arch/x86/kernel/dumpstack.c - linux - Git at Google

 /*
  *  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/utsname.h>
 #include <linux/hardirq.h>
 #include <linux/kdebug.h>
 #include <linux/module.h>
 #include <linux/ptrace.h>
 #include <linux/ftrace.h>
 #include <linux/kexec.h>
 #include <linux/bug.h>
 #include <linux/nmi.h>
 #include <linux/sysfs.h>

 #include <asm/stacktrace.h>


 int panic_on_unrecovered_nmi;
 int panic_on_io_nmi;
 unsigned int code_bytes = 64;
 int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
 static int die_counter;

 static void printk_stack_address(unsigned long address, int reliable,
 		void *data)
 {
 	printk("%s [<%p>] %s%pB\n",
 		(char *)data, (void *)address, reliable ? "" : "? ",
 		(void *)address);
 }

 void printk_address(unsigned long address)
 {
 	pr_cont(" [<%p>] %pS\n", (void *)address, (void *)address);
 }

 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 static void
 print_ftrace_graph_addr(unsigned long addr, void *data,
 			const struct stacktrace_ops *ops,
 			struct task_struct *task, int *graph)
 {
 	unsigned long ret_addr;
 	int index;

 	if (addr != (unsigned long)return_to_handler)
 		return;

 	index = task->curr_ret_stack;

 	if (!task->ret_stack || index < *graph)
 		return;

 	index -= *graph;
 	ret_addr = task->ret_stack[index].ret;

 	ops->address(data, ret_addr, 1);

 	(*graph)++;
 }
 #else
 static inline void
 print_ftrace_graph_addr(unsigned long addr, void *data,
 			const struct stacktrace_ops *ops,
 			struct task_struct *task, int *graph)
 { }
 #endif

 /*
  * x86-64 can have up to three kernel stacks:
  * process stack
  * interrupt stack
  * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
  */

 static inline int valid_stack_ptr(struct task_struct *task,
 			void *p, unsigned int size, void *end)
 {
 	void *t = task_stack_page(task);
 	if (end) {
 		if (p < end && p >= (end-THREAD_SIZE))
 			return 1;
 		else
 			return 0;
 	}
 	return p >= t && p < t + THREAD_SIZE - size;
 }

 unsigned long
 print_context_stack(struct task_struct *task,
 		unsigned long *stack, unsigned long bp,
 		const struct stacktrace_ops *ops, void *data,
 		unsigned long *end, int *graph)
 {
 	struct stack_frame *frame = (struct stack_frame *)bp;

 	/*
 	 * If we overflowed the stack into a guard page, jump back to the
 	 * bottom of the usable stack.
 	 */
 	if ((unsigned long)task_stack_page(task) - (unsigned long)stack <
 	    PAGE_SIZE)
 		stack = (unsigned long *)task_stack_page(task);

 	while (valid_stack_ptr(task, stack, sizeof(*stack), end)) {
 		unsigned long addr;

 		addr = *stack;
 		if (__kernel_text_address(addr)) {
 			if ((unsigned long) stack == bp + sizeof(long)) {
 				ops->address(data, addr, 1);
 				frame = frame->next_frame;
 				bp = (unsigned long) frame;
 			} else {
 				ops->address(data, addr, 0);
 			}
 			print_ftrace_graph_addr(addr, data, ops, task, graph);
 		}
 		stack++;
 	}
 	return bp;
 }
 EXPORT_SYMBOL_GPL(print_context_stack);

 unsigned long
 print_context_stack_bp(struct task_struct *task,
 		       unsigned long *stack, unsigned long bp,
 		       const struct stacktrace_ops *ops, void *data,
 		       unsigned long *end, int *graph)
 {
 	struct stack_frame *frame = (struct stack_frame *)bp;
 	unsigned long *ret_addr = &frame->return_address;

 	while (valid_stack_ptr(task, ret_addr, sizeof(*ret_addr), end)) {
 		unsigned long addr = *ret_addr;

 		if (!__kernel_text_address(addr))
 			break;

 		if (ops->address(data, addr, 1))
 			break;
 		frame = frame->next_frame;
 		ret_addr = &frame->return_address;
 		print_ftrace_graph_addr(addr, data, ops, task, graph);
 	}

 	return (unsigned long)frame;
 }
 EXPORT_SYMBOL_GPL(print_context_stack_bp);

 static int print_trace_stack(void *data, char *name)
 {
 	printk("%s <%s> ", (char *)data, name);
 	return 0;
 }

