aboutsummaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorH. Peter Anvin <hpa@linux.intel.com>2013-05-02 10:33:46 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-07 20:33:14 -0700
commitb10a905466923f7b937d3f85237095afc2a7f6bf (patch)
tree9539f2dee699e9a9ebddd89a47d26e723395cdc2 /arch
parent851b7ca2a2426f509736448407c641c5054147d4 (diff)
downloadvexpress-lsk-b10a905466923f7b937d3f85237095afc2a7f6bf.tar.gz
x86-64, init: Do not set NX bits on non-NX capable hardware
commit 78d77df71510a96e042de7ba6dbd7998103642cb upstream. 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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/head64.c3
-rw-r--r--arch/x86/kernel/head_64.S1
2 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index c5e403f6d86..1c68ccb50df 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -34,6 +34,7 @@
extern pgd_t early_level4_pgt[PTRS_PER_PGD];
extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
static unsigned int __initdata next_early_pgt = 2;
+pmdval_t __initdata early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
/* Wipe all early page tables except for the kernel symbol map */
static void __init reset_early_page_tables(void)
@@ -99,7 +100,7 @@ again:
pmd_p[i] = 0;
*pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
}
- pmd = (physaddr & PMD_MASK) + (__PAGE_KERNEL_LARGE & ~_PAGE_GLOBAL);
+ pmd = (physaddr & PMD_MASK) + early_pmd_flags;
pmd_p[pmd_index(address)] = pmd;
return 0;
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 */