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) 2000-2011 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 #ifndef EM_PPC64
64 #define EM_PPC64 21 // elf.h doesn't define this on Android
65 #endif
66
67
68 /* Report fatal errors */
69 __attribute__((noreturn))
barf(const char * format,...)70 static void barf ( const char *format, ... )
71 {
72 va_list vargs;
73
74 va_start(vargs, format);
75 fprintf(stderr, "valgrind: Cannot continue: ");
76 vfprintf(stderr, format, vargs);
77 fprintf(stderr, "\n");
78 va_end(vargs);
79
80 exit(1);
81 /*NOTREACHED*/
82 assert(0);
83 }
84
85 /* Search the path for the client program */
find_client(const char * clientname)86 static const char *find_client(const char *clientname)
87 {
88 static char fullname[PATH_MAX];
89 const char *path = getenv("PATH");
90 const char *colon;
91
92 while (path)
93 {
94 if ((colon = strchr(path, ':')) == NULL)
95 {
96 strcpy(fullname, path);
97 path = NULL;
98 }
99 else
100 {
101 memcpy(fullname, path, colon - path);
102 fullname[colon - path] = '\0';
103 path = colon + 1;
104 }
105
106 strcat(fullname, "/");
107 strcat(fullname, clientname);
108
109 if (access(fullname, R_OK|X_OK) == 0)
110 return fullname;
111 }
112
113 return clientname;
114 }
115
116 /* Examine the client and work out which platform it is for */
select_platform(const char * clientname)117 static const char *select_platform(const char *clientname)
118 {
119 int fd;
120 uint8_t header[4096];
121 ssize_t n_bytes;
122 const char *platform = NULL;
123
124 VG_(debugLog)(2, "launcher", "selecting platform for '%s'\n", clientname);
125
126 if (strchr(clientname, '/') == NULL)
127 clientname = find_client(clientname);
128
129 VG_(debugLog)(2, "launcher", "selecting platform for '%s'\n", clientname);
130
131 if ((fd = open(clientname, O_RDONLY)) < 0)
132 return NULL;
133 // barf("open(%s): %s", clientname, strerror(errno));
134
135 VG_(debugLog)(2, "launcher", "opened '%s'\n", clientname);
136
137 n_bytes = read(fd, header, sizeof(header));
138 close(fd);
139 if (n_bytes < 2) {
140 return NULL;
141 }
142
143 VG_(debugLog)(2, "launcher", "read %ld bytes from '%s'\n",
144 (long int)n_bytes, clientname);
145
146 if (header[0] == '#' && header[1] == '!') {
147 int i = 2;
148 char *interp = (char *)header + 2;
149
150 // Skip whitespace.
151 while (1) {
152 if (i == n_bytes) return NULL;
153 if (' ' != header[i] && '\t' != header[i]) break;
154 i++;
155 }
156
157 // Get the interpreter name.
158 interp = &header[i];
159 while (1) {
160 if (i == n_bytes) break;
161 if (isspace(header[i])) break;
162 i++;
163 }
164 if (i == n_bytes) return NULL;
165 header[i] = '\0';
166
167 platform = select_platform(interp);
168
169 } else if (n_bytes >= SELFMAG && memcmp(header, ELFMAG, SELFMAG) == 0) {
170
171 if (n_bytes >= sizeof(Elf32_Ehdr) && header[EI_CLASS] == ELFCLASS32) {
172 const Elf32_Ehdr *ehdr = (Elf32_Ehdr *)header;
173
174 if (header[EI_DATA] == ELFDATA2LSB) {
175 if (ehdr->e_machine == EM_386 &&
176 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
177 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
178 platform = "x86-linux";
179 }
180 else
181 if (ehdr->e_machine == EM_ARM &&
182 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
183 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
184 platform = "arm-linux";
185 }
186 }
187 else if (header[EI_DATA] == ELFDATA2MSB) {
188 if (ehdr->e_machine == EM_PPC &&
189 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
190 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
191 platform = "ppc32-linux";
192 }
193 }
194
195 } else if (n_bytes >= sizeof(Elf64_Ehdr) && header[EI_CLASS] == ELFCLASS64) {
196 const Elf64_Ehdr *ehdr = (Elf64_Ehdr *)header;
197
198 if (header[EI_DATA] == ELFDATA2LSB) {
199 if (ehdr->e_machine == EM_X86_64 &&
200 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
201 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
202 platform = "amd64-linux";
203 }
204 } else if (header[EI_DATA] == ELFDATA2MSB) {
205 # if !defined(VGPV_arm_linux_android) && !defined(VGPV_x86_linux_android)
206 if (ehdr->e_machine == EM_PPC64 &&
207 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
208 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
209 platform = "ppc64-linux";
210 }
211 else
212 if (ehdr->e_machine == EM_S390 &&
213 (ehdr->e_ident[EI_OSABI] == ELFOSABI_SYSV ||
214 ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX)) {
215 platform = "s390x-linux";
216 }
217 # endif
218 }
219 }
220 }
221
222 VG_(debugLog)(2, "launcher", "selected platform '%s'\n",
223 platform ? platform : "unknown");
224
225 return platform;
226 }
227
228 /* Where we expect to find all our aux files */
229 static const char *valgrind_lib = VG_LIBDIR;
230
main(int argc,char ** argv,char ** envp)231 int main(int argc, char** argv, char** envp)
232 {
233 int i, j, loglevel, r;
234 const char *toolname = NULL;
235 const char *clientname = NULL;
236 const char *platform;
237 const char *default_platform;
238 const char *cp;
239 char *toolfile;
240 char launcher_name[PATH_MAX+1];
241 char* new_line;
242 char** new_env;
243
244 /* Start the debugging-log system ASAP. First find out how many
245 "-d"s were specified. This is a pre-scan of the command line.
