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 static void printk_stack_address(unsigned long address, int reliable) 29 { 30 pr_cont(" [<%p>] %s%pB\n", 31 (void *)address, reliable ? "" : "? ", (void *)address); 32 } 33 34 void printk_address(unsigned long address) 35 { 36 pr_cont(" [<%p>] %pS\n", (void *)address, (void *)address); 37 } 38 39 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 40 static void 41 print_ftrace_graph_addr(unsigned long addr, void *data, 42 const struct stacktrace_ops *ops, 43 struct thread_info *tinfo, int *graph) 44 { 45 struct task_struct *task; 46 unsigned long ret_addr; 47 int index; 48 49 if (addr != (unsigned long)return_to_handler) 50 return; 51 52 task = tinfo->task; 53 index = task->curr_ret_stack; 54 55 if (!task->ret_stack || index < *graph) 56 return; 57 58 index -= *graph; 59 ret_addr = task->ret_stack[index].ret; 60 61 ops->address(data, ret_addr, 1); 62 63 (*graph)++; 64 } 65 #else 66 static inline void 67 print_ftrace_graph_addr(unsigned long addr, void *data, 68 const struct stacktrace_ops *ops, 69 struct thread_info *tinfo, int *graph) 70 { } 71 #endif 72 73 /* 74 * x86-64 can have up to three kernel stacks: 75 * process stack 76 * interrupt stack 77 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack 78 */ 79 80 static inline int valid_stack_ptr(struct thread_info *tinfo, 81 void *p, unsigned int size, void *end) 82 { 83 void *t = tinfo; 84 if (end) { 85 if (p < end && p >= (end-THREAD_SIZE)) 86 return 1; 87 else 88 return 0; 89 } 90 return p > t && p < t + THREAD_SIZE - size; 91 } 92 93 unsigned long 94 print_context_stack(struct thread_info *tinfo, 95 unsigned long *stack, unsigned long bp, 96 const struct stacktrace_ops *ops, void *data, 97 unsigned long *end, int *graph) 98 { 99 struct stack_frame *frame = (struct stack_frame *)bp; 100 101 while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) { 102 unsigned long addr; 103 104 addr = *stack; 105 if (__kernel_text_address(addr)) { 106 if ((unsigned long) stack == bp + sizeof(long)) { 107 ops->address(data, addr, 1); 108 frame = frame->next_frame; 109 bp = (unsigned long) frame; 110 } else { 111 ops->address(data, addr, 0); 112 } 113 print_ftrace_graph_addr(addr, data, ops, tinfo, graph); 114 } 115 stack++; 116 } 117 return bp; 118 } 119 EXPORT_SYMBOL_GPL(print_context_stack); 120 121 unsigned long 122 print_context_stack_bp(struct thread_info *tinfo, 123 unsigned long *stack, unsigned long bp, 124 const struct stacktrace_ops *ops, void *data, 125 unsigned long *end, int *graph) 126 { 127 struct stack_frame *frame = (struct stack_frame *)bp; 128 unsigned long *ret_addr = &frame->return_address; 129 130 while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) { 131 unsigned long addr = *ret_addr; 132 133 if (!__kernel_text_address(addr)) 134 break; 135 136 ops->address(data, addr, 1); 137 frame = frame->next_frame; 138 ret_addr = &frame->return_address; 139 print_ftrace_graph_addr(addr, data, ops, tinfo, graph); 140 } 141 142 return (unsigned long)frame; 143 } 144 EXPORT_SYMBOL_GPL(print_context_stack_bp); 145 146 static int print_trace_stack(void *data, char *name) 147 { 148 printk("%s <%s> ", (char *)data, name); 149 return 0; 150 } 151 152 /* 153 * Print one address/symbol entries per line. 154 */ 155 static void print_trace_address(void *data, unsigned long addr, int reliable) 156 { 157 touch_nmi_watchdog(); 158 printk(data); 159 printk_stack_address(addr, reliable); 160 } 161 162 static const struct stacktrace_ops print_trace_ops = { 163 .stack = print_trace_stack, 164 .address = print_trace_address, 165 .walk_stack = print_context_stack, 166 }; 167 168 void 169 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, 170 unsigned long *stack, unsigned long bp, char *log_lvl) 171 { 172 printk("%sCall Trace:\n", log_lvl); 173 dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl); 174 } 175 176 void show_trace(struct task_struct *task, struct pt_regs *regs, 177 unsigned long *stack, unsigned long bp) 178 { 179 show_trace_log_lvl(task, regs, stack, bp, ""); 180 } 181 182 void show_stack(struct task_struct *task, unsigned long *sp) 183 { 184 unsigned long bp = 0; 185 unsigned long stack; 186 187 /* 188 * Stack frames below this one aren't interesting. Don't show them 189 * if we're printing for %current. 