linux-kernel - [tip:x86/urgent] x86/mce: Fix copy/paste error in exception table entries

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Message-ID: <tip-26a37ab319a26d330bab298770d692bb9c852aff@git.kernel.org>
Date:   Wed, 22 Mar 2017 02:10:51 -0700
From:   tip-bot for Tony Luck <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     torvalds@...ux-foundation.org, bp@...en8.de, mingo@...nel.org,
        hpa@...or.com, luto@...nel.org, brgerst@...il.com,
        peterz@...radead.org, tglx@...utronix.de, dvlasenk@...hat.com,
        stable@...r.kernel.org, jpoimboe@...hat.com, tony.luck@...el.com,
        linux-kernel@...r.kernel.org
Subject: [tip:x86/urgent] x86/mce: Fix copy/paste error in exception table
 entries

Commit-ID:  26a37ab319a26d330bab298770d692bb9c852aff
Gitweb:     http://git.kernel.org/tip/26a37ab319a26d330bab298770d692bb9c852aff
Author:     Tony Luck <tony.luck@...el.com>
AuthorDate: Mon, 20 Mar 2017 14:40:30 -0700
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Wed, 22 Mar 2017 08:43:25 +0100

x86/mce: Fix copy/paste error in exception table entries

Back in commit:

  92b0729c34cab ("x86/mm, x86/mce: Add memcpy_mcsafe()")

... I made a copy/paste error setting up the exception table entries
and ended up with two for label .L_cache_w3 and none for .L_cache_w2.

This means that if we take a machine check on:

  .L_cache_w2: movq 2*8(%rsi), %r10

then we don't have an exception table entry for this instruction
and we can't recover.

Fix: s/3/2/

Signed-off-by: Tony Luck <tony.luck@...el.com>
Cc: <stable@...r.kernel.org>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Brian Gerst <brgerst@...il.com>
Cc: Denys Vlasenko <dvlasenk@...hat.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Josh Poimboeuf <jpoimboe@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Fixes: 92b0729c34cab ("x86/mm, x86/mce: Add memcpy_mcsafe()")
Link: http://lkml.kernel.org/r/1490046030-25862-1-git-send-email-tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/lib/memcpy_64.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index 779782f..9a53a06 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -290,7 +290,7 @@ EXPORT_SYMBOL_GPL(memcpy_mcsafe_unrolled)
 	_ASM_EXTABLE_FAULT(.L_copy_leading_bytes, .L_memcpy_mcsafe_fail)
 	_ASM_EXTABLE_FAULT(.L_cache_w0, .L_memcpy_mcsafe_fail)
 	_ASM_EXTABLE_FAULT(.L_cache_w1, .L_memcpy_mcsafe_fail)
-	_ASM_EXTABLE_FAULT(.L_cache_w3, .L_memcpy_mcsafe_fail)
+	_ASM_EXTABLE_FAULT(.L_cache_w2, .L_memcpy_mcsafe_fail)
 	_ASM_EXTABLE_FAULT(.L_cache_w3, .L_memcpy_mcsafe_fail)
 	_ASM_EXTABLE_FAULT(.L_cache_w4, .L_memcpy_mcsafe_fail)
 	_ASM_EXTABLE_FAULT(.L_cache_w5, .L_memcpy_mcsafe_fail)