linux-kernel - [tip: x86/mm] x86/idle: Standardize argument types for MONITOR{,X} and MWAIT{,X} instruction wrappers on 'u32'

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: <174362663333.14745.17539175188705861090.tip-bot2@tip-bot2>
Date: Wed, 02 Apr 2025 20:43:53 -0000
From: "tip-bot2 for Uros Bizjak" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Uros Bizjak <ubizjak@...il.com>, Ingo Molnar <mingo@...nel.org>,
 Andy Lutomirski <luto@...nel.org>, Brian Gerst <brgerst@...il.com>,
 Juergen Gross <jgross@...e.com>, Andrew Cooper <andrew.cooper3@...rix.com>,
 Rik van Riel <riel@...riel.com>, "H. Peter Anvin" <hpa@...or.com>,
 Peter Zijlstra <peterz@...radead.org>,
 "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
 Linus Torvalds <torvalds@...ux-foundation.org>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: x86/mm] x86/idle: Standardize argument types for MONITOR{,X}
 and MWAIT{,X} instruction wrappers on 'u32'

The following commit has been merged into the x86/mm branch of tip:

Commit-ID:     1ae899e413105aa81068d0282ab6e22974891d74
Gitweb:        https://git.kernel.org/tip/1ae899e413105aa81068d0282ab6e22974891d74
Author:        Uros Bizjak <ubizjak@...il.com>
AuthorDate:    Wed, 02 Apr 2025 20:08:05 +02:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Wed, 02 Apr 2025 22:26:17 +02:00

x86/idle: Standardize argument types for MONITOR{,X} and MWAIT{,X} instruction wrappers on 'u32'

MONITOR and MONITORX expect 32-bit unsigned integer arguments in the %ecx
and %edx registers. MWAIT and MWAITX expect 32-bit usigned int
argument in %eax and %ecx registers.

Some of the helpers around these instructions in <asm/mwait.h> are using
too wide types (long), standardize on u32 instead that makes it clear that
this is a hardware ABI.

[ mingo: Cleaned up the changelog. ]

Signed-off-by: Uros Bizjak <ubizjak@...il.com>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Brian Gerst <brgerst@...il.com>
Cc: Juergen Gross <jgross@...e.com>
Cc: Andrew Cooper <andrew.cooper3@...rix.com>
Cc: Rik van Riel <riel@...riel.com>
Cc: "H. Peter Anvin" <hpa@...or.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Link: https://lore.kernel.org/r/20250402180827.3762-1-ubizjak@gmail.com
---
 arch/x86/include/asm/mwait.h | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/mwait.h b/arch/x86/include/asm/mwait.h
index 54dc313..3377869 100644
--- a/arch/x86/include/asm/mwait.h
+++ b/arch/x86/include/asm/mwait.h
@@ -25,23 +25,21 @@
 #define TPAUSE_C01_STATE		1
 #define TPAUSE_C02_STATE		0
 
-static __always_inline void __monitor(const void *eax, unsigned long ecx,
-			     unsigned long edx)
+static __always_inline void __monitor(const void *eax, u32 ecx, u32 edx)
 {
 	/* "monitor %eax, %ecx, %edx;" */
 	asm volatile(".byte 0x0f, 0x01, 0xc8;"
 		     :: "a" (eax), "c" (ecx), "d"(edx));
 }
 
-static __always_inline void __monitorx(const void *eax, unsigned long ecx,
-			      unsigned long edx)
+static __always_inline void __monitorx(const void *eax, u32 ecx, u32 edx)
 {
 	/* "monitorx %eax, %ecx, %edx;" */
 	asm volatile(".byte 0x0f, 0x01, 0xfa;"
 		     :: "a" (eax), "c" (ecx), "d"(edx));
 }
 
-static __always_inline void __mwait(unsigned long eax, unsigned long ecx)
+static __always_inline void __mwait(u32 eax, u32 ecx)
 {
 	mds_idle_clear_cpu_buffers();
 
@@ -76,8 +74,7 @@ static __always_inline void __mwait(unsigned long eax, unsigned long ecx)
  * EAX                     (logical) address to monitor
  * ECX                     #GP if not zero
  */
-static __always_inline void __mwaitx(unsigned long eax, unsigned long ebx,
-				     unsigned long ecx)
+static __always_inline void __mwaitx(u32 eax, u32 ebx, u32 ecx)
 {
 	/* No MDS buffer clear as this is AMD/HYGON only */
 
@@ -95,7 +92,7 @@ static __always_inline void __mwaitx(unsigned long eax, unsigned long ebx,
  * executing mwait, it would otherwise go unnoticed and the next tick
  * would not be reprogrammed accordingly before mwait ever wakes up.
  */
-static __always_inline void __sti_mwait(unsigned long eax, unsigned long ecx)
+static __always_inline void __sti_mwait(u32 eax, u32 ecx)
 {
 	mds_idle_clear_cpu_buffers();
 	/* "mwait %eax, %ecx;" */