3.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: "H. Peter Anvin" <[email protected]> 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 <[email protected]> Signed-off-by: H. Peter Anvin <[email protected]> Link: http://lkml.kernel.org/r/1367476850.5660.2.camel@nexus Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/kernel/head64.c | 3 ++- arch/x86/kernel/head_64.S | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) --- 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; --- 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 */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
