ARM: allow unwinder to unwind recursive functions

Allow the unwinder to unwind recursive functions if the stack makes
progress, even if the PC is the same. This allows tracing through
recursive __switchdev_handle_port_attr_set() and similar.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c
index 4574e6a..11a964f 100644 (file)
--- a/arch/arm/kernel/unwind.c
+++ b/arch/arm/kernel/unwind.c
@@ -444,7 +444,7 @@ int unwind_frame(struct stackframe *frame)
                ctrl.vrs[PC] = ctrl.vrs[LR];
 
        /* check for infinite loop */
-       if (frame->pc == ctrl.vrs[PC])
+       if (frame->pc == ctrl.vrs[PC] && frame->sp == ctrl.vrs[SP])
                return -URC_FAILURE;
 
        frame->fp = ctrl.vrs[FP];