diff options
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 13 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 8 |
2 files changed, 17 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 4e7fb9c3bfa5..cdf79ab628c2 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1570,9 +1570,13 @@ void cpu_init(void) initialize_tlbstate_and_flush(); enter_lazy_tlb(&init_mm, me); - load_sp0(current->thread.sp0); + /* + * Initialize the TSS. Don't bother initializing sp0, as the initial + * task never enters user mode. + */ set_tss_desc(cpu, t); load_TR_desc(); + load_mm_ldt(&init_mm); clear_all_debug_regs(); @@ -1594,7 +1598,6 @@ void cpu_init(void) int cpu = smp_processor_id(); struct task_struct *curr = current; struct tss_struct *t = &per_cpu(cpu_tss, cpu); - struct thread_struct *thread = &curr->thread; wait_for_master_cpu(cpu); @@ -1625,9 +1628,13 @@ void cpu_init(void) initialize_tlbstate_and_flush(); enter_lazy_tlb(&init_mm, curr); - load_sp0(thread->sp0); + /* + * Initialize the TSS. Don't bother initializing sp0, as the initial + * task never enters user mode. + */ set_tss_desc(cpu, t); load_TR_desc(); + load_mm_ldt(&init_mm); t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap); diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index bd6b85fac666..ff8a9acbcf8b 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -48,7 +48,13 @@ */ __visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = { .x86_tss = { - .sp0 = TOP_OF_INIT_STACK, + /* + * .sp0 is only used when entering ring 0 from a lower + * privilege level. Since the init task never runs anything + * but ring 0 code, there is no need for a valid value here. + * Poison it. + */ + .sp0 = (1UL << (BITS_PER_LONG-1)) + 1, #ifdef CONFIG_X86_32 .ss0 = __KERNEL_DS, .ss1 = __KERNEL_CS, |