Commit-ID: 0c414367c04eeb00c3ebfee0b74c9e7f3b95fd62 Gitweb: https://git.kernel.org/tip/0c414367c04eeb00c3ebfee0b74c9e7f3b95fd62 Author: Jiri Slaby <jslaby@xxxxxxx> AuthorDate: Fri, 18 May 2018 08:47:11 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Thu, 21 Jun 2018 16:34:56 +0200 x86/stacktrace: Do not fail for ORC with regs on stack save_stack_trace_reliable now returns "non reliable" when there are kernel pt_regs on stack. This means an interrupt or exception happened somewhere down the route. It is a problem for the frame pointer unwinder, because the frame might not have been set up yet when the irq happened, so the unwinder might fail to unwind from the interrupted function. With ORC, this is not a problem, as ORC has out-of-band data. We can find ORC data even for the IP in the interrupted function and always unwind one level up reliably. So lift the check to apply only when CONFIG_FRAME_POINTER=y is enabled. Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Brian Gerst <brgerst@xxxxxxxxx> Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/lkml/20180518064713.26440-4-jslaby@xxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/kernel/stacktrace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index 6acf1d5ca832..7627455047c2 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -106,7 +106,8 @@ __save_stack_trace_reliable(struct stack_trace *trace, * unreliable. */ - return -EINVAL; + if (IS_ENABLED(CONFIG_FRAME_POINTER)) + return -EINVAL; } addr = unwind_get_return_address(&state); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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