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 #include <linux/ftrace.h>
  19
  20 #include <asm/stacktrace.h>
  21
  22 #include "dumpstack.h"
  23
  24 int panic_on_unrecovered_nmi;
  25 int panic_on_io_nmi;
  26 unsigned int code_bytes = 64;
  27 int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
  28 static int die_counter;
  29
  30 void printk_address(unsigned long address, int reliable)
  31 {
  32         printk(" [<%p>] %s%pS\n", (void *) address,
  33                         reliable ? "" : "? ", (void *) address);
  34 }
  35
  36 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  37 static void
  38 print_ftrace_graph_addr(unsigned long addr, void *data,
  39                         const struct stacktrace_ops *ops,
  40                         struct thread_info *tinfo, int *graph)
  41 {
  42         struct task_struct *task = tinfo->task;
  43         unsigned long ret_addr;
  44         int index = task->curr_ret_stack;
  45
  46         if (addr != (unsigned long)return_to_handler)
  47                 return;
  48
  49         if (!task->ret_stack || index < *graph)
  50                 return;
  51
  52         index -= *graph;
  53         ret_addr = task->ret_stack[index].ret;
  54
  55         ops->address(data, ret_addr, 1);
  56
  57         (*graph)++;
  58 }
  59 #else
  60 static inline void
  61 print_ftrace_graph_addr(unsigned long addr, void *data,
  62                         const struct stacktrace_ops *ops,
  63                         struct thread_info *tinfo, int *graph)
  64 { }
  65 #endif
  66
  67 /*
  68  * x86-64 can have up to three kernel stacks:
  69  * process stack
  70  * interrupt stack
  71  * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
  72  */
  73
  74 static inline int valid_stack_ptr(struct thread_info *tinfo,
  75                         void *p, unsigned int size, void *end)
  76 {
  77         void *t = tinfo;
  78         if (end) {
  79                 if (p < end && p >= (end-THREAD_SIZE))
  80                         return 1;
  81                 else
  82                         return 0;
  83         }
  84         return p > t && p < t + THREAD_SIZE - size;
  85 }
  86
  87 unsigned long
  88 print_context_stack(struct thread_info *tinfo,
  89                 unsigned long *stack, unsigned long bp,
  90                 const struct stacktrace_ops *ops, void *data,
  91                 unsigned long *end, int *graph)
  92 {
  93         struct stack_frame *frame = (struct stack_frame *)bp;
  94
  95         while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
  96                 unsigned long addr;
  97
  98                 addr = *stack;
  99                 if (__kernel_text_address(addr)) {
 100                         if ((unsigned long) stack == bp + sizeof(long)) {
 101                                 ops->address(data, addr, 1);
 102                                 frame = frame->next_frame;
 103                                 bp = (unsigned long) frame;
 104                         } else {
 105                                 ops->address(data, addr, 0);
 106                         }
 107                         print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
 108                 }
 109                 stack++;
 110         }
 111         return bp;
 112 }
 113
 114
 115 static void
 116 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
 117 {
 118         printk(data);
 119         print_symbol(msg, symbol);
 120         printk("\n");
 121 }
 122
 123 static void print_trace_warning(void *data, char *msg)
 124 {
 125         printk("%s%s\n", (char *)data, msg);
 126 }
 127
 128 static int print_trace_stack(void *data, char *name)
 129 {
 130         printk("%s <%s> ", (char *)data, name);
 131         return 0;
 132 }
 133
 134 /*
 135  * Print one address/symbol entries per line.
 136  */
 137 static void print_trace_address(void *data, unsigned long addr, int reliable)
 138 {
 139         touch_nmi_watchdog();
 140         printk(data);
 141         printk_address(addr, reliable);
 142 }
 143
 144 static const struct stacktrace_ops print_trace_ops = {
 145         .warning = print_trace_warning,
 146         .warning_symbol = print_trace_warning_symbol,
 147         .stack = print_trace_stack,
 148         .address = print_trace_address,
 149 };
 150
 151 void
 152 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
 153                 unsigned long *stack, unsigned long bp, char *log_lvl)
 154 {
 155         printk("%sCall Trace:\n", log_lvl);
 156         dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
 157 }
 158
 159 void show_trace(struct task_struct *task, struct pt_regs *regs,
 160                 unsigned long *stack, unsigned long bp)
 161 {
 162         show_trace_log_lvl(task, regs, stack, bp, "");
 163 }
 164
 165 void show_stack(struct task_struct *task, unsigned long *sp)
 166 {
 167         show_stack_log_lvl(task, NULL, sp, 0, "");
 168 }
 169
 170 /*
 171  * The architecture-independent dump_stack generator
 172  */
 173 void dump_stack(void)
 174 {
 175         unsigned long bp = 0;
 176         unsigned long stack;
 177
 178 #ifdef CONFIG_FRAME_POINTER
 179         if (!bp)
 180                 get_bp(bp);
 181 #endif
 182
 183         printk("Pid: %d, comm: %.20s %s %s %.*s\n",
 184                 current->pid, current->comm, print_tainted(),
 185                 init_utsname()->release,
 186                 (int)strcspn(init_utsname()->version, " "),
 187                 init_utsname()->version);
