[PATCH 5.0 099/117] xtensa: fix return_address

Greg Kroah-Hartman
2019-04-15T19:14:12Z

From: Max Filippov <jcmvbkbc@gmail.com>

commit ada770b1e74a77fff2d5f539bf6c42c25f4784db upstream.

return_address returns the address that is one level higher in the call
stack than requested in its argument, because level 0 corresponds to its
caller's return address. Use requested level as the number of stack
frames to skip.

This fixes the address reported by might_sleep and friends.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/xtensa/kernel/stacktrace.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/arch/xtensa/kernel/stacktrace.c
+++ b/arch/xtensa/kernel/stacktrace.c
@@ -253,10 +253,14 @@ static int return_address_cb(struct stac
return 1;
}

+/*
+ * level == 0 is for the return address from the caller of this function,
+ * not from this function itself.
+ */
unsigned long return_address(unsigned level)
{
struct return_addr_data r = {
- .skip = level + 1,
+ .skip = level,
};
walk_stackframe(stack_pointer(NULL), return_address_cb, &r);
return r.addr;