246 At the same time, look for the tool name. */
247 loglevel = 0;
248 for (i = 1; i < argc; i++) {
249 if (argv[i][0] != '-') {
250 clientname = argv[i];
251 break;
252 }
253 if (0 == strcmp(argv[i], "--")) {
254 if (i+1 < argc)
255 clientname = argv[i+1];
256 break;
257 }
258 if (0 == strcmp(argv[i], "-d"))
259 loglevel++;
260 if (0 == strncmp(argv[i], "--tool=", 7))
261 toolname = argv[i] + 7;
262 }
263
264 /* ... and start the debug logger. Now we can safely emit logging
265 messages all through startup. */
266 VG_(debugLog_startup)(loglevel, "Stage 1");
267
268 /* Make sure we know which tool we're using */
269 if (toolname) {
270 VG_(debugLog)(1, "launcher", "tool '%s' requested\n", toolname);
271 } else {
272 VG_(debugLog)(1, "launcher",
273 "no tool requested, defaulting to 'memcheck'\n");
274 toolname = "memcheck";
275 }
276
277 /* Select a platform to use if we can't decide that by looking at
278 the executable (eg because it's a shell script). Note that the
279 default_platform is not necessarily either the primary or
280 secondary build target. Instead it's chosen to maximise the
281 chances that /bin/sh will work on it. Hence for a primary
282 target of ppc64-linux we still choose ppc32-linux as the default
283 target, because on most ppc64-linux setups, the basic /bin,
284 /usr/bin, etc, stuff is built in 32-bit mode, not 64-bit
285 mode. */
286 if ((0==strcmp(VG_PLATFORM,"x86-linux")) ||
287 (0==strcmp(VG_PLATFORM,"amd64-linux")) ||
288 (0==strcmp(VG_PLATFORM,"ppc32-linux")) ||
289 (0==strcmp(VG_PLATFORM,"ppc64-linux")) ||
290 (0==strcmp(VG_PLATFORM,"arm-linux")) ||
291 (0==strcmp(VG_PLATFORM,"s390x-linux")))
292 default_platform = VG_PLATFORM;
293 else
294 barf("Unknown VG_PLATFORM '%s'", VG_PLATFORM);
295
296 /* Work out what platform to use, or use the default platform if
297 not possible. */
298 if (clientname == NULL) {
299 VG_(debugLog)(1, "launcher",
300 "no client specified, defaulting platform to '%s'\n",
301 default_platform);
302 platform = default_platform;
303 } else if ((platform = select_platform(clientname)) != NULL) {
304 VG_(debugLog)(1, "launcher", "selected platform '%s'\n", platform);
305 } else {
306 VG_(debugLog)(1, "launcher",
307 "no platform detected, defaulting platform to '%s'\n",
308 default_platform);
309 platform = default_platform;
310 }
311
312 /* Figure out the name of this executable (viz, the launcher), so
313 we can tell stage2. stage2 will use the name for recursive
314 invocations of valgrind on child processes. */
315 memset(launcher_name, 0, PATH_MAX+1);
316 r = readlink("/proc/self/exe", launcher_name, PATH_MAX);
317 if (r == -1) {
318 /* If /proc/self/exe can't be followed, don't give up. Instead
319 continue with an empty string for VALGRIND_LAUNCHER. In the
320 sys_execve wrapper, this is tested, and if found to be empty,
321 fail the execve. */
322 fprintf(stderr, "valgrind: warning (non-fatal): "
323 "readlink(\"/proc/self/exe\") failed.\n");
324 fprintf(stderr, "valgrind: continuing, however --trace-children=yes "
325 "will not work.\n");
326 }
327
328 /* tediously augment the env: VALGRIND_LAUNCHER=launcher_name */
329 new_line = malloc(strlen(VALGRIND_LAUNCHER) + 1
330 + strlen(launcher_name) + 1);
331 if (new_line == NULL)
332 barf("malloc of new_line failed.");
333 strcpy(new_line, VALGRIND_LAUNCHER);
334 strcat(new_line, "=");
335 strcat(new_line, launcher_name);
336
337 for (j = 0; envp[j]; j++)
338 ;
339 new_env = malloc((j+2) * sizeof(char*));
340 if (new_env == NULL)
341 barf("malloc of new_env failed.");
342 for (i = 0; i < j; i++)
343 new_env[i] = envp[i];
344 new_env[i++] = new_line;
345 new_env[i++] = NULL;
346 assert(i == j+2);
347
348 /* Establish the correct VALGRIND_LIB. */
349 cp = getenv(VALGRIND_LIB);
350
351 if (cp != NULL)
352 valgrind_lib = cp;
353
354 /* Build the stage2 invocation, and execve it. Bye! */
355 toolfile = malloc(strlen(valgrind_lib) + strlen(toolname) + strlen(platform) + 3);
356 if (toolfile == NULL)
357 barf("malloc of toolfile failed.");
358 sprintf(toolfile, "%s/%s-%s", valgrind_lib, toolname, platform);
359
360 VG_(debugLog)(1, "launcher", "launching %s\n", toolfile);
361
362 execve(toolfile, argv, new_env);
363
364 fprintf(stderr, "valgrind: failed to start tool '%s' for platform '%s': %s\n",
365 toolname, platform, strerror(errno));
366
367 exit(1);
368 }
369