Annotation of src/usr.bin/pmdb/aout_syms.c, Revision 1.11
1.11 ! deraadt 1: /* $OpenBSD: aout_syms.c,v 1.10 2003/04/25 20:07:09 pvalchev Exp $ */
1.1 art 2: /*
3: * Copyright (c) 2002 Federico Schwindt <fgsch@openbsd.org>
4: * All rights reserved.
5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: *
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. The name of the author may not be used to endorse or promote products
13: * derived from this software without specific prior written permission.
14: *
15: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
16: * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
17: * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
18: * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21: * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22: * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23: * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24: * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
1.7 fgsch 27: #include <sys/param.h>
28: #include <sys/ptrace.h>
29: #include <sys/mman.h>
30: #include <sys/stat.h>
31:
1.1 art 32: #include <stdio.h>
33: #include <stdlib.h>
34: #include <unistd.h>
35: #include <fcntl.h>
36: #include <string.h>
37: #include <err.h>
38:
39: #include <a.out.h>
40: #include <link.h>
41:
42: #include "pmdb.h"
43: #include "symbol.h"
44:
45: struct aout_symbol_handle {
46: struct sym_table ash_st;
47: int ash_fd;
48: char *ash_strtab;
49: u_int32_t ash_strsize;
50: struct nlist *ash_symtab;
51: int ash_symsize;
52: };
53:
54: #define ASH_TO_ST(ash) (&(ash)->ash_st)
55: #define ST_TO_ASH(st) ((struct aout_symbol_handle *)(st))
56:
57: struct sym_table *aout_open(const char *);
58: void aout_close(struct sym_table *);
59: char *aout_name_and_off(struct sym_table *, reg, reg *);
60: int aout_lookup(struct pstate *, const char *, reg *);
61: void aout_update(struct pstate *);
62:
63: struct sym_ops aout_sops = {
64: aout_open,
65: aout_close,
66: aout_name_and_off,
67: aout_lookup,
68: aout_update
69: };
70:
71: int
72: sym_check_aout(const char *name, struct pstate *ps)
73: {
74: struct exec ahdr;
1.4 fgsch 75: int error = 0;
1.1 art 76: int fd;
77:
78: if ((fd = open(name, O_RDONLY)) < 0)
1.4 fgsch 79: return (1);
1.1 art 80:
81: if (pread(fd, &ahdr, sizeof(ahdr), 0) != sizeof(ahdr)) {
1.4 fgsch 82: error = 1;
1.1 art 83: }
84:
1.5 fgsch 85: if (!error && N_BADMAG(ahdr)) {
1.4 fgsch 86: error = 1;
1.1 art 87: }
88:
89: close(fd);
90:
1.4 fgsch 91: if (!error)
92: ps->ps_sops = &aout_sops;
1.1 art 93:
1.4 fgsch 94: return (error);
1.1 art 95: }
96:
97: struct sym_table *
98: aout_open(const char *name)
99: {
100: struct aout_symbol_handle *ash;
1.7 fgsch 101: struct stat sb;
1.1 art 102: u_int32_t symoff, stroff;
103: struct exec ahdr;
104:
105: if ((ash = malloc(sizeof(*ash))) == NULL) {
106: return NULL;
107: }
108:
109: memset(ash, 0, sizeof(*ash));
110: ash->ash_fd = -1;
111:
112: if ((ash->ash_fd = open(name, O_RDONLY)) < 0) {
113: warn("open(%s)", name);
114: goto fail;
115: }
116:
117: if (pread(ash->ash_fd, &ahdr, sizeof(ahdr), 0) != sizeof(ahdr)) {
118: warn("pread(header)");
119: goto fail;
120: }
121:
122: if (N_BADMAG(ahdr)) {
123: warnx("Bad magic.");
124: goto fail;
125: }
1.7 fgsch 126:
127: /* Don't go further for stripped files. */
128: if (fstat(ash->ash_fd, &sb) < 0 || N_SYMOFF(ahdr) == sb.st_size ||
129: N_STROFF(ahdr) == sb.st_size)
130: goto fail;
1.1 art 131:
132: symoff = N_SYMOFF(ahdr);
133: ash->ash_symsize = ahdr.a_syms;
134: stroff = N_STROFF(ahdr);
1.8 art 135:
136: if (ahdr.a_syms == 0) {
137: warnx("No symbol table");
138: goto fail;
139: }
1.1 art 140:
141: if (pread(ash->ash_fd, &ash->ash_strsize, sizeof(u_int32_t),
142: stroff) != sizeof(u_int32_t)) {
143: warn("pread(strsize)");
144: goto fail;
145: }
146:
147: if ((ash->ash_strtab = mmap(NULL, ash->ash_strsize, PROT_READ,
148: MAP_SHARED, ash->ash_fd, stroff)) == MAP_FAILED) {
149: warn("mmap(strtab)");
150: goto fail;
151: }
152:
153: if ((ash->ash_symtab = mmap(NULL, ash->ash_symsize, PROT_READ,
154: MAP_SHARED, ash->ash_fd, symoff)) == MAP_FAILED) {
155: warn("mmap(symtab)");
156: goto fail;
157: }
158:
159: return (ASH_TO_ST(ash));
160: fail:
161:
162: aout_close(ASH_TO_ST(ash));
163: return (NULL);
164: }
165:
166: void
167: aout_close(struct sym_table *st)
168: {
169: struct aout_symbol_handle *ash = ST_TO_ASH(st);
