Annotation of src/usr.bin/strip/strip.c, Revision 1.1.1.1
1.1 deraadt 1: /*
2: * Copyright (c) 1988 Regents of the University of California.
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: * 3. All advertising materials mentioning features or use of this software
14: * must display the following acknowledgement:
15: * This product includes software developed by the University of
16: * California, Berkeley and its contributors.
17: * 4. Neither the name of the University nor the names of its contributors
18: * may be used to endorse or promote products derived from this software
19: * without specific prior written permission.
20: *
21: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31: * SUCH DAMAGE.
32: */
33:
34: #ifndef lint
35: char copyright[] =
36: "@(#) Copyright (c) 1988 Regents of the University of California.\n\
37: All rights reserved.\n";
38: #endif /* not lint */
39:
40: #ifndef lint
41: /*static char sccsid[] = "from: @(#)strip.c 5.8 (Berkeley) 11/6/91";*/
42: static char rcsid[] = "$Id: strip.c,v 1.13 1994/03/28 02:17:50 cgd Exp $";
43: #endif /* not lint */
44:
45: #include <sys/types.h>
46: #include <sys/stat.h>
47: #include <sys/mman.h>
48: #include <fcntl.h>
49: #include <errno.h>
50: #include <a.out.h>
51: #include <unistd.h>
52: #include <stdio.h>
53: #include <stdlib.h>
54: #include <string.h>
55:
56: typedef struct exec EXEC;
57: typedef struct nlist NLIST;
58:
59: #define strx n_un.n_strx
60:
61: void err __P((const char *fmt, ...));
62: int s_stab __P((const char *, int, EXEC *, struct stat *));
63: int s_sym __P((const char *, int, EXEC *, struct stat *));
64: void usage __P((void));
65:
66: int xflag = 0;
67:
68: main(argc, argv)
69: int argc;
70: char *argv[];
71: {
72: register int fd, nb;
73: EXEC *ep;
74: struct stat sb;
75: int (*sfcn)__P((const char *, int, EXEC *, struct stat *));
76: int ch, errors;
77: char *fn;
78:
79: sfcn = s_sym;
80: while ((ch = getopt(argc, argv, "dx")) != EOF)
81: switch(ch) {
82: case 'x':
83: xflag = 1;
84: /*FALLTHROUGH*/
85: case 'd':
86: sfcn = s_stab;
87: break;
88: case '?':
89: default:
90: usage();
91: }
92: argc -= optind;
93: argv += optind;
94:
95: errors = 0;
96: #define ERROR(x) errors |= 1; err("%s: %s", fn, strerror(x)); continue;
97: while (fn = *argv++) {
98: if ((fd = open(fn, O_RDWR)) < 0) {
99: ERROR(errno);
100: }
101: if (fstat(fd, &sb)) {
102: (void)close(fd);
103: ERROR(errno);
104: }
105: if (sb.st_size < sizeof(EXEC)) {
106: (void)close(fd);
107: ERROR(EFTYPE);
108: }
109: if ((ep = (EXEC *)mmap(NULL, sb.st_size, PROT_READ|PROT_WRITE,
110: MAP_SHARED, fd, (off_t)0)) == (EXEC *)-1) {
111: (void)close(fd);
112: ERROR(errno);
113: }
114: if (N_BADMAG(*ep)) {
115: munmap((caddr_t)ep, sb.st_size);
116: (void)close(fd);
117: ERROR(EFTYPE);
118: }
119: errors |= sfcn(fn, fd, ep, &sb);
120: munmap((caddr_t)ep, sb.st_size);
121: if (close(fd)) {
122: ERROR(errno);
123: }
124: }
125: #undef ERROR
126: exit(errors);
127: }
128:
129: int
130: s_sym(fn, fd, ep, sp)
131: const char *fn;
132: int fd;
133: register EXEC *ep;
134: struct stat *sp;
135: {
136: register char *neweof, *mineof;
137: int zmagic;
138:
139: zmagic = ep->a_data &&
140: (N_GETMAGIC(*ep) == ZMAGIC || N_GETMAGIC(*ep) == QMAGIC);
141:
142: /*
143: * If no symbols or data/text relocation info and
144: * the file data segment size is already minimized, quit.
145: */
146: if (!ep->a_syms && !ep->a_trsize && !ep->a_drsize) {
147: #if 0
148: if (!zmagic)
149: return 0;
150: if (sp->st_size < N_TRELOFF(*ep))
151: #endif
152: return 0;
153: }
154:
155: /*
156: * New file size is the header plus text and data segments; OMAGIC
157: * and NMAGIC formats have the text/data immediately following the
158: * header. ZMAGIC format wastes the rest of of header page.
