From: Ben Hutchings <ben@decadent.org.uk>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
Andres Salomon <dilinger@queued.net>,
Andy Lutomirski <luto@mit.edu>,
Arnaud Lacombe <lacombar@gmail.com>
Subject: [PATCH] x86-32: Fix alignment of alternative instruction entries
Date: Wed, 21 Sep 2011 05:45:13 +0100 [thread overview]
Message-ID: <1316580313.4122.21.camel@deadeye> (raw)
The altinstruction_entry macro was originally used only on x86-64,
and assumed 64-bit pointers and alignment.
Commit b4ca46e4e82a0a5976fe5eab85be585d75f8202f ("x86-32: Fix boot
with CONFIG_X86_INVD_BUG") introduced a use of the macro on x86-32.
Before this, the 64-bit pointers had been replaced by 32-bit offsets,
so it worked - in at least one case. However, the alignment is still
wrong for x86-32, which can result in zero-padding between entries and
a BUG in apply_alternatives.
Reported-by: Andres Salomon <dilinger@queued.net>
References: http://bugs.debian.org/640964
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/x86/include/asm/alternative-asm.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/x86/include/asm/alternative-asm.h b/arch/x86/include/asm/alternative-asm.h
index 4554cc6..d00dc2a 100644
--- a/arch/x86/include/asm/alternative-asm.h
+++ b/arch/x86/include/asm/alternative-asm.h
@@ -16,7 +16,7 @@
#endif
.macro altinstruction_entry orig alt feature orig_len alt_len
- .align 8
+ _ASM_ALIGN
.long \orig - .
.long \alt - .
.word \feature
--
1.7.5.4
next reply other threads:[~2011-09-21 4:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-21 4:45 Ben Hutchings [this message]
2011-09-21 10:06 ` [PATCH] x86-32: Fix alignment of alternative instruction entries Thomas Gleixner
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