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%pB\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 static int print_trace_stack(void *data, char *name) 139 { 140 printk("%s <%s> ", (char *)data, name); 141 return 0; 142 } 143 144 /* 145 * Print one address/symbol entries per line. 146 */ 147 static void print_trace_address(void *data, unsigned long addr, int reliable) 148 { 149 touch_nmi_watchdog(); 150 printk(data); 151 printk_address(addr, reliable); 152 } 153 154 static const struct stacktrace_ops print_trace_ops = { 155 .stack = print_trace_stack, 156 .address = print_trace_address, 157 .walk_stack = print_context_stack, 158 }; 159 160 void 161 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, 162 unsigned long *stack, unsigned long bp, char *log_lvl) 163 { 164 printk("%sCall Trace:\n", log_lvl); 165 dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl); 166 } 167 168 void show_trace(struct task_struct *task, struct pt_regs *regs, 169 unsigned long *stack, unsigned long bp) 170 { 171 show_trace_log_lvl(task, regs, stack, bp, ""); 172 } 173 174 void show_stack(struct task_struct *task, unsigned long *sp) 175 { 176 show_stack_log_lvl(task, NULL, sp, 0, ""); 177 } 178 179 /* 180 * The architecture-independent dump_stack generator 181 */ 182 void dump_stack(void) 183 { 184 unsigned long bp; 185 unsigned long stack; 186 187 bp = stack_frame(current, NULL); 188 printk("Pid: %d, comm: %.20s %s %s %.*s\n", 189 current->pid, current->comm, print_tainted(), 190 init_utsname()->release, 191 (int)strcspn(init_utsname()->version, " "), 192 init_utsname()->version); 193 show_trace(NULL, NULL, &stack, bp); 194 } 195 EXPORT_SYMBOL(dump_stack); 196 197 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; 198 static int die_owner = -1; 199 static unsigned int die_nest_count; 200 201 unsigned __kprobes long oops_begin(void) 202 { 203 int cpu; 204 unsigned long flags; 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 (!arch_spin_trylock(&die_lock)) { 212 if (cpu == die_owner) 213 /* nested oops. should stop eventually */; 214 else 215 arch_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 EXPORT_SYMBOL_GPL(oops_begin); 224 225 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr) 226 { 227 if (regs && kexec_should_crash(current)) 228 crash_kexec(regs); 229 230 bust_spinlocks(0); 231 die_owner = -1; 232 add_taint(TAINT_DIE); 233 die_nest_count--; 234 if (!die_nest_count) 235 /* Nest count reaches zero, release the lock. */ 236 arch_spin_unlock(&die_lock); 237 raw_local_irq_restore(flags); 238 oops_exit(); 239 240 if (!signr) 241 return; 242 if (in_interrupt()) 243 panic("Fatal exception in interrupt"); 244 if (panic_on_oops) 245 panic("Fatal exception"); 246 do_exit(signr); 247 } 248 249 int __kprobes __die(const char *str, struct pt_regs *regs, long err) 250 { 251 #ifdef CONFIG_X86_32 252 unsigned short ss; 253 unsigned long sp; 254 #endif 255 printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter); 256 #ifdef CONFIG_PREEMPT 257 printk("PREEMPT "); 258 #endif 259 #ifdef CONFIG_SMP 260 printk("SMP "); 261 #endif 262 #ifdef CONFIG_DEBUG_PAGEALLOC 263 printk("DEBUG_PAGEALLOC"); 264 #endif 265 printk("\n"); 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 if (user_mode_vm(regs)) { 273 sp = regs->sp; 274 ss = regs->ss & 0xffff; 275 } else { 276 sp = kernel_stack_pointer(regs); 277 savesegment(ss, ss); 278 } 279 printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip); 280 print_symbol("%s", regs->ip); 281 printk(" SS:ESP %04x:%08lx\n", ss, sp); 282 #else 283 /* Executive summary in case the oops scrolled away */ 284 printk(KERN_ALERT "RIP "); 285 printk_address(regs->ip, 1); 286 printk(" RSP <%016lx>\n", regs->sp); 287 #endif 288 return 0; 289 } 290 291 /* 292 * This is gone through when something in the kernel has done something bad 293 * and is about to be terminated: 294 */ 295 void die(const char *str, struct pt_regs *regs, long err) 296 { 297 unsigned long flags = oops_begin(); 298 int sig = SIGSEGV; 299 300 if (!user_mode_vm(regs)) 301 report_bug(regs->ip, regs); 302 303 if (__die(str, regs, err)) 304 sig = 0; 305 oops_end(flags, regs, sig); 306 } 307 308 static int __init kstack_setup(char *s) 309 { 310 if (!s) 311 return -EINVAL; 312 kstack_depth_to_print = simple_strtoul(s, NULL, 0); 313 return 0; 314 } 315 early_param("kstack", kstack_setup); 316 317 static int __init code_bytes_setup(char *s) 318 { 319 code_bytes = simple_strtoul(s, NULL, 0); 320 if (code_bytes > 8192) 321 code_bytes = 8192; 322 323 return 1; 324 } 325 __setup("code_bytes=", code_bytes_setup); 326