1 /*- 2 * Copyright (c) 2005 Antoine Brodin 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include "opt_ddb.h" 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #ifdef KTR 35 #include <sys/ktr.h> 36 #endif 37 #include <sys/linker.h> 38 #include <sys/malloc.h> 39 #include <sys/sbuf.h> 40 #include <sys/stack.h> 41 #include <sys/systm.h> 42 #include <sys/sysctl.h> 43 44 FEATURE(stack, "Support for capturing kernel stack"); 45 46 static MALLOC_DEFINE(M_STACK, "stack", "Stack Traces"); 47 48 static int stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen, 49 long *offset); 50 static int stack_symbol_ddb(vm_offset_t pc, const char **name, long *offset); 51 52 struct stack * 53 stack_create(void) 54 { 55 struct stack *st; 56 57 st = malloc(sizeof *st, M_STACK, M_WAITOK | M_ZERO); 58 return (st); 59 } 60 61 void 62 stack_destroy(struct stack *st) 63 { 64 65 free(st, M_STACK); 66 } 67 68 int 69 stack_put(struct stack *st, vm_offset_t pc) 70 { 71 72 if (st->depth < STACK_MAX) { 73 st->pcs[st->depth++] = pc; 74 return (0); 75 } else 76 return (-1); 77 } 78 79 void 80 stack_copy(const struct stack *src, struct stack *dst) 81 { 82 83 *dst = *src; 84 } 85 86 void 87 stack_zero(struct stack *st) 88 { 89 90 bzero(st, sizeof *st); 91 } 92 93 void 94 stack_print(const struct stack *st) 95 { 96 char namebuf[64]; 97 long offset; 98 int i; 99 100 KASSERT(st->depth <= STACK_MAX, ("bogus stack")); 101 for (i = 0; i < st->depth; i++) { 102 (void)stack_symbol(st->pcs[i], namebuf, sizeof(namebuf), 103 &offset); 104 printf("#%d %p at %s+%#lx\n", i, (void *)st->pcs[i], 105 namebuf, offset); 106 } 107 } 108 109 void 110 stack_print_short(const struct stack *st) 111 { 112 char namebuf[64]; 113 long offset; 114 int i; 115 116 KASSERT(st->depth <= STACK_MAX, ("bogus stack")); 117 for (i = 0; i < st->depth; i++) { 118 if (i > 0) 119 printf(" "); 120 if (stack_symbol(st->pcs[i], namebuf, sizeof(namebuf), 121 &offset) == 0) 122 printf("%s+%#lx", namebuf, offset); 123 else 124 printf("%p", (void *)st->pcs[i]); 125 } 126 printf("\n"); 127 } 128 129 void 130 stack_print_ddb(const struct stack *st) 131 { 132 const char *name; 133 long offset; 134 int i; 135 136 KASSERT(st->depth <= STACK_MAX, ("bogus stack")); 137 for (i = 0; i < st->depth; i++) { 138 stack_symbol_ddb(st->pcs[i], &name, &offset); 139 printf("#%d %p at %s+%#lx\n", i, (void *)st->pcs[i], 140 name, offset); 141 } 142 } 143 144 #if defined(DDB) || defined(WITNESS) 145 void 146 stack_print_short_ddb(const struct stack *st) 147 { 148 const char *name; 149 long offset; 150 int i; 151 152 KASSERT(st->depth <= STACK_MAX, ("bogus stack")); 153 for (i = 0; i < st->depth; i++) { 154 if (i > 0) 155 printf(" "); 156 if (stack_symbol_ddb(st->pcs[i], &name, &offset) == 0) 157 printf("%s+%#lx", name, offset); 158 else 159 printf("%p", (void *)st->pcs[i]); 160 } 161 printf("\n"); 162 } 163 #endif 164 165 /* 166 * Two print routines -- one for use from DDB and DDB-like contexts, the 167 * other for use in the live kernel. 168 */ 169 void 170 stack_sbuf_print(struct sbuf *sb, const struct stack *st) 171 { 172 char namebuf[64]; 173 long offset; 174 int i; 175 176 KASSERT(st->depth <= STACK_MAX, ("bogus stack")); 177 for (i = 0; i < st->depth; i++) { 178 (void)stack_symbol(st->pcs[i], namebuf, sizeof(namebuf), 179 &offset); 180 sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i], 181 namebuf, offset); 182 } 183 } 184 185 #if defined(DDB) || defined(WITNESS) 186 void 187 stack_sbuf_print_ddb(struct sbuf *sb, const struct stack *st) 188 { 189 const char *name; 190 long offset; 191 int i; 192 193 KASSERT(st->depth <= STACK_MAX, ("bogus stack")); 194 for (i = 0; i < st->depth; i++) { 195 (void)stack_symbol_ddb(st->pcs[i], &name, &offset); 196 sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i], 197 name, offset); 198 } 199 } 200 #endif 201 202 #ifdef KTR 203 void 204 stack_ktr(u_int mask, const char *file, int line, const struct stack *st, 205 u_int depth, int cheap) 206 { 207 #ifdef DDB 208 const char *name; 209 long offset; 210 int i; 211 #endif 212 213 KASSERT(st->depth <= STACK_MAX, ("bogus stack")); 214 if (cheap) { 215 ktr_tracepoint(mask, file, line, "#0 %p %p %p %p %p %p", 216 st->pcs[0], st->pcs[1], st->pcs[2], st->pcs[3], 217 st->pcs[4], st->pcs[5]); 218 if (st->depth <= 6) 219 return; 220 ktr_tracepoint(mask, file, line, "#1 %p %p %p %p %p %p", 221 st->pcs[6], st->pcs[7], st->pcs[8], st->pcs[9], 222 st->pcs[10], st->pcs[11]); 223 if (st->depth <= 12) 224 return; 225 ktr_tracepoint(mask, file, line, "#2 %p %p %p %p %p %p", 226 st->pcs[12], st->pcs[13], st->pcs[14], st->pcs[15], 227 st->pcs[16], st->pcs[17]); 228 #ifdef DDB 229 } else { 230 if (depth == 0 || st->depth < depth) 231 depth = st->depth; 232 for (i = 0; i < depth; i++) { 233 (void)stack_symbol_ddb(st->pcs[i], &name, &offset); 234 ktr_tracepoint(mask, file, line, "#%d %p at %s+%#lx", 235 i, st->pcs[i], (u_long)name, offset, 0, 0); 236 } 237 #endif 238 } 239 } 240 #endif 241 242 /* 243 * Two variants of stack symbol lookup -- one that uses the DDB interfaces 244 * and bypasses linker locking, and the other that doesn't. 245 */ 246 static int 247 stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen, long *offset) 248 { 249 250 if (linker_search_symbol_name((caddr_t)pc, namebuf, buflen, 251 offset) != 0) { 252 *offset = 0; 253 strlcpy(namebuf, "??", buflen); 254 return (ENOENT); 255 } else 256 return (0); 257 } 258 259 static int 260 stack_symbol_ddb(vm_offset_t pc, const char **name, long *offset) 261 { 262 linker_symval_t symval; 263 c_linker_sym_t sym; 264 265 if (linker_ddb_search_symbol((caddr_t)pc, &sym, offset) != 0) 266 goto out; 267 if (linker_ddb_symbol_values(sym, &symval) != 0) 268 goto out; 269 if (symval.name != NULL) { 270 *name = symval.name; 271 return (0); 272 } 273 out: 274 *offset = 0; 275 *name = "??"; 276 return (ENOENT); 277 } 278