159: */
160: neweof = (char *)ep + N_TRELOFF(*ep);
161:
162: #if 0
163: /*
164: * Unfortunately, this can't work correctly without changing the way
165: * the loader works. We could cap it at one page, or even fiddle with
166: * a_data and a_bss, but this only works for CLBYTES == NBPG. If we
167: * are on a system where, e.g., CLBYTES is 8k and NBPG is 4k, and we
168: * happen to remove 4.5k, we will lose. And we really don't want to
169: * fiddle with pages, because that breaks binary compatibility. Lose.
170: */
171:
172: if (zmagic) {
173: /*
174: * Get rid of unneeded zeroes at the end of the data segment
175: * to reduce the file size even more.
176: */
177: mineof = (char *)ep + N_DATOFF(*ep);
178: while (neweof > mineof && neweof[-1] == '\0')
179: neweof--;
180: }
181: #endif
182:
183: /* Set symbol size and relocation info values to 0. */
184: ep->a_syms = ep->a_trsize = ep->a_drsize = 0;
185:
186: /* Truncate the file. */
187: if (ftruncate(fd, neweof - (char *)ep)) {
188: err("%s: %s", fn, strerror(errno));
189: return 1;
190: }
191:
192: return 0;
193: }
194:
195: int
196: s_stab(fn, fd, ep, sp)
197: const char *fn;
198: int fd;
199: EXEC *ep;
200: struct stat *sp;
201: {
202: register int cnt, len, nsymcnt;
203: register char *nstr, *nstrbase, *p, *strbase;
204: register NLIST *sym, *nsym;
205: NLIST *symbase;
206:
207: /* Quit if no symbols. */
208: if (ep->a_syms == 0)
209: return 0;
210:
211: if (N_SYMOFF(*ep) >= sp->st_size) {
212: err("%s: bad symbol table", fn);
213: return 1;
214: }
215:
216: /*
217: * Initialize old and new symbol pointers. They both point to the
218: * beginning of the symbol table in memory, since we're deleting
219: * entries.
220: */
221: sym = nsym = symbase = (NLIST *)((char *)ep + N_SYMOFF(*ep));
222:
223: /*
224: * Allocate space for the new string table, initialize old and
225: * new string pointers. Handle the extra long at the beginning
226: * of the string table.
227: */
228: strbase = (char *)ep + N_STROFF(*ep);
229: if ((nstrbase = malloc((u_int)*(u_long *)strbase)) == NULL) {
230: err("%s", strerror(ENOMEM));
231: return 1;
232: }
233: nstr = nstrbase + sizeof(u_long);
234:
235: /*
236: * Read through the symbol table. For each non-debugging symbol,
237: * copy it and save its string in the new string table. Keep
238: * track of the number of symbols.
239: */
240: for (cnt = ep->a_syms / sizeof(NLIST); cnt--; ++sym)
241: if (!(sym->n_type & N_STAB) && sym->strx) {
242: *nsym = *sym;
243: nsym->strx = nstr - nstrbase;
244: p = strbase + sym->strx;
245: if (xflag &&
246: (!(sym->n_type & N_EXT) ||
247: (sym->n_type & ~N_EXT) == N_FN ||
248: strcmp(p, "gcc_compiled.") == 0 ||
249: strcmp(p, "gcc2_compiled.") == 0 ||
250: strncmp(p, "___gnu_compiled_", 16) == 0)) {
251: continue;
252: }
253: len = strlen(p) + 1;
254: bcopy(p, nstr, len);
255: nstr += len;
256: ++nsym;
257: }
258:
259: /* Fill in new symbol table size. */
260: ep->a_syms = (nsym - symbase) * sizeof(NLIST);
261:
262: /* Fill in the new size of the string table. */
263: *(u_long *)nstrbase = len = nstr - nstrbase;
264:
265: /*
266: * Copy the new string table into place. Nsym should be pointing
267: * at the address past the last symbol entry.
268: */
269: bcopy(nstrbase, (void *)nsym, len);
270: free(nstrbase);
271:
272: /* Truncate to the current length. */
273: if (ftruncate(fd, (char *)nsym + len - (char *)ep)) {
274: err("%s: %s", fn, strerror(errno));
275: return 1;
276: }
277:
278: return 0;
279: }
280:
281: void
282: usage()
283: {
284: (void)fprintf(stderr, "usage: strip [-dx] file ...\n");
285: exit(1);
286: }
287:
288: #if __STDC__
289: #include <stdarg.h>
290: #else
291: #include <varargs.h>
292: #endif
293:
294: void
295: #if __STDC__
296: err(const char *fmt, ...)
297: #else
298: err(fmt, va_alist)
299: char *fmt;
300: va_dcl
301: #endif
302: {
303: va_list ap;
304: #if __STDC__
305: va_start(ap, fmt);
306: #else
307: va_start(ap);
308: #endif
309: (void)fprintf(stderr, "strip: ");
310: (void)vfprintf(stderr, fmt, ap);
311: va_end(ap);
312: (void)fprintf(stderr, "\n");
313: }