From: Guo Ren <ren_guo@c-sky.com>
Date: Thu, 31 Jan 2019 06:34:37 +0000 (+0800)
Subject: csky: Fixup dead loop in show_stack
X-Git-Tag: v5.0-rc7~5^2
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=131aee8b9807bc98379fa5a0270389dbc7dcec90;p=linux-2.6-block.git

csky: Fixup dead loop in show_stack

When STACKTRACE is enabled, we must pass fp as stack for unwind,
otherwise random value in stack will casue a dead loop.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reported-by: Lu Baoquan <lu.baoquan@intellif.com>
---

diff --git a/arch/csky/kernel/dumpstack.c b/arch/csky/kernel/dumpstack.c
index 659253e9989c..d67f9777cfd9 100644
--- a/arch/csky/kernel/dumpstack.c
+++ b/arch/csky/kernel/dumpstack.c
@@ -38,7 +38,11 @@ void show_stack(struct task_struct *task, unsigned long *stack)
 		if (task)
 			stack = (unsigned long *)thread_saved_fp(task);
 		else
+#ifdef CONFIG_STACKTRACE
+			asm volatile("mov %0, r8\n":"=r"(stack)::"memory");
+#else
 			stack = (unsigned long *)&stack;
+#endif
 	}
 
 	show_trace(stack);