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v3.5.6
  1/*
  2 *  Copyright (C) 1991, 1992  Linus Torvalds
  3 *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
  4 */
  5#include <linux/kallsyms.h>
  6#include <linux/kprobes.h>
  7#include <linux/uaccess.h>
  8#include <linux/utsname.h>
  9#include <linux/hardirq.h>
 10#include <linux/kdebug.h>
 11#include <linux/module.h>
 12#include <linux/ptrace.h>
 
 
 13#include <linux/ftrace.h>
 14#include <linux/kexec.h>
 15#include <linux/bug.h>
 16#include <linux/nmi.h>
 17#include <linux/sysfs.h>
 
 18
 
 19#include <asm/stacktrace.h>
 20
 21
 22int panic_on_unrecovered_nmi;
 23int panic_on_io_nmi;
 24unsigned int code_bytes = 64;
 25int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
 26static int die_counter;
 27
 28void printk_address(unsigned long address, int reliable)
 29{
 30	printk(" [<%p>] %s%pB\n", (void *) address,
 31			reliable ? "" : "? ", (void *) address);
 32}
 33
 34#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 35static void
 36print_ftrace_graph_addr(unsigned long addr, void *data,
 37			const struct stacktrace_ops *ops,
 38			struct thread_info *tinfo, int *graph)
 39{
 40	struct task_struct *task;
 41	unsigned long ret_addr;
 42	int index;
 43
 44	if (addr != (unsigned long)return_to_handler)
 45		return;
 46
 47	task = tinfo->task;
 48	index = task->curr_ret_stack;
 
 
 49
 50	if (!task->ret_stack || index < *graph)
 51		return;
 52
 53	index -= *graph;
 54	ret_addr = task->ret_stack[index].ret;
 
 55
 56	ops->address(data, ret_addr, 1);
 
 57
 58	(*graph)++;
 59}
 60#else
 61static inline void
 62print_ftrace_graph_addr(unsigned long addr, void *data,
 63			const struct stacktrace_ops *ops,
 64			struct thread_info *tinfo, int *graph)
 65{ }
 66#endif
 67
 68/*
 69 * x86-64 can have up to three kernel stacks:
 70 * process stack
 71 * interrupt stack
 72 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
 73 */
 74
 75static inline int valid_stack_ptr(struct thread_info *tinfo,
 76			void *p, unsigned int size, void *end)
 77{
 78	void *t = tinfo;
 79	if (end) {
 80		if (p < end && p >= (end-THREAD_SIZE))
 81			return 1;
 82		else
 83			return 0;
 84	}
 85	return p > t && p < t + THREAD_SIZE - size;
 86}
 87
 88unsigned long
 89print_context_stack(struct thread_info *tinfo,
 90		unsigned long *stack, unsigned long bp,
 91		const struct stacktrace_ops *ops, void *data,
 92		unsigned long *end, int *graph)
 93{
 94	struct stack_frame *frame = (struct stack_frame *)bp;
 95
 96	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
 97		unsigned long addr;
 98
 99		addr = *stack;
100		if (__kernel_text_address(addr)) {
101			if ((unsigned long) stack == bp + sizeof(long)) {
102				ops->address(data, addr, 1);
103				frame = frame->next_frame;
104				bp = (unsigned long) frame;
105			} else {
106				ops->address(data, addr, 0);
107			}
108			print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
109		}
110		stack++;
111	}
112	return bp;
113}
114EXPORT_SYMBOL_GPL(print_context_stack);
115
116unsigned long
117print_context_stack_bp(struct thread_info *tinfo,
118		       unsigned long *stack, unsigned long bp,
119		       const struct stacktrace_ops *ops, void *data,
120		       unsigned long *end, int *graph)
121{
122	struct stack_frame *frame = (struct stack_frame *)bp;
123	unsigned long *ret_addr = &frame->return_address;
 
 
 
 
 
 
 
124
125	while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
126		unsigned long addr = *ret_addr;
127
128		if (!__kernel_text_address(addr))
129			break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
130
131		ops->address(data, addr, 1);
132		frame = frame->next_frame;
133		ret_addr = &frame->return_address;
134		print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
 
 
135	}
136
137	return (unsigned long)frame;
138}
139EXPORT_SYMBOL_GPL(print_context_stack_bp);
140
141static int print_trace_stack(void *data, char *name)
142{
143	printk("%s <%s> ", (char *)data, name);
144	return 0;
 
 
 
