From: Uros Bizjak Date: Thu, 4 Apr 2024 09:42:01 +0000 (+0200) Subject: x86/percpu: Fix x86_this_cpu_variable_test_bit() asm template X-Git-Tag: v6.10-rc1~198^2~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4c3677c077582f8665806def3f6dd35587793c69;p=thirdparty%2Fkernel%2Flinux.git x86/percpu: Fix x86_this_cpu_variable_test_bit() asm template Fix x86_this_cpu_variable_test_bit(), which is implemented with an incorrect asm template, where argument 2 (count argument) is considered a percpu variable. However, x86_this_cpu_test_bit() is currently used exclusively with constant bit number argument, so the called x86_this_cpu_variable_test_bit() function is never instantiated. The fix introduces named assembler operands to prevent this kind of error. Signed-off-by: Uros Bizjak Signed-off-by: Ingo Molnar Cc: Linus Torvalds Cc: "H. Peter Anvin" Link: https://lore.kernel.org/r/20240404094218.448963-1-ubizjak@gmail.com --- diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index 20696df5d5678..cbfbbe836ee23 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -586,10 +586,11 @@ static inline bool x86_this_cpu_variable_test_bit(int nr, { bool oldbit; - asm volatile("btl "__percpu_arg(2)",%1" + asm volatile("btl %[nr], " __percpu_arg([var]) CC_SET(c) : CC_OUT(c) (oldbit) - : "m" (*__my_cpu_ptr((unsigned long __percpu *)(addr))), "Ir" (nr)); + : [var] "m" (*__my_cpu_ptr((unsigned long __percpu *)(addr))), + [nr] "Ir" (nr)); return oldbit; }