1 /*
2 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24 #include <stdarg.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <fcntl.h>
29 #include <thread_db.h>
30 #include "libproc_impl.h"
31
32 static const char* alt_root = NULL;
33 static int alt_root_len = -1;
34
35 #define SA_ALTROOT "SA_ALTROOT"
36
37 static void init_alt_root() {
38 if (alt_root_len == -1) {
39 alt_root = getenv(SA_ALTROOT);
40 if (alt_root) {
41 alt_root_len = strlen(alt_root);
42 } else {
43 alt_root_len = 0;
44 }
45 }
46 }
47
48 int pathmap_open(const char* name) {
49 int fd;
50 char alt_path[PATH_MAX + 1];
51
52 init_alt_root();
53 fd = open(name, O_RDONLY);
54 if (fd >= 0) {
55 return fd;
56 }
57
58 if (alt_root_len > 0) {
59 strcpy(alt_path, alt_root);
60 strcat(alt_path, name);
61 fd = open(alt_path, O_RDONLY);
62 if (fd >= 0) {
63 print_debug("path %s substituted for %s\n", alt_path, name);
64 return fd;
65 }
66
67 if (strrchr(name, '/')) {
68 strcpy(alt_path, alt_root);
69 strcat(alt_path, strrchr(name, '/'));
70 fd = open(alt_path, O_RDONLY);
71 if (fd >= 0) {
72 print_debug("path %s substituted for %s\n", alt_path, name);
73 return fd;
74 }
75 }
76 }
77
78 return -1;
79 }
80
81 static bool _libsaproc_debug;
82
83 void print_debug(const char* format,...) {
84 if (_libsaproc_debug) {
85 va_list alist;
86
87 va_start(alist, format);
88 fputs("libsaproc DEBUG: ", stderr);
89 vfprintf(stderr, format, alist);
90 va_end(alist);
91 }
92 }
93
94 void print_error(const char* format,...) {
95 va_list alist;
96 va_start(alist, format);
97 fputs("ERROR: ", stderr);
98 vfprintf(stderr, format, alist);
99 va_end(alist);
100 }
101
102 bool is_debug() {
103 return _libsaproc_debug;
104 }
105
106 // initialize libproc
107 bool init_libproc(bool debug) {
108 // init debug mode
109 _libsaproc_debug = debug;
110
111 // initialize the thread_db library
112 if (td_init() != TD_OK) {
113 print_debug("libthread_db's td_init failed\n");
114 return false;
115 }
116
117 return true;
118 }
119
120 static void destroy_lib_info(struct ps_prochandle* ph) {
121 lib_info* lib = ph->libs;
122 while (lib) {
123 lib_info *next = lib->next;
124 if (lib->symtab) {
125 destroy_symtab(lib->symtab);
126 }
127 free(lib);
128 lib = next;
129 }
130 }
131
132 static void destroy_thread_info(struct ps_prochandle* ph) {
133 thread_info* thr = ph->threads;
134 while (thr) {
135 thread_info *next = thr->next;
136 free(thr);
137 thr = next;
138 }
139 }
140
141 // ps_prochandle cleanup
142
143 // ps_prochandle cleanup
144 void Prelease(struct ps_prochandle* ph) {
145 // do the "derived class" clean-up first
146 ph->ops->release(ph);
147 destroy_lib_info(ph);
148 destroy_thread_info(ph);
149 free(ph);
150 }
151
152 lib_info* add_lib_info(struct ps_prochandle* ph, const char* libname, uintptr_t base) {
153 return add_lib_info_fd(ph, libname, -1, base);
154 }
155
156 lib_info* add_lib_info_fd(struct ps_prochandle* ph, const char* libname, int fd, uintptr_t base) {
157 lib_info* newlib;
158
159 if ( (newlib = (lib_info*) calloc(1, sizeof(struct lib_info))) == NULL) {
160 print_debug("can't allocate memory for lib_info\n");
161 return NULL;
162 }
163
164 strncpy(newlib->name, libname, sizeof(newlib->name));
165 newlib->base = base;
166
167 if (fd == -1) {
168 if ( (newlib->fd = pathmap_open(newlib->name)) < 0) {
169 print_debug("can't open shared object %s\n", newlib->name);
170 free(newlib);
171 return NULL;
172 }
173 } else {
174 newlib->fd = fd;
175 }
176
177 // check whether we have got an ELF file. /proc/<pid>/map
178 // gives out all file mappings and not just shared objects
179 if (is_elf_file(newlib->fd) == false) {
180 close(newlib->fd);
181 free(newlib);
182 return NULL;
183 }
184
185 newlib->symtab = build_symtab(newlib->fd);
186 if (newlib->symtab == NULL) {
187 print_debug("symbol table build failed for %s\n", newlib->name);
188 }
189 else {
190 print_debug("built symbol table for %s\n", newlib->name);
191 }
192
193 // even if symbol table building fails, we add the lib_info.
