4.14-stable review patch. If anyone has any objections, please let me know.
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From: Max Filippov jcmvbkbc@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: stable@vger.kernel.org Signed-off-by: Max Filippov jcmvbkbc@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@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 @@ -314,8 +314,8 @@ 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; }