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) 2019, 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
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
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 [-ims] [-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-m allow input to have missing debug info\n"
79 "\t-o copy input to outfile and add CTF\n"
80 "\t-l set output container's label to specified value\n"
81 "\t-L set output container's label to value from environment\n",
82 ctfconvert_progname);
83 }
84
85 /*
86 * This is a bit unfortunate. Traditionally we do type uniquification across all
87 * modules in the kernel, including ip and unix against genunix. However, when
88 * _MACHDEP is defined, then the cpu_t ends up having an additional member
89 * (cpu_m), thus changing the ability for us to uniquify against it. This in
90 * turn causes a lot of type sprawl, as there's a lot of things that end up
91 * referring to the cpu_t and it chains out from there.
92 *
93 * So, if we find that a cpu_t has been defined and it has a couple of useful
94 * sentinel members and it does *not* have the cpu_m member, then we will try
95 * and lookup or create a forward declaration to the machcpu, append it to the
96 * end, and update the file.
97 *
98 * This currently is only invoked if an undocumented option -X is passed. This
99 * value is private to illumos and it can be changed at any time inside of it,
100 * so if -X wants to be used for something, it should be. The ability to rely on
101 * -X for others is strictly not an interface in any way, shape, or form.
102 *
103 * The following struct contains most of the information that we care about and
104 * that we want to validate exists before we decide what to do.
105 */
106
107 typedef struct ctfconvert_fixup {
108 boolean_t cf_cyclic; /* Do we have a cpu_cyclic member */
109 boolean_t cf_mcpu; /* We have a cpu_m member */
110 boolean_t cf_lastpad; /* Is the pad member the last entry */
111 ulong_t cf_padoff; /* offset of the pad */
112 } ctfconvert_fixup_t;
113
114 /* ARGSUSED */
115 static int
116 ctfconvert_fixup_genunix_cb(const char *name, ctf_id_t tid, ulong_t off,
117 void *arg)
118 {
119 ctfconvert_fixup_t *cfp = arg;
120
121 cfp->cf_lastpad = B_FALSE;
122 if (strcmp(name, "cpu_cyclic") == 0) {
123 cfp->cf_cyclic = B_TRUE;
124 return (0);
125 }
126
127 if (strcmp(name, "cpu_m") == 0) {
128 cfp->cf_mcpu = B_TRUE;
129 return (0);
130 }
131
132 if (strcmp(name, "cpu_m_pad") == 0) {
133 cfp->cf_lastpad = B_TRUE;
134 cfp->cf_padoff = off;
135 return (0);
136 }
137
138 return (0);
139 }
140
141 static void
142 ctfconvert_fixup_genunix(ctf_file_t *fp)
143 {
144 ctf_id_t cpuid, mcpu;
145 ssize_t sz;
146 ctfconvert_fixup_t cf;
147 int model, ptrsz;
148
149 cpuid = ctf_lookup_by_name(fp, "struct cpu");
150 if (cpuid == CTF_ERR)
151 return;
152
153 if (ctf_type_kind(fp, cpuid) != CTF_K_STRUCT)
154 return;
155
156 if ((sz = ctf_type_size(fp, cpuid)) == CTF_ERR)
157 return;
158
159 model = ctf_getmodel(fp);
160 VERIFY(model == CTF_MODEL_ILP32 || model == CTF_MODEL_LP64);
161 ptrsz = model == CTF_MODEL_ILP32 ? 4 : 8;
162
163 bzero(&cf, sizeof (ctfconvert_fixup_t));
164 if (ctf_member_iter(fp, cpuid, ctfconvert_fixup_genunix_cb, &cf) ==
165 CTF_ERR)
166 return;
167
168 /*
169 * Finally, we want to verify that the cpu_m is actually the last member
170 * that we have here.
171 */
172 if (cf.cf_cyclic == B_FALSE || cf.cf_mcpu == B_TRUE ||
173 cf.cf_lastpad == B_FALSE) {
174 return;
175 }
176
177 if (cf.cf_padoff + ptrsz * NBBY != sz * NBBY) {
178 return;
179 }
180
181 /*
182 * Okay, we're going to do this, try to find a struct machcpu. We either
183 * want a forward or a struct. If we find something else, error. If we
184 * find nothing, add a forward and then add the member.
