRAPH_TRACER depends on CONFIG_FUNCTION_TRACER,
>> ftrace.o doesn't need to appear for both symbols in Makefile.
>>
>> Then as ftrace.o is built only when CONFIG_FUNCTION_TRACER is selected
> 
> and since it implies CONFIG_DYNAMIC_FTRACE, CONFIG_DYNAMIC_FTRACE is not 
> needed in ftrace.c

Ok, added to the commit message

> 
>> ifdef CONFIG_FUNCTION_TRACER is not needed in ftrace.c
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/include/asm/book3s/32/pgtable.h | 2 +-
>>  arch/powerpc/include/asm/book3s/64/pgtable.h | 2 +-
>>  arch/powerpc/include/asm/module.h            | 4 ++--
>>  arch/powerpc/include/asm/nohash/pgtable.h    | 2 +-
>>  arch/powerpc/kernel/module_32.c              | 4 ++--
>>  arch/powerpc/kernel/module_64.c              | 6 +++---
>>  arch/powerpc/kernel/trace/Makefile           | 4 +---
>>  arch/powerpc/kernel/trace/ftrace.c           | 4 ----
>>  8 files changed, 11 insertions(+), 17 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h 
>> b/arch/powerpc/include/asm/book3s/32/pgtable.h
>> index 772e00dc4ef1..992aed626eb4 100644
>> --- a/arch/powerpc/include/asm/book3s/32/pgtable.h
>> +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
>> @@ -124,7 +124,7 @@ static inline bool pte_user(pte_t pte)
>>   * on platforms where such control is possible.
>>   */
>>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || 
>> defined(CONFIG_BDI_SWITCH) ||\
>> -    defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
>> +    defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_X
>>  #else
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_ROX
>> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h 
>> b/arch/powerpc/include/asm/book3s/64/pgtable.h
>> index 875730d5af40..cf01b609572f 100644
>> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
>> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
>> @@ -169,7 +169,7 @@
>>   * on platforms where such control is possible.
>>   */
>>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || 
>> defined(CONFIG_BDI_SWITCH) || \
>> -    defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
>> +    defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_X
>>  #else
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_ROX
>> diff --git a/arch/powerpc/include/asm/module.h 
>> b/arch/powerpc/include/asm/module.h
>> index 857d9ff24295..e6f5963fd96e 100644
>> --- a/arch/powerpc/include/asm/module.h
>> +++ b/arch/powerpc/include/asm/module.h
>> @@ -39,7 +39,7 @@ struct mod_arch_specific {
>>      unsigned int init_plt_section;
>>  #endif /* powerpc64 */
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>      unsigned long tramp;
>>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>      unsigned long tramp_regs;
>> @@ -68,7 +68,7 @@ struct mod_arch_specific {
>>  #    endif    /* MODULE */
>>  #endif
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>  #    ifdef MODULE
>>      asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
>>  #    endif    /* MODULE */
>> diff --git a/arch/powerpc/include/asm/nohash/pgtable.h 
>> b/arch/powerpc/include/asm/nohash/pgtable.h
>> index ac75f4ab0dba..2e8cf217a191 100644
>> --- a/arch/powerpc/include/asm/nohash/pgtable.h
>> +++ b/arch/powerpc/include/asm/nohash/pgtable.h
>> @@ -23,7 +23,7 @@
>>   * on platforms where such control is possible.
>>   */
>>  #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || 
>> defined(CONFIG_BDI_SWITCH) ||\
>> -    defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
>> +    defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_X
>>  #else
>>  #define PAGE_KERNEL_TEXT    PAGE_KERNEL_ROX
>> diff --git a/arch/powerpc/kernel/module_32.c 
>> b/arch/powerpc/kernel/module_32.c
>> index a0432ef46967..2aa368ce21c9 100644
>> --- a/arch/powerpc/kernel/module_32.c
>> +++ b/arch/powerpc/kernel/module_32.c
>> @@ -39,7 +39,7 @@ static unsigned int count_relocs(const Elf32_Rela 
>> *rela, unsigned int num)
>>              r_addend = rela[i].r_addend;
>>          }
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>      _count_relocs++;    /* add one for ftrace_caller */
>>  #endif
>>      return _count_relocs;
>> @@ -288,7 +288,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
>>      return 0;
>>  }
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>  int module_trampoline_target(struct module *mod, unsigned long addr,
>>                   unsigned long *target)
>>  {
>> diff --git a/arch/powerpc/kernel/module_64.c 
>> b/arch/powerpc/kernel/module_64.c
>> index 794720530442..b13a72665eee 100644
>> --- a/arch/powerpc/kernel/module_64.c
>> +++ b/arch/powerpc/kernel/module_64.c
>> @@ -207,7 +207,7 @@ static unsigned long get_stubs_size(const 
>> Elf64_Ehdr *hdr,
>>          }
>>      }
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>      /* make the trampoline to the ftrace_caller */
>>      relocs++;
>>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>> @@ -372,7 +372,7 @@ static bool is_mprofile_ftrace_call(const char *name)
>>  {
>>      if (!strcmp("_mcount", name))
>>          return true;
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>      if (!strcmp("ftrace_caller", name))
>>          return true;
>>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>> @@ -740,7 +740,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
>>      return 0;
>>  }
>>
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> +#ifdef CONFIG_FUNCTION_TRACER
>>  int module_trampoline_target(struct module *mod, unsigned long addr,
>>                   unsigned long *target)
>>  {
> 
> The below two changes to trace/Makefile and trace/ftrace.c make sense, 
> but I'm not sure the above changes are necessary.
> 
> For generic code (outside arch/powerpc/kernel/trace), I think it is good 
> to retain the actual dependency which is DYNAMIC_FTRACE. In my view, 
> gating some of the above code on FUNCTION_TRACER is also confusing. The 
> primary implication of always selecting DYNAMIC_FTRACE is within the 
> powerpc trace code, and it is good to keep it that way.

