From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Uros Bizjak <ubizjak@gmail.com>, Ingo Molnar <mingo@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Sasha Levin <sashal@kernel.org>,
dennis@kernel.org, tj@kernel.org, cl@linux.com,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, x86@kernel.org, linux-mm@kvack.org
Subject: [PATCH AUTOSEL 6.14 357/642] x86/locking: Use ALT_OUTPUT_SP() for percpu_{,try_}cmpxchg{64,128}_op()
Date: Mon, 5 May 2025 18:09:33 -0400 [thread overview]
Message-ID: <20250505221419.2672473-357-sashal@kernel.org> (raw)
In-Reply-To: <20250505221419.2672473-1-sashal@kernel.org>
From: Uros Bizjak <ubizjak@gmail.com>
[ Upstream commit 4087e16b033140cf2ce509ec23503bddec818a16 ]
percpu_{,try_}cmpxchg{64,128}() macros use CALL instruction inside
asm statement in one of their alternatives. Use ALT_OUTPUT_SP()
macro to add required dependence on %esp register.
ALT_OUTPUT_SP() implements the above dependence by adding
ASM_CALL_CONSTRAINT to its arguments. This constraint should be used
for any inline asm which has a CALL instruction, otherwise the
compiler may schedule the asm before the frame pointer gets set up
by the containing function, causing objtool to print a "call without
frame pointer save/setup" warning.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250214150929.5780-1-ubizjak@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/include/asm/percpu.h | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index afb9099fba9fc..9c47da5b0a2a2 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -350,9 +350,9 @@ do { \
\
asm qual (ALTERNATIVE("call this_cpu_cmpxchg8b_emu", \
"cmpxchg8b " __percpu_arg([var]), X86_FEATURE_CX8) \
- : [var] "+m" (__my_cpu_var(_var)), \
- "+a" (old__.low), \
- "+d" (old__.high) \
+ : ALT_OUTPUT_SP([var] "+m" (__my_cpu_var(_var)), \
+ "+a" (old__.low), \
+ "+d" (old__.high)) \
: "b" (new__.low), \
"c" (new__.high), \
"S" (&(_var)) \
@@ -381,10 +381,10 @@ do { \
asm qual (ALTERNATIVE("call this_cpu_cmpxchg8b_emu", \
"cmpxchg8b " __percpu_arg([var]), X86_FEATURE_CX8) \
CC_SET(z) \
- : CC_OUT(z) (success), \
- [var] "+m" (__my_cpu_var(_var)), \
- "+a" (old__.low), \
- "+d" (old__.high) \
+ : ALT_OUTPUT_SP(CC_OUT(z) (success), \
+ [var] "+m" (__my_cpu_var(_var)), \
+ "+a" (old__.low), \
+ "+d" (old__.high)) \
: "b" (new__.low), \
"c" (new__.high), \
"S" (&(_var)) \
@@ -421,9 +421,9 @@ do { \
\
asm qual (ALTERNATIVE("call this_cpu_cmpxchg16b_emu", \
"cmpxchg16b " __percpu_arg([var]), X86_FEATURE_CX16) \
- : [var] "+m" (__my_cpu_var(_var)), \
- "+a" (old__.low), \
- "+d" (old__.high) \
+ : ALT_OUTPUT_SP([var] "+m" (__my_cpu_var(_var)), \
+ "+a" (old__.low), \
+ "+d" (old__.high)) \
: "b" (new__.low), \
"c" (new__.high), \
"S" (&(_var)) \
@@ -452,10 +452,10 @@ do { \
asm qual (ALTERNATIVE("call this_cpu_cmpxchg16b_emu", \
"cmpxchg16b " __percpu_arg([var]), X86_FEATURE_CX16) \
CC_SET(z) \
- : CC_OUT(z) (success), \
- [var] "+m" (__my_cpu_var(_var)), \
- "+a" (old__.low), \
- "+d" (old__.high) \
+ : ALT_OUTPUT_SP(CC_OUT(z) (success), \
+ [var] "+m" (__my_cpu_var(_var)), \
+ "+a" (old__.low), \
+ "+d" (old__.high)) \
: "b" (new__.low), \
"c" (new__.high), \
"S" (&(_var)) \
--
2.39.5
prev parent reply other threads:[~2025-05-05 22:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20250505221419.2672473-1-sashal@kernel.org>
2025-05-05 22:04 ` [PATCH AUTOSEL 6.14 083/642] x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-UAPI headers Sasha Levin
2025-05-05 22:05 ` [PATCH AUTOSEL 6.14 109/642] s390/tlb: Use mm_has_pgste() instead of mm_alloc_pgste() Sasha Levin
2025-05-05 22:09 ` Sasha Levin [this message]
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