diff options
Diffstat (limited to 'arch/i386/kernel/cpu/common.c')
| -rw-r--r-- | arch/i386/kernel/cpu/common.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/arch/i386/kernel/cpu/common.c b/arch/i386/kernel/cpu/common.c index 2534e25ed74..4e63d8ce602 100644 --- a/arch/i386/kernel/cpu/common.c +++ b/arch/i386/kernel/cpu/common.c @@ -593,6 +593,14 @@ void __init early_cpu_init(void) #endif } +/* Make sure %gs is initialized properly in idle threads */ +struct pt_regs * __devinit idle_regs(struct pt_regs *regs) +{ + memset(regs, 0, sizeof(struct pt_regs)); + regs->xgs = __KERNEL_PDA; + return regs; +} + __cpuinit int alloc_gdt(int cpu) { struct Xgt_desc_struct *cpu_gdt_descr = &per_cpu(cpu_gdt_descr, cpu); @@ -644,6 +652,14 @@ struct i386_pda boot_pda = { ._pda = &boot_pda, }; +static inline void set_kernel_gs(void) +{ + /* Set %gs for this CPU's PDA. Memory clobber is to create a + barrier with respect to any PDA operations, so the compiler + doesn't move any before here. */ + asm volatile ("mov %0, %%gs" : : "r" (__KERNEL_PDA) : "memory"); +} + /* Initialize the CPU's GDT and PDA. The boot CPU does this for itself, but secondaries find this done for them. */ __cpuinit int init_gdt(int cpu, struct task_struct *idle) @@ -693,6 +709,7 @@ static void __cpuinit _cpu_init(int cpu, struct task_struct *curr) the boot CPU, this will transition from the boot gdt+pda to the real ones). */ load_gdt(cpu_gdt_descr); + set_kernel_gs(); if (cpu_test_and_set(cpu, cpu_initialized)) { printk(KERN_WARNING "CPU#%d already initialized!\n", cpu); @@ -731,8 +748,8 @@ static void __cpuinit _cpu_init(int cpu, struct task_struct *curr) __set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss); #endif - /* Clear %fs and %gs. */ - asm volatile ("movl %0, %%fs; movl %0, %%gs" : : "r" (0)); + /* Clear %fs. */ + asm volatile ("mov %0, %%fs" : : "r" (0)); /* Clear all 6 debug registers: */ set_debugreg(0, 0); |