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* [PATCH 0/2] Ftrace direct call samples improvements
@ 2023-04-27 14:06 Florent Revest
  2023-04-27 14:06 ` [PATCH 1/2] samples: ftrace: Save required argument registers in sample trampolines Florent Revest
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Florent Revest @ 2023-04-27 14:06 UTC (permalink / raw)
  To: linux-arm-kernel, linux-kernel, linux-trace-kernel
  Cc: rostedt, mhiramat, mark.rutland, kpsingh, xukuohai,
	Florent Revest

This series is a subset of [1] that didn't go through the arm64 tree.

- The first patch fixes a small bug when a direct call sample is loaded on x86
- The second patch adds arm64 support to all direct calls samples

They are sent together because the second one depends on the first one.

This series applies cleanly on Linus's master branch. It needs the first two
patches of [1] which, at the time of writing, don't seem to have made it to the
trace/linux-trace tree but I suppose they could be pulled from Linus's master

1: https://lore.kernel.org/bpf/20230405180250.2046566-1-revest@chromium.org/

Florent Revest (2):
  samples: ftrace: Save required argument registers in sample
    trampolines
  arm64: ftrace: Add direct call trampoline samples support

 arch/arm64/Kconfig                          |  2 ++
 samples/ftrace/ftrace-direct-modify.c       | 34 ++++++++++++++++++
 samples/ftrace/ftrace-direct-multi-modify.c | 40 +++++++++++++++++++++
 samples/ftrace/ftrace-direct-multi.c        | 24 +++++++++++++
 samples/ftrace/ftrace-direct-too.c          | 40 +++++++++++++++++----
 samples/ftrace/ftrace-direct.c              | 24 +++++++++++++
 6 files changed, 158 insertions(+), 6 deletions(-)

-- 
2.40.1.495.gc816e09b53d-goog


^ permalink raw reply	[flat|nested] 6+ messages in thread

• * [PATCH 1/2] samples: ftrace: Save required argument registers in sample trampolines
    2023-04-27 14:06 [PATCH 0/2] Ftrace direct call samples improvements Florent Revest
  @ 2023-04-27 14:06 ` Florent Revest
    2023-04-27 14:07 ` [PATCH 2/2] arm64: ftrace: Add direct call trampoline samples support Florent Revest
    2023-06-09 20:20 ` [PATCH 0/2] Ftrace direct call samples improvements Steven Rostedt
    2 siblings, 0 replies; 6+ messages in thread
  From: Florent Revest @ 2023-04-27 14:06 UTC (permalink / raw)
    To: linux-arm-kernel, linux-kernel, linux-trace-kernel
    Cc: rostedt, mhiramat, mark.rutland, kpsingh, xukuohai,
  	Florent Revest, stable
  
  The ftrace-direct-too sample traces the handle_mm_fault function whose
  signature changed since the introduction of the sample. Since:
  commit bce617edecad ("mm: do page fault accounting in handle_mm_fault")
  handle_mm_fault now has 4 arguments. Therefore, the sample trampoline
  should save 4 argument registers.
  
  s390 saves all argument registers already so it does not need a change
  but x86_64 needs an extra push and pop.
  
  This also evolves the signature of the tracing function to make it
  mirror the signature of the traced function.
  
  Cc: stable@vger.kernel.org
  Fixes: bce617edecad ("mm: do page fault accounting in handle_mm_fault")
  Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
  Reviewed-by: Mark Rutland <mark.rutland@arm.com>
  Signed-off-by: Florent Revest <revest@chromium.org>
  ---
   samples/ftrace/ftrace-direct-too.c | 14 ++++++++------
   1 file changed, 8 insertions(+), 6 deletions(-)
  
  diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
  index f28e7b99840f..71ed4ee8cb4a 100644
  --- a/samples/ftrace/ftrace-direct-too.c
  +++ b/samples/ftrace/ftrace-direct-too.c
  @@ -5,14 +5,14 @@
   #include <linux/ftrace.h>
   #include <asm/asm-offsets.h>
   
