2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
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/kexec.h>
14 #include <linux/bug.h>
15 #include <linux/nmi.h>
16 #include <linux/sysfs.h>
18 #include <asm/stacktrace.h>
20 #include "dumpstack.h"
22 static unsigned long *in_exception_stack(unsigned cpu
, unsigned long stack
,
23 unsigned *usedp
, char **idp
)
25 static char ids
[][8] = {
26 [DEBUG_STACK
- 1] = "#DB",
27 [NMI_STACK
- 1] = "NMI",
28 [DOUBLEFAULT_STACK
- 1] = "#DF",
29 [STACKFAULT_STACK
- 1] = "#SS",
30 [MCE_STACK
- 1] = "#MC",
31 #if DEBUG_STKSZ > EXCEPTION_STKSZ
32 [N_EXCEPTION_STACKS
...
33 N_EXCEPTION_STACKS
+ DEBUG_STKSZ
/ EXCEPTION_STKSZ
- 2] = "#DB[?]"
39 * Iterate over all exception stacks, and figure out whether
40 * 'stack' is in one of them:
42 for (k
= 0; k
< N_EXCEPTION_STACKS
; k
++) {
43 unsigned long end
= per_cpu(orig_ist
, cpu
).ist
[k
];
45 * Is 'stack' above this exception frame's end?
46 * If yes then skip to the next frame.
51 * Is 'stack' above this exception frame's start address?
52 * If yes then we found the right frame.
54 if (stack
>= end
- EXCEPTION_STKSZ
) {
56 * Make sure we only iterate through an exception
57 * stack once. If it comes up for the second time
58 * then there's something wrong going on - just
59 * break out and return NULL:
61 if (*usedp
& (1U << k
))
65 return (unsigned long *)end
;
68 * If this is a debug stack, and if it has a larger size than
69 * the usual exception stacks, then 'stack' might still
70 * be within the lower portion of the debug stack:
72 #if DEBUG_STKSZ > EXCEPTION_STKSZ
73 if (k
== DEBUG_STACK
- 1 && stack
>= end
- DEBUG_STKSZ
) {
74 unsigned j
= N_EXCEPTION_STACKS
- 1;
77 * Black magic. A large debug stack is composed of
78 * multiple exception stack entries, which we
79 * iterate through now. Dont look:
83 end
-= EXCEPTION_STKSZ
;
84 ids
[j
][4] = '1' + (j
- N_EXCEPTION_STACKS
);
85 } while (stack
< end
- EXCEPTION_STKSZ
);
86 if (*usedp
& (1U << j
))
90 return (unsigned long *)end
;
98 * x86-64 can have up to three kernel stacks:
101 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
104 void dump_trace(struct task_struct
*task
, struct pt_regs
*regs
,
105 unsigned long *stack
, unsigned long bp
,
106 const struct stacktrace_ops
*ops
, void *data
)
108 const unsigned cpu
= get_cpu();
109 unsigned long *irqstack_end
= (unsigned long *)cpu_pda(cpu
)->irqstackptr
;
111 struct thread_info
*tinfo
;
120 if (task
&& task
!= current
)
121 stack
= (unsigned long *)task
->thread
.sp
;
124 #ifdef CONFIG_FRAME_POINTER
126 if (task
== current
) {
127 /* Grab bp right from our regs */
130 /* bp is the last reg pushed by switch_to */
131 bp
= *(unsigned long *) task
->thread
.sp
;
137 * Print function call entries in all stacks, starting at the
138 * current stack address. If the stacks consist of nested
141 tinfo
= task_thread_info(task
);
144 unsigned long *estack_end
;
145 estack_end
= in_exception_stack(cpu
, (unsigned long)stack
,
149 if (ops
->stack(data
, id
) < 0)
152 bp
= print_context_stack(tinfo
, stack
, bp
, ops
,
153 data
, estack_end
, &graph
);
