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

diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h
index 62cef2113ca749ad933ee312b637a5b3f6fb4f76..fd1282a783ddbff9ba9fa77d7cb9c2351865020c 100644 (file)
--- 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");                                       \
                                                                        \