From d2e1446d81725c351dc73a03b397ce043fb18452 Mon Sep 17 00:00:00 2001
From: Meizu OpenSource <patchwork@meizu.com>
Date: Mon, 15 Aug 2016 10:19:42 +0800
Subject: first commit

---
 arch/x86/kernel/dumpstack_32.c | 138 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 138 insertions(+)
 create mode 100644 arch/x86/kernel/dumpstack_32.c

(limited to 'arch/x86/kernel/dumpstack_32.c')

diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
new file mode 100644
index 000000000..f2a1770ca
--- /dev/null
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -0,0 +1,138 @@
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
+ */
+#include <linux/kallsyms.h>
+#include <linux/kprobes.h>
+#include <linux/uaccess.h>
+#include <linux/hardirq.h>
+#include <linux/kdebug.h>
+#include <linux/module.h>
+#include <linux/ptrace.h>
+#include <linux/kexec.h>
+#include <linux/sysfs.h>
+#include <linux/bug.h>
+#include <linux/nmi.h>
+
+#include <asm/stacktrace.h>
+
+
+void dump_trace(struct task_struct *task, struct pt_regs *regs,
+		unsigned long *stack, unsigned long bp,
+		const struct stacktrace_ops *ops, void *data)
+{
+	int graph = 0;
+
+	if (!task)
+		task = current;
+
+	if (!stack) {
+		unsigned long dummy;
+
+		stack = &dummy;
+		if (task && task != current)
+			stack = (unsigned long *)task->thread.sp;
+	}
+
+	if (!bp)
+		bp = stack_frame(task, regs);
+
+	for (;;) {
+		struct thread_info *context;
+
+		context = (struct thread_info *)
+			((unsigned long)stack & (~(THREAD_SIZE - 1)));
+		bp = ops->walk_stack(context, stack, bp, ops, data, NULL, &graph);
+
+		stack = (unsigned long *)context->previous_esp;
+		if (!stack)
+			break;
+		if (ops->stack(data, "IRQ") < 0)
+			break;
+		touch_nmi_watchdog();
+	}
+}
+EXPORT_SYMBOL(dump_trace);
+
+void
+show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+		   unsigned long *sp, unsigned long bp, char *log_lvl)
+{
+	unsigned long *stack;
+	int i;
+
+	if (sp == NULL) {
+		if (task)
+			sp = (unsigned long *)task->thread.sp;
+		else
+			sp = (unsigned long *)&sp;
+	}
+
+	stack = sp;
+	for (i = 0; i < kstack_depth_to_print; i++) {
+		if (kstack_end(stack))
+			break;
+		if (i && ((i % STACKSLOTS_PER_LINE) == 0))
+			pr_cont("\n");
+		pr_cont(" %08lx", *stack++);
+		touch_nmi_watchdog();
+	}
+	pr_cont("\n");
+	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
+}
+
+
+void show_regs(struct pt_regs *regs)
+{
+	int i;
+
+	show_regs_print_info(KERN_EMERG);
+	__show_regs(regs, !user_mode_vm(regs));
+
+	/*
+	 * When in-kernel, we also print out the stack and code at the
+	 * time of the fault..
+	 */
+	if (!user_mode_vm(regs)) {
+		unsigned int code_prologue = code_bytes * 43 / 64;
+		unsigned int code_len = code_bytes;
+		unsigned char c;
+		u8 *ip;
+
+		pr_emerg("Stack:\n");
+		show_stack_log_lvl(NULL, regs, &regs->sp, 0, KERN_EMERG);
+
+		pr_emerg("Code:");
+
+		ip = (u8 *)regs->ip - code_prologue;
+		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
+			/* try starting at IP */
+			ip = (u8 *)regs->ip;
+			code_len = code_len - code_prologue + 1;
+		}
+		for (i = 0; i < code_len; i++, ip++) {
+			if (ip < (u8 *)PAGE_OFFSET ||
+					probe_kernel_address(ip, c)) {
+				pr_cont("  Bad EIP value.");
+				break;
+			}
+			if (ip == (u8 *)regs->ip)
+				pr_cont(" <%02x>", c);
+			else
+				pr_cont(" %02x", c);
+		}
+	}
+	pr_cont("\n");
+}
+
+int is_valid_bugaddr(unsigned long ip)
+{
+	unsigned short ud2;
+
+	if (ip < PAGE_OFFSET)
+		return 0;
+	if (probe_kernel_address((unsigned short *)ip, ud2))
+		return 0;
+
+	return ud2 == 0x0b0f;
+}
-- 
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