  -extern void my_direct_func(struct vm_area_struct *vma,
  -			   unsigned long address, unsigned int flags);
  +extern void my_direct_func(struct vm_area_struct *vma, unsigned long address,
  +			   unsigned int flags, struct pt_regs *regs);
   
  -void my_direct_func(struct vm_area_struct *vma,
  -			unsigned long address, unsigned int flags)
  +void my_direct_func(struct vm_area_struct *vma, unsigned long address,
  +		    unsigned int flags, struct pt_regs *regs)
   {
  -	trace_printk("handle mm fault vma=%p address=%lx flags=%x\n",
  -		     vma, address, flags);
  +	trace_printk("handle mm fault vma=%p address=%lx flags=%x regs=%p\n",
  +		     vma, address, flags, regs);
   }
   
   extern void my_tramp(void *);
  @@ -34,7 +34,9 @@ asm (
   "	pushq %rdi\n"
   "	pushq %rsi\n"
   "	pushq %rdx\n"
  +"	pushq %rcx\n"
   "	call my_direct_func\n"
  +"	popq %rcx\n"
   "	popq %rdx\n"
   "	popq %rsi\n"
   "	popq %rdi\n"
  -- 
  2.40.1.495.gc816e09b53d-goog
  
  
  ^ permalink raw reply related	[flat|nested] 6+ messages in thread

• * [PATCH 2/2] arm64: ftrace: Add direct call trampoline samples support
    2023-04-27 14:06 [PATCH 0/2] Ftrace direct call samples improvements Florent Revest
    2023-04-27 14:06 ` [PATCH 1/2] samples: ftrace: Save required argument registers in sample trampolines Florent Revest
  @ 2023-04-27 14:07 ` Florent Revest
    2023-06-09 20:20 ` [PATCH 0/2] Ftrace direct call samples improvements Steven Rostedt
    2 siblings, 0 replies; 6+ messages in thread
  From: Florent Revest @ 2023-04-27 14:07 UTC (permalink / raw)
    To: linux-arm-kernel, linux-kernel, linux-trace-kernel
    Cc: rostedt, mhiramat, mark.rutland, kpsingh, xukuohai,
  	Florent Revest
  
  The ftrace samples need per-architecture trampoline implementations
  to save and restore argument registers around the calls to
  my_direct_func* and to restore polluted registers (eg: x30).
  
  These samples also include <asm/asm-offsets.h> which, on arm64, is not
  necessary and redefines previously defined macros (resulting in
  warnings) so these includes are guarded by !CONFIG_ARM64.
  
  Reviewed-by: Mark Rutland <mark.rutland@arm.com>
  Tested-by: Mark Rutland <mark.rutland@arm.com>
  Signed-off-by: Florent Revest <revest@chromium.org>
  ---
   arch/arm64/Kconfig                          |  2 ++
   samples/ftrace/ftrace-direct-modify.c       | 34 ++++++++++++++++++
   samples/ftrace/ftrace-direct-multi-modify.c | 40 +++++++++++++++++++++
   samples/ftrace/ftrace-direct-multi.c        | 24 +++++++++++++
   samples/ftrace/ftrace-direct-too.c          | 26 ++++++++++++++
   samples/ftrace/ftrace-direct.c              | 24 +++++++++++++
   6 files changed, 150 insertions(+)
  
  diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
  index 3f5bf55050e8..e98d6b7845c4 100644
  --- a/arch/arm64/Kconfig
  +++ b/arch/arm64/Kconfig
  @@ -195,6 +195,8 @@ config ARM64
   		    !CC_OPTIMIZE_FOR_SIZE)
   	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
   		if DYNAMIC_FTRACE_WITH_ARGS
  +	select HAVE_SAMPLE_FTRACE_DIRECT
  +	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
   	select HAVE_EFFICIENT_UNALIGNED_ACCESS
   	select HAVE_FAST_GUP
   	select HAVE_FTRACE_MCOUNT_RECORD
  diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
  index 25fba66f61c0..98d1b7385f08 100644
  --- a/samples/ftrace/ftrace-direct-modify.c
  +++ b/samples/ftrace/ftrace-direct-modify.c
  @@ -2,7 +2,9 @@
   #include <linux/module.h>
   #include <linux/kthread.h>
   #include <linux/ftrace.h>
  +#ifndef CONFIG_ARM64
   #include <asm/asm-offsets.h>
  +#endif
   
