FreeBSD/Linux Kernel Cross Reference
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: releng/9.2/sys/kern/subr_stack.c 219028 2011-02-25 10:11:01Z netchild $");
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(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 (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(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(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 #ifdef DDB
145 void
146 stack_print_short_ddb(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, 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 #ifdef DDB
186 void
187 stack_sbuf_print_ddb(struct sbuf *sb, 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, struct stack *st, u_int depth,
205 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 }
Cache object: d4aeb44ea588a468262b7d889e7aebcf
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