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authorH. Peter Anvin <hpa@linux.intel.com>2013-05-02 10:33:46 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2013-05-02 11:27:35 -0700
commit78d77df71510a96e042de7ba6dbd7998103642cb (patch)
tree9b948900c1493a5f1711b59235db842bc40adfb1 /arch/x86/kernel/head_64.S
parentcc456c4e7cac3837a86aaa7ca3cb9f488d44d196 (diff)
x86-64, init: Do not set NX bits on non-NX capable hardware
During early init, we would incorrectly set the NX bit even if the NX feature was not supported. Instead, only set this bit if NX is actually available and enabled. We already do very early detection of the NX bit to enable it in EFER, this simply extends this detection to the early page table mask. Reported-by: Fernando Luis Vázquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1367476850.5660.2.camel@nexus Cc: <stable@vger.kernel.org> v3.9
Diffstat (limited to 'arch/x86/kernel/head_64.S')
-rw-r--r--arch/x86/kernel/head_64.S1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 6859e9626442..08f7e8039099 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -200,6 +200,7 @@ ENTRY(secondary_startup_64)
btl $20,%edi /* No Execute supported? */
jnc 1f
btsl $_EFER_NX, %eax
+ btsq $_PAGE_BIT_NX,early_pmd_flags(%rip)
1: wrmsr /* Make changes effective */
/* Setup cr0 */