drm: merge Linux master into HEAD
[linux-2.6] / arch / x86 / kernel / dumpstack.c
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/kexec.h>
14 #include <linux/bug.h>
15 #include <linux/nmi.h>
16 #include <linux/sysfs.h>
17
18 #include <asm/stacktrace.h>
19
20 #include "dumpstack.h"
21
22 int panic_on_unrecovered_nmi;
23 unsigned int code_bytes = 64;
24 int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
25 static int die_counter;
26
27 void printk_address(unsigned long address, int reliable)
28 {
29         printk(" [<%p>] %s%pS\n", (void *) address,
30                         reliable ? "" : "? ", (void *) address);
31 }
32
33 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
34 static void
35 print_ftrace_graph_addr(unsigned long addr, void *data,
36                         const struct stacktrace_ops *ops,
37                         struct thread_info *tinfo, int *graph)
38 {
39         struct task_struct *task = tinfo->task;
40         unsigned long ret_addr;
41         int index = task->curr_ret_stack;
42
43         if (addr != (unsigned long)return_to_handler)
44                 return;
45
46         if (!task->ret_stack || index < *graph)
47                 return;
48
49         index -= *graph;
50         ret_addr = task->ret_stack[index].ret;
51
52         ops->address(data, ret_addr, 1);
53
54         (*graph)++;
55 }
56 #else
57 static inline void
58 print_ftrace_graph_addr(unsigned long addr, void *data,
59                         const struct stacktrace_ops *ops,
60                         struct thread_info *tinfo, int *graph)
61 { }
62 #endif
63
64 /*
65  * x86-64 can have up to three kernel stacks:
66  * process stack
67  * interrupt stack
68  * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
69  */
70
71 static inline int valid_stack_ptr(struct thread_info *tinfo,
72                         void *p, unsigned int size, void *end)
73 {
74         void *t = tinfo;
75         if (end) {
76                 if (p < end && p >= (end-THREAD_SIZE))
77                         return 1;
78                 else
79                         return 0;
80         }
81         return p > t && p < t + THREAD_SIZE - size;
82 }
83
84 unsigned long
85 print_context_stack(struct thread_info *tinfo,
86                 unsigned long *stack, unsigned long bp,
87                 const struct stacktrace_ops *ops, void *data,
88                 unsigned long *end, int *graph)
89 {
90         struct stack_frame *frame = (struct stack_frame *)bp;
91
92         while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
93                 unsigned long addr;
94
95                 addr = *stack;
96                 if (__kernel_text_address(addr)) {
97                         if ((unsigned long) stack == bp + sizeof(long)) {
98                                 ops->address(data, addr, 1);
99                                 frame = frame->next_frame;
100                                 bp = (unsigned long) frame;
101                         } else {
102                                 ops->address(data, addr, 0);
103                         }
104                         print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
105                 }
106                 stack++;
107         }
108         return bp;
109 }
110
111
112 static void
113 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
114 {
115         printk(data);
116         print_symbol(msg, symbol);
117         printk("\n");
118 }
119
120 static void print_trace_warning(void *data, char *msg)
121 {
122         printk("%s%s\n", (char *)data, msg);
123 }
124
125 static int print_trace_stack(void *data, char *name)
126 {
127         printk("%s <%s> ", (char *)data, name);
128         return 0;
129 }
130
131 /*
132  * Print one address/symbol entries per line.
133  */
134 static void print_trace_address(void *data, unsigned long addr, int reliable)
135 {
136         touch_nmi_watchdog();
137         printk(data);
138         printk_address(addr, reliable);
139 }
140
141 static const struct stacktrace_ops print_trace_ops = {
142         .warning = print_trace_warning,
143         .warning_symbol = print_trace_warning_symbol,
144         .stack = print_trace_stack,
145         .address = print_trace_address,
146 };
147
148 void
149 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
150                 unsigned long *stack, unsigned long bp, char *log_lvl)
151 {
152         printk("%sCall Trace:\n", log_lvl);
153         dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
154 }
155
156 void show_trace(struct task_struct *task, struct pt_regs *regs,
157                 unsigned long *stack, unsigned long bp)
158 {
159         show_trace_log_lvl(task, regs, stack, bp, "");
160 }
161
162 void show_stack(struct task_struct *task, unsigned long *sp)
163 {
164         show_stack_log_lvl(task, NULL, sp, 0, "");
165 }
166
167 /*
168  * The architecture-independent dump_stack generator
169  */
170 void dump_stack(void)
171 {
172         unsigned long bp = 0;
173         unsigned long stack;
174
175 #ifdef CONFIG_FRAME_POINTER
176         if (!bp)
177                 get_bp(bp);
178 #endif
179
180         printk("Pid: %d, comm: %.20s %s %s %.*s\n",
181                 current->pid, current->comm, print_tainted(),
