csky: Fixup calltrace panic

The implementation of show_stack will panic with wrong fp:

addr    = *fp++;

because the fp isn't checked properly.

The current implementations of show_stack, wchan and stack_trace
haven't been designed properly, so just deprecate them.

This patch is a reference to riscv's way, all codes are modified from
arm's. The patch is passed with:

 - cat /proc/<pid>/stack
 - cat /proc/<pid>/wchan
 - echo c > /proc/sysrq-trigger

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

1 files changed, 0 insertions, 49 deletions

diff --git a/arch/csky/kernel/dumpstack.c b/arch/csky/kernel/dumpstack.c
deleted file mode 100644
index d67f9777cfd9..000000000000
--- a/arch/csky/kernel/dumpstack.c
+++ /dev/null
@@ -1,49 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
-
-#include <linux/ptrace.h>
-
-int kstack_depth_to_print = 48;
-
-void show_trace(unsigned long *stack)
-{
-	unsigned long *stack_end;
-	unsigned long *stack_start;
-	unsigned long *fp;
-	unsigned long addr;
-
-	addr = (unsigned long) stack & THREAD_MASK;
-	stack_start = (unsigned long *) addr;
-	stack_end = (unsigned long *) (addr + THREAD_SIZE);
-
-	fp = stack;
-	pr_info("\nCall Trace:");
-
-	while (fp > stack_start && fp < stack_end) {
-#ifdef CONFIG_STACKTRACE
-		addr	= fp[1];
-		fp	= (unsigned long *) fp[0];
-#else
-		addr	= *fp++;
-#endif
-		if (__kernel_text_address(addr))
-			pr_cont("\n[<%08lx>] %pS", addr, (void *)addr);
-	}
-	pr_cont("\n");
-}
-
-void show_stack(struct task_struct *task, unsigned long *stack)
-{
-	if (!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);
-}