1
2 /*--------------------------------------------------------------------*/
3 /*--- Launching valgrind m_launcher.c ---*/
4 /*--------------------------------------------------------------------*/
5
6 /*
7 This file is part of Valgrind, a dynamic binary instrumentation
8 framework.
9
10 Copyright (C) 2000-2012 Julian Seward
11 jseward@acm.org
12
13 This program is free software; you can redistribute it and/or
14 modify it under the terms of the GNU General Public License as
15 published by the Free Software Foundation; either version 2 of the
16 License, or (at your option) any later version.
17
18 This program is distributed in the hope that it will be useful, but
19 WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 General Public License for more details.
22
23 You should have received a copy of the GNU General Public License
24 along with this program; if not, write to the Free Software
25 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26 02111-1307, USA.
27
28 The GNU General Public License is contained in the file COPYING.
29 */
30
31 /* Note: this is a "normal" program and not part of Valgrind proper,
32 and so it doesn't have to conform to Valgrind's arcane rules on
33 no-glibc-usage etc. */
34
35 /* Include valgrind headers before system headers to avoid problems
36 with the system headers #defining things which are used as names
37 of structure members in vki headers. */
38
39 #include "pub_core_debuglog.h"
40 #include "pub_core_vki.h" // Avoids warnings from
41 // pub_core_libcfile.h
42 #include "pub_core_libcproc.h" // For VALGRIND_LIB, VALGRIND_LAUNCHER
43 #include "pub_core_ume.h"
44
45 #include <assert.h>
46 #include <ctype.h>
47 #include <elf.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54
55
56
57 #define PATH_MAX 4096 /* POSIX refers to this a lot but I dunno
58 where it is defined */
59
60 #ifndef EM_X86_64
61 #define EM_X86_64 62 // elf.h doesn't define this on some older systems
62 #endif
63
64 /* Report fatal errors */
65 __attribute__((noreturn))
barf(const char * format,...)66 static void barf ( const char *format, ... )
67 {
68 va_list vargs;
69
70 va_start(vargs, format);
71 fprintf(stderr, "valgrind: Cannot continue: ");
72 vfprintf(stderr, format, vargs);
73 fprintf(stderr, "\n");
74 va_end(vargs);
75
76 exit(1);
77 /*NOTREACHED*/
78 assert(0);
79 }
80
81 /* Search the path for the client program */
find_client(const char * clientname)82 static const char *find_client(const char *clientname)
83 {
84 static char fullname[PATH_MAX];
85 const char *path = getenv("PATH");
86 const char *colon;
87
88 while (path)
89 {
90 if ((colon = strchr(path, ':')) == NULL)
91 {
92 strcpy(fullname, path);
93 path = NULL;
94 }
95 else
96 {
97 memcpy(fullname, path, colon - path);
98 fullname[colon - path] = '\0';
99 path = colon + 1;
100 }
101
102 strcat(fullname, "/");
103 strcat(fullname, clientname);
104
105 if (access(fullname, R_OK|X_OK) == 0)
106 return fullname;
107 }
108
109 return clientname;
110 }
111
112 /* Examine the client and work out which platform it is for */
select_platform(const char * clientname)113 static const char *select_platform(const char *clientname)
114 {
115 int fd;
116 uint8_t header[4096];
117 ssize_t n_bytes;
118 const char *platform = NULL;
119
120 VG_(debugLog)(2, "launcher", "selecting platform for '%s'\n", clientname);
121
122 if (strchr(clientname, '/') == NULL)
123 clientname = find_client(clientname);
124
125 VG_(debugLog)(2, "launcher", "selecting platform for '%s'\n", clientname);
126
127 if ((fd = open(clientname, O_RDONLY)) < 0)
128 return NULL;
129 // barf("open(%s): %s", clientname, strerror(errno));
130
131 VG_(debugLog)(2, "launcher", "opened '%s'\n", clientname);
132
133 n_bytes = read(fd, header, sizeof(header));
134 close(fd);
135 if (n_bytes < 2) {
136 return NULL;
137 }
138
139 VG_(debugLog)(2, "launcher", "read %ld bytes from '%s'\n",
140 (long int)n_bytes, clientname);
141
142 if (header[0] == '#' && header[1] == '!') {
143 int i = 2;
144 char *interp = (char *)header + 2;
145
146 // Skip whitespace.
