diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2025-02-14 16:07:46 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-02-21 15:56:08 +0100 |
| commit | 4087e16b033140cf2ce509ec23503bddec818a16 (patch) | |
| tree | 8152aa082d17a37c6f47575870f871b9c41cdcfb | |
| parent | 0ad2507d5d93f39619fc42372c347d6006b64319 (diff) | |
x86/locking: Use ALT_OUTPUT_SP() for percpu_{,try_}cmpxchg{64,128}_op()
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
| -rw-r--r-- | arch/x86/include/asm/percpu.h | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index e525cd85f999..0ab991fba7de 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)) \ |