   extern void my_direct_func1(void);
   extern void my_direct_func2(void);
  @@ -96,6 +98,38 @@ asm (
   
   #endif /* CONFIG_S390 */
   
  +#ifdef CONFIG_ARM64
  +
  +asm (
  +"	.pushsection    .text, \"ax\", @progbits\n"
  +"	.type		my_tramp1, @function\n"
  +"	.globl		my_tramp1\n"
  +"   my_tramp1:"
  +"	bti	c\n"
  +"	sub	sp, sp, #16\n"
  +"	stp	x9, x30, [sp]\n"
  +"	bl	my_direct_func1\n"
  +"	ldp	x30, x9, [sp]\n"
  +"	add	sp, sp, #16\n"
  +"	ret	x9\n"
  +"	.size		my_tramp1, .-my_tramp1\n"
  +
  +"	.type		my_tramp2, @function\n"
  +"	.globl		my_tramp2\n"
  +"   my_tramp2:"
  +"	bti	c\n"
  +"	sub	sp, sp, #16\n"
  +"	stp	x9, x30, [sp]\n"
  +"	bl	my_direct_func2\n"
  +"	ldp	x30, x9, [sp]\n"
  +"	add	sp, sp, #16\n"
  +"	ret	x9\n"
  +"	.size		my_tramp2, .-my_tramp2\n"
  +"	.popsection\n"
  +);
  +
  +#endif /* CONFIG_ARM64 */
  +
   static struct ftrace_ops direct;
   
   static unsigned long my_tramp = (unsigned long)my_tramp1;
  diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
  index f72623899602..26956c8fc513 100644
  --- a/samples/ftrace/ftrace-direct-multi-modify.c
  +++ b/samples/ftrace/ftrace-direct-multi-modify.c
  @@ -2,7 +2,9 @@
   #include <linux/module.h>
   #include <linux/kthread.h>
   #include <linux/ftrace.h>
  +#ifndef CONFIG_ARM64
   #include <asm/asm-offsets.h>
  +#endif
   
   extern void my_direct_func1(unsigned long ip);
   extern void my_direct_func2(unsigned long ip);
  @@ -103,6 +105,44 @@ asm (
   
   #endif /* CONFIG_S390 */
   
  +#ifdef CONFIG_ARM64
  +
  +asm (
  +"	.pushsection    .text, \"ax\", @progbits\n"
  +"	.type		my_tramp1, @function\n"
  +"	.globl		my_tramp1\n"
  +"   my_tramp1:"
  +"	bti	c\n"
  +"	sub	sp, sp, #32\n"
  +"	stp	x9, x30, [sp]\n"
  +"	str	x0, [sp, #16]\n"
  +"	mov	x0, x30\n"
  +"	bl	my_direct_func1\n"
  +"	ldp	x30, x9, [sp]\n"
  +"	ldr	x0, [sp, #16]\n"
  +"	add	sp, sp, #32\n"
  +"	ret	x9\n"
  +"	.size		my_tramp1, .-my_tramp1\n"
  +
  +"	.type		my_tramp2, @function\n"
  +"	.globl		my_tramp2\n"
  +"   my_tramp2:"
  +"	bti	c\n"
  +"	sub	sp, sp, #32\n"
  +"	stp	x9, x30, [sp]\n"
  +"	str	x0, [sp, #16]\n"
  +"	mov	x0, x30\n"
  +"	bl	my_direct_func2\n"
  +"	ldp	x30, x9, [sp]\n"
  +"	ldr	x0, [sp, #16]\n"
  +"	add	sp, sp, #32\n"
  +"	ret	x9\n"
  +"	.size		my_tramp2, .-my_tramp2\n"
  +"	.popsection\n"
  +);
  +
  +#endif /* CONFIG_ARM64 */
  +
   static unsigned long my_tramp = (unsigned long)my_tramp1;
   static unsigned long tramps[2] = {
   	(unsigned long)my_tramp1,
  diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
  index 1547c2c6be02..b2ac90e0c02e 100644
  --- a/samples/ftrace/ftrace-direct-multi.c
  +++ b/samples/ftrace/ftrace-direct-multi.c
  @@ -4,7 +4,9 @@
   #include <linux/mm.h> /* for handle_mm_fault() */
   #include <linux/ftrace.h>
   #include <linux/sched/stat.h>
  +#ifndef CONFIG_ARM64
   #include <asm/asm-offsets.h>
  +#endif
   
