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, bp == 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);