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authorJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2009-09-21 16:34:06 -0400
committerJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2009-09-21 16:49:43 -0400
commitb75fe4e5b869f8dbebd36df64a7fcda0c5b318ed (patch)
treecba533110e8514184ddc63ab2ea37c38dc8a1861
parent79b520e87e1214cfa107bdc8528b5d6c055a8b82 (diff)
xen: check EFER for NX before setting up GDT mapping
x86-64 assumes NX is available by default, so we need to explicitly check for it before using NX. Some first-generation Intel x86-64 processors didn't support NX, and even recent systems allow it to be disabled in BIOS. [ Impact: prevent Xen crash on NX-less 64-bit machines ] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stable Kernel <stable@kernel.org>
-rw-r--r--arch/x86/mm/Makefile1
-rw-r--r--arch/x86/xen/enlighten.c10
2 files changed, 6 insertions, 5 deletions
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 9b5a9f59a478..dd313d035de7 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -4,6 +4,7 @@ obj-y := init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
4# Make sure __phys_addr has no stackprotector 4# Make sure __phys_addr has no stackprotector
5nostackp := $(call cc-option, -fno-stack-protector) 5nostackp := $(call cc-option, -fno-stack-protector)
6CFLAGS_physaddr.o := $(nostackp) 6CFLAGS_physaddr.o := $(nostackp)
7CFLAGS_init.o := $(nostackp)
7 8
8obj-$(CONFIG_SMP) += tlb.o 9obj-$(CONFIG_SMP) += tlb.o
9 10
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 0dd0c2c6cae0..5d701bf66a23 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1083,6 +1083,11 @@ asmlinkage void __init xen_start_kernel(void)
1083 1083
1084 __supported_pte_mask |= _PAGE_IOMAP; 1084 __supported_pte_mask |= _PAGE_IOMAP;
1085 1085
1086#ifdef CONFIG_X86_64
1087 /* Work out if we support NX */
1088 check_efer();
1089#endif
1090
1086 xen_setup_features(); 1091 xen_setup_features();
1087 1092
1088 /* Get mfn list */ 1093 /* Get mfn list */
@@ -1123,11 +1128,6 @@ asmlinkage void __init xen_start_kernel(void)
1123 1128
1124 pgd = (pgd_t *)xen_start_info->pt_base; 1129 pgd = (pgd_t *)xen_start_info->pt_base;
1125 1130
1126#ifdef CONFIG_X86_64
1127 /* Work out if we support NX */
1128 check_efer();
1129#endif
1130
1131 /* Don't do the full vcpu_info placement stuff until we have a 1131 /* Don't do the full vcpu_info placement stuff until we have a
1132 possible map and a non-dummy shared_info. */ 1132 possible map and a non-dummy shared_info. */
1133 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0]; 1133 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];