unsigned long irq_stack_ptr;
/*
- * Use raw_smp_processor_id() to avoid false-positives from
- * CONFIG_DEBUG_PREEMPT. get_wchan() calls unwind_frame() on sleeping
- * task stacks, we can be pre-empted in this case, so
- * {raw_,}smp_processor_id() may give us the wrong value. Sleeping
- * tasks can't ever be on an interrupt stack, so regardless of cpu,
- * the checks will always fail.
+ * Switching between stacks is valid when tracing current and in
+ * non-preemptible context.
*/
- irq_stack_ptr = IRQ_STACK_PTR(raw_smp_processor_id());
+ if (tsk == current && !preemptible())
+ irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id());
+ else
+ irq_stack_ptr = 0;
low = frame->sp;
/* irq stacks are not THREAD_SIZE aligned */