xref: /illumos-gate/usr/src/cmd/ctfconvert/ctfconvert.c (revision 49ee6bfbbe326d1f0bbc34934ab8b07a000305c4)
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
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 [-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
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
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
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
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