   extern void my_direct_func(unsigned long ip);
   
  @@ -66,6 +68,28 @@ asm (
   
   #endif /* CONFIG_S390 */
   
  +#ifdef CONFIG_ARM64
  +
  +asm (
  +"	.pushsection	.text, \"ax\", @progbits\n"
  +"	.type		my_tramp, @function\n"
  +"	.globl		my_tramp\n"
  +"   my_tramp:"
  +"	bti	c\n"
  +"	sub	sp, sp, #32\n"
  +"	stp	x9, x30, [sp]\n"
  +"	str	x0, [sp, #16]\n"
  +"	mov	x0, x30\n"
  +"	bl	my_direct_func\n"
  +"	ldp	x30, x9, [sp]\n"
  +"	ldr	x0, [sp, #16]\n"
  +"	add	sp, sp, #32\n"
  +"	ret	x9\n"
  +"	.size		my_tramp, .-my_tramp\n"
  +"	.popsection\n"
  +);
  +
  +#endif /* CONFIG_ARM64 */
   static struct ftrace_ops direct;
   
   static int __init ftrace_direct_multi_init(void)
  diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
  index 71ed4ee8cb4a..38f6f677f913 100644
  --- a/samples/ftrace/ftrace-direct-too.c
  +++ b/samples/ftrace/ftrace-direct-too.c
  @@ -3,7 +3,9 @@
   
   #include <linux/mm.h> /* for handle_mm_fault() */
   #include <linux/ftrace.h>
  +#ifndef CONFIG_ARM64
   #include <asm/asm-offsets.h>
  +#endif
   
   extern void my_direct_func(struct vm_area_struct *vma, unsigned long address,
   			   unsigned int flags, struct pt_regs *regs);
  @@ -72,6 +74,30 @@ asm (
   
   #endif /* CONFIG_S390 */
   
  +#ifdef CONFIG_ARM64
  +
  +asm (
  +"	.pushsection	.text, \"ax\", @progbits\n"
  +"	.type		my_tramp, @function\n"
  +"	.globl		my_tramp\n"
  +"   my_tramp:"
  +"	bti	c\n"
  +"	sub	sp, sp, #48\n"
  +"	stp	x9, x30, [sp]\n"
  +"	stp	x0, x1, [sp, #16]\n"
  +"	stp	x2, x3, [sp, #32]\n"
  +"	bl	my_direct_func\n"
  +"	ldp	x30, x9, [sp]\n"
  +"	ldp	x0, x1, [sp, #16]\n"
  +"	ldp	x2, x3, [sp, #32]\n"
  +"	add	sp, sp, #48\n"
  +"	ret	x9\n"
  +"	.size		my_tramp, .-my_tramp\n"
  +"	.popsection\n"
  +);
  +
  +#endif /* CONFIG_ARM64 */
  +
   static struct ftrace_ops direct;
   
   static int __init ftrace_direct_init(void)
  diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
  index d81a9473b585..e5312f9c15d3 100644
  --- a/samples/ftrace/ftrace-direct.c
  +++ b/samples/ftrace/ftrace-direct.c
  @@ -3,7 +3,9 @@
   