Ok I keep only the changes to trace directory for now.

> 
>> diff --git a/arch/powerpc/kernel/trace/Makefile 
>> b/arch/powerpc/kernel/trace/Makefile
>> index fc32ec30b297..af8527538fe4 100644
>> --- a/arch/powerpc/kernel/trace/Makefile
>> +++ b/arch/powerpc/kernel/trace/Makefile
>> @@ -14,9 +14,7 @@ obj64-$(CONFIG_FUNCTION_TRACER)        += 
>> ftrace_mprofile.o
>>  else
>>  obj64-$(CONFIG_FUNCTION_TRACER)        += ftrace_64_pg.o
>>  endif
>> -obj-$(CONFIG_FUNCTION_TRACER)        += ftrace_low.o
>> -obj-$(CONFIG_DYNAMIC_FTRACE)        += ftrace.o
>> -obj-$(CONFIG_FUNCTION_GRAPH_TRACER)    += ftrace.o
>> +obj-$(CONFIG_FUNCTION_TRACER)        += ftrace_low.o ftrace.o
>>  obj-$(CONFIG_TRACING)            += trace_clock.o
>>
>>  obj-$(CONFIG_PPC64)            += $(obj64-y)
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index 2c7e42e439bb..188f59f4ee4a 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -28,9 +28,6 @@
>>  #include <asm/syscall.h>
>>  #include <asm/inst.h>
>>
>> -
>> -#ifdef CONFIG_DYNAMIC_FTRACE
>> -
>>  /*
>>   * We generally only have a single long_branch tramp and at most 2 or 
>> 3 plt
>>   * tramps generated. But, we don't use the plt tramps currently. We 
>> also allot
>> @@ -783,7 +780,6 @@ int __init ftrace_dyn_arch_init(void)
>>      return 0;
>>  }
>>  #endif
>> -#endif /* CONFIG_DYNAMIC_FTRACE */
>>
>>  #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>>
>> -- 
>> 2.35.1
>>
> 
> - Naveen

Re: [PATCH v1 08/22] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64

[Christophe Leroy]

