sys/kern/subr_stack.c

   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
  43 static MALLOC_DEFINE(M_STACK, "stack", "Stack Traces");
  44
  45 static void stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen,
  46             long *offset);
  47 #ifdef DDB
  48 static void stack_symbol_ddb(vm_offset_t pc, char *namebuf, u_int buflen,
  49             long *offset);
  50 #endif
  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(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(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                 stack_symbol(st->pcs[i], namebuf, sizeof(namebuf), &offset);
 103                 printf("#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
 104                     namebuf, offset);
 105         }
 106 }
 107
 108 #ifdef DDB
 109 void
 110 stack_print_ddb(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                 stack_symbol_ddb(st->pcs[i], namebuf, sizeof(namebuf),
 119                     &offset);
 120                 printf("#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
 121                     namebuf, offset);
 122         }
 123 }
 124 #endif
 125
 126 /*
 127  * Two print routines -- one for use from DDB and DDB-like contexts, the
 128  * other for use in the live kernel.
 129  */
 130 void
 131 stack_sbuf_print(struct sbuf *sb, struct stack *st)
 132 {
 133         char namebuf[64];
 134         long offset;
 135         int i;
 136
 137         KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
 138         for (i = 0; i < st->depth; i++) {
 139                 stack_symbol(st->pcs[i], namebuf, sizeof(namebuf), &offset);
 140                 sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
 141                     namebuf, offset);
 142         }
 143 }
 144
 145 #ifdef DDB
 146 void
 147 stack_sbuf_print_ddb(struct sbuf *sb, struct stack *st)
 148 {
 149         char namebuf[64];
 150         long offset;
 151         int i;
 152
 153         KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
 154         for (i = 0; i < st->depth; i++) {
 155                 stack_symbol_ddb(st->pcs[i], namebuf, sizeof(namebuf),
 156                     &offset);
 157                 sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
 158                     namebuf, offset);
 159         }
 160 }
 161
 162 #ifdef KTR
 163 void
 164 stack_ktr(u_int mask, const char *file, int line, struct stack *st, u_int depth,
 165     int cheap)
 166 {
 167         char namebuf[64];
 168         long offset;
 169         int i;
 170
 171         KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
 172         if (cheap) {
 173                 ktr_tracepoint(mask, file, line, "#0 %p %p %p %p %p %p",
 174                     st->pcs[0], st->pcs[1], st->pcs[2], st->pcs[3],
 175                     st->pcs[4], st->pcs[5]);
 176                 if (st->depth <= 6)
 177                         return;
 178                 ktr_tracepoint(mask, file, line, "#1 %p %p %p %p %p %p",
 179                     st->pcs[6], st->pcs[7], st->pcs[8], st->pcs[9],
 180                     st->pcs[10], st->pcs[11]);
 181                 if (st->depth <= 12)
 182                         return;
 183                 ktr_tracepoint(mask, file, line, "#2 %p %p %p %p %p %p",
 184                     st->pcs[12], st->pcs[13], st->pcs[14], st->pcs[15],
 185                     st->pcs[16], st->pcs[17]);
 186         } else {
 187                 if (depth == 0 || st->depth < depth)
 188                         depth = st->depth;
 189                 for (i = 0; i < depth; i++) {
 190                         stack_symbol_ddb(st->pcs[i], namebuf,
 191                             sizeof(namebuf), &offset);
 192                         ktr_tracepoint(mask, file, line, "#%d %p at %s+%#lx",
 193                             i, st->pcs[i], (u_long)namebuf, offset, 0, 0);
 194                 }
 195         }
 196 }
 197 #endif
 198 #endif
 199
 200 /*
 201  * Two variants of stack symbol lookup -- one that uses the DDB interfaces
 202  * and bypasses linker locking, and the other that doesn't.
 203  */
 204 static void
 205 stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen, long *offset)
 206 {
 207
 208         if (linker_search_symbol_name((caddr_t)pc, namebuf, buflen,
 209             offset) != 0) {
 210                 *offset = 0;
 211                 strlcpy(namebuf, "??", buflen);
 212         }
 213 }
 214
 215 #ifdef DDB
 216 static void
 217 stack_symbol_ddb(vm_offset_t pc, char *namebuf, u_int buflen, long *offset)
 218 {
 219
 220         if (linker_ddb_search_symbol_name((caddr_t)pc, namebuf, buflen,
 221             offset) != 0) {
 222                 *offset = 0;
 223                 strlcpy(namebuf, "??", buflen);
 224         };
 225 }
 226 #endif