lkml.org 
[lkml]   [2015]   [Jul]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC 2/3] arm64: refactor save_stack_trace()
On Thu, 16 Jul 2015 10:08:03 +0900
AKASHI Takahiro <takahiro.akashi@linaro.org> wrote:

> On 07/16/2015 09:27 AM, AKASHI Takahiro wrote:
> > On 07/16/2015 01:13 AM, Steven Rostedt wrote:
> >> On Wed, 15 Jul 2015 10:55:36 -0400
> >> Steven Rostedt <rostedt@goodmis.org> wrote:
> >>
> >>
> >>> I'll take a look at it and try to clean up the code.
> >>
> >> Does the following patch make sense for you?
> >
> > Looks nice. The patch greatly simplifies changes on arm64 side.
>
> As follows:
>
> - Takahiro AKASHI
>

How should we go forward with this. Want me to make my change to my
tree, and pull this patch in with it? I can set up for a 4.3 release.

Then if I can get an Acked-by from one of the arm64 maintainers, I can
have this go through my tree?

-- Steve


> diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h
> index c5534fa..868d6f1 100644
> --- a/arch/arm64/include/asm/ftrace.h
> +++ b/arch/arm64/include/asm/ftrace.h
> @@ -15,6 +15,7 @@
>
> #define MCOUNT_ADDR ((unsigned long)_mcount)
> #define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE
> +#define FTRACE_STACK_FRAME_OFFSET 4 /* sync it up with stacktrace.c */
>
> #ifndef __ASSEMBLY__
> #include <linux/compat.h>
> diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
> index 1da6029..2c1bf7d 100644
> --- a/include/linux/ftrace.h
> +++ b/include/linux/ftrace.h
> @@ -260,6 +260,13 @@ static inline void ftrace_kill(void) { }
> #endif /* CONFIG_FUNCTION_TRACER */
>
> #ifdef CONFIG_STACK_TRACER
> +/*
> + * the offset value to add to return address from save_stack_trace()
> + */
> +#ifndef FTRACE_STACK_FRAME_OFFSET
> +#define FTRACE_STACK_FRAME_OFFSET 0
> +#endif
> +
> extern int stack_tracer_enabled;
> int
> stack_trace_sysctl(struct ctl_table *table, int write,
> diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
> index 9384647..c5b9748 100644
> --- a/kernel/trace/trace_stack.c
> +++ b/kernel/trace/trace_stack.c
> @@ -105,7 +105,7 @@ check_stack(unsigned long ip, unsigned long *stack)
>
> /* Skip over the overhead of the stack tracer itself */
> for (i = 0; i < max_stack_trace.nr_entries; i++) {
> - if (stack_dump_trace[i] == ip)
> + if ((stack_dump_trace[i] + FTRACE_STACK_FRAME_OFFSET) == ip)
> break;
> }
>
> @@ -131,7 +131,8 @@ check_stack(unsigned long ip, unsigned long *stack)
> p = start;
>
> for (; p < top && i < max_stack_trace.nr_entries; p++) {
> - if (*p == stack_dump_trace[i]) {
> + if (*p == (stack_dump_trace[i]
> + + FTRACE_STACK_FRAME_OFFSET)) {
> stack_dump_trace[x] = stack_dump_trace[i++];
> this_size = stack_dump_index[x++] =
> (top - p) * sizeof(unsigned long);



\
 
 \ /
  Last update: 2015-07-16 04:01    [W:1.606 / U:0.000 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site