154 ops
->stack(data
, "<EOE>");
156 * We link to the next stack via the
157 * second-to-last pointer (index -2 to end) in the
160 stack
= (unsigned long *) estack_end
[-2];
164 unsigned long *irqstack
;
165 irqstack
= irqstack_end
-
166 (IRQSTACKSIZE
- 64) / sizeof(*irqstack
);
168 if (stack
>= irqstack
&& stack
< irqstack_end
) {
169 if (ops
->stack(data
, "IRQ") < 0)
171 bp
= print_context_stack(tinfo
, stack
, bp
,
172 ops
, data
, irqstack_end
, &graph
);
174 * We link to the next stack (which would be
175 * the process stack normally) the last
176 * pointer (index -1 to end) in the IRQ stack:
178 stack
= (unsigned long *) (irqstack_end
[-1]);
180 ops
->stack(data
, "EOI");
188 * This handles the process stack:
190 bp
= print_context_stack(tinfo
, stack
, bp
, ops
, data
, NULL
, &graph
);
193 EXPORT_SYMBOL(dump_trace
);
196 show_stack_log_lvl(struct task_struct
*task
, struct pt_regs
*regs
,
197 unsigned long *sp
, unsigned long bp
, char *log_lvl
)
199 unsigned long *stack
;
201 const int cpu
= smp_processor_id();
202 unsigned long *irqstack_end
=
203 (unsigned long *) (cpu_pda(cpu
)->irqstackptr
);
204 unsigned long *irqstack
=
205 (unsigned long *) (cpu_pda(cpu
)->irqstackptr
- IRQSTACKSIZE
);
208 * debugging aid: "show_stack(NULL, NULL);" prints the
209 * back trace for this cpu.
214 sp
= (unsigned long *)task
->thread
.sp
;
216 sp
= (unsigned long *)&sp
;
220 for (i
= 0; i
< kstack_depth_to_print
; i
++) {
221 if (stack
>= irqstack
&& stack
<= irqstack_end
) {
222 if (stack
== irqstack_end
) {
223 stack
= (unsigned long *) (irqstack_end
[-1]);
227 if (((long) stack
& (THREAD_SIZE
-1)) == 0)
230 if (i
&& ((i
% STACKSLOTS_PER_LINE
) == 0))
231 printk("\n%s", log_lvl
);
232 printk(" %016lx", *stack
++);
233 touch_nmi_watchdog();
236 show_trace_log_lvl(task
, regs
, sp
, bp
, log_lvl
);
239 void show_registers(struct pt_regs
*regs
)
243 const int cpu
= smp_processor_id();
244 struct task_struct
*cur
= cpu_pda(cpu
)->pcurrent
;
247 printk("CPU %d ", cpu
);
248 __show_regs(regs
, 1);
249 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
250 cur
->comm
, cur
->pid
, task_thread_info(cur
), cur
);
253 * When in-kernel, we also print out the stack and code at the
254 * time of the fault..
256 if (!user_mode(regs
)) {
257 unsigned int code_prologue
= code_bytes
* 43 / 64;
258 unsigned int code_len
= code_bytes
;
262 printk(KERN_EMERG
"Stack:\n");
263 show_stack_log_lvl(NULL
, regs
, (unsigned long *)sp
,
264 regs
->bp
, KERN_EMERG
);
266 printk(KERN_EMERG
"Code: ");
268 ip
= (u8
*)regs
->ip
- code_prologue
;
269 if (ip
< (u8
*)PAGE_OFFSET
|| probe_kernel_address(ip
, c
)) {
270 /* try starting at IP */
272 code_len
= code_len
- code_prologue
+ 1;
274 for (i
= 0; i
< code_len
; i
++, ip
++) {
275 if (ip
< (u8
*)PAGE_OFFSET
||
276 probe_kernel_address(ip
, c
)) {
277 printk(" Bad RIP value.");
280 if (ip
== (u8
*)regs
->ip
)
281 printk("<%02x> ", c
);
289 int is_valid_bugaddr(unsigned long ip
)
293 if (__copy_from_user(&ud2
, (const void __user
*) ip
, sizeof(ud2
)))
296 return ud2
== 0x0b0f;
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