194 // This is because we may need to read from the ELF file for core file
195 // address read functionality. lookup_symbol checks for NULL symtab.
196 if (ph->libs) {
197 ph->lib_tail->next = newlib;
198 ph->lib_tail = newlib;
199 } else {
200 ph->libs = ph->lib_tail = newlib;
201 }
202 ph->num_libs++;
203
204 return newlib;
205 }
206
207 // lookup for a specific symbol
208 uintptr_t lookup_symbol(struct ps_prochandle* ph, const char* object_name,
209 const char* sym_name) {
210 // ignore object_name. search in all libraries
211 // FIXME: what should we do with object_name?? The library names are obtained
212 // by parsing /proc/<pid>/maps, which may not be the same as object_name.
213 // What we need is a utility to map object_name to real file name, something
214 // dlopen() does by looking at LD_LIBRARY_PATH and /etc/ld.so.cache. For
215 // now, we just ignore object_name and do a global search for the symbol.
216
217 lib_info* lib = ph->libs;
218 while (lib) {
219 if (lib->symtab) {
220 uintptr_t res = search_symbol(lib->symtab, lib->base, sym_name, NULL);
221 if (res) return res;
222 }
223 lib = lib->next;
224 }
225
226 print_debug("lookup failed for symbol '%s' in obj '%s'\n",
227 sym_name, object_name);
228 return (uintptr_t) NULL;
229 }
230
231
232 const char* symbol_for_pc(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* poffset) {
233 const char* res = NULL;
234 lib_info* lib = ph->libs;
235 while (lib) {
236 if (lib->symtab && addr >= lib->base) {
237 res = nearest_symbol(lib->symtab, addr - lib->base, poffset);
238 if (res) return res;
239 }
240 lib = lib->next;
241 }
242 return NULL;
243 }
244
245 // add a thread to ps_prochandle
246 thread_info* add_thread_info(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) {
247 thread_info* newthr;
248 if ( (newthr = (thread_info*) calloc(1, sizeof(thread_info))) == NULL) {
249 print_debug("can't allocate memory for thread_info\n");
250 return NULL;
251 }
252
253 // initialize thread info
254 newthr->pthread_id = pthread_id;
255 newthr->lwp_id = lwp_id;
256
257 // add new thread to the list
258 newthr->next = ph->threads;
259 ph->threads = newthr;
260 ph->num_threads++;
261 return newthr;
262 }
263
264
265 // struct used for client data from thread_db callback
266 struct thread_db_client_data {
267 struct ps_prochandle* ph;
268 thread_info_callback callback;
269 };
270
271 // callback function for libthread_db
272 static int thread_db_callback(const td_thrhandle_t *th_p, void *data) {
273 struct thread_db_client_data* ptr = (struct thread_db_client_data*) data;
274 td_thrinfo_t ti;
275 td_err_e err;
276
277 memset(&ti, 0, sizeof(ti));
278 err = td_thr_get_info(th_p, &ti);
279 if (err != TD_OK) {
280 print_debug("libthread_db : td_thr_get_info failed, can't get thread info\n");
281 return err;
282 }
283
284 print_debug("thread_db : pthread %d (lwp %d)\n", ti.ti_tid, ti.ti_lid);
285
286 if (ptr->callback(ptr->ph, (pthread_t)ti.ti_tid, ti.ti_lid) != true)
287 return TD_ERR;
288
289 return TD_OK;
290 }
291
292 // read thread_info using libthread_db
293 bool read_thread_info(struct ps_prochandle* ph, thread_info_callback cb) {
294 struct thread_db_client_data mydata;
295 td_thragent_t* thread_agent = NULL;
296 if (td_ta_new(ph, &thread_agent) != TD_OK) {
297 print_debug("can't create libthread_db agent\n");
298 return false;
299 }
300
301 mydata.ph = ph;
302 mydata.callback = cb;
303
304 // we use libthread_db iterator to iterate thru list of threads.
