linux-kernel - [PATCH 07/20] x86/alternative: Remove operand numbering restrictions

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: <3a2c1e24ebc72d6c32294b094fc3fefd9c2afdc2.1741988314.git.jpoimboe@kernel.org>
Date: Fri, 14 Mar 2025 14:41:20 -0700
From: Josh Poimboeuf <jpoimboe@...nel.org>
To: x86@...nel.org
Cc: linux-kernel@...r.kernel.org,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Borislav Petkov <bp@...en8.de>,
	"H. Peter Anvin" <hpa@...or.com>,
	Uros Bizjak <ubizjak@...il.com>,
	Andrew Cooper <andrew.cooper3@...rix.com>,
	Ingo Molnar <mingo@...nel.org>
Subject: [PATCH 07/20] x86/alternative: Remove operand numbering restrictions

alternative_input() and alternative_io() arbitrarily require input
constraint operand numbering to start at index 1.  No more callers rely
on that.  Simplify the interfaces by removing that restriction.

Signed-off-by: Josh Poimboeuf <jpoimboe@...nel.org>
---
 arch/x86/include/asm/alternative.h | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 484dfea35aaa..3804b82cb03c 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -214,17 +214,15 @@ static inline int alternatives_text_reserved(void *start, void *end)
  *
  * Peculiarities:
  * No memory clobber here.
- * Argument numbers start with 1.
- * Leaving an unused argument 0 to keep API compatibility.
  */
 #define alternative_input(oldinstr, newinstr, ft_flags, input...)	\
 	asm_inline volatile(ALTERNATIVE(oldinstr, newinstr, ft_flags) \
-		: : "i" (0), ## input)
+		: : input)
 
 /* Like alternative_input, but with a single output argument */
 #define alternative_io(oldinstr, newinstr, ft_flags, output, input...)	\
 	asm_inline volatile(ALTERNATIVE(oldinstr, newinstr, ft_flags)	\
-		: output : "i" (0), ## input)
+		: output : input)
 
 /*
  * Like alternative_io, but for replacing a direct call with another one.
-- 
2.48.1