[PATCH 2/3] x86/ptrace: Always inline v8086_mode() for instrumentation

From: Borislav Petkov
Date: Fri Feb 04 2022 - 03:30:34 EST


From: Borislav Petkov <bp@xxxxxxx>

Instrumentation glue like KASAN causes the following warning:

vmlinux.o: warning: objtool: mce_gather_info()+0x5f: call to v8086_mode.constprop.0() leaves .noinstr.text section

due to gcc creating a function call for that oneliner. Force-inline it
and even save some vmlinux bytes (.config is close to an allmodconfig):

text data bss dec hex filename
209431677 208257651 34411048 452100376 1af28118 vmlinux.before
209431519 208257615 34411048 452100182 1af28056 vmlinux.after

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
arch/x86/include/asm/ptrace.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 703663175a5a..4357e0f2cd5f 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -137,7 +137,7 @@ static __always_inline int user_mode(struct pt_regs *regs)
#endif
}

-static inline int v8086_mode(struct pt_regs *regs)
+static __always_inline int v8086_mode(struct pt_regs *regs)
{
#ifdef CONFIG_X86_32
return (regs->flags & X86_VM_MASK);
--
2.29.2