   #include <linux/sched.h> /* for wake_up_process() */
   #include <linux/ftrace.h>
  +#ifndef CONFIG_ARM64
   #include <asm/asm-offsets.h>
  +#endif
   
   extern void my_direct_func(struct task_struct *p);
   
  @@ -63,6 +65,28 @@ asm (
   
   #endif /* CONFIG_S390 */
   
  +#ifdef CONFIG_ARM64
  +
  +asm (
  +"	.pushsection	.text, \"ax\", @progbits\n"
  +"	.type		my_tramp, @function\n"
  +"	.globl		my_tramp\n"
  +"   my_tramp:"
  +"	bti	c\n"
  +"	sub	sp, sp, #32\n"
  +"	stp	x9, x30, [sp]\n"
  +"	str	x0, [sp, #16]\n"
  +"	bl	my_direct_func\n"
  +"	ldp	x30, x9, [sp]\n"
  +"	ldr	x0, [sp, #16]\n"
  +"	add	sp, sp, #32\n"
  +"	ret	x9\n"
  +"	.size		my_tramp, .-my_tramp\n"
  +"	.popsection\n"
  +);
  +
  +#endif /* CONFIG_ARM64 */
  +
   static struct ftrace_ops direct;
   
   static int __init ftrace_direct_init(void)
  -- 
  2.40.1.495.gc816e09b53d-goog
  
  
  ^ permalink raw reply related	[flat|nested] 6+ messages in thread

• * Re: [PATCH 0/2] Ftrace direct call samples improvements
    2023-04-27 14:06 [PATCH 0/2] Ftrace direct call samples improvements Florent Revest
    2023-04-27 14:06 ` [PATCH 1/2] samples: ftrace: Save required argument registers in sample trampolines Florent Revest
    2023-04-27 14:07 ` [PATCH 2/2] arm64: ftrace: Add direct call trampoline samples support Florent Revest
  @ 2023-06-09 20:20 ` Steven Rostedt
    2023-06-10  8:28   ` Catalin Marinas
    2 siblings, 1 reply; 6+ messages in thread
  From: Steven Rostedt @ 2023-06-09 20:20 UTC (permalink / raw)
    To: Florent Revest
    Cc: linux-arm-kernel, linux-kernel, linux-trace-kernel, mhiramat,
  	mark.rutland, kpsingh, xukuohai, Catalin Marinas
  
  On Thu, 27 Apr 2023 16:06:58 +0200
  Florent Revest <revest@chromium.org> wrote:
  
  > This series is a subset of [1] that didn't go through the arm64 tree.
  > 
  > - The first patch fixes a small bug when a direct call sample is loaded on x86
  > - The second patch adds arm64 support to all direct calls samples
  > 
  > They are sent together because the second one depends on the first one.
  > 
  > This series applies cleanly on Linus's master branch. It needs the first two
  > patches of [1] which, at the time of writing, don't seem to have made it to the
  > trace/linux-trace tree but I suppose they could be pulled from Linus's master
  > 
  > 1: https://lore.kernel.org/bpf/20230405180250.2046566-1-revest@chromium.org/
  > 
  > Florent Revest (2):
  >   samples: ftrace: Save required argument registers in sample
  >     trampolines
  >   arm64: ftrace: Add direct call trampoline samples support
  
  Is this going through the arm64 tree, or should it go through mine?
  
