From: "Madhavan T. Venkataraman" <[email protected]>
Introduce arch_stack_walk_reliable() for ARM64. This works like
arch_stack_walk() except that it returns -EINVAL if the stack trace is not
reliable.
Until all the reliability checks are in place, arch_stack_walk_reliable()
may not be used by livepatch. But it may be used by debug and test code.
Signed-off-by: Madhavan T. Venkataraman <[email protected]>
Reviewed-by: Mark Brown <[email protected]>
---
arch/arm64/kernel/stacktrace.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 8bfe31cbee46..4902fac5745f 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -342,3 +342,25 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
unwind(&state, consume_entry, cookie);
}
+
+/*
+ * arch_stack_walk_reliable() may not be used for livepatch until all of
+ * the reliability checks are in place in unwind_consume(). However,
+ * debug and test code can choose to use it even if all the checks are not
+ * in place.
+ */
+noinline int notrace arch_stack_walk_reliable(stack_trace_consume_fn consume_fn,
+ void *cookie,
+ struct task_struct *task)
+{
+ struct unwind_state state;
+ bool reliable;
+
+ if (task == current)
+ unwind_init_from_current(&state, task);
+ else
+ unwind_init_from_task(&state, task);
+
+ reliable = unwind(&state, consume_fn, cookie);
+ return reliable ? 0 : -EINVAL;
+}
--
2.25.1