From 5416c2663517ebd0be0664c4d4ce3df0b116c059 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 17 Aug 2009 12:25:41 -0700 Subject: [PATCH 1/2] x86: make sure load_percpu_segment has no stackprotector load_percpu_segment() is used to set up the per-cpu segment registers, which are also used for -fstack-protector. Make sure that the load_percpu_segment() function doesn't have stackprotector enabled. [ Impact: allow percpu setup before calling stack-protected functions ] Signed-off-by: Jeremy Fitzhardinge --- arch/x86/kernel/cpu/Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index 4e242f9a06e4..8b5b9b625ede 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -7,6 +7,10 @@ ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_common.o = -pg endif +# Make sure load_percpu_segment has no stackprotector +nostackp := $(call cc-option, -fno-stack-protector) +CFLAGS_common.o := $(nostackp) + obj-y := intel_cacheinfo.o addon_cpuid_features.o obj-y += proc.o capflags.o powerflags.o common.o obj-y += vmware.o hypervisor.o From ce2eef33d35cd7b932492b5a81fb0febd2b323cd Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 17 Aug 2009 12:26:53 -0700 Subject: [PATCH 2/2] xen: rearrange things to fix stackprotector Make sure the stack-protector segment registers are properly set up before calling any functions which may have stack-protection compiled into them. [ Impact: prevent Xen early-boot crash when stack-protector is enabled ] Signed-off-by: Jeremy Fitzhardinge --- arch/x86/xen/Makefile | 4 ++++ arch/x86/xen/enlighten.c | 22 ++++++++++------------ 2 files changed, 14 insertions(+), 12 deletions(-) diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile index 3b767d03fd6a..a5b9288b7da4 100644 --- a/arch/x86/xen/Makefile +++ b/arch/x86/xen/Makefile @@ -5,6 +5,10 @@ CFLAGS_REMOVE_time.o = -pg CFLAGS_REMOVE_irq.o = -pg endif +# Make sure early boot has no stackprotector +nostackp := $(call cc-option, -fno-stack-protector) +CFLAGS_enlighten.o := $(nostackp) + obj-y := enlighten.o setup.o multicalls.o mmu.o irq.o \ time.o xen-asm.o xen-asm_$(BITS).o \ grant-table.o suspend.o diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index f09e8c36ee80..edcf72a3c29c 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -925,10 +925,6 @@ asmlinkage void __init xen_start_kernel(void) xen_domain_type = XEN_PV_DOMAIN; - BUG_ON(memcmp(xen_start_info->magic, "xen-3", 5) != 0); - - xen_setup_features(); - /* Install Xen paravirt ops */ pv_info = xen_info; pv_init_ops = xen_init_ops; @@ -937,8 +933,15 @@ asmlinkage void __init xen_start_kernel(void) pv_apic_ops = xen_apic_ops; pv_mmu_ops = xen_mmu_ops; - xen_init_irq_ops(); +#ifdef CONFIG_X86_64 + /* + * Setup percpu state. We only need to do this for 64-bit + * because 32-bit already has %fs set properly. + */ + load_percpu_segment(0); +#endif + xen_init_irq_ops(); xen_init_cpuid_mask(); #ifdef CONFIG_X86_LOCAL_APIC @@ -948,6 +951,8 @@ asmlinkage void __init xen_start_kernel(void) set_xen_basic_apic_ops(); #endif + xen_setup_features(); + if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) { pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start; pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit; @@ -955,13 +960,6 @@ asmlinkage void __init xen_start_kernel(void) machine_ops = xen_machine_ops; -#ifdef CONFIG_X86_64 - /* - * Setup percpu state. We only need to do this for 64-bit - * because 32-bit already has %fs set properly. - */ - load_percpu_segment(0); -#endif /* * The only reliable way to retain the initial address of the * percpu gdt_page is to remember it here, so we can go and