Le 18/04/2022 à 08:40, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target()
>> for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the
>> one for PPC64.
>>
>> Same for __ftrace_make_call().
>>
>> Make them common.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/kernel/trace/ftrace.c | 108 +++--------------------------
>>  1 file changed, 8 insertions(+), 100 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index 1b05d33f96c6..2c7e42e439bb 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -114,7 +114,6 @@ static unsigned long find_bl_target(unsigned long 
>> ip, ppc_inst_t op)
>>  }
>>
>>  #ifdef CONFIG_MODULES
>> -#ifdef CONFIG_PPC64
>>  static int
>>  __ftrace_make_nop(struct module *mod,
>>            struct dyn_ftrace *rec, unsigned long addr)
>> @@ -154,10 +153,11 @@ __ftrace_make_nop(struct module *mod,
>>          return -EINVAL;
>>      }
>>
>> -#ifdef CONFIG_MPROFILE_KERNEL
>> -    /* When using -mkernel_profile there is no load to jump over */
>> +    /* When using -mkernel_profile or PPC32 there is no load to jump 
>> over */
>                       -mprofile-kernel
> 
> Since you are modifying that line anyway ^^
> 
> 
>>      pop = ppc_inst(PPC_RAW_NOP());
>>
>> +#ifdef CONFIG_PPC64
>> +#ifdef CONFIG_MPROFILE_KERNEL
>>      if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
>>          pr_err("Fetching instruction at %lx failed.\n", ip - 4);
>>          return -EFAULT;
>> @@ -201,6 +201,7 @@ __ftrace_make_nop(struct module *mod,
>>          return -EINVAL;
>>      }
>>  #endif /* CONFIG_MPROFILE_KERNEL */
>> +#endif /* PPC64 */
>>
>>      if (patch_instruction((u32 *)ip, pop)) {
>>          pr_err("Patching NOP failed.\n");
>> @@ -209,48 +210,6 @@ __ftrace_make_nop(struct module *mod,
>>
>>      return 0;
>>  }
>> -
>> -#else /* !PPC64 */
>> -static int
>> -__ftrace_make_nop(struct module *mod,
>> -          struct dyn_ftrace *rec, unsigned long addr)
>> -{
>> -    ppc_inst_t op;
>> -    unsigned long ip = rec->ip;
>> -    unsigned long tramp, ptr;
>> -
>> -    if (copy_from_kernel_nofault(&op, (void *)ip, MCOUNT_INSN_SIZE))
>> -        return -EFAULT;
>> -
>> -    /* Make sure that that this is still a 24bit jump */
>> -    if (!is_bl_op(op)) {
>> -        pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
>> -        return -EINVAL;
>> -    }
>> -
>> -    /* lets find where the pointer goes */
>> -    tramp = find_bl_target(ip, op);
>> -
>> -    /* Find where the trampoline jumps to */
>> -    if (module_trampoline_target(mod, tramp, &ptr)) {
>> -        pr_err("Failed to get trampoline target\n");
>> -        return -EFAULT;
>> -    }
>> -
>> -    if (ptr != addr) {
>> -        pr_err("Trampoline location %08lx does not match addr\n",
>> -               tramp);
>> -        return -EINVAL;
>> -    }
>> -
>> -    op = ppc_inst(PPC_RAW_NOP());
>> -
>> -    if (patch_instruction((u32 *)ip, op))
>> -        return -EPERM;
>> -
>> -    return 0;
>> -}
>> -#endif /* PPC64 */
>>  #endif /* CONFIG_MODULES */
>>
>>  static unsigned long find_ftrace_tramp(unsigned long ip)
>> @@ -437,13 +396,12 @@ int ftrace_make_nop(struct module *mod,
>>  }
>>
>>  #ifdef CONFIG_MODULES
>> -#ifdef CONFIG_PPC64
>>  /*
>>   * Examine the existing instructions for __ftrace_make_call.
>>   * They should effectively be a NOP, and follow formal constraints,
>>   * depending on the ABI. Return false if they don't.
>>   */
>> -#ifndef CONFIG_MPROFILE_KERNEL
>> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> 
> It is better to gate this on PPC64_ELF_ABI_v1

Ok I do that with the new CONFIG_PPC64_ELF_ABI_V1.

> 
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> @@ -465,7 +423,7 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, 
>> ppc_inst_t op1)
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> -    /* look for patched "NOP" on ppc64 with -mprofile-kernel */
>> +    /* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
>>      if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
>>          return 0;
>>      return 1;
>> @@ -484,8 +442,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, 
>> unsigned long addr)
>>      if (copy_inst_from_kernel_nofault(op, ip))
>>          return -EFAULT;
>>
>> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>      if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
>>          return -EFAULT;
>> +#endif
> 
> Here too...
> 

Done

Christophe

Re: [PATCH v1 08/22] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64

[Christophe Leroy]