 
145}
146
147/*
148 * Print one address/symbol entries per line.
149 */
150static void print_trace_address(void *data, unsigned long addr, int reliable)
151{
152	touch_nmi_watchdog();
153	printk(data);
154	printk_address(addr, reliable);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
155}
156
157static const struct stacktrace_ops print_trace_ops = {
158	.stack			= print_trace_stack,
159	.address		= print_trace_address,
160	.walk_stack		= print_context_stack,
161};
162
163void
164show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
165		unsigned long *stack, unsigned long bp, char *log_lvl)
166{
 
 
 
 
 
 
167	printk("%sCall Trace:\n", log_lvl);
168	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
169}
170
171void show_trace(struct task_struct *task, struct pt_regs *regs,
172		unsigned long *stack, unsigned long bp)
173{
174	show_trace_log_lvl(task, regs, stack, bp, "");
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
175}
176
177void show_stack(struct task_struct *task, unsigned long *sp)
 
178{
179	show_stack_log_lvl(task, NULL, sp, 0, "");
 
 
 
 
 
 
 
 
 
180}
181
182/*
183 * The architecture-independent dump_stack generator
184 */
185void dump_stack(void)
186{
187	unsigned long bp;
188	unsigned long stack;
189
190	bp = stack_frame(current, NULL);
191	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
192		current->pid, current->comm, print_tainted(),
193		init_utsname()->release,
194		(int)strcspn(init_utsname()->version, " "),
195		init_utsname()->version);
196	show_trace(NULL, NULL, &stack, bp);
197}
198EXPORT_SYMBOL(dump_stack);
199
200static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
201static int die_owner = -1;
202static unsigned int die_nest_count;
203
204unsigned __kprobes long oops_begin(void)
205{
206	int cpu;
207	unsigned long flags;
208
209	oops_enter();
210
211	/* racy, but better than risking deadlock. */
212	raw_local_irq_save(flags);
213	cpu = smp_processor_id();
214	if (!arch_spin_trylock(&die_lock)) {
215		if (cpu == die_owner)
216			/* nested oops. should stop eventually */;
217		else
218			arch_spin_lock(&die_lock);
219	}
220	die_nest_count++;
221	die_owner = cpu;
222	console_verbose();
223	bust_spinlocks(1);
224	return flags;
225}
226EXPORT_SYMBOL_GPL(oops_begin);
227
228void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
 
 
229{
230	if (regs && kexec_should_crash(current))
231		crash_kexec(regs);
232
233	bust_spinlocks(0);
234	die_owner = -1;
235	add_taint(TAINT_DIE);
236	die_nest_count--;
237	if (!die_nest_count)
238		/* Nest count reaches zero, release the lock. */
239		arch_spin_unlock(&die_lock);
240	raw_local_irq_restore(flags);
241	oops_exit();
242
 
 
 
243	if (!signr)
244		return;
245	if (in_interrupt())
246		panic("Fatal exception in interrupt");
247	if (panic_on_oops)
248		panic("Fatal exception");
249	do_exit(signr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
250}
 
251
252int __kprobes __die(const char *str, struct pt_regs *regs, long err)
253{
254#ifdef CONFIG_X86_32
255	unsigned short ss;
256	unsigned long sp;
257#endif
258	printk(KERN_DEFAULT
259	       "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
260#ifdef CONFIG_PREEMPT
261	printk("PREEMPT ");
262#endif
263#ifdef CONFIG_SMP
264	printk("SMP ");
265#endif
266#ifdef CONFIG_DEBUG_PAGEALLOC
267	printk("DEBUG_PAGEALLOC");
268#endif
269	printk("\n");
270	if (notify_die(DIE_OOPS, str, regs, err,
271			current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
272		return 1;
273
274	show_regs(regs);
275#ifdef CONFIG_X86_32
276	if (user_mode_vm(regs)) {
277		sp = regs->sp;
278		ss = regs->ss & 0xffff;
279	} else {
280		sp = kernel_stack_pointer(regs);
281		savesegment(ss, ss);
282	}
283	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
284	print_symbol("%s", regs->ip);
285	printk(" SS:ESP %04x:%08lx\n", ss, sp);
286#else
287	/* Executive summary in case the oops scrolled away */
288	printk(KERN_ALERT "RIP ");
289	printk_address(regs->ip, 1);
290	printk(" RSP <%016lx>\n", regs->sp);
291#endif
292	return 0;
293}
 
 
 
 
 
 
 
