git.oblomov.eu Git - linux-2.6/blob - 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 #include <linux/ftrace.h>
  18
  19 #include <asm/stacktrace.h>
  20
  21 #include "dumpstack.h"
  22
  23 int panic_on_unrecovered_nmi;
  24 unsigned int code_bytes = 64;
  25 int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
  26 static int die_counter;
  27
  28 void printk_address(unsigned long address, int reliable)
  29 {
  30         printk(" [<%p>] %s%pS\n", (void *) address,
  31                         reliable ? "" : "? ", (void *) address);
  32 }
  33
  34 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  35 static void
  36 print_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 = tinfo->task;
  41         unsigned long ret_addr;
  42         int index = task->curr_ret_stack;
  43
  44         if (addr != (unsigned long)return_to_handler)
  45                 return;
  46
  47         if (!task->ret_stack || index < *graph)
  48                 return;
  49
  50         index -= *graph;
  51         ret_addr = task->ret_stack[index].ret;
  52
  53         ops->address(data, ret_addr, 1);
  54
  55         (*graph)++;
  56 }
  57 #else
  58 static inline void
  59 print_ftrace_graph_addr(unsigned long addr, void *data,
  60                         const struct stacktrace_ops *ops,
  61                         struct thread_info *tinfo, int *graph)
  62 { }
  63 #endif
  64
  65 /*
  66  * x86-64 can have up to three kernel stacks:
  67  * process stack
  68  * interrupt stack
  69  * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
  70  */
  71
  72 static inline int valid_stack_ptr(struct thread_info *tinfo,
  73                         void *p, unsigned int size, void *end)
  74 {
  75         void *t = tinfo;
  76         if (end) {
  77                 if (p < end && p >= (end-THREAD_SIZE))
  78                         return 1;
  79                 else
  80                         return 0;
  81         }
  82         return p > t && p < t + THREAD_SIZE - size;
  83 }
  84
  85 unsigned long
  86 print_context_stack(struct thread_info *tinfo,
  87                 unsigned long *stack, unsigned long bp,
  88                 const struct stacktrace_ops *ops, void *data,
  89                 unsigned long *end, int *graph)
  90 {
  91         struct stack_frame *frame = (struct stack_frame *)bp;
  92
  93         while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
  94                 unsigned long addr;
  95
  96                 addr = *stack;
  97                 if (__kernel_text_address(addr)) {
  98                         if ((unsigned long) stack == bp + sizeof(long)) {
  99                                 ops->address(data, addr, 1);
 100                                 frame = frame->next_frame;
 101                                 bp = (unsigned long) frame;
 102                         } else {
 103                                 ops->address(data, addr, bp == 0);
 104                         }
 105                         print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
 106                 }
 107                 stack++;
 108         }
 109         return bp;
 110 }
 111
 112
 113 static void
 114 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
 115 {
 116         printk(data);
 117         print_symbol(msg, symbol);
 118         printk("\n");
 119 }
 120
 121 static void print_trace_warning(void *data, char *msg)
 122 {
 123         printk("%s%s\n", (char *)data, msg);
 124 }
 125
 126 static int print_trace_stack(void *data, char *name)
 127 {
 128         printk("%s <%s> ", (char *)data, name);
 129         return 0;
 130 }
 131
 132 /*
 133  * Print one address/symbol entries per line.
 134  */
 135 static void print_trace_address(void *data, unsigned long addr, int reliable)
 136 {
 137         touch_nmi_watchdog();
 138         printk(data);
 139         printk_address(addr, reliable);
 140 }
 141
 142 static const struct stacktrace_ops print_trace_ops = {
 143         .warning = print_trace_warning,
 144         .warning_symbol = print_trace_warning_symbol,
 145         .stack = print_trace_stack,
 146         .address = print_trace_address,
 147 };
 148
 149 void
 150 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
 151                 unsigned long *stack, unsigned long bp, char *log_lvl)
 152 {
 153         printk("%sCall Trace:\n", log_lvl);
 154         dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
 155 }
 156
 157 void show_trace(struct task_struct *task, struct pt_regs *regs,
 158                 unsigned long *stack, unsigned long bp)
 159 {
 160         show_trace_log_lvl(task, regs, stack, bp, "");
 161 }
 162
 163 void show_stack(struct task_struct *task, unsigned long *sp)
 164 {
 165         show_stack_log_lvl(task, NULL, sp, 0, "");
 166 }
 167
 168 /*
 169  * The architecture-independent dump_stack generator
 170  */
 171 void dump_stack(void)
 172 {
 173         unsigned long bp = 0;
 174         unsigned long stack;
 175
 176 #ifdef CONFIG_FRAME_POINTER
 177         if (!bp)
 178                 get_bp(bp);
 179 #endif
 180
 181         printk("Pid: %d, comm: %.20s %s %s %.*s\n",
 182                 current->pid, current->comm, print_tainted(),
 183                 init_utsname()->release,
 184                 (int)strcspn(init_utsname()->version, " "),
 185                 init_utsname()->version);
 186         show_trace(NULL, NULL, &stack, bp);
 187 }
