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| author | Linus Walleij <linus.walleij@linaro.org> | 2016-03-10 09:29:25 +0700 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2016-03-10 09:29:25 +0700 |
| commit | cc998d8bc74341f6bbbcd63ab4449a6acfc45ee9 (patch) | |
| tree | 2f4e23fa1ceb83b3e720afd52d9a5ef2be26c77e /arch/arm64/kernel/stacktrace.c | |
| parent | d2d13ed01362ecddc3f76f9cca31b0cd5d663a7e (diff) | |
| parent | 81f70ba233d5f660e1ea5fe23260ee323af5d53a (diff) | |
Merge tag 'v4.5-rc5' into devel
Linux 4.5-rc5
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 && |