Le 18/04/2022 à 08:40, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target()
>> for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the
>> one for PPC64.
>>
>> Same for __ftrace_make_call().
>>
>> Make them common.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>  arch/powerpc/kernel/trace/ftrace.c | 108 +++--------------------------
>>  1 file changed, 8 insertions(+), 100 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/trace/ftrace.c 
>> b/arch/powerpc/kernel/trace/ftrace.c
>> index 1b05d33f96c6..2c7e42e439bb 100644
>> --- a/arch/powerpc/kernel/trace/ftrace.c
>> +++ b/arch/powerpc/kernel/trace/ftrace.c
>> @@ -114,7 +114,6 @@ static unsigned long find_bl_target(unsigned long 
>> ip, ppc_inst_t op)
>>  }
>>
>>  #ifdef CONFIG_MODULES
>> -#ifdef CONFIG_PPC64
>>  static int
>>  __ftrace_make_nop(struct module *mod,
>>            struct dyn_ftrace *rec, unsigned long addr)
>> @@ -154,10 +153,11 @@ __ftrace_make_nop(struct module *mod,
>>          return -EINVAL;
>>      }
>>
>> -#ifdef CONFIG_MPROFILE_KERNEL
>> -    /* When using -mkernel_profile there is no load to jump over */
>> +    /* When using -mkernel_profile or PPC32 there is no load to jump 
>> over */
>                       -mprofile-kernel
> 
> Since you are modifying that line anyway ^^
> 
> 
>>      pop = ppc_inst(PPC_RAW_NOP());
>>
>> +#ifdef CONFIG_PPC64
>> +#ifdef CONFIG_MPROFILE_KERNEL
>>      if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
>>          pr_err("Fetching instruction at %lx failed.\n", ip - 4);
>>          return -EFAULT;
>> @@ -201,6 +201,7 @@ __ftrace_make_nop(struct module *mod,
>>          return -EINVAL;
>>      }
>>  #endif /* CONFIG_MPROFILE_KERNEL */
>> +#endif /* PPC64 */
>>
>>      if (patch_instruction((u32 *)ip, pop)) {
>>          pr_err("Patching NOP failed.\n");
>> @@ -209,48 +210,6 @@ __ftrace_make_nop(struct module *mod,
>>
>>      return 0;
>>  }
>> -
>> -#else /* !PPC64 */
>> -static int
>> -__ftrace_make_nop(struct module *mod,
>> -          struct dyn_ftrace *rec, unsigned long addr)
>> -{
>> -    ppc_inst_t op;
>> -    unsigned long ip = rec->ip;
>> -    unsigned long tramp, ptr;
>> -
>> -    if (copy_from_kernel_nofault(&op, (void *)ip, MCOUNT_INSN_SIZE))
>> -        return -EFAULT;
>> -
>> -    /* Make sure that that this is still a 24bit jump */
>> -    if (!is_bl_op(op)) {
>> -        pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
>> -        return -EINVAL;
>> -    }
>> -
>> -    /* lets find where the pointer goes */
>> -    tramp = find_bl_target(ip, op);
>> -
>> -    /* Find where the trampoline jumps to */
>> -    if (module_trampoline_target(mod, tramp, &ptr)) {
>> -        pr_err("Failed to get trampoline target\n");
>> -        return -EFAULT;
>> -    }
>> -
>> -    if (ptr != addr) {
>> -        pr_err("Trampoline location %08lx does not match addr\n",
>> -               tramp);
>> -        return -EINVAL;
>> -    }
>> -
>> -    op = ppc_inst(PPC_RAW_NOP());
>> -
>> -    if (patch_instruction((u32 *)ip, op))
>> -        return -EPERM;
>> -
>> -    return 0;
>> -}
>> -#endif /* PPC64 */
>>  #endif /* CONFIG_MODULES */
>>
>>  static unsigned long find_ftrace_tramp(unsigned long ip)
>> @@ -437,13 +396,12 @@ int ftrace_make_nop(struct module *mod,
>>  }
>>
>>  #ifdef CONFIG_MODULES
>> -#ifdef CONFIG_PPC64
>>  /*
>>   * Examine the existing instructions for __ftrace_make_call.
>>   * They should effectively be a NOP, and follow formal constraints,
>>   * depending on the ABI. Return false if they don't.
>>   */
>> -#ifndef CONFIG_MPROFILE_KERNEL
>> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> 
> It is better to gate this on PPC64_ELF_ABI_v1

Ok I do that with the new CONFIG_PPC64_ELF_ABI_V1.

> 
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> @@ -465,7 +423,7 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, 
>> ppc_inst_t op1)
>>  static int
>>  expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
>>  {
>> -    /* look for patched "NOP" on ppc64 with -mprofile-kernel */
>> +    /* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
>>      if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
>>          return 0;
>>      return 1;
>> @@ -484,8 +442,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, 
>> unsigned long addr)
>>      if (copy_inst_from_kernel_nofault(op, ip))
>>          return -EFAULT;
>>
>> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>      if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
>>          return -EFAULT;
>> +#endif
> 
> Here too...
> 

Done

Christophe