 
294
295/*
296 * This is gone through when something in the kernel has done something bad
297 * and is about to be terminated:
298 */
299void die(const char *str, struct pt_regs *regs, long err)
300{
301	unsigned long flags = oops_begin();
302	int sig = SIGSEGV;
303
304	if (!user_mode_vm(regs))
305		report_bug(regs->ip, regs);
306
307	if (__die(str, regs, err))
308		sig = 0;
309	oops_end(flags, regs, sig);
310}
311
312static int __init kstack_setup(char *s)
313{
314	ssize_t ret;
315	unsigned long val;
316
317	if (!s)
318		return -EINVAL;
319
320	ret = kstrtoul(s, 0, &val);
321	if (ret)
322		return ret;
323	kstack_depth_to_print = val;
324	return 0;
 
325}
326early_param("kstack", kstack_setup);
327
328static int __init code_bytes_setup(char *s)
329{
330	ssize_t ret;
331	unsigned long val;
332
333	if (!s)
334		return -EINVAL;
335
336	ret = kstrtoul(s, 0, &val);
337	if (ret)
338		return ret;
339
340	code_bytes = val;
341	if (code_bytes > 8192)
342		code_bytes = 8192;
343
344	return 1;
 
 
 
 
345}
346__setup("code_bytes=", code_bytes_setup);
v5.9
  1/*
  2 *  Copyright (C) 1991, 1992  Linus Torvalds
  3 *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
  4 */
  5#include <linux/kallsyms.h>
  6#include <linux/kprobes.h>
  7#include <linux/uaccess.h>
  8#include <linux/utsname.h>
  9#include <linux/hardirq.h>
 10#include <linux/kdebug.h>
 11#include <linux/module.h>
 12#include <linux/ptrace.h>
 13#include <linux/sched/debug.h>
 14#include <linux/sched/task_stack.h>
 15#include <linux/ftrace.h>
 16#include <linux/kexec.h>
 17#include <linux/bug.h>
 18#include <linux/nmi.h>
 19#include <linux/sysfs.h>
 20#include <linux/kasan.h>
 21
 22#include <asm/cpu_entry_area.h>
 23#include <asm/stacktrace.h>
 24#include <asm/unwind.h>
 25
 26int panic_on_unrecovered_nmi;
 27int panic_on_io_nmi;
 
 
 28static int die_counter;
 29
 30static struct pt_regs exec_summary_regs;
 
 
 
 
 31
 32bool in_task_stack(unsigned long *stack, struct task_struct *task,
 33		   struct stack_info *info)
 
 
 
 34{
 35	unsigned long *begin = task_stack_page(task);
 36	unsigned long *end   = task_stack_page(task) + THREAD_SIZE;
 
 37
 38	if (stack < begin || stack >= end)
 39		return false;
 40
 41	info->type	= STACK_TYPE_TASK;
 42	info->begin	= begin;
 43	info->end	= end;
 44	info->next_sp	= NULL;
 45
 46	return true;
 47}
 48
 49bool in_entry_stack(unsigned long *stack, struct stack_info *info)
 50{
 51	struct entry_stack *ss = cpu_entry_stack(smp_processor_id());
 52
 53	void *begin = ss;
 54	void *end = ss + 1;
 55
 56	if ((void *)stack < begin || (void *)stack >= end)
 57		return false;
 
 
 
 
 
 
 
 58
 59	info->type	= STACK_TYPE_ENTRY;
 60	info->begin	= begin;
 61	info->end	= end;
 62	info->next_sp	= NULL;
 
 
 63
 64	return true;
 
 
 
 
 
 
 
 
 
 
 65}
 66
 67static void printk_stack_address(unsigned long address, int reliable,
 68				 const char *log_lvl)
 69{
 70	touch_nmi_watchdog();
 71	printk("%s %s%pB\n", log_lvl, reliable ? "" : "? ", (void *)address);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 72}
 
 73
 74static int copy_code(struct pt_regs *regs, u8 *buf, unsigned long src,
 75		     unsigned int nbytes)
 
 
 
