[PATCH RESEND 1/2] locking/atomic/x86: Use ALT_OUTPUT_SP() for __alternative_atomic64()

From: Uros Bizjak
Date: Sun Nov 03 2024 - 11:10:13 EST


CONFIG_X86_CMPXCHG64 variant of x86_32 __alternative_atomic64()
macro uses CALL instruction inside asm statement. Use
ALT_OUTPUT_SP() macro to add required dependence on %esp register.

Fixes: 819165fb34b9 ("x86: Adjust asm constraints in atomic64 wrappers")
Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Jan Beulich <JBeulich@xxxxxxxx>
---
arch/x86/include/asm/atomic64_32.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/atomic64_32.h b/arch/x86/include/asm/atomic64_32.h
index 1f650b4dde50..6c6e9b9f98a4 100644
--- a/arch/x86/include/asm/atomic64_32.h
+++ b/arch/x86/include/asm/atomic64_32.h
@@ -51,7 +51,8 @@ static __always_inline s64 arch_atomic64_read_nonatomic(const atomic64_t *v)
#ifdef CONFIG_X86_CMPXCHG64
#define __alternative_atomic64(f, g, out, in...) \
asm volatile("call %c[func]" \
- : out : [func] "i" (atomic64_##g##_cx8), ## in)
+ : ALT_OUTPUT_SP(out) \
+ : [func] "i" (atomic64_##g##_cx8), ## in)

#define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8)
#else
--
2.42.0