Re: [PATCH 1/2] Compiler Attributes: naked was fixed in gcc 4.6

[Stefan Agner]

On 13.09.2018 16:59, Miguel Ojeda wrote:
> 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
> 
> Cc: Stefan Agner 
> Cc: Rasmus Villemoes 
> Cc: Eli Friedman 
> Cc: Christopher Li 
> Cc: Kees Cook 
> Cc: Ingo Molnar 
> Cc: Geert Uytterhoeven 
> Cc: Arnd Bergmann 
> Cc: Greg Kroah-Hartman 
> Cc: Masahiro Yamada 
> Cc: Joe Perches 
> Cc: Dominique Martinet 
> Cc: Linus Torvalds 
> Cc: linux-spa...@vger.kernel.org
> Reviewed-by: Luc Van Oostenryck 
> Reviewed-by: Nick Desaulniers 
> Signed-off-by: Miguel Ojeda 

Reviewed-by: Stefan Agner 

--
Stefan

> ---
>  include/linux/compiler-gcc.h | 8 +---
>  1 file changed, 1 insertion(+), 7 deletions(-)
> 
> diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
> index 763bbad1e258..25d3dd6b2702 100644
> --- a/include/linux/compiler-gcc.h
> +++ b/include/linux/compiler-gcc.h
> @@ -84,14 +84,8 @@
>   * 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.[56] 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
>  
>  #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), 
> __COUNTER__)

[PATCH 1/2] Compiler Attributes: naked was fixed in gcc 4.6

[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

Cc: Stefan Agner 
Cc: Rasmus Villemoes 
Cc: Eli Friedman 
Cc: Christopher Li 
Cc: Kees Cook 
Cc: Ingo Molnar 
Cc: Geert Uytterhoeven 
Cc: Arnd Bergmann 
Cc: Greg Kroah-Hartman 
Cc: Masahiro Yamada 
Cc: Joe Perches 
Cc: Dominique Martinet 
Cc: Linus Torvalds 
Cc: linux-spa...@vger.kernel.org
Reviewed-by: Luc Van Oostenryck 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Miguel Ojeda 
---
 include/linux/compiler-gcc.h | 8 +---
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 763bbad1e258..25d3dd6b2702 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -84,14 +84,8 @@
  * 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.[56] 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
 
 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
 
-- 
2.17.1