190 */ 191 if (!sp && (!task || task == current)) { 192 sp = &stack; 193 bp = stack_frame(current, NULL); 194 } 195 196 show_stack_log_lvl(task, NULL, sp, bp, ""); 197 } 198 199 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; 200 static int die_owner = -1; 201 static unsigned int die_nest_count; 202 203 unsigned __kprobes long oops_begin(void) 204 { 205 int cpu; 206 unsigned long flags; 207 208 oops_enter(); 209 210 /* racy, but better than risking deadlock. */ 211 raw_local_irq_save(flags); 212 cpu = smp_processor_id(); 213 if (!arch_spin_trylock(&die_lock)) { 214 if (cpu == die_owner) 215 /* nested oops. should stop eventually */; 216 else 217 arch_spin_lock(&die_lock); 218 } 219 die_nest_count++; 220 die_owner = cpu; 221 console_verbose(); 222 bust_spinlocks(1); 223 return flags; 224 } 225 EXPORT_SYMBOL_GPL(oops_begin); 226 227 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr) 228 { 229 if (regs && kexec_should_crash(current)) 230 crash_kexec(regs); 231 232 bust_spinlocks(0); 233 die_owner = -1; 234 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 235 die_nest_count--; 236 if (!die_nest_count) 237 /* Nest count reaches zero, release the lock. */ 238 arch_spin_unlock(&die_lock); 239 raw_local_irq_restore(flags); 240 oops_exit(); 241 242 if (!signr) 243 return; 244 if (in_interrupt()) 245 panic("Fatal exception in interrupt"); 246 if (panic_on_oops) 247 panic("Fatal exception"); 248 do_exit(signr); 249 } 250 251 int __kprobes __die(const char *str, struct pt_regs *regs, long err) 252 { 253 #ifdef CONFIG_X86_32 254 unsigned short ss; 255 unsigned long sp; 256 #endif 257 printk(KERN_DEFAULT 258 "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter); 259 #ifdef CONFIG_PREEMPT 260 printk("PREEMPT "); 261 #endif 262 #ifdef CONFIG_SMP 263 printk("SMP "); 264 #endif 265 #ifdef CONFIG_DEBUG_PAGEALLOC 266 printk("DEBUG_PAGEALLOC"); 267 #endif 268 printk("\n"); 269 if (notify_die(DIE_OOPS, str, regs, err, 270 current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP) 271 return 1; 272 273 print_modules(); 274 show_regs(regs); 275 #ifdef CONFIG_X86_32 276 if (user_mode_vm(regs)) { 277 sp = regs->sp; 278 ss = regs->ss & 0xffff; 279 } else { 280 sp = kernel_stack_pointer(regs); 281 savesegment(ss, ss); 282 } 283 printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip); 284 print_symbol("%s", regs->ip); 285 printk(" SS:ESP %04x:%08lx\n", ss, sp); 286 #else 287 /* Executive summary in case the oops scrolled away */ 288 printk(KERN_ALERT "RIP "); 289 printk_address(regs->ip); 290 printk(" RSP <%016lx>\n", regs->sp); 291 #endif 292 return 0; 293 } 294 295 /* 296 * This is gone through when something in the kernel has done something bad 297 * and is about to be terminated: 298 */ 299 void die(const char *str, struct pt_regs *regs, long err) 300 { 301 unsigned long flags = oops_begin(); 302 int sig = SIGSEGV; 303 304 if (!user_mode_vm(regs)) 305 report_bug(regs->ip, regs); 306 307 if (__die(str, regs, err)) 308 sig = 0; 309 oops_end(flags, regs, sig); 310 } 311 312 static int __init kstack_setup(char *s) 313 { 314 ssize_t ret; 315 unsigned long val; 316 317 if (!s) 318 return -EINVAL; 319 320 ret = kstrtoul(s, 0, &val); 321 if (ret) 322 return ret; 323 kstack_depth_to_print = val; 324 return 0; 325 } 326 early_param("kstack", kstack_setup); 327 328 static int __init code_bytes_setup(char *s) 329 { 330 ssize_t ret; 331 unsigned long val; 332 333 if (!s) 334 return -EINVAL; 335 336 ret = kstrtoul(s, 0, &val); 337 if (ret) 338 return ret; 339 340 code_bytes = val; 341 if (code_bytes > 8192) 342 code_bytes = 8192; 343 344 return 1; 345 } 346 __setup("code_bytes=", code_bytes_setup); 347