 /*
  * Print one address/symbol entries per line.
  */
 static int print_trace_address(void *data, unsigned long addr, int reliable)
 {
 	touch_nmi_watchdog();
 	printk_stack_address(addr, reliable, data);
 	return 0;
 }

 static const struct stacktrace_ops print_trace_ops = {
 	.stack			= print_trace_stack,
 	.address		= print_trace_address,
 	.walk_stack		= print_context_stack,
 };

 void
 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *stack, unsigned long bp, char *log_lvl)
 {
 	printk("%sCall Trace:\n", log_lvl);
 	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
 }

 void show_trace(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *stack, unsigned long bp)
 {
 	show_trace_log_lvl(task, regs, stack, bp, "");
 }

 void show_stack(struct task_struct *task, unsigned long *sp)
 {
 	unsigned long bp = 0;
 	unsigned long stack;

 	/*
 	 * Stack frames below this one aren't interesting.  Don't show them
 	 * if we're printing for %current.
 	 */
 	if (!sp && (!task || task == current)) {
 		sp = &stack;
 		bp = stack_frame(current, NULL);
 	}

 	show_stack_log_lvl(task, NULL, sp, bp, "");
 }

 void show_stack_regs(struct pt_regs *regs)
 {
 	show_stack_log_lvl(current, regs, (unsigned long *)regs->sp, regs->bp, "");
 }

 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
 static int die_owner = -1;
 static unsigned int die_nest_count;

 unsigned long oops_begin(void)
 {
 	int cpu;
 	unsigned long flags;

 	oops_enter();

 	/* racy, but better than risking deadlock. */
 	raw_local_irq_save(flags);
 	cpu = smp_processor_id();
 	if (!arch_spin_trylock(&die_lock)) {
 		if (cpu == die_owner)
 			/* nested oops. should stop eventually */;
 		else
 			arch_spin_lock(&die_lock);
 	}
 	die_nest_count++;
 	die_owner = cpu;
 	console_verbose();
 	bust_spinlocks(1);
 	return flags;
 }
 EXPORT_SYMBOL_GPL(oops_begin);
 NOKPROBE_SYMBOL(oops_begin);

 void __noreturn rewind_stack_do_exit(int signr);

 void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
 {
 	if (regs && kexec_should_crash(current))
 		crash_kexec(regs);

 	bust_spinlocks(0);
 	die_owner = -1;
 	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 	die_nest_count--;
 	if (!die_nest_count)
 		/* Nest count reaches zero, release the lock. */
 		arch_spin_unlock(&die_lock);
 	raw_local_irq_restore(flags);
 	oops_exit();

 	if (!signr)
 		return;
 	if (in_interrupt())
 		panic("Fatal exception in interrupt");
 	if (panic_on_oops)
 		panic("Fatal exception");

 	/*
 	 * We're not going to return, but we might be on an IST stack or
 	 * have very little stack space left.  Rewind the stack and kill
 	 * the task.
 	 */
 	rewind_stack_do_exit(signr);
 }
 NOKPROBE_SYMBOL(oops_end);

 int __die(const char *str, struct pt_regs *regs, long err)
 {
 #ifdef CONFIG_X86_32
 	unsigned short ss;
 	unsigned long sp;
 #endif
 	printk(KERN_DEFAULT
 	       "%s: %04lx [#%d]%s%s%s%s\n", str, err & 0xffff, ++die_counter,
 	       IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT"         : "",
 	       IS_ENABLED(CONFIG_SMP)     ? " SMP"             : "",
 	       debug_pagealloc_enabled()  ? " DEBUG_PAGEALLOC" : "",
 	       IS_ENABLED(CONFIG_KASAN)   ? " KASAN"           : "");