 76{
 77	if (!user_mode(regs))
 78		return copy_from_kernel_nofault(buf, (u8 *)src, nbytes);
 79
 80	/*
 81	 * Make sure userspace isn't trying to trick us into dumping kernel
 82	 * memory by pointing the userspace instruction pointer at it.
 83	 */
 84	if (__chk_range_not_ok(src, nbytes, TASK_SIZE_MAX))
 85		return -EINVAL;
 86
 87	return copy_from_user_nmi(buf, (void __user *)src, nbytes);
 88}
 89
 90/*
 91 * There are a couple of reasons for the 2/3rd prologue, courtesy of Linus:
 92 *
 93 * In case where we don't have the exact kernel image (which, if we did, we can
 94 * simply disassemble and navigate to the RIP), the purpose of the bigger
 95 * prologue is to have more context and to be able to correlate the code from
 96 * the different toolchains better.
 97 *
 98 * In addition, it helps in recreating the register allocation of the failing
 99 * kernel and thus make sense of the register dump.
100 *
101 * What is more, the additional complication of a variable length insn arch like
102 * x86 warrants having longer byte sequence before rIP so that the disassembler
103 * can "sync" up properly and find instruction boundaries when decoding the
104 * opcode bytes.
105 *
106 * Thus, the 2/3rds prologue and 64 byte OPCODE_BUFSIZE is just a random
107 * guesstimate in attempt to achieve all of the above.
108 */
109void show_opcodes(struct pt_regs *regs, const char *loglvl)
110{
111#define PROLOGUE_SIZE 42
112#define EPILOGUE_SIZE 21
113#define OPCODE_BUFSIZE (PROLOGUE_SIZE + 1 + EPILOGUE_SIZE)
114	u8 opcodes[OPCODE_BUFSIZE];
115	unsigned long prologue = regs->ip - PROLOGUE_SIZE;
116
117	if (copy_code(regs, opcodes, prologue, sizeof(opcodes))) {
118		printk("%sCode: Bad RIP value.\n", loglvl);
119	} else {
120		printk("%sCode: %" __stringify(PROLOGUE_SIZE) "ph <%02x> %"
121		       __stringify(EPILOGUE_SIZE) "ph\n", loglvl, opcodes,
122		       opcodes[PROLOGUE_SIZE], opcodes + PROLOGUE_SIZE + 1);
123	}
 
 
124}
 
125
126void show_ip(struct pt_regs *regs, const char *loglvl)
127{
128#ifdef CONFIG_X86_32
129	printk("%sEIP: %pS\n", loglvl, (void *)regs->ip);
130#else
131	printk("%sRIP: %04x:%pS\n", loglvl, (int)regs->cs, (void *)regs->ip);
132#endif
133	show_opcodes(regs, loglvl);
134}
135
136void show_iret_regs(struct pt_regs *regs, const char *log_lvl)
 
 
 
137{
138	show_ip(regs, log_lvl);
139	printk("%sRSP: %04x:%016lx EFLAGS: %08lx", log_lvl, (int)regs->ss,
140		regs->sp, regs->flags);
141}
142
143static void show_regs_if_on_stack(struct stack_info *info, struct pt_regs *regs,
144				  bool partial, const char *log_lvl)
145{
146	/*
147	 * These on_stack() checks aren't strictly necessary: the unwind code
148	 * has already validated the 'regs' pointer.  The checks are done for
149	 * ordering reasons: if the registers are on the next stack, we don't
150	 * want to print them out yet.  Otherwise they'll be shown as part of
151	 * the wrong stack.  Later, when show_trace_log_lvl() switches to the
152	 * next stack, this function will be called again with the same regs so
153	 * they can be printed in the right context.
154	 */
155	if (!partial && on_stack(info, regs, sizeof(*regs))) {
156		__show_regs(regs, SHOW_REGS_SHORT, log_lvl);
157
158	} else if (partial && on_stack(info, (void *)regs + IRET_FRAME_OFFSET,
159				       IRET_FRAME_SIZE)) {
160		/*
161		 * When an interrupt or exception occurs in entry code, the
162		 * full pt_regs might not have been saved yet.  In that case
163		 * just print the iret frame.
164		 */
165		show_iret_regs(regs, log_lvl);
166	}
167}
168
169void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
170			unsigned long *stack, const char *log_lvl)
 
 
 
 
 
 
 
171{
172	struct unwind_state state;
173	struct stack_info stack_info = {0};
174	unsigned long visit_mask = 0;
175	int graph_idx = 0;
176	bool partial = false;
177
178	printk("%sCall Trace:\n", log_lvl);
 
