1 /*
2 * This file and its contents are supplied under the terms of the
3 * Common Development and Distribution License ("CDDL"), version 1.0.
4 * You may only use this file in accordance with the terms of version
5 * 1.0 of the CDDL.
6 *
7 * A full copy of the text of the CDDL should have accompanied this
8 * source. A copy of the CDDL is also available via the Internet at
9 * http://www.illumos.org/license/CDDL.
10 */
11
12 /*
13 * Copyright (c) 2015, Joyent, Inc.
14 */
15
16 /*
17 * Create CTF from extant debugging information
18 */
19
20 #include <stdio.h>
21 #include <unistd.h>
22 #include <stdlib.h>
23 #include <stdarg.h>
24 #include <sys/types.h>
25 #include <sys/stat.h>
26 #include <fcntl.h>
27 #include <errno.h>
28 #include <libelf.h>
29 #include <libctf.h>
30 #include <string.h>
31 #include <libgen.h>
32 #include <limits.h>
33 #include <strings.h>
34 #include <sys/debug.h>
35
36 #define CTFCONVERT_OK 0
37 #define CTFCONVERT_FATAL 1
38 #define CTFCONVERT_USAGE 2
39
40 #define CTFCONVERT_DEFAULT_NTHREADS 4
41
42 #define CTFCONVERT_ALTEXEC "CTFCONVERT_ALTEXEC"
43
44 static char *ctfconvert_progname;
45
46 static void
ctfconvert_fatal(const char * fmt,...)47 ctfconvert_fatal(const char *fmt, ...)
48 {
49 va_list ap;
50
51 (void) fprintf(stderr, "%s: ", ctfconvert_progname);
52 va_start(ap, fmt);
53 (void) vfprintf(stderr, fmt, ap);
54 va_end(ap);
55
56 exit(CTFCONVERT_FATAL);
57 }
58
59
60 static void
ctfconvert_usage(const char * fmt,...)61 ctfconvert_usage(const char *fmt, ...)
62 {
63 if (fmt != NULL) {
64 va_list ap;
65
66 (void) fprintf(stderr, "%s: ", ctfconvert_progname);
67 va_start(ap, fmt);
68 (void) vfprintf(stderr, fmt, ap);
69 va_end(ap);
70 }
71
72 (void) fprintf(stderr, "Usage: %s [-is] [-j nthrs] [-l label | "
73 "-L labelenv] [-o outfile] input\n"
74 "\n"
75 "\t-i ignore files not built partially from C sources\n"
76 "\t-j use nthrs threads to perform the merge\n"
77 "\t-k keep around original input file on failure\n"
78 "\t-o copy input to outfile and add CTF\n"
79 "\t-l set output container's label to specified value\n"
80 "\t-L set output container's label to value from environment\n",
81 ctfconvert_progname);
82 }
83
84 /*
85 * This is a bit unfortunate. Traditionally we do type uniquification across all
86 * modules in the kernel, including ip and unix against genunix. However, when
87 * _MACHDEP is defined, then the cpu_t ends up having an additional member
88 * (cpu_m), thus changing the ability for us to uniquify against it. This in
89 * turn causes a lot of type sprawl, as there's a lot of things that end up
90 * referring to the cpu_t and it chains out from there.
91 *
92 * So, if we find that a cpu_t has been defined and it has a couple of useful
93 * sentinel members and it does *not* have the cpu_m member, then we will try
94 * and lookup or create a forward declaration to the machcpu, append it to the
95 * end, and update the file.
96 *
97 * This currently is only invoked if an undocumented option -X is passed. This
98 * value is private to illumos and it can be changed at any time inside of it,
99 * so if -X wants to be used for something, it should be. The ability to rely on
100 * -X for others is strictly not an interface in any way, shape, or form.
101 *
102 * The following struct contains most of the information that we care about and
103 * that we want to validate exists before we decide what to do.