185 */
186 mcpu = ctf_lookup_by_name(fp, "struct machcpu");
187 if (mcpu == CTF_ERR) {
188 mcpu = ctf_add_forward(fp, CTF_ADD_NONROOT, "machcpu",
189 CTF_K_STRUCT);
190 if (mcpu == CTF_ERR) {
191 ctfconvert_fatal("failed to add 'struct machcpu' "
192 "forward: %s", ctf_errmsg(ctf_errno(fp)));
193 }
194 } else {
195 int kind;
196 if ((kind = ctf_type_kind(fp, mcpu)) == CTF_ERR) {
197 ctfconvert_fatal("failed to get the type kind for "
198 "the struct machcpu: %s",
199 ctf_errmsg(ctf_errno(fp)));
200 }
201
202 if (kind != CTF_K_STRUCT && kind != CTF_K_FORWARD)
203 ctfconvert_fatal("encountered a struct machcpu of the "
204 "wrong type, found type kind %d\n", kind);
205 }
206
207 if (ctf_update(fp) == CTF_ERR) {
208 ctfconvert_fatal("failed to update output file: %s\n",
209 ctf_errmsg(ctf_errno(fp)));
210 }
211
212 if (ctf_add_member(fp, cpuid, "cpu_m", mcpu, sz * NBBY) == CTF_ERR) {
213 ctfconvert_fatal("failed to add the m_cpu member: %s\n",
214 ctf_errmsg(ctf_errno(fp)));
215 }
216
217 if (ctf_update(fp) == CTF_ERR) {
218 ctfconvert_fatal("failed to update output file: %s\n",
219 ctf_errmsg(ctf_errno(fp)));
220 }
221
222 VERIFY(ctf_type_size(fp, cpuid) == sz);
223 }
224
225 static void
226 ctfconvert_altexec(char **argv)
227 {
228 const char *alt;
229 char *altexec;
230
231 alt = getenv(CTFCONVERT_ALTEXEC);
232 if (alt == NULL || *alt == '\0')
233 return;
234
235 altexec = strdup(alt);
236 if (altexec == NULL)
237 ctfconvert_fatal("failed to allocate memory for altexec\n");
238 if (unsetenv(CTFCONVERT_ALTEXEC) != 0)
239 ctfconvert_fatal("failed to unset %s from environment: %s\n",
240 CTFCONVERT_ALTEXEC, strerror(errno));
241
242 (void) execv(altexec, argv);
243 ctfconvert_fatal("failed to execute alternate program %s: %s",
244 altexec, strerror(errno));
245 }
246
247 int
248 main(int argc, char *argv[])
249 {
250 int c, ifd, err;
251 boolean_t keep = B_FALSE;
252 uint_t flags = 0;
253 uint_t nthreads = CTFCONVERT_DEFAULT_NTHREADS;
254 const char *outfile = NULL;
255 const char *label = NULL;
256 const char *infile = NULL;
257 char *tmpfile;
258 ctf_file_t *ofp;
259 long argj;
260 char *eptr;
261 char buf[4096];
262 boolean_t optx = B_FALSE;
263 boolean_t ignore_non_c = B_FALSE;
264
265 ctfconvert_progname = basename(argv[0]);
266
267 ctfconvert_altexec(argv);
268
269 while ((c = getopt(argc, argv, ":ij:kl:L:mo:X")) != -1) {
270 switch (c) {
271 case 'i':
272 ignore_non_c = B_TRUE;
273 break;
274 case 'j':
275 errno = 0;
276 argj = strtol(optarg, &eptr, 10);
277 if (errno != 0 || argj == LONG_MAX ||
278 argj > 1024 || *eptr != '\0') {
279 ctfconvert_fatal("invalid argument for -j: "
280 "%s\n", optarg);
281 }
282 nthreads = (uint_t)argj;
283 break;
284 case 'k':
285 keep = B_TRUE;
286 break;
287 case 'l':
288 label = optarg;
289 break;
290 case 'L':
291 label = getenv(optarg);
292 break;
293 case 'm':
294 flags |= CTF_ALLOW_MISSING_DEBUG;
295 break;
296 case 'o':
297 outfile = optarg;
