[RFC v5 47/57] arm64: assembler: Add macro to annotate asm function having non standard stack-frame.

Julien Thierry jthierry at redhat.com
Thu Jan 9 08:02:50 PST 2020


From: Raphael Gault <raphael.gault at arm.com>

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 at arm.com>
Signed-off-by: Julien Thierry <jthierry at redhat.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
+	 */
+	.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 */
--
2.21.0




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