csky: Debug and Ptrace GDB

This patch adds arch ptrace implementation, stack dump and bug.h.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 66 insertions, 0 deletions

diff --git a/arch/csky/kernel/dumpstack.c b/arch/csky/kernel/dumpstack.c
new file mode 100644
index 000000000000..a9a03ac57ec5
--- /dev/null
+++ b/arch/csky/kernel/dumpstack.c
@@ -0,0 +1,66 @@
+// 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 *endstack;
+	unsigned long addr;
+	int i;
+
+	pr_info("Call Trace:\n");
+	addr = (unsigned long)stack + THREAD_SIZE - 1;
+	endstack = (unsigned long *)(addr & -THREAD_SIZE);
+	i = 0;
+	while (stack + 1 <= endstack) {
+		addr = *stack++;
+		/*
+		 * If the address is either in the text segment of the
+		 * kernel, or in the region which contains vmalloc'ed
+		 * memory, it *may* be the address of a calling
+		 * routine; if so, print it so that someone tracing
+		 * down the cause of the crash will be able to figure
+		 * out the call path that was taken.
+		 */
+		if (__kernel_text_address(addr)) {
+#ifndef CONFIG_KALLSYMS
+			if (i % 5 == 0)
+				pr_cont("\n       ");
+#endif
+			pr_cont(" [<%08lx>] %pS\n", addr, (void *)addr);
+			i++;
+		}
+	}
+	pr_cont("\n");
+}
+
+void show_stack(struct task_struct *task, unsigned long *stack)
+{
+	unsigned long *p;
+	unsigned long *endstack;
+	int i;
+
+	if (!stack) {
+		if (task)
+			stack = (unsigned long *)task->thread.esp0;
+		else
+			stack = (unsigned long *)&stack;
+	}
+	endstack = (unsigned long *)
+		(((unsigned long)stack + THREAD_SIZE - 1) & -THREAD_SIZE);
+
+	pr_info("Stack from %08lx:", (unsigned long)stack);
+	p = stack;
+	for (i = 0; i < kstack_depth_to_print; i++) {
+		if (p + 1 > endstack)
+			break;
+		if (i % 8 == 0)
+			pr_cont("\n       ");
+		pr_cont(" %08lx", *p++);
+	}
+	pr_cont("\n");
+	show_trace(stack);
+}