[tip: locking/core] locking/atomic/x86: Use ALT_OUTPUT_SP() for __arch_{,try_}cmpxchg64_emu()

["tip-bot2 for Uros Bizjak" <tip-bot2@linutronix.de>]

The following commit has been merged into the locking/core branch of tip:

Commit-ID:     25cf4fbb596d730476afcc0fb87a9d708db14078
Gitweb:        https://git.kernel.org/tip/25cf4fbb596d730476afcc0fb87a9d708db14078
Author:        Uros Bizjak <ubizjak@gmail.com>
AuthorDate:    Sun, 03 Nov 2024 17:09:32 +01:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Tue, 05 Nov 2024 12:55:34 +01:00

locking/atomic/x86: Use ALT_OUTPUT_SP() for __arch_{,try_}cmpxchg64_emu()

x86_32 __arch_{,try_}cmpxchg64_emu()() macros use CALL instruction
inside asm statement. Use ALT_OUTPUT_SP() macro to add required
dependence on %esp register.

Fixes: 79e1dd05d1a2 ("x86: Provide an alternative() based cmpxchg64()")
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20241103160954.3329-2-ubizjak@gmail.com
---
 arch/x86/include/asm/cmpxchg_32.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h
index 62cef21..fd1282a 100644
--- a/arch/x86/include/asm/cmpxchg_32.h
+++ b/arch/x86/include/asm/cmpxchg_32.h
@@ -94,7 +94,7 @@ static __always_inline bool __try_cmpxchg64_local(volatile u64 *ptr, u64 *oldp, 
 	asm volatile(ALTERNATIVE(_lock_loc				\
 				 "call cmpxchg8b_emu",			\
 				 _lock "cmpxchg8b %a[ptr]", X86_FEATURE_CX8) \
-		     : "+a" (o.low), "+d" (o.high)			\
+		     : ALT_OUTPUT_SP("+a" (o.low), "+d" (o.high))	\
 		     : "b" (n.low), "c" (n.high), [ptr] "S" (_ptr)	\
 		     : "memory");					\
 									\
@@ -123,8 +123,8 @@ static __always_inline u64 arch_cmpxchg64_local(volatile u64 *ptr, u64 old, u64 
 				 "call cmpxchg8b_emu",			\
 				 _lock "cmpxchg8b %a[ptr]", X86_FEATURE_CX8) \
 		     CC_SET(e)						\
-		     : CC_OUT(e) (ret),					\
-		       "+a" (o.low), "+d" (o.high)			\
+		     : ALT_OUTPUT_SP(CC_OUT(e) (ret),			\
+				     "+a" (o.low), "+d" (o.high))	\
 		     : "b" (n.low), "c" (n.high), [ptr] "S" (_ptr)	\
 		     : "memory");					\
 									\