4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Max Filippov <jcmvb...@gmail.com>
commit d90b88fd3653f1fb66ecc6571b860d5a5749fa56 upstream.
Stack unwinding is implemented incorrectly in xtensa get_wchan: instead
of extracting a0 and a1 registers from the spill location under the
stack pointer it extracts a word pointed to by the stack pointer and
subtracts 4 or 3 from it.
Cc: sta...@vger.kernel.org
Signed-off-by: Max Filippov <jcmvb...@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/xtensa/kernel/process.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -320,8 +320,8 @@ unsigned long get_wchan(struct task_stru
/* Stack layout: sp-4: ra, sp-3: sp' */
- pc = MAKE_PC_FROM_RA(*(unsigned long*)sp - 4, sp);
- sp = *(unsigned long *)sp - 3;
+ pc = MAKE_PC_FROM_RA(SPILL_SLOT(sp, 0), sp);
+ sp = SPILL_SLOT(sp, 1);
} while (count++ < 16);
return 0;
}
