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

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Message-Id: <1490046030-25862-1-git-send-email-tony.luck@intel.com>
Date:   Mon, 20 Mar 2017 14:40:30 -0700
From:   "Luck, Tony" <tony.luck@...el.com>
To:     Ingo Molnar <mingo@...nel.org>
Cc:     Tony Luck <tony.luck@...el.com>,
        LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH] x86/mce: Fix copy/paste error in exception table entries.

From: Tony Luck <tony.luck@...el.com>

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/

Cc: LKML <linux-kernel@...r.kernel.org>
Fixes: 92b0729c34cab ("x86/mm, x86/mce: Add memcpy_mcsafe()")
Signed-off-by: Tony Luck <tony.luck@...el.com>
---
 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 779782f58324..9a53a06e5a3e 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)
-- 
2.7.4