From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Anvin , =?UTF-8?q?Fernando=20Luis=20V=C3=A1zquez=20Cao?= , Linus Torvalds Subject: [ 07/21] x86: Fix bit corruption at CPU resume time Date: Wed, 22 May 2013 15:10:25 -0700 Message-Id: <20130522205233.510330591@linuxfoundation.org> In-Reply-To: <20130522205232.597066680@linuxfoundation.org> References: <20130522205232.597066680@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Linus Torvalds commit 5e427ec2d066b48a5c27b3a5a3315f7e4e729077 upstream. In commit 78d77df71510 ("x86-64, init: Do not set NX bits on non-NX capable hardware") we added the early_pmd_flags that gets the NX bit set when a CPU supports NX. However, the new variable was marked __initdata, because the main _use_ of this is in an __init routine. However, the bit setting happens from secondary_startup_64(), which is called not only at bootup, but on every secondary CPU start. Including resuming from STR and at CPU hotplug time. So the value cannot be __initdata. Reported-bisected-and-tested-by: Michal Hocko Acked-by: Peter Anvin Cc: Fernando Luis Vázquez Cao Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/head64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -34,7 +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); +pmdval_t 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)