---

yaml
---
r: 153740
b: refs/heads/master
c: c894ed6
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 7436127ce9042f95a10bb5423f726fd63a61934d
+refs/heads/master: c894ed6956f126d60d888e8efc5fb3a595ba89ae

trunk/arch/arm/kernel/unwind.c

@@ -212,7 +212,8 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl)
 			ctrl->vrs[14] = *vsp++;
 		ctrl->vrs[SP] = (unsigned long)vsp;
 	} else if (insn == 0xb0) {
-		ctrl->vrs[PC] = ctrl->vrs[LR];
+		if (ctrl->vrs[PC] == 0)
+			ctrl->vrs[PC] = ctrl->vrs[LR];
 		/* no further processing */
 		ctrl->entries = 0;
 	} else if (insn == 0xb1) {
@@ -309,18 +310,20 @@ int unwind_frame(struct stackframe *frame)
 	}
 
 	while (ctrl.entries > 0) {
-		int urc;
-
-		if (ctrl.vrs[SP] < low || ctrl.vrs[SP] >= high)
-			return -URC_FAILURE;
-		urc = unwind_exec_insn(&ctrl);
+		int urc = unwind_exec_insn(&ctrl);
 		if (urc < 0)
 			return urc;
+		if (ctrl.vrs[SP] < low || ctrl.vrs[SP] >= high)
+			return -URC_FAILURE;
 	}
 
 	if (ctrl.vrs[PC] == 0)
 		ctrl.vrs[PC] = ctrl.vrs[LR];
 
+	/* check for infinite loop */
+	if (frame->pc == ctrl.vrs[PC])
+		return -URC_FAILURE;
+
 	frame->fp = ctrl.vrs[FP];
 	frame->sp = ctrl.vrs[SP];
 	frame->lr = ctrl.vrs[LR];
@@ -332,7 +335,6 @@ int unwind_frame(struct stackframe *frame)
 void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 {
 	struct stackframe frame;
-	unsigned long high, low;
 	register unsigned long current_sp asm ("sp");
 
 	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
@@ -362,9 +364,6 @@ void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 		frame.pc = thread_saved_pc(tsk);
 	}
 
-	low = frame.sp & ~(THREAD_SIZE - 1);
-	high = low + THREAD_SIZE;
-
 	while (1) {
 		int urc;
 		unsigned long where = frame.pc;