 
179
180	unwind_start(&state, task, regs, stack);
181	stack = stack ? : get_stack_pointer(task, regs);
182	regs = unwind_get_entry_regs(&state, &partial);
183
184	/*
185	 * Iterate through the stacks, starting with the current stack pointer.
186	 * Each stack has a pointer to the next one.
187	 *
188	 * x86-64 can have several stacks:
189	 * - task stack
190	 * - interrupt stack
191	 * - HW exception stacks (double fault, nmi, debug, mce)
192	 * - entry stack
193	 *
194	 * x86-32 can have up to four stacks:
195	 * - task stack
196	 * - softirq stack
197	 * - hardirq stack
198	 * - entry stack
199	 */
200	for ( ; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) {
201		const char *stack_name;
202
203		if (get_stack_info(stack, task, &stack_info, &visit_mask)) {
204			/*
205			 * We weren't on a valid stack.  It's possible that
206			 * we overflowed a valid stack into a guard page.
207			 * See if the next page up is valid so that we can
208			 * generate some kind of backtrace if this happens.
209			 */
210			stack = (unsigned long *)PAGE_ALIGN((unsigned long)stack);
211			if (get_stack_info(stack, task, &stack_info, &visit_mask))
212				break;
213		}
214
215		stack_name = stack_type_name(stack_info.type);
216		if (stack_name)
217			printk("%s <%s>\n", log_lvl, stack_name);
218
219		if (regs)
220			show_regs_if_on_stack(&stack_info, regs, partial, log_lvl);
221
222		/*
223		 * Scan the stack, printing any text addresses we find.  At the
224		 * same time, follow proper stack frames with the unwinder.
225		 *
226		 * Addresses found during the scan which are not reported by
227		 * the unwinder are considered to be additional clues which are
228		 * sometimes useful for debugging and are prefixed with '?'.
229		 * This also serves as a failsafe option in case the unwinder
230		 * goes off in the weeds.
231		 */
232		for (; stack < stack_info.end; stack++) {
233			unsigned long real_addr;
234			int reliable = 0;
235			unsigned long addr = READ_ONCE_NOCHECK(*stack);
236			unsigned long *ret_addr_p =
237				unwind_get_return_address_ptr(&state);
238
239			if (!__kernel_text_address(addr))
240				continue;
241
242			/*
243			 * Don't print regs->ip again if it was already printed
244			 * by show_regs_if_on_stack().
245			 */
246			if (regs && stack == &regs->ip)
247				goto next;
248
249			if (stack == ret_addr_p)
250				reliable = 1;
251
252			/*
253			 * When function graph tracing is enabled for a
254			 * function, its return address on the stack is
255			 * replaced with the address of an ftrace handler
256			 * (return_to_handler).  In that case, before printing
257			 * the "real" address, we want to print the handler
258			 * address as an "unreliable" hint that function graph
259			 * tracing was involved.
260			 */
261			real_addr = ftrace_graph_ret_addr(task, &graph_idx,
262							  addr, stack);
263			if (real_addr != addr)
264				printk_stack_address(addr, 0, log_lvl);
265			printk_stack_address(real_addr, reliable, log_lvl);
266
267			if (!reliable)
268				continue;
269
270next:
271			/*
272			 * Get the next frame from the unwinder.  No need to
273			 * check for an error: if anything goes wrong, the rest
274			 * of the addresses will just be printed as unreliable.
275			 */
276			unwind_next_frame(&state);
277
278			/* if the frame has entry regs, print them */
279			regs = unwind_get_entry_regs(&state, &partial);
280			if (regs)
281				show_regs_if_on_stack(&stack_info, regs, partial, log_lvl);
282		}
283
284		if (stack_name)
285			printk("%s </%s>\n", log_lvl, stack_name);
286	}
287}
288
289void show_stack(struct task_struct *task, unsigned long *sp,
290		       const char *loglvl)
291{
292	task = task ? : current;
293
294	/*
295	 * Stack frames below this one aren't interesting.  Don't show them
296	 * if we're printing for %current.
297	 */
298	if (!sp && task == current)
299		sp = get_stack_pointer(current, NULL);
300
301	show_trace_log_lvl(task, NULL, sp, loglvl);
302}
303
304void show_stack_regs(struct pt_regs *regs)
 
 
 
305{
306	show_trace_log_lvl(current, regs, NULL, KERN_DEFAULT);
 
 
 
 
 
 
 
 
 
