The following commit has been merged into the x86/urgent branch of tip: Commit-ID: f1d9a2abff66aa8156fbc1493abed468db63ea48 Gitweb: https://git.kernel.org/tip/f1d9a2abff66aa8156fbc1493abed468db63ea48 Author: Miroslav Benes <mbenes@xxxxxxx> AuthorDate: Sat, 25 Apr 2020 05:03:07 -05:00 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Sat, 25 Apr 2020 12:22:29 +02:00 x86/unwind/orc: Don't skip the first frame for inactive tasks When unwinding an inactive task, the ORC unwinder skips the first frame by default. If both the 'regs' and 'first_frame' parameters of unwind_start() are NULL, 'state->sp' and 'first_frame' are later initialized to the same value for an inactive task. Given there is a "less than or equal to" comparison used at the end of __unwind_start() for skipping stack frames, the first frame is skipped. Drop the equal part of the comparison and make the behavior equivalent to the frame pointer unwinder. Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") Reviewed-by: Miroslav Benes <mbenes@xxxxxxx> Signed-off-by: Miroslav Benes <mbenes@xxxxxxx> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Dave Jones <dsj@xxxxxx> Cc: Jann Horn <jannh@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vince Weaver <vincent.weaver@xxxxxxxxx> Link: https://lore.kernel.org/r/7f08db872ab59e807016910acdbe82f744de7065.1587808742.git.jpoimboe@xxxxxxxxxx --- arch/x86/kernel/unwind_orc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index 45166fd..e9f5a20 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -657,7 +657,7 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task, /* Otherwise, skip ahead to the user-specified starting frame: */ while (!unwind_done(state) && (!on_stack(&state->stack_info, first_frame, sizeof(long)) || - state->sp <= (unsigned long)first_frame)) + state->sp < (unsigned long)first_frame)) unwind_next_frame(state); return;
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