[tip: locking/core] x86/ptrace: Always inline v8086_mode() for instrumentation

[tip-bot2 for Borislav Petkov]

The following commit has been merged into the locking/core branch of tip:

Commit-ID:     b008893b08dcc8c30d756db05c229a1491bcb992
Gitweb:        https://git.kernel.org/tip/b008893b08dcc8c30d756db05c229a1491bcb992
Author:        Borislav Petkov <bp@xxxxxxx>
AuthorDate:    Fri, 04 Feb 2022 09:30:14 +01:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Sat, 12 Feb 2022 22:07:13 +01:00

x86/ptrace: Always inline v8086_mode() for instrumentation

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>
Acked-by: Marco Elver <elver@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220204083015.17317-3-bp@xxxxxxxxx
---
 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 7036631..4357e0f 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);