307}
 
308
309static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
310static int die_owner = -1;
311static unsigned int die_nest_count;
312
313unsigned long oops_begin(void)
314{
315	int cpu;
316	unsigned long flags;
317
318	oops_enter();
319
320	/* racy, but better than risking deadlock. */
321	raw_local_irq_save(flags);
322	cpu = smp_processor_id();
323	if (!arch_spin_trylock(&die_lock)) {
324		if (cpu == die_owner)
325			/* nested oops. should stop eventually */;
326		else
327			arch_spin_lock(&die_lock);
328	}
329	die_nest_count++;
330	die_owner = cpu;
331	console_verbose();
332	bust_spinlocks(1);
333	return flags;
334}
335NOKPROBE_SYMBOL(oops_begin);
336
337void __noreturn rewind_stack_do_exit(int signr);
338
339void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
340{
341	if (regs && kexec_should_crash(current))
342		crash_kexec(regs);
343
344	bust_spinlocks(0);
345	die_owner = -1;
346	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
347	die_nest_count--;
348	if (!die_nest_count)
349		/* Nest count reaches zero, release the lock. */
350		arch_spin_unlock(&die_lock);
351	raw_local_irq_restore(flags);
352	oops_exit();
353
354	/* Executive summary in case the oops scrolled away */
355	__show_regs(&exec_summary_regs, SHOW_REGS_ALL, KERN_DEFAULT);
356
357	if (!signr)
358		return;
359	if (in_interrupt())
360		panic("Fatal exception in interrupt");
361	if (panic_on_oops)
362		panic("Fatal exception");
363
364	/*
365	 * We're not going to return, but we might be on an IST stack or
366	 * have very little stack space left.  Rewind the stack and kill
367	 * the task.
368	 * Before we rewind the stack, we have to tell KASAN that we're going to
369	 * reuse the task stack and that existing poisons are invalid.
370	 */
371	kasan_unpoison_task_stack(current);
372	rewind_stack_do_exit(signr);
373}
374NOKPROBE_SYMBOL(oops_end);
375
376static void __die_header(const char *str, struct pt_regs *regs, long err)
377{
378	const char *pr = "";
379
380	/* Save the regs of the first oops for the executive summary later. */
381	if (!die_counter)
382		exec_summary_regs = *regs;
383
384	if (IS_ENABLED(CONFIG_PREEMPTION))
385		pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT";
386
387	printk(KERN_DEFAULT
388	       "%s: %04lx [#%d]%s%s%s%s%s\n", str, err & 0xffff, ++die_counter,
389	       pr,
390	       IS_ENABLED(CONFIG_SMP)     ? " SMP"             : "",
391	       debug_pagealloc_enabled()  ? " DEBUG_PAGEALLOC" : "",
392	       IS_ENABLED(CONFIG_KASAN)   ? " KASAN"           : "",
393	       IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION) ?
394	       (boot_cpu_has(X86_FEATURE_PTI) ? " PTI" : " NOPTI") : "");
395}
396NOKPROBE_SYMBOL(__die_header);
397
398static int __die_body(const char *str, struct pt_regs *regs, long err)
399{
400	show_regs(regs);
401	print_modules();
402
 
 
 
 
 
 
 
 
 
 
 
 
 
403	if (notify_die(DIE_OOPS, str, regs, err,
404			current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
405		return 1;
406
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
407	return 0;
408}
409NOKPROBE_SYMBOL(__die_body);
410
411int __die(const char *str, struct pt_regs *regs, long err)
412{
413	__die_header(str, regs, err);
414	return __die_body(str, regs, err);
415}
416NOKPROBE_SYMBOL(__die);
417
418/*
419 * This is gone through when something in the kernel has done something bad
420 * and is about to be terminated:
421 */
422void die(const char *str, struct pt_regs *regs, long err)
423{
424	unsigned long flags = oops_begin();
425	int sig = SIGSEGV;
426
 
 
 
427	if (__die(str, regs, err))
428		sig = 0;
429	oops_end(flags, regs, sig);
430}
431
432void die_addr(const char *str, struct pt_regs *regs, long err, long gp_addr)
433{
434	unsigned long flags = oops_begin();
435	int sig = SIGSEGV;
 
 
 
436
437	__die_header(str, regs, err);
438	if (gp_addr)
439		kasan_non_canonical_hook(gp_addr);
440	if (__die_body(str, regs, err))
441		sig = 0;
442	oops_end(flags, regs, sig);
443}
 
444
445void show_regs(struct pt_regs *regs)
446{
447	enum show_regs_mode print_kernel_regs;
 
 
 
 
448
449	show_regs_print_info(KERN_DEFAULT);
 
 
450
451	print_kernel_regs = user_mode(regs) ? SHOW_REGS_USER : SHOW_REGS_ALL;
452	__show_regs(regs, print_kernel_regs, KERN_DEFAULT);
 
453
454	/*
455	 * When in-kernel, we also print out the stack at the time of the fault..
456	 */
457	if (!user_mode(regs))
458		show_trace_log_lvl(current, regs, NULL, KERN_DEFAULT);
459}