104 */
105
106 typedef struct ctfconvert_fixup {
107 boolean_t cf_cyclic; /* Do we have a cpu_cyclic member */
108 boolean_t cf_mcpu; /* We have a cpu_m member */
109 boolean_t cf_lastpad; /* Is the pad member the last entry */
110 ulong_t cf_padoff; /* offset of the pad */
111 } ctfconvert_fixup_t;
112
113 /* ARGSUSED */
114 static int
ctfconvert_fixup_genunix_cb(const char * name,ctf_id_t tid,ulong_t off,void * arg)115 ctfconvert_fixup_genunix_cb(const char *name, ctf_id_t tid, ulong_t off,
116 void *arg)
117 {
118 ctfconvert_fixup_t *cfp = arg;
119
120 cfp->cf_lastpad = B_FALSE;
121 if (strcmp(name, "cpu_cyclic") == 0) {
122 cfp->cf_cyclic = B_TRUE;
123 return (0);
124 }
125
126 if (strcmp(name, "cpu_m") == 0) {
127 cfp->cf_mcpu = B_TRUE;
128 return (0);
129 }
130
131 if (strcmp(name, "cpu_m_pad") == 0) {
132 cfp->cf_lastpad = B_TRUE;
133 cfp->cf_padoff = off;
134 return (0);
135 }
136
137 return (0);
138 }
139
140 static void
ctfconvert_fixup_genunix(ctf_file_t * fp)141 ctfconvert_fixup_genunix(ctf_file_t *fp)
142 {
143 ctf_id_t cpuid, mcpu;
144 ssize_t sz;
145 ctfconvert_fixup_t cf;
146 int model, ptrsz;
147
148 cpuid = ctf_lookup_by_name(fp, "struct cpu");
149 if (cpuid == CTF_ERR)
150 return;
151
152 if (ctf_type_kind(fp, cpuid) != CTF_K_STRUCT)
153 return;
154
155 if ((sz = ctf_type_size(fp, cpuid)) == CTF_ERR)
156 return;
157
158 model = ctf_getmodel(fp);
159 VERIFY(model == CTF_MODEL_ILP32 || model == CTF_MODEL_LP64);
160 ptrsz = model == CTF_MODEL_ILP32 ? 4 : 8;
161
162 bzero(&cf, sizeof (ctfconvert_fixup_t));
163 if (ctf_member_iter(fp, cpuid, ctfconvert_fixup_genunix_cb, &cf) ==
164 CTF_ERR)
165 return;
166
167 /*
168 * Finally, we want to verify that the cpu_m is actually the last member
169 * that we have here.
170 */
171 if (cf.cf_cyclic == B_FALSE || cf.cf_mcpu == B_TRUE ||
172 cf.cf_lastpad == B_FALSE) {
173 return;
174 }
175
176 if (cf.cf_padoff + ptrsz * NBBY != sz * NBBY) {
177 return;
178 }
179
180 /*
181 * Okay, we're going to do this, try to find a struct machcpu. We either
182 * want a forward or a struct. If we find something else, error. If we
183 * find nothing, add a forward and then add the member.
184 */
185 mcpu = ctf_lookup_by_name(fp, "struct machcpu");
186 if (mcpu == CTF_ERR) {
187 mcpu = ctf_add_forward(fp, CTF_ADD_NONROOT, "machcpu",
188 CTF_K_STRUCT);
189 if (mcpu == CTF_ERR) {
190 ctfconvert_fatal("failed to add 'struct machcpu' "
191 "forward: %s", ctf_errmsg(ctf_errno(fp)));
192 }
193 } else {
194 int kind;
195 if ((kind = ctf_type_kind(fp, mcpu)) == CTF_ERR) {
196 ctfconvert_fatal("failed to get the type kind for "
197 "the struct machcpu: %s",
198 ctf_errmsg(ctf_errno(fp)));
199 }
200
201 if (kind != CTF_K_STRUCT && kind != CTF_K_FORWARD)
202 ctfconvert_fatal("encountered a struct machcpu of the "
203 "wrong type, found type kind %d\n", kind);
204 }
205
206 if (ctf_update(fp) == CTF_ERR) {
207 ctfconvert_fatal("failed to update output file: %s\n",
208 ctf_errmsg(ctf_errno(fp)));
209 }
210
211 if (ctf_add_member(fp, cpuid, "cpu_m", mcpu, sz * NBBY) == CTF_ERR) {
212 ctfconvert_fatal("failed to add the m_cpu member: %s\n",
213 ctf_errmsg(ctf_errno(fp)));
214 }
215
216 if (ctf_update(fp) == CTF_ERR) {
217 ctfconvert_fatal("failed to update output file: %s\n",
218 ctf_errmsg(ctf_errno(fp)));
219 }
220
221 VERIFY(ctf_type_size(fp, cpuid) == sz);
222 }
223
224 static void
ctfconvert_altexec(char ** argv)225 ctfconvert_altexec(char **argv)
226 {
227 const char *alt;
228 char *altexec;
229
230 alt = getenv(CTFCONVERT_ALTEXEC);
231 if (alt == NULL || *alt == '\0')
232 return;
233
234 altexec = strdup(alt);
235 if (altexec == NULL)
236 ctfconvert_fatal("failed to allocate memory for altexec\n");
237 if (unsetenv(CTFCONVERT_ALTEXEC) != 0)
238 ctfconvert_fatal("failed to unset %s from environment: %s\n",
239 CTFCONVERT_ALTEXEC, strerror(errno));
