Messages in this thread | | | Date | Mon, 3 Oct 2022 12:38:59 +0100 | From | Mark Rutland <> | Subject | Re: [PATCH V6 04/11] compiler_types.h: Add __noinstr_section() for noinstr |
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On Sat, Oct 01, 2022 at 09:24:44PM -0400, guoren@kernel.org wrote: > From: Lai Jiangshan <laijs@linux.alibaba.com> > > And it will be extended for C entry code. > > Cc: Borislav Petkov <bp@alien8.de> > Reviewed-by: Miguel Ojeda <ojeda@kernel.org> > Reviewed-by: Kees Cook <keescook@chromium.org> > Suggested-by: Nick Desaulniers <ndesaulniers@google.com> > Suggested-by: Peter Zijlstra <peterz@infradead.org> > Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> > --- > include/linux/compiler_types.h | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h > index 4f2a819fd60a..e9ce11ea4d8b 100644 > --- a/include/linux/compiler_types.h > +++ b/include/linux/compiler_types.h > @@ -227,9 +227,11 @@ struct ftrace_likely_data { > #endif > > /* Section for code which can't be instrumented at all */ > -#define noinstr \ > - noinline notrace __attribute((__section__(".noinstr.text"))) \ > - __no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage > +#define __noinstr_section(section) \ > + noinline notrace __section(section) __no_profile \ > + __no_kcsan __no_sanitize_address __no_sanitize_coverage > + > +#define noinstr __noinstr_section(".noinstr.text")
One thing proably worth noting here is that while KPROBES will avoid instrumenting `.noinstr.text`, that won't happen automatically for other __noinstr_section() sections, and that will need to be inhibited through other means (e.g. the kprobes blacklist, explicit NOKPROBE_SYMBOL() annotation, or otherwise).
Thanks, Mark.
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