struct task_struct *
__switch_to(struct task_struct *prev_p, struct task_struct *next_p)
{
- struct thread_struct *prev = &prev_p->thread,
- *next = &next_p->thread;
+ struct thread_struct *prev = &prev_p->thread;
+ struct thread_struct *next = &next_p->thread;
int cpu = smp_processor_id();
struct tss_struct *tss = &per_cpu(init_tss, cpu);
unsigned fsindex, gsindex;
/*
* Switch FS and GS.
+ *
+ * Segment register != 0 always requires a reload. Also
+ * reload when it has changed. When prev process used 64bit
+ * base always reload to avoid an information leak.
*/
- {
- /* segment register != 0 always requires a reload.
- also reload when it has changed.
- when prev process used 64bit base always reload
- to avoid an information leak. */
- if (unlikely(fsindex | next->fsindex | prev->fs)) {
- loadsegment(fs, next->fsindex);
- /* check if the user used a selector != 0
- * if yes clear 64bit base, since overloaded base
- * is always mapped to the Null selector
- */
- if (fsindex)
+ if (unlikely(fsindex | next->fsindex | prev->fs)) {
+ loadsegment(fs, next->fsindex);
+ /*
+ * Check if the user used a selector != 0; if yes
+ * clear 64bit base, since overloaded base is always
+ * mapped to the Null selector
+ */
+ if (fsindex)
prev->fs = 0;
- }
- /* when next process has a 64bit base use it */
- if (next->fs)
- wrmsrl(MSR_FS_BASE, next->fs);
- prev->fsindex = fsindex;
-
- if (unlikely(gsindex | next->gsindex | prev->gs)) {
- load_gs_index(next->gsindex);
- if (gsindex)
+ }
+ /* when next process has a 64bit base use it */
+ if (next->fs)
+ wrmsrl(MSR_FS_BASE, next->fs);
+ prev->fsindex = fsindex;
+
+ if (unlikely(gsindex | next->gsindex | prev->gs)) {
+ load_gs_index(next->gsindex);
+ if (gsindex)
prev->gs = 0;
- }
- if (next->gs)
- wrmsrl(MSR_KERNEL_GS_BASE, next->gs);
- prev->gsindex = gsindex;
}
+ if (next->gs)
+ wrmsrl(MSR_KERNEL_GS_BASE, next->gs);
+ prev->gsindex = gsindex;
/* Must be after DS reload */
unlazy_fpu(prev_p);
write_pda(pcurrent, next_p);
write_pda(kernelstack,
- (unsigned long)task_stack_page(next_p) + THREAD_SIZE - PDA_STACKOFFSET);
+ (unsigned long)task_stack_page(next_p) +
+ THREAD_SIZE - PDA_STACKOFFSET);
#ifdef CONFIG_CC_STACKPROTECTOR
write_pda(stack_canary, next_p->stack_canary);
/*