static atomic64_t io_bitmap_sequence;
+void io_bitmap_exit(void)
+{
+ struct io_bitmap *iobm = current->thread.io_bitmap;
+
+ current->thread.io_bitmap = NULL;
+ clear_thread_flag(TIF_IO_BITMAP);
+ preempt_disable();
+ tss_update_io_bitmap();
+ preempt_enable();
+ kfree(iobm);
+}
+
/*
* this changes the io permissions bitmap in the current task.
*/
* Search for a (possibly new) maximum. This is simple and stupid,
* to keep it obviously correct:
*/
- max_long = 0;
+ max_long = UINT_MAX;
for (i = 0; i < IO_BITMAP_LONGS; i++) {
if (iobm->bitmap[i] != ~0UL)
max_long = i;
}
+ /* All permissions dropped? */
+ if (max_long == UINT_MAX) {
+ io_bitmap_exit();
+ return 0;
+ }
iobm->max = (max_long + 1) * sizeof(unsigned long);
void exit_thread(struct task_struct *tsk)
{
struct thread_struct *t = &tsk->thread;
- struct io_bitmap *iobm = t->io_bitmap;
struct fpu *fpu = &t->fpu;
- struct tss_struct *tss;
-
- if (iobm) {
- preempt_disable();
- tss = this_cpu_ptr(&cpu_tss_rw);
-
- t->io_bitmap = NULL;
- clear_thread_flag(TIF_IO_BITMAP);
- /* Invalidate the io bitmap base in the TSS */
- tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET_INVALID;
- preempt_enable();
- kfree(iobm);
- }
+
+ if (test_thread_flag(TIF_IO_BITMAP))
+ io_bitmap_exit();
free_vm86(t);