This is a note to let you know that I've just added the patch titled
x86, smap: Don't enable SMAP if CONFIG_X86_SMAP is disabled
to the 3.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-smap-don-t-enable-smap-if-config_x86_smap-is-disabled.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 03bbd596ac04fef47ce93a730b8f086d797c3021 Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa@xxxxxxxxxxxxxxx>
Date: Thu, 13 Feb 2014 07:34:30 -0800
Subject: x86, smap: Don't enable SMAP if CONFIG_X86_SMAP is disabled
From: "H. Peter Anvin" <hpa@xxxxxxxxxxxxxxx>
commit 03bbd596ac04fef47ce93a730b8f086d797c3021 upstream.
If SMAP support is not compiled into the kernel, don't enable SMAP in
CR4 -- in fact, we should clear it, because the kernel doesn't contain
the proper STAC/CLAC instructions for SMAP support.
Found by Fengguang Wu's test system.
Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20140213124550.GA30497@localhost
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/common.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -284,8 +284,13 @@ static __always_inline void setup_smap(s
raw_local_save_flags(eflags);
BUG_ON(eflags & X86_EFLAGS_AC);
- if (cpu_has(c, X86_FEATURE_SMAP))
+ if (cpu_has(c, X86_FEATURE_SMAP)) {
+#ifdef CONFIG_X86_SMAP
set_in_cr4(X86_CR4_SMAP);
+#else
+ clear_in_cr4(X86_CR4_SMAP);
+#endif
+ }
}
/*
Patches currently in stable-queue which might be from hpa@xxxxxxxxxxxxxxx are
queue-3.12/x86-smap-smap_violation-is-bogus-if-config_x86_smap-is-off.patch
queue-3.12/x86-smap-don-t-enable-smap-if-config_x86_smap-is-disabled.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html