182                 init_utsname()->release,
183                 (int)strcspn(init_utsname()->version, " "),
184                 init_utsname()->version);
185         show_trace(NULL, NULL, &stack, bp);
186 }
187 EXPORT_SYMBOL(dump_stack);
188
189 static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
190 static int die_owner = -1;
191 static unsigned int die_nest_count;
192
193 unsigned __kprobes long oops_begin(void)
194 {
195         int cpu;
196         unsigned long flags;
197
198         oops_enter();
199
200         /* racy, but better than risking deadlock. */
201         raw_local_irq_save(flags);
202         cpu = smp_processor_id();
203         if (!__raw_spin_trylock(&die_lock)) {
204                 if (cpu == die_owner)
205                         /* nested oops. should stop eventually */;
206                 else
207                         __raw_spin_lock(&die_lock);
208         }
209         die_nest_count++;
210         die_owner = cpu;
211         console_verbose();
212         bust_spinlocks(1);
213         return flags;
214 }
215
216 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
217 {
218         if (regs && kexec_should_crash(current))
219                 crash_kexec(regs);
220
221         bust_spinlocks(0);
222         die_owner = -1;
223         add_taint(TAINT_DIE);
224         die_nest_count--;
225         if (!die_nest_count)
226                 /* Nest count reaches zero, release the lock. */
227                 __raw_spin_unlock(&die_lock);
228         raw_local_irq_restore(flags);
229         oops_exit();
230
231         if (!signr)
232                 return;
233         if (in_interrupt())
234                 panic("Fatal exception in interrupt");
235         if (panic_on_oops)
236                 panic("Fatal exception");
237         do_exit(signr);
238 }
239
240 int __kprobes __die(const char *str, struct pt_regs *regs, long err)
241 {
242 #ifdef CONFIG_X86_32
243         unsigned short ss;
244         unsigned long sp;
245 #endif
246         printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
247 #ifdef CONFIG_PREEMPT
248         printk("PREEMPT ");
249 #endif
250 #ifdef CONFIG_SMP
251         printk("SMP ");
252 #endif
253 #ifdef CONFIG_DEBUG_PAGEALLOC
254         printk("DEBUG_PAGEALLOC");
255 #endif
256         printk("\n");
257         sysfs_printk_last_file();
258         if (notify_die(DIE_OOPS, str, regs, err,
259                         current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
260                 return 1;
261
262         show_registers(regs);
263 #ifdef CONFIG_X86_32
264         sp = (unsigned long) (&regs->sp);
265         savesegment(ss, ss);
266         if (user_mode(regs)) {
267                 sp = regs->sp;
268                 ss = regs->ss & 0xffff;
269         }
270         printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
271         print_symbol("%s", regs->ip);
272         printk(" SS:ESP %04x:%08lx\n", ss, sp);
273 #else
274         /* Executive summary in case the oops scrolled away */
275         printk(KERN_ALERT "RIP ");
276         printk_address(regs->ip, 1);
277         printk(" RSP <%016lx>\n", regs->sp);
278 #endif
279         return 0;
280 }
281
282 /*
283  * This is gone through when something in the kernel has done something bad
284  * and is about to be terminated:
285  */
286 void die(const char *str, struct pt_regs *regs, long err)
287 {
288         unsigned long flags = oops_begin();
289         int sig = SIGSEGV;
290
291         if (!user_mode_vm(regs))
292                 report_bug(regs->ip, regs);
293
294         if (__die(str, regs, err))
295                 sig = 0;
296         oops_end(flags, regs, sig);
297 }
298
299 void notrace __kprobes
300 die_nmi(char *str, struct pt_regs *regs, int do_panic)
301 {
302         unsigned long flags;
303
304         if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
305                 return;
306
307         /*
308          * We are in trouble anyway, lets at least try
309          * to get a message out.
310          */
311         flags = oops_begin();
312         printk(KERN_EMERG "%s", str);
313         printk(" on CPU%d, ip %08lx, registers:\n",
314                 smp_processor_id(), regs->ip);
315         show_registers(regs);
316         oops_end(flags, regs, 0);
317         if (do_panic || panic_on_oops)
318                 panic("Non maskable interrupt");
319         nmi_exit();
320         local_irq_enable();
321         do_exit(SIGBUS);
322 }
323
324 static int __init oops_setup(char *s)
325 {
326         if (!s)
327                 return -EINVAL;
328         if (!strcmp(s, "panic"))
329                 panic_on_oops = 1;
330         return 0;
331 }
332 early_param("oops", oops_setup);
333
334 static int __init kstack_setup(char *s)
335 {
336         if (!s)
337                 return -EINVAL;
338         kstack_depth_to_print = simple_strtoul(s, NULL, 0);
339         return 0;
340 }
341 early_param("kstack", kstack_setup);
342
343 static int __init code_bytes_setup(char *s)
344 {
345         code_bytes = simple_strtoul(s, NULL, 0);
346         if (code_bytes > 8192)
347                 code_bytes = 8192;
348
349         return 1;
350 }
351 __setup("code_bytes=", code_bytes_setup);