 188 EXPORT_SYMBOL(dump_stack);
 189
 190 static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
 191 static int die_owner = -1;
 192 static unsigned int die_nest_count;
 193
 194 unsigned __kprobes long oops_begin(void)
 195 {
 196         int cpu;
 197         unsigned long flags;
 198
 199         /* notify the hw-branch tracer so it may disable tracing and
 200            add the last trace to the trace buffer -
 201            the earlier this happens, the more useful the trace. */
 202         trace_hw_branch_oops();
 203
 204         oops_enter();
 205
 206         /* racy, but better than risking deadlock. */
 207         raw_local_irq_save(flags);
 208         cpu = smp_processor_id();
 209         if (!__raw_spin_trylock(&die_lock)) {
 210                 if (cpu == die_owner)
 211                         /* nested oops. should stop eventually */;
 212                 else
 213                         __raw_spin_lock(&die_lock);
 214         }
 215         die_nest_count++;
 216         die_owner = cpu;
 217         console_verbose();
 218         bust_spinlocks(1);
 219         return flags;
 220 }
 221
 222 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
 223 {
 224         if (regs && kexec_should_crash(current))
 225                 crash_kexec(regs);
 226
 227         bust_spinlocks(0);
 228         die_owner = -1;
 229         add_taint(TAINT_DIE);
 230         die_nest_count--;
 231         if (!die_nest_count)
 232                 /* Nest count reaches zero, release the lock. */
 233                 __raw_spin_unlock(&die_lock);
 234         raw_local_irq_restore(flags);
 235         oops_exit();
 236
 237         if (!signr)
 238                 return;
 239         if (in_interrupt())
 240                 panic("Fatal exception in interrupt");
 241         if (panic_on_oops)
 242                 panic("Fatal exception");
 243         do_exit(signr);
 244 }
 245
 246 int __kprobes __die(const char *str, struct pt_regs *regs, long err)
 247 {
 248 #ifdef CONFIG_X86_32
 249         unsigned short ss;
 250         unsigned long sp;
 251 #endif
 252         printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
 253 #ifdef CONFIG_PREEMPT
 254         printk("PREEMPT ");
 255 #endif
 256 #ifdef CONFIG_SMP
 257         printk("SMP ");
 258 #endif
 259 #ifdef CONFIG_DEBUG_PAGEALLOC
 260         printk("DEBUG_PAGEALLOC");
 261 #endif
 262         printk("\n");
 263         sysfs_printk_last_file();
 264         if (notify_die(DIE_OOPS, str, regs, err,
 265                         current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
 266                 return 1;
 267
 268         show_registers(regs);
 269 #ifdef CONFIG_X86_32
 270         sp = (unsigned long) (&regs->sp);
 271         savesegment(ss, ss);
 272         if (user_mode(regs)) {
 273                 sp = regs->sp;
 274                 ss = regs->ss & 0xffff;
 275         }
 276         printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
 277         print_symbol("%s", regs->ip);
 278         printk(" SS:ESP %04x:%08lx\n", ss, sp);
 279 #else
 280         /* Executive summary in case the oops scrolled away */
 281         printk(KERN_ALERT "RIP ");
 282         printk_address(regs->ip, 1);
 283         printk(" RSP <%016lx>\n", regs->sp);
 284 #endif
 285         return 0;
 286 }
 287
 288 /*
 289  * This is gone through when something in the kernel has done something bad
 290  * and is about to be terminated:
 291  */
 292 void die(const char *str, struct pt_regs *regs, long err)
 293 {
 294         unsigned long flags = oops_begin();
 295         int sig = SIGSEGV;
 296
 297         if (!user_mode_vm(regs))
 298                 report_bug(regs->ip, regs);
 299
 300         if (__die(str, regs, err))
 301                 sig = 0;
 302         oops_end(flags, regs, sig);
 303 }
 304
 305 void notrace __kprobes
 306 die_nmi(char *str, struct pt_regs *regs, int do_panic)
 307 {
 308         unsigned long flags;
 309
 310         if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
 311                 return;
 312
 313         /*
 314          * We are in trouble anyway, lets at least try
 315          * to get a message out.
 316          */
 317         flags = oops_begin();
 318         printk(KERN_EMERG "%s", str);
 319         printk(" on CPU%d, ip %08lx, registers:\n",
 320                 smp_processor_id(), regs->ip);
 321         show_registers(regs);
 322         oops_end(flags, regs, 0);
 323         if (do_panic || panic_on_oops)
 324                 panic("Non maskable interrupt");
 325         nmi_exit();
 326         local_irq_enable();
 327         do_exit(SIGBUS);
 328 }
 329
 330 static int __init oops_setup(char *s)
 331 {
 332         if (!s)
 333                 return -EINVAL;
 334         if (!strcmp(s, "panic"))
 335                 panic_on_oops = 1;
 336         return 0;
 337 }
 338 early_param("oops", oops_setup);
 339
 340 static int __init kstack_setup(char *s)
 341 {
 342         if (!s)
 343                 return -EINVAL;
 344         kstack_depth_to_print = simple_strtoul(s, NULL, 0);
 345         return 0;
 346 }
 347 early_param("kstack", kstack_setup);
 348
 349 static int __init code_bytes_setup(char *s)
 350 {
 351         code_bytes = simple_strtoul(s, NULL, 0);
 352         if (code_bytes > 8192)
 353                 code_bytes = 8192;
 354
 355         return 1;
 356 }
 357 __setup("code_bytes=", code_bytes_setup);