1 files changed, 8 insertions, 1 deletions

diff --git a/arch/x86/kernel/unwind_guess.c b/arch/x86/kernel/unwind_guess.c
index 9298993dc8b7..2d721e533cf4 100644
--- a/arch/x86/kernel/unwind_guess.c
+++ b/arch/x86/kernel/unwind_guess.c
@@ -47,7 +47,14 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task,
         get_stack_info(first_frame, state->task, &state->stack_info,
                        &state->stack_mask);
 
-        if (!__kernel_text_address(*first_frame))
+        /*
+         * The caller can provide the address of the first frame directly
+         * (first_frame) or indirectly (regs->sp) to indicate which stack frame
+         * to start unwinding at.  Skip ahead until we reach it.
+         */
+        if (!unwind_done(state) &&
+            (!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
+            !__kernel_text_address(*first_frame)))
                 unwind_next_frame(state);
 }
 EXPORT_SYMBOL_GPL(__unwind_start);