 	if (notify_die(DIE_OOPS, str, regs, err,
 			current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
 		return 1;

 	print_modules();
 	show_regs(regs);
 #ifdef CONFIG_X86_32
 	if (user_mode(regs)) {
 		sp = regs->sp;
 		ss = regs->ss & 0xffff;
 	} else {
 		sp = kernel_stack_pointer(regs);
 		savesegment(ss, ss);
 	}
 	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
 	print_symbol("%s", regs->ip);
 	printk(" SS:ESP %04x:%08lx\n", ss, sp);
 #else
 	/* Executive summary in case the oops scrolled away */
 	printk(KERN_ALERT "RIP ");
 	printk_address(regs->ip);
 	printk(" RSP <%016lx>\n", regs->sp);
 #endif
 	return 0;
 }
 NOKPROBE_SYMBOL(__die);

 /*
  * This is gone through when something in the kernel has done something bad
  * and is about to be terminated:
  */
 void die(const char *str, struct pt_regs *regs, long err)
 {
 	unsigned long flags = oops_begin();
 	int sig = SIGSEGV;

 	if (!user_mode(regs))
 		report_bug(regs->ip, regs);

 	if (__die(str, regs, err))
 		sig = 0;
 	oops_end(flags, regs, sig);
 }

 static int __init kstack_setup(char *s)
 {
 	ssize_t ret;
 	unsigned long val;

 	if (!s)
 		return -EINVAL;

 	ret = kstrtoul(s, 0, &val);
 	if (ret)
 		return ret;
 	kstack_depth_to_print = val;
 	return 0;
 }
 early_param("kstack", kstack_setup);

 static int __init code_bytes_setup(char *s)
 {
 	ssize_t ret;
 	unsigned long val;

 	if (!s)
 		return -EINVAL;

 	ret = kstrtoul(s, 0, &val);
 	if (ret)
 		return ret;

 	code_bytes = val;
 	if (code_bytes > 8192)
 		code_bytes = 8192;

 	return 1;
 }
 __setup("code_bytes=", code_bytes_setup);
	/*
	* 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/utsname.h>
	#include <linux/hardirq.h>
	#include <linux/kdebug.h>
	#include <linux/module.h>
	#include <linux/ptrace.h>
	#include <linux/ftrace.h>
	#include <linux/kexec.h>
	#include <linux/bug.h>
	#include <linux/nmi.h>
	#include <linux/sysfs.h>

	#include <asm/stacktrace.h>


	int panic_on_unrecovered_nmi;
	int panic_on_io_nmi;
	unsigned int code_bytes = 64;
	int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
	static int die_counter;

	static void printk_stack_address(unsigned long address, int reliable,
	void *data)
	{
	printk("%s [<%p>] %s%pB\n",
	(char )data, (void )address, reliable ? "" : "? ",
	(void *)address);
	}

	void printk_address(unsigned long address)
	{
	pr_cont(" [<%p>] %pS\n", (void )address, (void )address);
	}

	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	static void
	print_ftrace_graph_addr(unsigned long addr, void *data,
	const struct stacktrace_ops *ops,
	struct task_struct task, int graph)
	{
	unsigned long ret_addr;
	int index;

	if (addr != (unsigned long)return_to_handler)
	return;

	index = task->curr_ret_stack;

	if (!task->ret_stack \|\| index < *graph)
	return;

	index -= *graph;
	ret_addr = task->ret_stack[index].ret;

	ops->address(data, ret_addr, 1);

	(*graph)++;
	}
	#else
	static inline void
	print_ftrace_graph_addr(unsigned long addr, void *data,
	const struct stacktrace_ops *ops,
	struct task_struct task, int graph)
	{ }
	#endif

