diff options
| author | Ondrej Zary <linux@rainbow-software.org> | 2009-08-11 20:00:11 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-12 11:49:41 +0200 |
| commit | e8055139d996e85722984968472868d6dccb1490 (patch) | |
| tree | daf1dcd35c814da2c282a3f31ab683fb79ba4bb9 /arch/x86 | |
| parent | x86: Clear incorrectly forced X86_FEATURE_LAHF_LM flag (diff) | |
| download | linux-e8055139d996e85722984968472868d6dccb1490.tar.xz linux-e8055139d996e85722984968472868d6dccb1490.zip | |
x86: Fix oops in identify_cpu() on CPUs without CPUID
Kernel is broken for x86 CPUs without CPUID since 2.6.28. It
crashes with NULL pointer dereference in identify_cpu():
766 generic_identify(c);
767
768--> if (this_cpu->c_identify)
769 this_cpu->c_identify(c);
this_cpu is NULL. This is because it's only initialized in
get_cpu_vendor() function, which is not called if the CPU has
no CPUID instruction.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
LKML-Reference: <200908112000.15993.linux@rainbow-software.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 48 |
1 files changed, 24 insertions, 24 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index f1961c07af9a..5ce60a88027b 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -59,7 +59,30 @@ void __init setup_cpu_local_masks(void) alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask); } -static const struct cpu_dev *this_cpu __cpuinitdata; +static void __cpuinit default_init(struct cpuinfo_x86 *c) +{ +#ifdef CONFIG_X86_64 + display_cacheinfo(c); +#else + /* Not much we can do here... */ + /* Check if at least it has cpuid */ + if (c->cpuid_level == -1) { + /* No cpuid. It must be an ancient CPU */ + if (c->x86 == 4) + strcpy(c->x86_model_id, "486"); + else if (c->x86 == 3) + strcpy(c->x86_model_id, "386"); + } +#endif +} + +static const struct cpu_dev __cpuinitconst default_cpu = { + .c_init = default_init, + .c_vendor = "Unknown", + .c_x86_vendor = X86_VENDOR_UNKNOWN, +}; + +static const struct cpu_dev *this_cpu __cpuinitdata = &default_cpu; DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = { #ifdef CONFIG_X86_64 @@ -332,29 +355,6 @@ void switch_to_new_gdt(int cpu) static const struct cpu_dev *__cpuinitdata cpu_devs[X86_VENDOR_NUM] = {}; -static void __cpuinit default_init(struct cpuinfo_x86 *c) -{ -#ifdef CONFIG_X86_64 - display_cacheinfo(c); -#else - /* Not much we can do here... */ - /* Check if at least it has cpuid */ - if (c->cpuid_level == -1) { - /* No cpuid. It must be an ancient CPU */ - if (c->x86 == 4) - strcpy(c->x86_model_id, "486"); - else if (c->x86 == 3) - strcpy(c->x86_model_id, "386"); - } -#endif -} - -static const struct cpu_dev __cpuinitconst default_cpu = { - .c_init = default_init, - .c_vendor = "Unknown", - .c_x86_vendor = X86_VENDOR_UNKNOWN, -}; - static void __cpuinit get_model_name(struct cpuinfo_x86 *c) { unsigned int *v; |