[PATCH] Fix jump label with RO/NX module protection

From: matthieu castet
Date: Sun Jan 23 2011 - 09:46:12 EST


I think it should be applied before 2.6.38 release, because without
this patch there can be crash if RO/NX module protection and jump label are enabled.
>From 0eeba453aaba0ebff86f0a7ad9bfb8afbde0c0dc Mon Sep 17 00:00:00 2001
From: Matthieu CASTET <castet.matthieu@xxxxxxx>
Date: Thu, 20 Jan 2011 21:25:03 +0100
Subject: [PATCH] Fix jump table in module init section

If we use jump table in module init, there are marked
as removed in __jump_table section after init is done.

But we already applied ro permissions on the module, so
we can't modify a read only section (crash in
remove_jump_label_module_init).

Make the __jump_table section rw.

Signed-off-by: Matthieu CASTET <castet.matthieu@xxxxxxx>
---
arch/x86/include/asm/jump_label.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h
index f52d42e..574dbc2 100644
--- a/arch/x86/include/asm/jump_label.h
+++ b/arch/x86/include/asm/jump_label.h
@@ -14,7 +14,7 @@
do { \
asm goto("1:" \
JUMP_LABEL_INITIAL_NOP \
- ".pushsection __jump_table, \"a\" \n\t"\
+ ".pushsection __jump_table, \"aw\" \n\t"\
_ASM_PTR "1b, %l[" #label "], %c0 \n\t" \
".popsection \n\t" \
: : "i" (key) : : label); \
--
1.7.2.3