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/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
  22 int panic_on_unrecovered_nmi;
  23 int panic_on_io_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, 0);
 104                         }
 105                         print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
 106                 }
 107                 stack++;
 108         }
 109         return bp;
 110 }
 111 EXPORT_SYMBOL_GPL(print_context_stack);
 112
 113 unsigned long
 114 print_context_stack_bp(struct thread_info *tinfo,
 115                        unsigned long *stack, unsigned long bp,
 116                        const struct stacktrace_ops *ops, void *data,
 117                        unsigned long *end, int *graph)
 118 {
 119         struct stack_frame *frame = (struct stack_frame *)bp;
 120         unsigned long *ret_addr = &frame->return_address;
 121
 122         while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
 123                 unsigned long addr = *ret_addr;
 124
 125                 if (!__kernel_text_address(addr))
 126                         break;
 127
 128                 ops->address(data, addr, 1);
 129                 frame = frame->next_frame;
 130                 ret_addr = &frame->return_address;
 131                 print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
 132         }
 133
 134         return (unsigned long)frame;
 135 }
 136 EXPORT_SYMBOL_GPL(print_context_stack_bp);
 137
 138
 139 static void
 140 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
 141 {
 142         printk(data);
 143         print_symbol(msg, symbol);
 144         printk("\n");
 145 }
 146
 147 static void print_trace_warning(void *data, char *msg)
 148 {
 149         printk("%s%s\n", (char *)data, msg);
 150 }
 151
 152 static int print_trace_stack(void *data, char *name)
 153 {
 154         printk("%s <%s> ", (char *)data, name);
 155         return 0;
 156 }
 157
 158 /*
 159  * Print one address/symbol entries per line.
 160  */
 161 static void print_trace_address(void *data, unsigned long addr, int reliable)
 162 {
 163         touch_nmi_watchdog();
 164         printk(data);
 165         printk_address(addr, reliable);
 166 }
 167
 168 static const struct stacktrace_ops print_trace_ops = {
 169         .warning                = print_trace_warning,
 170         .warning_symbol         = print_trace_warning_symbol,
 171         .stack                  = print_trace_stack,
 172         .address                = print_trace_address,
 173         .walk_stack             = print_context_stack,
 174 };
 175
 176 void
 177 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
 178                 unsigned long *stack, unsigned long bp, char *log_lvl)
 179 {
 180         printk("%sCall Trace:\n", log_lvl);
 181         dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
 182 }
 183
 184 void show_trace(struct task_struct *task, struct pt_regs *regs,
 185                 unsigned long *stack, unsigned long bp)
 186 {
 187         show_trace_log_lvl(task, regs, stack, bp, "");
 188 }
 189
 190 void show_stack(struct task_struct *task, unsigned long *sp)
 191 {
 192         show_stack_log_lvl(task, NULL, sp, 0, "");
 193 }
 194
 195 /*
 196  * The architecture-independent dump_stack generator
 197  */
 198 void dump_stack(void)
 199 {
 200         unsigned long bp = 0;
 201         unsigned long stack;
 202
 203 #ifdef CONFIG_FRAME_POINTER
 204         if (!bp)
 205                 get_bp(bp);
 206 #endif
 207
 208         printk("Pid: %d, comm: %.20s %s %s %.*s\n",
 209                 current->pid, current->comm, print_tainted(),
 210                 init_utsname()->release,
 211                 (int)strcspn(init_utsname()->version, " "),
 212                 init_utsname()->version);
 213         show_trace(NULL, NULL, &stack, bp);
 214 }
 215 EXPORT_SYMBOL(dump_stack);
 216
 217 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
 218 static int die_owner = -1;
 219 static unsigned int die_nest_count;
 220
 221 unsigned __kprobes long oops_begin(void)
 222 {
 223         int cpu;
 224         unsigned long flags;
 225
 226         oops_enter();
 227
 228         /* racy, but better than risking deadlock. */
 229         raw_local_irq_save(flags);
 230         cpu = smp_processor_id();
 231         if (!arch_spin_trylock(&die_lock)) {
 232                 if (cpu == die_owner)
 233                         /* nested oops. should stop eventually */;
 234                 else
 235                         arch_spin_lock(&die_lock);
