diff mbox series

[RFC,v4,12/18] arm64: assembler: Add macro to annotate asm function having non standard stack-frame.

Message ID 20190816122403.14994-13-raphael.gault@arm.com (mailing list archive)
State New, archived
Headers show
Series objtool: Add support for arm64 | expand

Commit Message

Raphael Gault Aug. 16, 2019, 12:23 p.m. UTC
Some functions don't have standard stack-frames but are intended
this way. In order for objtool to ignore those particular cases
we add a macro that enables us to annotate the cases we chose
to mark as particular.

Signed-off-by: Raphael Gault <raphael.gault@arm.com>
---
 include/linux/frame.h | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

Comments

Josh Poimboeuf Aug. 22, 2019, 8:10 p.m. UTC | #1
On Fri, Aug 16, 2019 at 01:23:57PM +0100, Raphael Gault wrote:
> Some functions don't have standard stack-frames but are intended
> this way. In order for objtool to ignore those particular cases
> we add a macro that enables us to annotate the cases we chose
> to mark as particular.
> 
> Signed-off-by: Raphael Gault <raphael.gault@arm.com>
> ---
>  include/linux/frame.h | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/frame.h b/include/linux/frame.h
> index 02d3ca2d9598..1e35e58ab259 100644
> --- a/include/linux/frame.h
> +++ b/include/linux/frame.h
> @@ -11,14 +11,31 @@
>   *
>   * For more information, see tools/objtool/Documentation/stack-validation.txt.
>   */
> +#ifndef __ASSEMBLY__
>  #define STACK_FRAME_NON_STANDARD(func) \
>  	static void __used __section(.discard.func_stack_frame_non_standard) \
>  		*__func_stack_frame_non_standard_##func = func
> +#else
> +	/*
> +	 * This macro is the arm64 assembler equivalent of the
> +	 * macro STACK_FRAME_NON_STANDARD define at
> +	 * ~/include/linux/frame.h
> +	 */

This comment is a bit confusing as it's referring to its own header
file.  And it's not arm64-specific.  I don't think we really need a
comment here anyway.

> +	.macro	asm_stack_frame_non_standard	func
> +	.pushsection ".discard.func_stack_frame_non_standard"
> +	.quad	\func
> +	.popsection
> +	.endm

Can you call it STACK_FRAME_NON_STANDARD for consistency with the
non-asm version?
diff mbox series

Patch

diff --git a/include/linux/frame.h b/include/linux/frame.h
index 02d3ca2d9598..1e35e58ab259 100644
--- a/include/linux/frame.h
+++ b/include/linux/frame.h
@@ -11,14 +11,31 @@ 
  *
  * For more information, see tools/objtool/Documentation/stack-validation.txt.
  */
+#ifndef __ASSEMBLY__
 #define STACK_FRAME_NON_STANDARD(func) \
 	static void __used __section(.discard.func_stack_frame_non_standard) \
 		*__func_stack_frame_non_standard_##func = func
+#else
+	/*
+	 * This macro is the arm64 assembler equivalent of the
+	 * macro STACK_FRAME_NON_STANDARD define at
+	 * ~/include/linux/frame.h
+	 */
+	.macro	asm_stack_frame_non_standard	func
+	.pushsection ".discard.func_stack_frame_non_standard"
+	.quad	\func
+	.popsection
+	.endm
 
+#endif /* __ASSEMBLY__ */
 #else /* !CONFIG_STACK_VALIDATION */
 
+#ifndef __ASSEMBLY__
 #define STACK_FRAME_NON_STANDARD(func)
-
+#else
+	.macro	asm_stack_frame_non_standard	func
+	.endm
+#endif /* __ASSEMBLY__ */
 #endif /* CONFIG_STACK_VALIDATION */
 
 #endif /* _LINUX_FRAME_H */