240
241 (void) execv(altexec, argv);
242 ctfconvert_fatal("failed to execute alternate program %s: %s",
243 altexec, strerror(errno));
244 }
245
246 int
main(int argc,char * argv[])247 main(int argc, char *argv[])
248 {
249 int c, ifd, err;
250 boolean_t keep = B_FALSE;
251 uint_t flags = 0;
252 uint_t nthreads = CTFCONVERT_DEFAULT_NTHREADS;
253 const char *outfile = NULL;
254 const char *label = NULL;
255 const char *infile = NULL;
256 char *tmpfile;
257 ctf_file_t *ofp;
258 long argj;
259 char *eptr;
260 char buf[4096];
261 boolean_t optx = B_FALSE;
262
263 ctfconvert_progname = basename(argv[0]);
264
265 ctfconvert_altexec(argv);
266
267 while ((c = getopt(argc, argv, ":j:kl:L:o:iX")) != -1) {
268 switch (c) {
269 case 'k':
270 keep = B_TRUE;
271 break;
272 case 'l':
273 label = optarg;
274 break;
275 case 'L':
276 label = getenv(optarg);
277 break;
278 case 'j':
279 errno = 0;
280 argj = strtol(optarg, &eptr, 10);
281 if (errno != 0 || argj == LONG_MAX ||
282 argj > 1024 || *eptr != '\0') {
283 ctfconvert_fatal("invalid argument for -j: "
284 "%s\n", optarg);
285 }
286 nthreads = (uint_t)argj;
287 break;
288 case 'o':
289 outfile = optarg;
290 break;
291 case 'i':
292 flags |= CTF_CONVERT_F_IGNNONC;
293 break;
294 case 'X':
295 optx = B_TRUE;
296 break;
297 case ':':
298 ctfconvert_usage("Option -%c requires an operand\n",
299 optopt);
300 return (CTFCONVERT_USAGE);
301 case '?':
302 ctfconvert_usage("Unknown option: -%c\n", optopt);
303 return (CTFCONVERT_USAGE);
304 }
305 }
306
307 argv += optind;
308 argc -= optind;
309
310 if (argc < 1) {
311 ctfconvert_usage("Missing required input file\n");
312 return (CTFCONVERT_USAGE);
313 }
314 infile = argv[0];
315
316 if (elf_version(EV_CURRENT) == EV_NONE)
317 ctfconvert_fatal("failed to initialize libelf: library is "
318 "out of date\n");
319
320 ifd = open(infile, O_RDONLY);
321 if (ifd < 0) {
322 ctfconvert_fatal("failed to open input file %s: %s\n", infile,
323 strerror(errno));
324 }
325
326 /*
327 * By default we remove the input file on failure unless we've been
328 * given an output file or -k has been specified.
329 */
330 if (outfile != NULL && strcmp(infile, outfile) != 0)
331 keep = B_TRUE;
332
333 ofp = ctf_fdconvert(ifd, label, nthreads, flags, &err, buf,
334 sizeof (buf));
335 if (ofp == NULL) {
336 /*
337 * -i says that we shouldn't concern ourselves with source files
338 * that weren't built from C source code in part. Because this
339 * has been traditionally used across all of illumos, we still
340 * honor it.
341 */
342 if ((flags & CTF_CONVERT_F_IGNNONC) != 0 &&
343 err == ECTF_CONVNOCSRC) {
344 exit(CTFCONVERT_OK);
345 }
346 if (keep == B_FALSE)
347 (void) unlink(infile);
348 ctfconvert_fatal("CTF conversion failed: %s\n",
349 err == ECTF_CONVBKERR ? buf : ctf_errmsg(err));
350 }
351
352 if (optx == B_TRUE)
353 ctfconvert_fixup_genunix(ofp);
354
355 tmpfile = NULL;
356 if (outfile == NULL || strcmp(infile, outfile) == 0) {
357 if (asprintf(&tmpfile, "%s.ctf", infile) == -1) {
358 if (keep == B_FALSE)
359 (void) unlink(infile);
360 ctfconvert_fatal("failed to allocate memory for "
361 "temporary file: %s\n", strerror(errno));
362 }
363 outfile = tmpfile;
364 }
365 err = ctf_elfwrite(ofp, infile, outfile, CTF_ELFWRITE_F_COMPRESS);
366 if (err == CTF_ERR) {
367 (void) unlink(outfile);
368 if (keep == B_FALSE)
369 (void) unlink(infile);
370 ctfconvert_fatal("failed to write CTF section to output file: "
371 "%s", ctf_errmsg(ctf_errno(ofp)));
372 }
373 ctf_close(ofp);
374
375 if (tmpfile != NULL) {
376 if (rename(tmpfile, infile) != 0) {
377 int e = errno;
378 (void) unlink(outfile);
379 if (keep == B_FALSE)
380 (void) unlink(infile);
381 ctfconvert_fatal("failed to rename temporary file: "
382 "%s\n", strerror(e));
383 }
384 }
385 free(tmpfile);
386
387 return (CTFCONVERT_OK);
388 }
389