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: stable@vger.kernel.org Signed-off-by: Max Filippov jcmvbkbc@gmail.com --- arch/xtensa/kernel/process.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c index 74969a437a37..2e73395f0560 100644 --- a/arch/xtensa/kernel/process.c +++ b/arch/xtensa/kernel/process.c @@ -321,8 +321,8 @@ unsigned long get_wchan(struct task_struct *p)

/* 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; }