ARM: 5977/1: arm: Enable backtrace printing on oops when PC is corrupted

If PC points outside kernel text, start printing the backtrace at LR
instead.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c
index 786ac2b6914a..50292cd9c120 100644
--- a/arch/arm/kernel/unwind.c
+++ b/arch/arm/kernel/unwind.c
@@ -359,7 +359,9 @@ void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk)
                 frame.fp = regs->ARM_fp;
                 frame.sp = regs->ARM_sp;
                 frame.lr = regs->ARM_lr;
-                frame.pc = regs->ARM_pc;
+                /* PC might be corrupted, use LR in that case. */
+                frame.pc = kernel_text_address(regs->ARM_pc)
+                         ? regs->ARM_pc : regs->ARM_lr;
         } else if (tsk == current) {
                 frame.fp = (unsigned long)__builtin_frame_address(0);
                 frame.sp = current_sp;