diff options
Diffstat (limited to 'arch/i386/kernel/process.c')
| -rw-r--r-- | arch/i386/kernel/process.c | 43 |
1 files changed, 25 insertions, 18 deletions
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c index e3f362e8af5b..b45cbf93d439 100644 --- a/arch/i386/kernel/process.c +++ b/arch/i386/kernel/process.c @@ -164,7 +164,7 @@ static inline void play_dead(void) */ local_irq_disable(); while (1) - __asm__ __volatile__("hlt":::"memory"); + halt(); } #else static inline void play_dead(void) @@ -313,16 +313,12 @@ void show_regs(struct pt_regs * regs) printk(" DS: %04x ES: %04x\n", 0xffff & regs->xds,0xffff & regs->xes); - __asm__("movl %%cr0, %0": "=r" (cr0)); - __asm__("movl %%cr2, %0": "=r" (cr2)); - __asm__("movl %%cr3, %0": "=r" (cr3)); - /* This could fault if %cr4 does not exist */ - __asm__("1: movl %%cr4, %0 \n" - "2: \n" - ".section __ex_table,\"a\" \n" - ".long 1b,2b \n" - ".previous \n" - : "=r" (cr4): "0" (0)); + cr0 = read_cr0(); + cr2 = read_cr2(); + cr3 = read_cr3(); + if (current_cpu_data.x86 > 4) { + cr4 = read_cr4(); + } printk("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", cr0, cr2, cr3, cr4); show_trace(NULL, ®s->esp); } @@ -682,21 +678,26 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas __unlazy_fpu(prev_p); /* - * Reload esp0, LDT and the page table pointer: + * Reload esp0. */ load_esp0(tss, next); /* - * Load the per-thread Thread-Local Storage descriptor. + * Save away %fs and %gs. No need to save %es and %ds, as + * those are always kernel segments while inside the kernel. + * Doing this before setting the new TLS descriptors avoids + * the situation where we temporarily have non-reloadable + * segments in %fs and %gs. This could be an issue if the + * NMI handler ever used %fs or %gs (it does not today), or + * if the kernel is running inside of a hypervisor layer. */ - load_TLS(next, cpu); + savesegment(fs, prev->fs); + savesegment(gs, prev->gs); /* - * Save away %fs and %gs. No need to save %es and %ds, as - * those are always kernel segments while inside the kernel. + * Load the per-thread Thread-Local Storage descriptor. */ - asm volatile("mov %%fs,%0":"=m" (prev->fs)); - asm volatile("mov %%gs,%0":"=m" (prev->gs)); + load_TLS(next, cpu); /* * Restore %fs and %gs if needed. @@ -711,6 +712,12 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas loadsegment(gs, next->gs); /* + * Restore IOPL if needed. + */ + if (unlikely(prev->iopl != next->iopl)) + set_iopl_mask(next->iopl); + + /* * Now maybe reload the debug registers */ if (unlikely(next->debugreg[7])) { |