 236         }
 237         die_nest_count++;
 238         die_owner = cpu;
 239         console_verbose();
 240         bust_spinlocks(1);
 241         return flags;
 242 }
 243
 244 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
 245 {
 246         if (regs && kexec_should_crash(current))
 247                 crash_kexec(regs);
 248
 249         bust_spinlocks(0);
 250         die_owner = -1;
 251         add_taint(TAINT_DIE);
 252         die_nest_count--;
 253         if (!die_nest_count)
 254                 /* Nest count reaches zero, release the lock. */
 255                 arch_spin_unlock(&die_lock);
 256         raw_local_irq_restore(flags);
 257         oops_exit();
 258
 259         if (!signr)
 260                 return;
 261         if (in_interrupt())
 262                 panic("Fatal exception in interrupt");
 263         if (panic_on_oops)
 264                 panic("Fatal exception");
 265         do_exit(signr);
 266 }
 267
 268 int __kprobes __die(const char *str, struct pt_regs *regs, long err)
 269 {
 270 #ifdef CONFIG_X86_32
 271         unsigned short ss;
 272         unsigned long sp;
 273 #endif
 274         printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
 275 #ifdef CONFIG_PREEMPT
 276         printk("PREEMPT ");
 277 #endif
 278 #ifdef CONFIG_SMP
 279         printk("SMP ");
 280 #endif
 281 #ifdef CONFIG_DEBUG_PAGEALLOC
 282         printk("DEBUG_PAGEALLOC");
 283 #endif
 284         printk("\n");
 285         sysfs_printk_last_file();
 286         if (notify_die(DIE_OOPS, str, regs, err,
 287                         current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
 288                 return 1;
 289
 290         show_registers(regs);
 291 #ifdef CONFIG_X86_32
 292         if (user_mode_vm(regs)) {
 293                 sp = regs->sp;
 294                 ss = regs->ss & 0xffff;
 295         } else {
 296                 sp = kernel_stack_pointer(regs);
 297                 savesegment(ss, ss);
 298         }
 299         printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
 300         print_symbol("%s", regs->ip);
 301         printk(" SS:ESP %04x:%08lx\n", ss, sp);
 302 #else
 303         /* Executive summary in case the oops scrolled away */
 304         printk(KERN_ALERT "RIP ");
 305         printk_address(regs->ip, 1);
 306         printk(" RSP <%016lx>\n", regs->sp);
 307 #endif
 308         return 0;
 309 }
 310
 311 /*
 312  * This is gone through when something in the kernel has done something bad
 313  * and is about to be terminated:
 314  */
 315 void die(const char *str, struct pt_regs *regs, long err)
 316 {
 317         unsigned long flags = oops_begin();
 318         int sig = SIGSEGV;
 319
 320         if (!user_mode_vm(regs))
 321                 report_bug(regs->ip, regs);
 322
 323         if (__die(str, regs, err))
 324                 sig = 0;
 325         oops_end(flags, regs, sig);
 326 }
 327
 328 void notrace __kprobes
 329 die_nmi(char *str, struct pt_regs *regs, int do_panic)
 330 {
 331         unsigned long flags;
 332
 333         if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
 334                 return;
 335
 336         /*
 337          * We are in trouble anyway, lets at least try
 338          * to get a message out.
 339          */
 340         flags = oops_begin();
 341         printk(KERN_EMERG "%s", str);
 342         printk(" on CPU%d, ip %08lx, registers:\n",
 343                 smp_processor_id(), regs->ip);
 344         show_registers(regs);
 345         oops_end(flags, regs, 0);
 346         if (do_panic || panic_on_oops)
 347                 panic("Non maskable interrupt");
 348         nmi_exit();
 349         local_irq_enable();
 350         do_exit(SIGBUS);
 351 }
 352
 353 static int __init oops_setup(char *s)
 354 {
 355         if (!s)
 356                 return -EINVAL;
 357         if (!strcmp(s, "panic"))
 358                 panic_on_oops = 1;
 359         return 0;
 360 }
 361 early_param("oops", oops_setup);
 362
 363 static int __init kstack_setup(char *s)
 364 {
 365         if (!s)
 366                 return -EINVAL;
 367         kstack_depth_to_print = simple_strtoul(s, NULL, 0);
 368         return 0;
 369 }
 370 early_param("kstack", kstack_setup);
 371
 372 static int __init code_bytes_setup(char *s)
 373 {
 374         code_bytes = simple_strtoul(s, NULL, 0);
 375         if (code_bytes > 8192)
 376                 code_bytes = 8192;
 377
 378         return 1;
 379 }
 380 __setup("code_bytes=", code_bytes_setup);