{
/* endless idle loop with no priority at all */
while (1) {
- void (*idle)(void) = pm_idle;
- if (!idle)
- idle = default_idle;
- while (!need_resched())
+ while (!need_resched()) {
+ void (*idle)(void);
+ /*
+ * Mark this as an RCU critical section so that
+ * synchronize_kernel() in the unload path waits
+ * for our completion.
+ */
+ rcu_read_lock();
+ idle = pm_idle;
+ if (!idle)
+ idle = default_idle;
idle();
+ rcu_read_unlock();
+ }
schedule();
}
}
if (cpu_has(c, X86_FEATURE_MWAIT)) {
/*
* Skip, if setup has overridden idle.
- * Also, take care of system with asymmetric CPUs.
- * Use, mwait_idle only if all cpus support it.
- * If not, we fallback to default_idle()
+ * One CPU supports mwait => All CPUs supports mwait
*/
if (!pm_idle) {
if (!printed) {
}
pm_idle = mwait_idle;
}
- return;
}
- pm_idle = default_idle;
- return;
}
static int __init idle_setup (char *str)
void exit_thread(void)
{
struct task_struct *me = current;
+ struct thread_struct *t = &me->thread;
if (me->thread.io_bitmap_ptr) {
- struct tss_struct *tss = init_tss + get_cpu();
- kfree(me->thread.io_bitmap_ptr);
- me->thread.io_bitmap_ptr = NULL;
- tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
+ struct tss_struct *tss = &per_cpu(init_tss, get_cpu());
+
+ kfree(t->io_bitmap_ptr);
+ t->io_bitmap_ptr = NULL;
+ /*
+ * Careful, clear this in the TSS too:
+ */
+ memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
+ t->io_bitmap_max = 0;
put_cpu();
}
}
if (unlikely(me->thread.io_bitmap_ptr != NULL)) {
p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL);
- if (!p->thread.io_bitmap_ptr)
+ if (!p->thread.io_bitmap_ptr) {
+ p->thread.io_bitmap_max = 0;
return -ENOMEM;
+ }
memcpy(p->thread.io_bitmap_ptr, me->thread.io_bitmap_ptr, IO_BITMAP_BYTES);
}
}
err = 0;
out:
- if (err && p->thread.io_bitmap_ptr)
+ if (err && p->thread.io_bitmap_ptr) {
kfree(p->thread.io_bitmap_ptr);
+ p->thread.io_bitmap_max = 0;
+ }
return err;
}
struct thread_struct *prev = &prev_p->thread,
*next = &next_p->thread;
int cpu = smp_processor_id();
- struct tss_struct *tss = init_tss + cpu;
+ struct tss_struct *tss = &per_cpu(init_tss, cpu);
unlazy_fpu(prev_p);
* Handle the IO bitmap
*/
if (unlikely(prev->io_bitmap_ptr || next->io_bitmap_ptr)) {
- if (next->io_bitmap_ptr) {
+ if (next->io_bitmap_ptr)
/*
- * 2 cachelines copy ... not good, but not that
- * bad either. Anyone got something better?
- * This only affects processes which use ioperm().
- */
- memcpy(tss->io_bitmap, next->io_bitmap_ptr, IO_BITMAP_BYTES);
- tss->io_bitmap_base = IO_BITMAP_OFFSET;
- } else {
+ * Copy the relevant range of the IO bitmap.
+ * Normally this is 128 bytes or less:
+ */
+ memcpy(tss->io_bitmap, next->io_bitmap_ptr,
+ max(prev->io_bitmap_max, next->io_bitmap_max));
+ else {
/*
- * a bitmap offset pointing outside of the TSS limit
- * causes a nicely controllable SIGSEGV if a process
- * tries to use a port IO instruction. The first
- * sys_ioperm() call sets up the bitmap properly.
+ * Clear any possible leftover bits:
*/
- tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
+ memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
}
}
clear_thread_flag(TIF_IA32);
}
-asmlinkage long sys_fork(struct pt_regs regs)
+asmlinkage long sys_fork(struct pt_regs *regs)
{
- return do_fork(SIGCHLD, regs.rsp, ®s, 0, NULL, NULL);
+ return do_fork(SIGCHLD, regs->rsp, regs, 0, NULL, NULL);
}
-asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp, void __user *parent_tid, void __user *child_tid, struct pt_regs regs)
+asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp, void __user *parent_tid, void __user *child_tid, struct pt_regs *regs)
{
if (!newsp)
- newsp = regs.rsp;
- return do_fork(clone_flags & ~CLONE_IDLETASK, newsp, ®s, 0,
- parent_tid, child_tid);
+ newsp = regs->rsp;
+ return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
}
/*
* do not have enough call-clobbered registers to hold all
* the information you need.
*/
-asmlinkage long sys_vfork(struct pt_regs regs)
+asmlinkage long sys_vfork(struct pt_regs *regs)
{
- return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.rsp, ®s, 0,
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->rsp, regs, 0,
NULL, NULL);
}