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 #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, 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         oops_enter();
 200
 201         /* racy, but better than risking deadlock. */
 202         raw_local_irq_save(flags);
 203         cpu = smp_processor_id();
 204         if (!__raw_spin_trylock(&die_lock)) {
 205                 if (cpu == die_owner)
 206                         /* nested oops. should stop eventually */;
 207                 else
 208                         __raw_spin_lock(&die_lock);
 209         }
 210         die_nest_count++;
 211         die_owner = cpu;
 212         console_verbose();
 213         bust_spinlocks(1);
 214         return flags;
 215 }
 216
 217 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
 218 {
 219         if (regs && kexec_should_crash(current))
 220                 crash_kexec(regs);
 221
 222         bust_spinlocks(0);
 223         die_owner = -1;
 224         add_taint(TAINT_DIE);
 225         die_nest_count--;
 226         if (!die_nest_count)
 227                 /* Nest count reaches zero, release the lock. */
 228                 __raw_spin_unlock(&die_lock);
 229         raw_local_irq_restore(flags);
 230         oops_exit();
 231
 232         if (!signr)
 233                 return;
 234         if (in_interrupt())
 235                 panic("Fatal exception in interrupt");
 236         if (panic_on_oops)
 237                 panic("Fatal exception");
 238         do_exit(signr);
 239 }
 240
 241 int __kprobes __die(const char *str, struct pt_regs *regs, long err)
 242 {
 243 #ifdef CONFIG_X86_32
 244         unsigned short ss;
 245         unsigned long sp;
 246 #endif
 247         printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
 248 #ifdef CONFIG_PREEMPT
 249         printk("PREEMPT ");
 250 #endif
 251 #ifdef CONFIG_SMP
 252         printk("SMP ");
 253 #endif
 254 #ifdef CONFIG_DEBUG_PAGEALLOC
 255         printk("DEBUG_PAGEALLOC");
 256 #endif
 257         printk("\n");
 258         sysfs_printk_last_file();
 259         if (notify_die(DIE_OOPS, str, regs, err,
 260                         current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
 261                 return 1;
 262
 263         show_registers(regs);
 264 #ifdef CONFIG_X86_32
 265         sp = (unsigned long) (&regs->sp);
 266         savesegment(ss, ss);
 267         if (user_mode(regs)) {
 268                 sp = regs->sp;
 269                 ss = regs->ss & 0xffff;
 270         }
 271         printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
 272         print_symbol("%s", regs->ip);
 273         printk(" SS:ESP %04x:%08lx\n", ss, sp);
 274 #else
 275         /* Executive summary in case the oops scrolled away */
 276         printk(KERN_ALERT "RIP ");
 277         printk_address(regs->ip, 1);
 278         printk(" RSP <%016lx>\n", regs->sp);
 279 #endif
 280         return 0;
 281 }
 282
 283 /*
 284  * This is gone through when something in the kernel has done something bad
 285  * and is about to be terminated:
 286  */
 287 void die(const char *str, struct pt_regs *regs, long err)
 288 {
 289         unsigned long flags = oops_begin();
 290         int sig = SIGSEGV;
 291
 292         if (!user_mode_vm(regs))
 293                 report_bug(regs->ip, regs);
 294
 295         if (__die(str, regs, err))
 296                 sig = 0;
 297         oops_end(flags, regs, sig);
 298 }
 299
 300 void notrace __kprobes
 301 die_nmi(char *str, struct pt_regs *regs, int do_panic)
 302 {
 303         unsigned long flags;
 304
 305         if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
 306                 return;
 307
 308         /*
 309          * We are in trouble anyway, lets at least try
 310          * to get a message out.
 311          */
 312         flags = oops_begin();
 313         printk(KERN_EMERG "%s", str);
 314         printk(" on CPU%d, ip %08lx, registers:\n",
 315                 smp_processor_id(), regs->ip);
 316         show_registers(regs);
 317         oops_end(flags, regs, 0);
 318         if (do_panic || panic_on_oops)
 319                 panic("Non maskable interrupt");
 320         nmi_exit();
 321         local_irq_enable();
 322         do_exit(SIGBUS);
 323 }
 324
 325 static int __init oops_setup(char *s)
 326 {
 327         if (!s)
 328                 return -EINVAL;
 329         if (!strcmp(s, "panic"))
 330                 panic_on_oops = 1;
 331         return 0;
 332 }
 333 early_param("oops", oops_setup);
 334
 335 static int __init kstack_setup(char *s)
 336 {
 337         if (!s)
 338                 return -EINVAL;
 339         kstack_depth_to_print = simple_strtoul(s, NULL, 0);
 340         return 0;
 341 }
 342 early_param("kstack", kstack_setup);
 343
 344 static int __init code_bytes_setup(char *s)
 345 {
 346         code_bytes = simple_strtoul(s, NULL, 0);
 347         if (code_bytes > 8192)
 348                 code_bytes = 8192;
 349
 350         return 1;
 351 }
 352 __setup("code_bytes=", code_bytes_setup);