	/*
	* x86-64 can have up to three kernel stacks:
	* process stack
	* interrupt stack
	* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
	*/

	static inline int valid_stack_ptr(struct task_struct *task,
	void p, unsigned int size, void end)
	{
	void *t = task_stack_page(task);
	if (end) {
	if (p < end && p >= (end-THREAD_SIZE))
	return 1;
	else
	return 0;
	}
	return p >= t && p < t + THREAD_SIZE - size;
	}

	unsigned long
	print_context_stack(struct task_struct *task,
	unsigned long *stack, unsigned long bp,
	const struct stacktrace_ops ops, void data,
	unsigned long end, int graph)
	{
	struct stack_frame frame = (struct stack_frame )bp;

	/*
	* If we overflowed the stack into a guard page, jump back to the
	* bottom of the usable stack.
	*/
	if ((unsigned long)task_stack_page(task) - (unsigned long)stack <
	PAGE_SIZE)
	stack = (unsigned long *)task_stack_page(task);

	while (valid_stack_ptr(task, stack, sizeof(*stack), end)) {
	unsigned long addr;

	addr = *stack;
	if (__kernel_text_address(addr)) {
	if ((unsigned long) stack == bp + sizeof(long)) {
	ops->address(data, addr, 1);
	frame = frame->next_frame;
	bp = (unsigned long) frame;
	} else {
	ops->address(data, addr, 0);
	}
	print_ftrace_graph_addr(addr, data, ops, task, graph);
	}
	stack++;
	}
	return bp;
	}
	EXPORT_SYMBOL_GPL(print_context_stack);

	unsigned long
	print_context_stack_bp(struct task_struct *task,
	unsigned long *stack, unsigned long bp,
	const struct stacktrace_ops ops, void data,
	unsigned long end, int graph)
	{
	struct stack_frame frame = (struct stack_frame )bp;
	unsigned long *ret_addr = &frame->return_address;

	while (valid_stack_ptr(task, ret_addr, sizeof(*ret_addr), end)) {
	unsigned long addr = *ret_addr;

	if (!__kernel_text_address(addr))
	break;

	if (ops->address(data, addr, 1))
	break;
	frame = frame->next_frame;
	ret_addr = &frame->return_address;
	print_ftrace_graph_addr(addr, data, ops, task, graph);
	}

	return (unsigned long)frame;
	}
	EXPORT_SYMBOL_GPL(print_context_stack_bp);

	static int print_trace_stack(void data, char name)
	{
	printk("%s <%s> ", (char *)data, name);
	return 0;
	}

	/*
	* Print one address/symbol entries per line.
	*/
	static int print_trace_address(void *data, unsigned long addr, int reliable)
	{
	touch_nmi_watchdog();
	printk_stack_address(addr, reliable, data);
	return 0;
	}

	static const struct stacktrace_ops print_trace_ops = {
	.stack = print_trace_stack,
	.address = print_trace_address,
	.walk_stack = print_context_stack,
	};

	void
	show_trace_log_lvl(struct task_struct task, struct pt_regs regs,
	unsigned long stack, unsigned long bp, char log_lvl)
	{
	printk("%sCall Trace:\n", log_lvl);
	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
	}

	void show_trace(struct task_struct task, struct pt_regs regs,
	unsigned long *stack, unsigned long bp)
	{
	show_trace_log_lvl(task, regs, stack, bp, "");
	}

	void show_stack(struct task_struct task, unsigned long sp)
	{
	unsigned long bp = 0;
	unsigned long stack;

	/*
	* Stack frames below this one aren't interesting. Don't show them
	* if we're printing for %current.
	*/
	if (!sp && (!task \|\| task == current)) {
	sp = &stack;
	bp = stack_frame(current, NULL);
	}

	show_stack_log_lvl(task, NULL, sp, bp, "");
	}

	void show_stack_regs(struct pt_regs *regs)
	{
	show_stack_log_lvl(current, regs, (unsigned long *)regs->sp, regs->bp, "");
	}

	static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
	static int die_owner = -1;
	static unsigned int die_nest_count;

	unsigned long oops_begin(void)
	{
	int cpu;
	unsigned long flags;

	oops_enter();

