1 /*
2 * Copyright (c) 2003, 2010, 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 bool is_debug() {
95 return _libsaproc_debug;
96 }
97
98 // initialize libproc
99 bool init_libproc(bool debug) {
100 // init debug mode
101 _libsaproc_debug = debug;
102
103 // initialize the thread_db library
104 if (td_init() != TD_OK) {
105 print_debug("libthread_db's td_init failed\n");
106 return false;
107 }
108
109 return true;
110 }
111
112 static void destroy_lib_info(struct ps_prochandle* ph) {
113 lib_info* lib = ph->libs;
114 while (lib) {
115 lib_info *next = lib->next;
116 if (lib->symtab) {
117 destroy_symtab(lib->symtab);
118 }
119 free(lib);
120 lib = next;
121 }
122 }
123
124 static void destroy_thread_info(struct ps_prochandle* ph) {
125 thread_info* thr = ph->threads;
126 while (thr) {
127 thread_info *next = thr->next;
128 free(thr);
129 thr = next;
130 }
131 }
132
133 // ps_prochandle cleanup
134
135 // ps_prochandle cleanup
136 void Prelease(struct ps_prochandle* ph) {
137 // do the "derived class" clean-up first
138 ph->ops->release(ph);
139 destroy_lib_info(ph);
140 destroy_thread_info(ph);
141 free(ph);
142 }
143
144 lib_info* add_lib_info(struct ps_prochandle* ph, const char* libname, uintptr_t base) {
145 return add_lib_info_fd(ph, libname, -1, base);
146 }
147
148 lib_info* add_lib_info_fd(struct ps_prochandle* ph, const char* libname, int fd, uintptr_t base) {
149 lib_info* newlib;
150
151 if ( (newlib = (lib_info*) calloc(1, sizeof(struct lib_info))) == NULL) {
152 print_debug("can't allocate memory for lib_info\n");
153 return NULL;
154 }
155
156 strncpy(newlib->name, libname, sizeof(newlib->name));
157 newlib->base = base;
158
159 if (fd == -1) {
160 if ( (newlib->fd = pathmap_open(newlib->name)) < 0) {
161 print_debug("can't open shared object %s\n", newlib->name);
162 free(newlib);
163 return NULL;
164 }
165 } else {
166 newlib->fd = fd;
167 }
168
169 // check whether we have got an ELF file. /proc/<pid>/map
170 // gives out all file mappings and not just shared objects
171 if (is_elf_file(newlib->fd) == false) {
172 close(newlib->fd);
173 free(newlib);
174 return NULL;
175 }
176
177 newlib->symtab = build_symtab(newlib->fd);
178 if (newlib->symtab == NULL) {
179 print_debug("symbol table build failed for %s\n", newlib->name);
180 }
181 else {
182 print_debug("built symbol table for %s\n", newlib->name);
183 }
184
185 // even if symbol table building fails, we add the lib_info.
186 // This is because we may need to read from the ELF file for core file
187 // address read functionality. lookup_symbol checks for NULL symtab.
188 if (ph->libs) {
189 ph->lib_tail->next = newlib;
190 ph->lib_tail = newlib;
191 } else {
192 ph->libs = ph->lib_tail = newlib;
193 }
194 ph->num_libs++;
195
196 return newlib;
197 }
198
199 // lookup for a specific symbol
200 uintptr_t lookup_symbol(struct ps_prochandle* ph, const char* object_name,
201 const char* sym_name) {
202 // ignore object_name. search in all libraries
203 // FIXME: what should we do with object_name?? The library names are obtained
204 // by parsing /proc/<pid>/maps, which may not be the same as object_name.
205 // What we need is a utility to map object_name to real file name, something
206 // dlopen() does by looking at LD_LIBRARY_PATH and /etc/ld.so.cache. For
207 // now, we just ignore object_name and do a global search for the symbol.
208
209 lib_info* lib = ph->libs;
210 while (lib) {
211 if (lib->symtab) {
212 uintptr_t res = search_symbol(lib->symtab, lib->base, sym_name, NULL);
213 if (res) return res;
214 }
215 lib = lib->next;
216 }
217
218 print_debug("lookup failed for symbol '%s' in obj '%s'\n",
219 sym_name, object_name);
220 return (uintptr_t) NULL;
221 }
222
223
224 const char* symbol_for_pc(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* poffset) {
225 const char* res = NULL;
226 lib_info* lib = ph->libs;
227 while (lib) {
228 if (lib->symtab && addr >= lib->base) {
229 res = nearest_symbol(lib->symtab, addr - lib->base, poffset);
230 if (res) return res;
231 }
232 lib = lib->next;
233 }
234 return NULL;
235 }
236
237 // add a thread to ps_prochandle
238 thread_info* add_thread_info(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) {
239 thread_info* newthr;
240 if ( (newthr = (thread_info*) calloc(1, sizeof(thread_info))) == NULL) {
241 print_debug("can't allocate memory for thread_info\n");
242 return NULL;
243 }
244
245 // initialize thread info
246 newthr->pthread_id = pthread_id;
247 newthr->lwp_id = lwp_id;
248
249 // add new thread to the list
250 newthr->next = ph->threads;
251 ph->threads = newthr;
252 ph->num_threads++;
253 return newthr;
254 }
255
256
257 // struct used for client data from thread_db callback
258 struct thread_db_client_data {
259 struct ps_prochandle* ph;
260 thread_info_callback callback;
261 };
262
263 // callback function for libthread_db
264 static int thread_db_callback(const td_thrhandle_t *th_p, void *data) {
265 struct thread_db_client_data* ptr = (struct thread_db_client_data*) data;
266 td_thrinfo_t ti;
267 td_err_e err;
268
269 memset(&ti, 0, sizeof(ti));
270 err = td_thr_get_info(th_p, &ti);
271 if (err != TD_OK) {
272 print_debug("libthread_db : td_thr_get_info failed, can't get thread info\n");
273 return err;
274 }
275
276 print_debug("thread_db : pthread %d (lwp %d)\n", ti.ti_tid, ti.ti_lid);
277
278 if (ptr->callback(ptr->ph, (pthread_t)ti.ti_tid, ti.ti_lid) != true)
279 return TD_ERR;
280
281 return TD_OK;
282 }
283
284 // read thread_info using libthread_db
285 bool read_thread_info(struct ps_prochandle* ph, thread_info_callback cb) {
286 struct thread_db_client_data mydata;
287 td_thragent_t* thread_agent = NULL;
288 if (td_ta_new(ph, &thread_agent) != TD_OK) {
289 print_debug("can't create libthread_db agent\n");
290 return false;
291 }
292
293 mydata.ph = ph;
294 mydata.callback = cb;
295
296 // we use libthread_db iterator to iterate thru list of threads.
