Re: [PATCH v3 04/22] x86/doublefault: Make memmove() notrace/NOKPROBE

Steven Rostedt
2020-02-19T15:36:20Z

On Wed, 19 Feb 2020 15:47:28 +0100
Peter Zijlstra <peterz@infradead.org> wrote:

> --- a/arch/x86/lib/memcpy_32.c
> +++ b/arch/x86/lib/memcpy_32.c
> @@ -21,7 +21,7 @@ __visible void *memset(void *s, int c, s
> }
> EXPORT_SYMBOL(memset);
>
> -__visible void *memmove(void *dest, const void *src, size_t n)
> +__visible notrace void *memmove(void *dest, const void *src, size_t n)
> {
> int d0,d1,d2,d3,d4,d5;
> char *ret = dest;
> @@ -207,3 +207,8 @@ __visible void *memmove(void *dest, cons
>
> }
> EXPORT_SYMBOL(memmove);

Hmm, for things like this, which is adding notrace because of a single
instance of it (although it is fine to trace in any other instance), it
would be nice to have a gcc helper that could call "memmove+5" which
would skip the tracing portion.

-- Steve