Messages in this thread Patch in this message | | | From | Miroslav Benes <> | Subject | [PATCH] x86/unwind/orc: Do not skip the first frame unless explicitly asked for | Date | Wed, 4 Mar 2020 13:32:59 +0100 |
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ORC unwinder can currently skip the first frame even if a user does not ask for it. If both regs and first_frame parameters of unwind_start() are set to NULL, state->sp and first_frame are later initialized to the same value for an inactive task. Given there is "less than or equal to" comparison used at the end of __unwind_start() for skipping stack frames, the first frame is always skipped in this case.
Drop the equal part of the comparison and make it equivalent to the frame pointer unwinder.
Signed-off-by: Miroslav Benes <mbenes@suse.cz> --- 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 e9cc182aa97e..8452518cc20a 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -651,7 +651,7 @@ 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; -- 2.25.1
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