xref: /freebsd/sys/kern/subr_stack.c (revision 09c817ba36db7c3a4ff5e25ac55816ca181a403d)
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 int stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen,
46 	    long *offset);
47 #ifdef DDB
48 static int stack_symbol_ddb(vm_offset_t pc, const char **name, long *offset);
49 #endif
50 
51 struct stack *
52 stack_create(void)
53 {
54 	struct stack *st;
55 
56 	st = malloc(sizeof *st, M_STACK, M_WAITOK | M_ZERO);
57 	return (st);
58 }
59 
60 void
61 stack_destroy(struct stack *st)
62 {
63 
64 	free(st, M_STACK);
65 }
66 
67 int
68 stack_put(struct stack *st, vm_offset_t pc)
69 {
70 
71 	if (st->depth < STACK_MAX) {
72 		st->pcs[st->depth++] = pc;
73 		return (0);
74 	} else
75 		return (-1);
76 }
77 
78 void
79 stack_copy(struct stack *src, struct stack *dst)
80 {
81 
82 	*dst = *src;
83 }
84 
85 void
86 stack_zero(struct stack *st)
87 {
88 
89 	bzero(st, sizeof *st);
90 }
91 
92 void
93 stack_print(struct stack *st)
94 {
95 	char namebuf[64];
96 	long offset;
97 	int i;
98 
99 	KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
100 	for (i = 0; i < st->depth; i++) {
101 		(void)stack_symbol(st->pcs[i], namebuf, sizeof(namebuf),
102 		    &offset);
103 		printf("#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
104 		    namebuf, offset);
105 	}
106 }
107 
108 void
109 stack_print_short(struct stack *st)
110 {
111 	char namebuf[64];
112 	long offset;
113 	int i;
114 
115 	KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
116 	for (i = 0; i < st->depth; i++) {
117 		if (i > 0)
118 			printf(" ");
119 		if (stack_symbol(st->pcs[i], namebuf, sizeof(namebuf),
120 		    &offset) == 0)
121 			printf("%s+%#lx", namebuf, offset);
122 		else
123 			printf("%p", (void *)st->pcs[i]);
124 	}
125 	printf("\n");
126 }
127 
128 #ifdef DDB
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 void
145 stack_print_short_ddb(struct stack *st)
146 {
147 	const char *name;
148 	long offset;
149 	int i;
150 
151 	KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
152 	for (i = 0; i < st->depth; i++) {
153 		if (i > 0)
154 			printf(" ");
155 		if (stack_symbol_ddb(st->pcs[i], &name, &offset) == 0)
156 			printf("%s+%#lx", name, offset);
157 		else
158 			printf("%p", (void *)st->pcs[i]);
159 	}
160 	printf("\n");
161 }
162 #endif
163 
164 /*
165  * Two print routines -- one for use from DDB and DDB-like contexts, the
166  * other for use in the live kernel.
167  */
168 void
169 stack_sbuf_print(struct sbuf *sb, struct stack *st)
170 {
171 	char namebuf[64];
172 	long offset;
173 	int i;
174 
175 	KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
176 	for (i = 0; i < st->depth; i++) {
177 		(void)stack_symbol(st->pcs[i], namebuf, sizeof(namebuf),
178 		    &offset);
179 		sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
180 		    namebuf, offset);
181 	}
182 }
183 
184 #ifdef DDB
185 void
186 stack_sbuf_print_ddb(struct sbuf *sb, struct stack *st)
187 {
188 	const char *name;
189 	long offset;
190 	int i;
191 
192 	KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
193 	for (i = 0; i < st->depth; i++) {
194 		(void)stack_symbol_ddb(st->pcs[i], &name, &offset);
195 		sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
196 		    name, offset);
197 	}
198 }
199 #endif
200 
201 #ifdef KTR
202 void
203 stack_ktr(u_int mask, const char *file, int line, struct stack *st, u_int depth,
204     int cheap)
205 {
206 #ifdef DDB
207 	const char *name;
208 	long offset;
209 	int i;
210 #endif
211 
212 	KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
213 	if (cheap) {
214 		ktr_tracepoint(mask, file, line, "#0 %p %p %p %p %p %p",
215 		    st->pcs[0], st->pcs[1], st->pcs[2], st->pcs[3],
216 		    st->pcs[4], st->pcs[5]);
217 		if (st->depth <= 6)
218 			return;
219 		ktr_tracepoint(mask, file, line, "#1 %p %p %p %p %p %p",
220 		    st->pcs[6], st->pcs[7], st->pcs[8], st->pcs[9],
221 		    st->pcs[10], st->pcs[11]);
222 		if (st->depth <= 12)
223 			return;
224 		ktr_tracepoint(mask, file, line, "#2 %p %p %p %p %p %p",
225 		    st->pcs[12], st->pcs[13], st->pcs[14], st->pcs[15],
226 		    st->pcs[16], st->pcs[17]);
227 #ifdef DDB
228 	} else {
229 		if (depth == 0 || st->depth < depth)
230 			depth = st->depth;
231 		for (i = 0; i < depth; i++) {
232 			(void)stack_symbol_ddb(st->pcs[i], &name, &offset);
233 			ktr_tracepoint(mask, file, line, "#%d %p at %s+%#lx",
234 			    i, st->pcs[i], (u_long)name, offset, 0, 0);
235 		}
236 #endif
237 	}
238 }
239 #endif
240 
241 /*
242  * Two variants of stack symbol lookup -- one that uses the DDB interfaces
243  * and bypasses linker locking, and the other that doesn't.
244  */
245 static int
246 stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen, long *offset)
247 {
248 
249 	if (linker_search_symbol_name((caddr_t)pc, namebuf, buflen,
250 	    offset) != 0) {
251 		*offset = 0;
252 		strlcpy(namebuf, "??", buflen);
253 		return (ENOENT);
254 	} else
255 		return (0);
256 }
257 
258 #ifdef DDB
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 #endif
279