Messages in this thread Patch in this message | | | Date | Wed, 19 Aug 2009 17:29:17 -0700 | From | Jeremy Fitzhardinge <> | Subject | [GIT PULL] Fix Xen boot with CONFIG_CC_STACKPROTECTOR |
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Hi Ingo,
Here's a couple of little changes which prevents an early boot crash under Xen, due to the stackprotector preamble using segment registers before they're set up. I only need to disable stackprotector for a handful of functions, but unfortunately it looks like it can only be disabled on a per-file basis.
Thanks, J
The following changes since commit 64f1607ffbbc772685733ea63e6f7f4183df1b16: Linus Torvalds (1): Linux 2.6.31-rc6
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git bugfix
Jeremy Fitzhardinge (2): x86: make sure load_percpu_segment has no stackprotector xen: rearrange things to fix stackprotector
arch/x86/kernel/cpu/Makefile | 4 ++++ arch/x86/xen/Makefile | 4 ++++ arch/x86/xen/enlighten.c | 22 ++++++++++------------ 3 files changed, 18 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index 4e242f9..8b5b9b6 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 diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile index 3b767d0..a5b9288 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 f09e8c3..edcf72a 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
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