298 break;
299 case 'X':
300 optx = B_TRUE;
301 break;
302 case ':':
303 ctfconvert_usage("Option -%c requires an operand\n",
304 optopt);
305 return (CTFCONVERT_USAGE);
306 case '?':
307 ctfconvert_usage("Unknown option: -%c\n", optopt);
308 return (CTFCONVERT_USAGE);
309 }
310 }
311
312 argv += optind;
313 argc -= optind;
314
315 if (argc != 1) {
316 ctfconvert_usage("Exactly one input file is required\n");
317 return (CTFCONVERT_USAGE);
318 }
319 infile = argv[0];
320
321 if (elf_version(EV_CURRENT) == EV_NONE)
322 ctfconvert_fatal("failed to initialize libelf: library is "
323 "out of date\n");
324
325 ifd = open(infile, O_RDONLY);
326 if (ifd < 0) {
327 ctfconvert_fatal("failed to open input file %s: %s\n", infile,
328 strerror(errno));
329 }
330
331 /*
332 * By default we remove the input file on failure unless we've been
333 * given an output file or -k has been specified.
334 */
335 if (outfile != NULL && strcmp(infile, outfile) != 0)
336 keep = B_TRUE;
337
338 ofp = ctf_fdconvert(ifd, label, nthreads, flags, &err, buf,
339 sizeof (buf));
340 if (ofp == NULL) {
341 /*
342 * Normally, ctfconvert requires that its input file has at
343 * least one C-source compilation unit, and that every C-source
344 * compilation unit has DWARF. This is to avoid accidentally
345 * leaving out useful CTF.
346 *
347 * However, for the benefit of intransigent build environments,
348 * the -i and -m options can be used to relax this.
349 */
350 if (err == ECTF_CONVNOCSRC && ignore_non_c) {
351 exit(CTFCONVERT_OK);
352 }
353
354 if (err == ECTF_CONVNODEBUG &&
355 (flags & CTF_ALLOW_MISSING_DEBUG) != 0) {
356 exit(CTFCONVERT_OK);
357 }
358
359 if (keep == B_FALSE)
360 (void) unlink(infile);
361
362 if (err == ECTF_CONVBKERR || err == ECTF_CONVNODEBUG) {
363 ctfconvert_fatal("%s", buf);
364 } else {
365 ctfconvert_fatal("CTF conversion failed: %s\n",
366 ctf_errmsg(err));
367 }
368 }
369
370 if (optx == B_TRUE)
371 ctfconvert_fixup_genunix(ofp);
372
373 tmpfile = NULL;
374 if (outfile == NULL || strcmp(infile, outfile) == 0) {
375 if (asprintf(&tmpfile, "%s.ctf", infile) == -1) {
376 if (keep == B_FALSE)
377 (void) unlink(infile);
378 ctfconvert_fatal("failed to allocate memory for "
379 "temporary file: %s\n", strerror(errno));
380 }
381 outfile = tmpfile;
382 }
383 err = ctf_elfwrite(ofp, infile, outfile, CTF_ELFWRITE_F_COMPRESS);
384 if (err == CTF_ERR) {
385 (void) unlink(outfile);
386 if (keep == B_FALSE)
387 (void) unlink(infile);
388 ctfconvert_fatal("failed to write CTF section to output file: "
389 "%s", ctf_errmsg(ctf_errno(ofp)));
390 }
391 ctf_close(ofp);
392
393 if (tmpfile != NULL) {
394 if (rename(tmpfile, infile) != 0) {
395 int e = errno;
396 (void) unlink(outfile);
397 if (keep == B_FALSE)
398 (void) unlink(infile);
399 ctfconvert_fatal("failed to rename temporary file: "
400 "%s\n", strerror(e));
401 }
402 }
403 free(tmpfile);
404
405 return (CTFCONVERT_OK);
406 }