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