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From: Borislav Petkov <bp@alien8.de>
To: Tony Luck <tony.luck@intel.com>
Cc: Jakub Kicinski <kuba@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Marco Elver <elver@google.com>, X86 ML <x86@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 2/3] x86/ptrace: Always inline v8086_mode() for instrumentation
Date: Fri,  4 Feb 2022 09:30:14 +0100	[thread overview]
Message-ID: <20220204083015.17317-3-bp@alien8.de> (raw)
In-Reply-To: <20220204083015.17317-1-bp@alien8.de>

From: Borislav Petkov <bp@suse.de>

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@suse.de>
---
 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


  parent reply	other threads:[~2022-02-04  8:30 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-04  8:30 [PATCH 0/3] x86/mce: Fix more noinstr fun Borislav Petkov
2022-02-04  8:30 ` [PATCH 1/3] cpumask: Add a x86-specific cpumask_clear_cpu() helper Borislav Petkov
2022-02-04 16:46   ` Luck, Tony
2022-02-04 18:04     ` Borislav Petkov
2022-02-13 10:59   ` [tip: locking/core] " tip-bot2 for Borislav Petkov
2022-02-04  8:30 ` Borislav Petkov [this message]
2022-02-13 10:59   ` [tip: locking/core] x86/ptrace: Always inline v8086_mode() for instrumentation tip-bot2 for Borislav Petkov
2022-02-04  8:30 ` [PATCH 3/3] x86/mce: Use arch atomic and bit helpers Borislav Petkov
2022-02-14 10:03   ` [tip: ras/core] " tip-bot2 for Borislav Petkov
2022-02-04 11:24 ` [PATCH 0/3] x86/mce: Fix more noinstr fun Marco Elver
2022-02-04 14:48   ` Borislav Petkov

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