170:
171: if (ash->ash_fd != -1)
172: close(ash->ash_fd);
173:
174: munmap(ash->ash_strtab, ash->ash_strsize);
175: munmap(ash->ash_symtab, ash->ash_symsize);
176: free(ash);
177: }
178:
179: char *
180: aout_name_and_off(struct sym_table *st, reg pc, reg *offs)
181: {
182: struct aout_symbol_handle *ash = ST_TO_ASH(st);
183: struct nlist *s, *bests = NULL;
184: int bestoff = 0;
185: int nsyms, i;
186: char *symn;
187:
1.3 art 188: #define SYMVAL(S) (unsigned long)((S)->n_value + st->st_offs)
1.1 art 189:
190: nsyms = ash->ash_symsize / sizeof(struct nlist);
191:
192: bests = NULL;
193: for (i = 0; i < nsyms; i++) {
194: s = &ash->ash_symtab[i];
195:
196: if (s->n_value == 0 ||
197: s->n_un.n_strx == 0)
198: continue;
199:
200: symn = &ash->ash_strtab[s->n_un.n_strx];
201: if (SYMVAL(s) <= pc && SYMVAL(s) > bestoff &&
202: symn[0] != '\0' && strcmp(symn, "gcc2_compiled.")) {
203: bests = s;
204: bestoff = SYMVAL(s);
205: }
206: }
207:
208: if ((s = bests) == NULL)
209: return (NULL);
210:
211: *offs = pc - SYMVAL(s);
212:
213: return &ash->ash_strtab[s->n_un.n_strx];
214: }
215:
216: static struct nlist *
217: aout_lookup_table(struct aout_symbol_handle *ash, const char *name)
218: {
219: int nsyms, i;
220: char *symn;
221: struct nlist *s = NULL;
222:
223: nsyms = ash->ash_symsize / sizeof(struct nlist);
224: for (i = 0; i < nsyms; i++) {
225: s = &ash->ash_symtab[i];
226: symn = &ash->ash_strtab[s->n_un.n_strx];
227: if (strcmp(name, symn) == 0)
228: break;
229: }
230:
231: if (i == nsyms)
232: return (NULL);
233:
234: return (s);
235: }
236:
237: int
238: aout_lookup(struct pstate *ps, const char *name, reg *res)
239: {
240: struct sym_table *st;
1.11 ! deraadt 241: struct nlist *s = NULL;
1.1 art 242: int first = 1;
243: char *sname = (char *)name;
244:
245: restart:
246: TAILQ_FOREACH(st, &ps->ps_syms, st_list) {
247: if ((s = aout_lookup_table(ST_TO_ASH(st), sname)) != NULL)
248: break;
249: }
250:
251: if (!first)
252: free(sname);
253:
254: if (s == NULL) {
255: if (first) {
1.10 pvalchev 256: if (asprintf(&sname, "_%s", sname) != -1) {
1.1 art 257: first = 0;
258: goto restart;
259: }
260: }
261:
262: return (-1);
263: }
264:
1.3 art 265: *res = s->n_value + st->st_offs;
1.1 art 266: return (0);
267: }
268:
269: /*
270: * Called after execution started so that we can load any dynamic symbols.
271: */
272: void
273: aout_update(struct pstate *ps)
274: {
275: struct _dynamic dyn;
276: struct so_debug sdeb;
277: struct section_dispatch_table sdt;
278: struct so_map som;
279: off_t somp;
280: reg addr;
281: struct nlist *s;
282:
283: if ((s = aout_lookup_table(ST_TO_ASH(ps->ps_sym_exe), "__DYNAMIC")) == NULL) {
284: warnx("Can't find __DYNAMIC");
285: return;
286: }
1.3 art 287: addr = s->n_value + ps->ps_sym_exe->st_offs;
1.1 art 288:
1.9 art 289: if (process_read(ps, addr, &dyn, sizeof(dyn)) < 0) {
1.1 art 290: warn("Can't read __DYNAMIC");
291: return;
292: }
293:
294: if (dyn.d_version != LD_VERSION_BSD) {
295: warn("Can't handle __DYNAMIC version %d", dyn.d_version);
296: return;
297: }
298:
1.9 art 299: if (process_read(ps, (off_t)(reg)dyn.d_debug, &sdeb, sizeof(sdeb)) < 0) {
1.1 art 300: warn("Can't read __DYNAMIC.d_debug");
301: return;
302: }
303:
304: if (sdeb.dd_version != 0) {
305: warn("Can't handle so_debug version %d", sdeb.dd_version);
306: return;
307: }
308:
1.9 art 309: if (process_read(ps, (off_t)(reg)dyn.d_un.d_sdt, &sdt, sizeof(sdt)) < 0) {
1.1 art 310: warn("Can't read section dispatch table");
311: return;
312: }
313:
314: somp = (off_t)(reg)sdt.sdt_loaded;
315: while (somp) {
316: char fname[MAXPATHLEN];
317: int i;
318:
1.9 art 319: if (process_read(ps, somp, &som, sizeof(som)) < 0) {
1.1 art 320: warn("Can't read so_map");
321: break;
322: }
323: somp = (off_t)(reg)som.som_next;
1.9 art 324: if (process_read(ps, (off_t)(reg)som.som_path, fname,
1.1 art 325: sizeof(fname)) < 0) {
326: warn("Can't read so filename");
327: continue;
328: }
329:
330: /* sanity check the file name */
331: for (i = 0; i < MAXPATHLEN; i++)
332: if (fname[i] == '\0')
333: break;
334: if (i == MAXPATHLEN) {
335: warnx("so filename invalid");
336: continue;
337: }
338:
1.3 art 339: if (st_open(ps, fname, (reg)som.som_addr) == NULL)
1.1 art 340: warn("symbol loading failed");
341: }
342: }
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