  -- Steve
  
  
  > 
  >  arch/arm64/Kconfig                          |  2 ++
  >  samples/ftrace/ftrace-direct-modify.c       | 34 ++++++++++++++++++
  >  samples/ftrace/ftrace-direct-multi-modify.c | 40 +++++++++++++++++++++
  >  samples/ftrace/ftrace-direct-multi.c        | 24 +++++++++++++
  >  samples/ftrace/ftrace-direct-too.c          | 40 +++++++++++++++++----
  >  samples/ftrace/ftrace-direct.c              | 24 +++++++++++++
  >  6 files changed, 158 insertions(+), 6 deletions(-)
  > 
  
  
  ^ permalink raw reply	[flat|nested] 6+ messages in thread

• • * Re: [PATCH 0/2] Ftrace direct call samples improvements
      2023-06-09 20:20 ` [PATCH 0/2] Ftrace direct call samples improvements Steven Rostedt
    @ 2023-06-10  8:28   ` Catalin Marinas
      2023-07-10 21:40     ` Steven Rostedt
      0 siblings, 1 reply; 6+ messages in thread
    From: Catalin Marinas @ 2023-06-10  8:28 UTC (permalink / raw)
      To: Steven Rostedt
      Cc: Florent Revest, linux-arm-kernel, linux-kernel,
    	linux-trace-kernel, mhiramat, mark.rutland, kpsingh, xukuohai
    
    On Fri, Jun 09, 2023 at 04:20:46PM -0400, Steven Rostedt wrote:
    > On Thu, 27 Apr 2023 16:06:58 +0200
    > Florent Revest <revest@chromium.org> wrote:
    > 
    > > This series is a subset of [1] that didn't go through the arm64 tree.
    > > 
    > > - The first patch fixes a small bug when a direct call sample is loaded on x86
    > > - The second patch adds arm64 support to all direct calls samples
    > > 
    > > They are sent together because the second one depends on the first one.
    > > 
    > > This series applies cleanly on Linus's master branch. It needs the first two
    > > patches of [1] which, at the time of writing, don't seem to have made it to the
    > > trace/linux-trace tree but I suppose they could be pulled from Linus's master
    > > 
    > > 1: https://lore.kernel.org/bpf/20230405180250.2046566-1-revest@chromium.org/
    > > 
    > > Florent Revest (2):
    > >   samples: ftrace: Save required argument registers in sample
    > >     trampolines
    > >   arm64: ftrace: Add direct call trampoline samples support
    > 
    > Is this going through the arm64 tree, or should it go through mine?
    
    Feel free to take it through your tree.
    
    Acked-by: Catalin Marinas <catalin.marinas@arm.com>
    
    ^ permalink raw reply	[flat|nested] 6+ messages in thread

  • • * Re: [PATCH 0/2] Ftrace direct call samples improvements
        2023-06-10  8:28   ` Catalin Marinas
      @ 2023-07-10 21:40     ` Steven Rostedt
        0 siblings, 0 replies; 6+ messages in thread
      From: Steven Rostedt @ 2023-07-10 21:40 UTC (permalink / raw)
        To: Catalin Marinas
        Cc: Florent Revest, linux-arm-kernel, linux-kernel,
      	linux-trace-kernel, mhiramat, mark.rutland, kpsingh, xukuohai
      
      On Sat, 10 Jun 2023 09:28:36 +0100
      Catalin Marinas <catalin.marinas@arm.com> wrote:
      
      > > Is this going through the arm64 tree, or should it go through mine?  
      > 
      > Feel free to take it through your tree.
      > 
      > Acked-by: Catalin Marinas <catalin.marinas@arm.com>
      
      I think I missed your email and let this drop. I'll add it now. As it's
      sample code, it should still be OK to add to the rc releases.
      
      -- Steve
      
      ^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2023-07-10 21:40 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-04-27 14:06 [PATCH 0/2] Ftrace direct call samples improvements Florent Revest
2023-04-27 14:06 ` [PATCH 1/2] samples: ftrace: Save required argument registers in sample trampolines Florent Revest
2023-04-27 14:07 ` [PATCH 2/2] arm64: ftrace: Add direct call trampoline samples support Florent Revest
2023-06-09 20:20 ` [PATCH 0/2] Ftrace direct call samples improvements Steven Rostedt
2023-06-10  8:28   ` Catalin Marinas
2023-07-10 21:40     ` Steven Rostedt

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