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); 381