147 while (1) {
148 if (i == n_bytes) return NULL;
149 if (' ' != header[i] && '\t' != header[i]) break;
150 i++;
151 }
152
153 // Get the interpreter name.
154 interp = &header[i];
155 while (1) {
156 if (i == n_bytes) break;
157 if (isspace(header[i])) break;
158 i++;
159 }
160 if (i == n_bytes) return NULL;
161 header[i] = '\0';
162
163 platform = select_platform(interp);
164
165 } else if (n_bytes >= SELFMAG && memcmp(header, ELFMAG, SELFMAG) == 0) {
166
167 if (n_bytes >= sizeof(Elf32_Ehdr) && header[EI_CLASS] == ELFCLASS32) {
168 const Elf32_Ehdr *ehdr = (Elf32_Ehdr *)header;
169
170 if (header[EI_DATA] == ELFDATA2LSB) {
171 if (ehdr->e_machine == EM_386 &&
172 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
173 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
174 platform = "x86-linux";
175 }
176 else
177 if (ehdr->e_machine == EM_ARM &&
178 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
179 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
180 platform = "arm-linux";
181 }
182 else
183 if (ehdr->e_machine == EM_MIPS &&
184 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
185 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
186 platform = "mips32-linux";
187 }
188 }
189 else if (header[EI_DATA] == ELFDATA2MSB) {
190 if (ehdr->e_machine == EM_PPC &&
191 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
192 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
193 platform = "ppc32-linux";
194 }
195 else
196 if (ehdr->e_machine == EM_MIPS &&
197 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
198 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
199 platform = "mips32-linux";
200 }
201 }
202
203 } else if (n_bytes >= sizeof(Elf64_Ehdr) && header[EI_CLASS] == ELFCLASS64) {
204 const Elf64_Ehdr *ehdr = (Elf64_Ehdr *)header;
205
206 if (header[EI_DATA] == ELFDATA2LSB) {
207 if (ehdr->e_machine == EM_X86_64 &&
208 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
209 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
210 platform = "amd64-linux";
211 }
212 } else if (header[EI_DATA] == ELFDATA2MSB) {
213 # if !defined(VGPV_arm_linux_android) && !defined(VGPV_x86_linux_android)
214 if (ehdr->e_machine == EM_PPC64 &&
215 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
216 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
217 platform = "ppc64-linux";
218 }
219 else
220 if (ehdr->e_machine == EM_S390 &&
221 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
222 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
223 platform = "s390x-linux";
224 }
225 # endif
226 }
227 }
228 }
229
230 VG_(debugLog)(2, "launcher", "selected platform '%s'\n",
231 platform ? platform : "unknown");
232
233 return platform;
234 }
235
236 /* Where we expect to find all our aux files */
237 static const char *valgrind_lib = VG_LIBDIR;
238
main(int argc,char ** argv,char ** envp)239 int main(int argc, char** argv, char** envp)
240 {
241 int i, j, loglevel, r;
242 const char *toolname = NULL;
243 const char *clientname = NULL;
244 const char *platform;
245 const char *default_platform;
246 const char *cp;
247 char *toolfile;
248 char launcher_name[PATH_MAX+1];
249 char* new_line;
250 char** new_env;
251
252 /* Start the debugging-log system ASAP. First find out how many
253 "-d"s were specified. This is a pre-scan of the command line.