 188         show_trace(NULL, NULL, &stack, bp);
 189 }
 190 EXPORT_SYMBOL(dump_stack);
 191
 192 static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
 193 static int die_owner = -1;
 194 static unsigned int die_nest_count;
 195
 196 unsigned __kprobes long oops_begin(void)
 197 {
 198         int cpu;
 199         unsigned long flags;
 200
 201         /* notify the hw-branch tracer so it may disable tracing and
 202            add the last trace to the trace buffer -
 203            the earlier this happens, the more useful the trace. */
 204         trace_hw_branch_oops();
 205
 206         oops_enter();
 207
 208         /* racy, but better than risking deadlock. */
 209         raw_local_irq_save(flags);
 210         cpu = smp_processor_id();
 211         if (!__raw_spin_trylock(&die_lock)) {
 212                 if (cpu == die_owner)
 213                         /* nested oops. should stop eventually */;
 214                 else
 215                         __raw_spin_lock(&die_lock);
 216         }
 217         die_nest_count++;
 218         die_owner = cpu;
 219         console_verbose();
 220         bust_spinlocks(1);
 221         return flags;
 222 }
 223
 224 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
 225 {
 226         if (regs && kexec_should_crash(current))
 227                 crash_kexec(regs);
 228
 229         bust_spinlocks(0);
 230         die_owner = -1;
 231         add_taint(TAINT_DIE);
 232         die_nest_count--;
 233         if (!die_nest_count)
 234                 /* Nest count reaches zero, release the lock. */
 235                 __raw_spin_unlock(&die_lock);
 236         raw_local_irq_restore(flags);
 237         oops_exit();
 238
 239         if (!signr)
 240                 return;
 241         if (in_interrupt())
 242                 panic("Fatal exception in interrupt");
 243         if (panic_on_oops)
 244                 panic("Fatal exception");
 245         do_exit(signr);
 246 }
 247
 248 int __kprobes __die(const char *str, struct pt_regs *regs, long err)
 249 {
 250 #ifdef CONFIG_X86_32
 251         unsigned short ss;
 252         unsigned long sp;
 253 #endif
 254         printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
 255 #ifdef CONFIG_PREEMPT
 256         printk("PREEMPT ");
 257 #endif
 258 #ifdef CONFIG_SMP
 259         printk("SMP ");
 260 #endif
 261 #ifdef CONFIG_DEBUG_PAGEALLOC
 262         printk("DEBUG_PAGEALLOC");
 263 #endif
 264         printk("\n");
 265         sysfs_printk_last_file();
 266         if (notify_die(DIE_OOPS, str, regs, err,
 267                         current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
 268                 return 1;
 269
 270         show_registers(regs);
 271 #ifdef CONFIG_X86_32
 272         sp = (unsigned long) (&regs->sp);
 273         savesegment(ss, ss);
 274         if (user_mode(regs)) {
 275                 sp = regs->sp;
 276                 ss = regs->ss & 0xffff;
 277         }
 278         printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
 279         print_symbol("%s", regs->ip);
 280         printk(" SS:ESP %04x:%08lx\n", ss, sp);
 281 #else
 282         /* Executive summary in case the oops scrolled away */
 283         printk(KERN_ALERT "RIP ");
 284         printk_address(regs->ip, 1);
 285         printk(" RSP <%016lx>\n", regs->sp);
 286 #endif
 287         return 0;
 288 }
 289
 290 /*
 291  * This is gone through when something in the kernel has done something bad
 292  * and is about to be terminated:
 293  */
 294 void die(const char *str, struct pt_regs *regs, long err)
 295 {
 296         unsigned long flags = oops_begin();
 297         int sig = SIGSEGV;
 298
 299         if (!user_mode_vm(regs))
 300                 report_bug(regs->ip, regs);
 301
 302         if (__die(str, regs, err))
 303                 sig = 0;
 304         oops_end(flags, regs, sig);
 305 }
 306
 307 void notrace __kprobes
 308 die_nmi(char *str, struct pt_regs *regs, int do_panic)
 309 {
 310         unsigned long flags;
 311
 312         if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
 313                 return;
 314
 315         /*
 316          * We are in trouble anyway, lets at least try
 317          * to get a message out.
 318          */
 319         flags = oops_begin();
 320         printk(KERN_EMERG "%s", str);
 321         printk(" on CPU%d, ip %08lx, registers:\n",
 322                 smp_processor_id(), regs->ip);
 323         show_registers(regs);
 324         oops_end(flags, regs, 0);
 325         if (do_panic || panic_on_oops)
 326                 panic("Non maskable interrupt");
 327         nmi_exit();
 328         local_irq_enable();
 329         do_exit(SIGBUS);
 330 }
 331
 332 static int __init oops_setup(char *s)
 333 {
 334         if (!s)
 335                 return -EINVAL;
 336         if (!strcmp(s, "panic"))
 337                 panic_on_oops = 1;
 338         return 0;
 339 }
 340 early_param("oops", oops_setup);
 341
 342 static int __init kstack_setup(char *s)
 343 {
 344         if (!s)
 345                 return -EINVAL;
 346         kstack_depth_to_print = simple_strtoul(s, NULL, 0);
 347         return 0;
 348 }
 349 early_param("kstack", kstack_setup);
 350
 351 static int __init code_bytes_setup(char *s)
 352 {
 353         code_bytes = simple_strtoul(s, NULL, 0);
 354         if (code_bytes > 8192)
 355                 code_bytes = 8192;
 356
 357         return 1;
 358 }
 359 __setup("code_bytes=", code_bytes_setup);