diff options
| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-03-01 16:38:16 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-03-01 16:38:16 -0800 |
| commit | 523462df282fc527a01bceca5125017e2259fbf5 (patch) | |
| tree | b3cca26b719ce1f46f203e2f86334525a2f50e14 /arch/arm64/kernel/stacktrace.c | |
| parent | 35bf7692e765c2275bf93fe573f7ca868ab73453 (diff) | |
| parent | fc77dbd34c5c99bce46d40a2491937c3bcbd10af (diff) | |
| download | lwn-523462df282fc527a01bceca5125017e2259fbf5.tar.gz lwn-523462df282fc527a01bceca5125017e2259fbf5.zip | |
Merge 4.5-rc6 into char-misc-next
We want the fixes in here, and others are sending us pull requests based
on this kernel tree.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/kernel/stacktrace.c')
| -rw-r--r-- | arch/arm64/kernel/stacktrace.c | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index 4fad9787ab46..d9751a4769e7 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -44,14 +44,13 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) 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 */ @@ -64,8 +63,8 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) return -EINVAL; frame->sp = fp + 0x10; - frame->fp = *(unsigned long *)(fp); - frame->pc = *(unsigned long *)(fp + 8); + frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp)); + frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8)); #ifdef CONFIG_FUNCTION_GRAPH_TRACER if (tsk && tsk->ret_stack && |