Re: [PATCH] stacktrace: Move documentation for arch_stack_walk_reliable() to header

[Miroslav Benes]

On Mon, 18 Jan 2021, Mark Brown wrote:

> Currently arch_stack_wallk_reliable() is documented with an identical
> comment in both x86 and S/390 implementations which is a bit redundant.
> Move this to the header and convert to kerneldoc while we're at it.

Makes sense.
 
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Cc: Jiri Kosina <jikos@xxxxxxxxxx>
> Cc: Miroslav Benes <mbenes@xxxxxxx>
> Cc: Petr Mladek <pmladek@xxxxxxxx>
> Cc: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
> Cc: x86@xxxxxxxxxx
> Cc: linux-s390@xxxxxxxxxxxxxxx
> Cc: live-patching@xxxxxxxxxxxxxxx
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>

Reviewed-by: Miroslav Benes <mbenes@xxxxxxx>

> diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c
> index 7f1266c24f6b..101477b3e263 100644
> --- a/arch/s390/kernel/stacktrace.c
> +++ b/arch/s390/kernel/stacktrace.c
> @@ -24,12 +24,6 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
>  	}
>  }
>  
> -/*
> - * This function returns an error if it detects any unreliable features of the
> - * stack.  Otherwise it guarantees that the stack trace is reliable.
> - *
> - * If the task is not 'current', the caller *must* ensure the task is inactive.
> - */
>  int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
>  			     void *cookie, struct task_struct *task)
>  {

Just a note. arch/powerpc/kernel/stacktrace.c has the same for 
__save_stack_trace_tsk_reliable(), but it would not be nice to pollute 
include/linux/stacktrace.h with that in my opinion. It is an old 
infrastructure after all.

Miroslav