Re: [PATCH 5/7] Compiler Attributes: naked was fixed in gcc 4.6
From: Arnd Bergmann
Date: Fri Aug 31 2018 - 15:48:31 EST
On Fri, Aug 31, 2018 at 7:05 PM Miguel Ojeda
> Commit 9c695203a7dd ("compiler-gcc.h: gcc-4.5 needs noclone
> and noinline on __naked functions") added noinline and noclone
> as a workaround for a gcc 4.5 bug, which was resolved in 4.6.0.
> Since now the minimum gcc supported version is 4.6,
> we can clean it up.
> See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44290
> and https://godbolt.org/z/h6NMIL
> diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
> index 66e1eb8822d9..fdf2fbe6d544 100644
> --- a/include/linux/compiler-gcc.h
> +++ b/include/linux/compiler-gcc.h
> @@ -77,14 +77,8 @@
> * to trace naked functions because then mcount is called without
> * stack and frame pointer being set up and there is no chance to
> * restore the lr register to the value before mcount was called.
> - *
> - * The asm() bodies of naked functions often depend on standard calling
> - * conventions, therefore they must be noinline and noclone.
> - *
> - * GCC 4. currently fail to enforce this, so we must do so ourselves.
> - * See GCC PR44290.
> -#define __naked __attribute__((naked)) noinline __noclone notrace
> +#define __naked __attribute__((naked)) notrace
Good catch. Can this be moved into linux/compiler.h now so we
don't need separate definitions for clang and gcc?