x86/hweight: Use ASM_CALL_CONSTRAINT in inline asm()
authorUros Bizjak <ubizjak@gmail.com>
Wed, 12 Mar 2025 12:38:44 +0000 (13:38 +0100)
committerIngo Molnar <mingo@kernel.org>
Wed, 19 Mar 2025 10:26:58 +0000 (11:26 +0100)
commit194a613088a8c9dae300dfb08433287cee803e8d
treef1fa848ace9e1d891c6140d0f73c0aef30d42d18
parent72899899e4f9de0b545218e66bf14cfa2579f2f8
x86/hweight: Use ASM_CALL_CONSTRAINT in inline asm()

Use ASM_CALL_CONSTRAINT to prevent inline asm() that includes call
instruction from being scheduled before the frame pointer gets set
up by the containing function. This unconstrained scheduling might
cause objtool to print a "call without frame pointer save/setup"
warning. Current versions of compilers don't seem to trigger this
condition, but without this constraint there's nothing to prevent
the compiler from scheduling the insn in front of frame creation.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250312123905.149298-2-ubizjak@gmail.com
arch/x86/include/asm/arch_hweight.h