	/* racy, but better than risking deadlock. */
	raw_local_irq_save(flags);
	cpu = smp_processor_id();
	if (!arch_spin_trylock(&die_lock)) {
	if (cpu == die_owner)
	/* nested oops. should stop eventually */;
	else
	arch_spin_lock(&die_lock);
	}
	die_nest_count++;
	die_owner = cpu;
	console_verbose();
	bust_spinlocks(1);
	return flags;
	}
	EXPORT_SYMBOL_GPL(oops_begin);
	NOKPROBE_SYMBOL(oops_begin);

	void __noreturn rewind_stack_do_exit(int signr);

	void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
	{
	if (regs && kexec_should_crash(current))
	crash_kexec(regs);

	bust_spinlocks(0);
	die_owner = -1;
	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
	die_nest_count--;
	if (!die_nest_count)
	/* Nest count reaches zero, release the lock. */
	arch_spin_unlock(&die_lock);
	raw_local_irq_restore(flags);
	oops_exit();

	if (!signr)
	return;
	if (in_interrupt())
	panic("Fatal exception in interrupt");
	if (panic_on_oops)
	panic("Fatal exception");

	/*
	* We're not going to return, but we might be on an IST stack or
	* have very little stack space left. Rewind the stack and kill
	* the task.
	*/
	rewind_stack_do_exit(signr);
	}
	NOKPROBE_SYMBOL(oops_end);

	int __die(const char str, struct pt_regs regs, long err)
	{
	#ifdef CONFIG_X86_32
	unsigned short ss;
	unsigned long sp;
	#endif
	printk(KERN_DEFAULT
	"%s: %04lx [#%d]%s%s%s%s\n", str, err & 0xffff, ++die_counter,
	IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
	IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
	debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
	IS_ENABLED(CONFIG_KASAN) ? " KASAN" : "");

	if (notify_die(DIE_OOPS, str, regs, err,
	current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
	return 1;

	print_modules();
	show_regs(regs);
	#ifdef CONFIG_X86_32
	if (user_mode(regs)) {
	sp = regs->sp;
	ss = regs->ss & 0xffff;
	} else {
	sp = kernel_stack_pointer(regs);
	savesegment(ss, ss);
	}
	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
	print_symbol("%s", regs->ip);
	printk(" SS:ESP %04x:%08lx\n", ss, sp);
	#else
	/* Executive summary in case the oops scrolled away */
	printk(KERN_ALERT "RIP ");
	printk_address(regs->ip);
	printk(" RSP <%016lx>\n", regs->sp);
	#endif
	return 0;
	}
	NOKPROBE_SYMBOL(__die);

	/*
	* This is gone through when something in the kernel has done something bad
	* and is about to be terminated:
	*/
	void die(const char str, struct pt_regs regs, long err)
	{
	unsigned long flags = oops_begin();
	int sig = SIGSEGV;

	if (!user_mode(regs))
	report_bug(regs->ip, regs);

	if (__die(str, regs, err))
	sig = 0;
	oops_end(flags, regs, sig);
	}

	static int __init kstack_setup(char *s)
	{
	ssize_t ret;
	unsigned long val;

	if (!s)
	return -EINVAL;

	ret = kstrtoul(s, 0, &val);
	if (ret)
	return ret;
	kstack_depth_to_print = val;
	return 0;
	}
	early_param("kstack", kstack_setup);

	static int __init code_bytes_setup(char *s)
	{
	ssize_t ret;
	unsigned long val;

	if (!s)
	return -EINVAL;

	ret = kstrtoul(s, 0, &val);
	if (ret)
	return ret;

	code_bytes = val;
	if (code_bytes > 8192)
	code_bytes = 8192;

	return 1;
	}
	__setup("code_bytes=", code_bytes_setup);