254 At the same time, look for the tool name. */
255 loglevel = 0;
256 for (i = 1; i < argc; i++) {
257 if (argv[i][0] != '-') {
258 clientname = argv[i];
259 break;
260 }
261 if (0 == strcmp(argv[i], "--")) {
262 if (i+1 < argc)
263 clientname = argv[i+1];
264 break;
265 }
266 if (0 == strcmp(argv[i], "-d"))
267 loglevel++;
268 if (0 == strncmp(argv[i], "--tool=", 7))
269 toolname = argv[i] + 7;
270 }
271
272 /* ... and start the debug logger. Now we can safely emit logging
273 messages all through startup. */
274 VG_(debugLog_startup)(loglevel, "Stage 1");
275
276 /* Make sure we know which tool we're using */
277 if (toolname) {
278 VG_(debugLog)(1, "launcher", "tool '%s' requested\n", toolname);
279 } else {
280 VG_(debugLog)(1, "launcher",
281 "no tool requested, defaulting to 'memcheck'\n");
282 toolname = "memcheck";
283 }
284
285 /* Select a platform to use if we can't decide that by looking at
286 the executable (eg because it's a shell script). Note that the
287 default_platform is not necessarily either the primary or
288 secondary build target. Instead it's chosen to maximise the
289 chances that /bin/sh will work on it. Hence for a primary
290 target of ppc64-linux we still choose ppc32-linux as the default
291 target, because on most ppc64-linux setups, the basic /bin,
292 /usr/bin, etc, stuff is built in 32-bit mode, not 64-bit
293 mode. */
294 if ((0==strcmp(VG_PLATFORM,"x86-linux")) ||
295 (0==strcmp(VG_PLATFORM,"amd64-linux")) ||
296 (0==strcmp(VG_PLATFORM,"ppc32-linux")) ||
297 (0==strcmp(VG_PLATFORM,"ppc64-linux")) ||
298 (0==strcmp(VG_PLATFORM,"arm-linux")) ||
299 (0==strcmp(VG_PLATFORM,"s390x-linux")) ||
300 (0==strcmp(VG_PLATFORM,"mips32-linux")))
301 default_platform = VG_PLATFORM;
302 else
303 barf("Unknown VG_PLATFORM '%s'", VG_PLATFORM);
304
305 /* Work out what platform to use, or use the default platform if
306 not possible. */
307 if (clientname == NULL) {
308 VG_(debugLog)(1, "launcher",
309 "no client specified, defaulting platform to '%s'\n",
310 default_platform);
311 platform = default_platform;
312 } else if ((platform = select_platform(clientname)) != NULL) {
313 VG_(debugLog)(1, "launcher", "selected platform '%s'\n", platform);
314 } else {
315 VG_(debugLog)(1, "launcher",
316 "no platform detected, defaulting platform to '%s'\n",
317 default_platform);
318 platform = default_platform;
319 }
320
321 /* Figure out the name of this executable (viz, the launcher), so
322 we can tell stage2. stage2 will use the name for recursive
323 invocations of valgrind on child processes. */
324 memset(launcher_name, 0, PATH_MAX+1);
325 r = readlink("/proc/self/exe", launcher_name, PATH_MAX);
326 if (r == -1) {
327 /* If /proc/self/exe can't be followed, don't give up. Instead
328 continue with an empty string for VALGRIND_LAUNCHER. In the
329 sys_execve wrapper, this is tested, and if found to be empty,
330 fail the execve. */
331 fprintf(stderr, "valgrind: warning (non-fatal): "
332 "readlink(\"/proc/self/exe\") failed.\n");
333 fprintf(stderr, "valgrind: continuing, however --trace-children=yes "
334 "will not work.\n");
335 }
336
337 /* tediously augment the env: VALGRIND_LAUNCHER=launcher_name */
338 new_line = malloc(strlen(VALGRIND_LAUNCHER) + 1
339 + strlen(launcher_name) + 1);
340 if (new_line == NULL)
341 barf("malloc of new_line failed.");
342 strcpy(new_line, VALGRIND_LAUNCHER);
343 strcat(new_line, "=");
344 strcat(new_line, launcher_name);
345
346 for (j = 0; envp[j]; j++)
347 ;
348 new_env = malloc((j+2) * sizeof(char*));
349 if (new_env == NULL)
350 barf("malloc of new_env failed.");
351 for (i = 0; i < j; i++)
352 new_env[i] = envp[i];
353 new_env[i++] = new_line;
354 new_env[i++] = NULL;
355 assert(i == j+2);
356
357 /* Establish the correct VALGRIND_LIB. */
358 cp = getenv(VALGRIND_LIB);
359
360 if (cp != NULL)
361 valgrind_lib = cp;
362
363 /* Build the stage2 invocation, and execve it. Bye! */
364 toolfile = malloc(strlen(valgrind_lib) + strlen(toolname) + strlen(platform) + 3);
365 if (toolfile == NULL)
366 barf("malloc of toolfile failed.");
367 sprintf(toolfile, "%s/%s-%s", valgrind_lib, toolname, platform);
368
369 VG_(debugLog)(1, "launcher", "launching %s\n", toolfile);
370
371 execve(toolfile, argv, new_env);
372
373 fprintf(stderr, "valgrind: failed to start tool '%s' for platform '%s': %s\n",
374 toolname, platform, strerror(errno));
375
376 exit(1);
377 }
378