linux-kernel - [PATCH -tip] x86/asm: Use %a instead of %c(%%rip) in rip_rel

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-next>] [day] [month] [year] [list]

Message-ID: <20250504184342.125253-1-ubizjak@gmail.com>
Date: Sun,  4 May 2025 20:43:23 +0200
From: Uros Bizjak <ubizjak@...il.com>
To: x86@...nel.org,
	linux-kernel@...r.kernel.org
Cc: Uros Bizjak <ubizjak@...il.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...nel.org>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Ard Biesheuvel <ardb@...nel.org>
Subject: [PATCH -tip] x86/asm: Use %a instead of %c(%%rip) in rip_rel_ptr()

The "a" asm operand modifier substitutes a memory reference, with the
actual operand treated as address.  For x86_64, when a symbol is
provided, the "a" modifier emits "sym(%rip)" instead of "sym".

No functional changes intended.

Signed-off-by: Uros Bizjak <ubizjak@...il.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: "H. Peter Anvin" <hpa@...or.com>
Cc: Ard Biesheuvel <ardb@...nel.org>
---
 arch/x86/include/asm/asm.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index f963848024a5..d7610b99b8d8 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -116,7 +116,7 @@
 #ifndef __ASSEMBLER__
 static __always_inline __pure void *rip_rel_ptr(void *p)
 {
-	asm("leaq %c1(%%rip), %0" : "=r"(p) : "i"(p));
+	asm("leaq %a1, %0" : "=r"(p) : "i"(p));
 
 	return p;
 }
-- 
2.49.0