linux-kernel - [PATCH v2 48/62] objtool: Make STACK_FRAME_NON

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5a0ab7bfd7a64f1051cd7719327fa1f111082b29.1746821544.git.jpoimboe@kernel.org>
Date: Fri,  9 May 2025 13:17:12 -0700
From: Josh Poimboeuf <jpoimboe@...nel.org>
To: x86@...nel.org
Cc: linux-kernel@...r.kernel.org,
	Petr Mladek <pmladek@...e.com>,
	Miroslav Benes <mbenes@...e.cz>,
	Joe Lawrence <joe.lawrence@...hat.com>,
	live-patching@...r.kernel.org,
	Song Liu <song@...nel.org>,
	laokz <laokz@...mail.com>,
	Jiri Kosina <jikos@...nel.org>,
	Marcos Paulo de Souza <mpdesouza@...e.com>,
	Weinan Liu <wnliu@...gle.com>,
	Fazla Mehrab <a.mehrab@...edance.com>,
	Chen Zhongjin <chenzhongjin@...wei.com>,
	Puranjay Mohan <puranjay@...nel.org>
Subject: [PATCH v2 48/62] objtool: Make STACK_FRAME_NON_STANDARD consistent

The C version of STACK_FRAME_NON_STANDARD differs from its asm
counterpart in that it creates eight-byte entries (vs four) and creates
a superfluous temporary variable.

Make the entry sizes consistent by converting the C version to four byte
entries.

Signed-off-by: Josh Poimboeuf <jpoimboe@...nel.org>
---
 include/linux/objtool.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index 483dd3131826..d4137a46ee70 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -33,9 +33,10 @@
  *
  * For more information, see tools/objtool/Documentation/objtool.txt.
  */
-#define STACK_FRAME_NON_STANDARD(func) \
-	static void __used __section(".discard.func_stack_frame_non_standard") \
-		*__func_stack_frame_non_standard_##func = func
+#define STACK_FRAME_NON_STANDARD(func)						\
+	asm(".pushsection .discard.func_stack_frame_non_standard, \"aw\"\n\t"	\
+	    ".long " __stringify(func) " - .\n\t"				\
+	    ".popsection")
 
 /*
  * STACK_FRAME_NON_STANDARD_FP() is a frame-pointer-specific function ignore
-- 
2.49.0