diff options
| author | H. Peter Anvin <hpa@linux.intel.com> | 2013-05-02 10:33:46 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-05-02 11:27:35 -0700 |
| commit | 78d77df71510a96e042de7ba6dbd7998103642cb (patch) | |
| tree | 9b948900c1493a5f1711b59235db842bc40adfb1 /arch/x86/kernel/head_64.S | |
| parent | cc456c4e7cac3837a86aaa7ca3cb9f488d44d196 (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.S | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 6859e962644..08f7e803909 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 */ |