305 if (td_ta_thr_iter(thread_agent, thread_db_callback, &mydata,
306 TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
307 TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS) != TD_OK) {
308 td_ta_delete(thread_agent);
309 return false;
310 }
311
312 // delete thread agent
313 td_ta_delete(thread_agent);
314 return true;
315 }
316
317
318 // get number of threads
319 int get_num_threads(struct ps_prochandle* ph) {
320 return ph->num_threads;
321 }
322
323 // get lwp_id of n'th thread
324 lwpid_t get_lwp_id(struct ps_prochandle* ph, int index) {
325 int count = 0;
326 thread_info* thr = ph->threads;
327 while (thr) {
328 if (count == index) {
329 return thr->lwp_id;
330 }
331 count++;
332 thr = thr->next;
333 }
334 return -1;
335 }
336
337 // get regs for a given lwp
338 bool get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id, struct reg* regs) {
339 return ph->ops->get_lwp_regs(ph, lwp_id, regs);
340 }
341
342 // get number of shared objects
343 int get_num_libs(struct ps_prochandle* ph) {
344 return ph->num_libs;
345 }
346
347 // get name of n'th solib
348 const char* get_lib_name(struct ps_prochandle* ph, int index) {
349 int count = 0;
350 lib_info* lib = ph->libs;
351 while (lib) {
352 if (count == index) {
353 return lib->name;
354 }
355 count++;
356 lib = lib->next;
357 }
358 return NULL;
359 }
360
361 // get base address of a lib
362 uintptr_t get_lib_base(struct ps_prochandle* ph, int index) {
363 int count = 0;
364 lib_info* lib = ph->libs;
365 while (lib) {
366 if (count == index) {
367 return lib->base;
368 }
369 count++;
370 lib = lib->next;
371 }
372 return (uintptr_t)NULL;
373 }
374
375 bool find_lib(struct ps_prochandle* ph, const char *lib_name) {
376 lib_info *p = ph->libs;
377 while (p) {
378 if (strcmp(p->name, lib_name) == 0) {
379 return true;
380 }
381 p = p->next;
382 }
383 return false;
384 }
385
386 //--------------------------------------------------------------------------
387 // proc service functions
388
389 // ps_pglobal_lookup() looks up the symbol sym_name in the symbol table
390 // of the load object object_name in the target process identified by ph.
391 // It returns the symbol's value as an address in the target process in
392 // *sym_addr.
393
394 ps_err_e ps_pglobal_lookup(struct ps_prochandle *ph, const char *object_name,
395 const char *sym_name, psaddr_t *sym_addr) {
396 *sym_addr = (psaddr_t) lookup_symbol(ph, object_name, sym_name);
397 return (*sym_addr ? PS_OK : PS_NOSYM);
398 }
399
400 // read "size" bytes info "buf" from address "addr"
401 ps_err_e ps_pread(struct ps_prochandle *ph, psaddr_t addr,
402 void *buf, size_t size) {
403 return ph->ops->p_pread(ph, (uintptr_t) addr, buf, size)? PS_OK: PS_ERR;
404 }
405
406 // write "size" bytes of data to debuggee at address "addr"
407 ps_err_e ps_pwrite(struct ps_prochandle *ph, psaddr_t addr,
408 const void *buf, size_t size) {
409 return ph->ops->p_pwrite(ph, (uintptr_t)addr, buf, size)? PS_OK: PS_ERR;
410 }
411
412 // fill in ptrace_lwpinfo for lid
413 ps_err_e ps_linfo(struct ps_prochandle *ph, lwpid_t lwp_id, void *linfo) {
414 return ph->ops->get_lwp_info(ph, lwp_id, linfo)? PS_OK: PS_ERR;
415 }
416
417 // needed for when libthread_db is compiled with TD_DEBUG defined
418 void
419 ps_plog (const char *format, ...)
420 {
421 va_list alist;
422
423 va_start(alist, format);
424 vfprintf(stderr, format, alist);
425 va_end(alist);
426 }
427
428 // ------------------------------------------------------------------------
429 // Functions below this point are not yet implemented. They are here only
430 // to make the linker happy.
431
432 ps_err_e ps_lsetfpregs(struct ps_prochandle *ph, lwpid_t lid, const prfpregset_t *fpregs) {
433 print_debug("ps_lsetfpregs not implemented\n");
434 return PS_OK;
435 }
436
437 ps_err_e ps_lsetregs(struct ps_prochandle *ph, lwpid_t lid, const prgregset_t gregset) {
438 print_debug("ps_lsetregs not implemented\n");
439 return PS_OK;
440 }
441
442 ps_err_e ps_lgetfpregs(struct ps_prochandle *ph, lwpid_t lid, prfpregset_t *fpregs) {
443 print_debug("ps_lgetfpregs not implemented\n");
444 return PS_OK;
445 }
446
447 ps_err_e ps_lgetregs(struct ps_prochandle *ph, lwpid_t lid, prgregset_t gregset) {
448 print_debug("ps_lgetfpregs not implemented\n");
449 return PS_OK;
450 }
451
452 ps_err_e ps_lstop(struct ps_prochandle *ph, lwpid_t lid) {
453 print_debug("ps_lstop not implemented\n");
454 return PS_OK;
455 }
456
457 ps_err_e ps_pcontinue(struct ps_prochandle *ph) {
458 print_debug("ps_pcontinue not implemented\n");
459 return PS_OK;
460 }