297 if (td_ta_thr_iter(thread_agent, thread_db_callback, &mydata,
298 TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
299 TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS) != TD_OK) {
300 td_ta_delete(thread_agent);
301 return false;
302 }
303
304 // delete thread agent
305 td_ta_delete(thread_agent);
306 return true;
307 }
308
309
310 // get number of threads
311 int get_num_threads(struct ps_prochandle* ph) {
312 return ph->num_threads;
313 }
314
315 // get lwp_id of n'th thread
316 lwpid_t get_lwp_id(struct ps_prochandle* ph, int index) {
317 int count = 0;
318 thread_info* thr = ph->threads;
319 while (thr) {
320 if (count == index) {
321 return thr->lwp_id;
322 }
323 count++;
324 thr = thr->next;
325 }
326 return -1;
327 }
328
329 // get regs for a given lwp
330 bool get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id, struct reg* regs) {
331 return ph->ops->get_lwp_regs(ph, lwp_id, regs);
332 }
333
334 // get number of shared objects
335 int get_num_libs(struct ps_prochandle* ph) {
336 return ph->num_libs;
337 }
338
339 // get name of n'th solib
340 const char* get_lib_name(struct ps_prochandle* ph, int index) {
341 int count = 0;
342 lib_info* lib = ph->libs;
343 while (lib) {
344 if (count == index) {
345 return lib->name;
346 }
347 count++;
348 lib = lib->next;
349 }
350 return NULL;
351 }
352
353 // get base address of a lib
354 uintptr_t get_lib_base(struct ps_prochandle* ph, int index) {
355 int count = 0;
356 lib_info* lib = ph->libs;
357 while (lib) {
358 if (count == index) {
359 return lib->base;
360 }
361 count++;
362 lib = lib->next;
363 }
364 return (uintptr_t)NULL;
365 }
366
367 bool find_lib(struct ps_prochandle* ph, const char *lib_name) {
368 lib_info *p = ph->libs;
369 while (p) {
370 if (strcmp(p->name, lib_name) == 0) {
371 return true;
372 }
373 p = p->next;
374 }
375 return false;
376 }
377
378 //--------------------------------------------------------------------------
379 // proc service functions
380
381 // ps_pglobal_lookup() looks up the symbol sym_name in the symbol table
382 // of the load object object_name in the target process identified by ph.
383 // It returns the symbol's value as an address in the target process in
384 // *sym_addr.
385
386 ps_err_e ps_pglobal_lookup(struct ps_prochandle *ph, const char *object_name,
387 const char *sym_name, psaddr_t *sym_addr) {
388 *sym_addr = (psaddr_t) lookup_symbol(ph, object_name, sym_name);
389 return (*sym_addr ? PS_OK : PS_NOSYM);
390 }
391
392 // read "size" bytes info "buf" from address "addr"
393 ps_err_e ps_pread(struct ps_prochandle *ph, psaddr_t addr,
394 void *buf, size_t size) {
395 return ph->ops->p_pread(ph, (uintptr_t) addr, buf, size)? PS_OK: PS_ERR;
396 }
397
398 // write "size" bytes of data to debuggee at address "addr"
399 ps_err_e ps_pwrite(struct ps_prochandle *ph, psaddr_t addr,
400 const void *buf, size_t size) {
401 return ph->ops->p_pwrite(ph, (uintptr_t)addr, buf, size)? PS_OK: PS_ERR;
402 }
403
404 // fill in ptrace_lwpinfo for lid
405 ps_err_e ps_linfo(struct ps_prochandle *ph, lwpid_t lwp_id, void *linfo) {
406 return ph->ops->get_lwp_info(ph, lwp_id, linfo)? PS_OK: PS_ERR;
407 }
408
409 // needed for when libthread_db is compiled with TD_DEBUG defined
410 void
411 ps_plog (const char *format, ...)
412 {
413 va_list alist;
414
415 va_start(alist, format);
416 vfprintf(stderr, format, alist);
417 va_end(alist);
418 }
419
420 // ------------------------------------------------------------------------
421 // Functions below this point are not yet implemented. They are here only
422 // to make the linker happy.
423
424 ps_err_e ps_lsetfpregs(struct ps_prochandle *ph, lwpid_t lid, const prfpregset_t *fpregs) {
425 print_debug("ps_lsetfpregs not implemented\n");
426 return PS_OK;
427 }
428
429 ps_err_e ps_lsetregs(struct ps_prochandle *ph, lwpid_t lid, const prgregset_t gregset) {
430 print_debug("ps_lsetregs not implemented\n");
431 return PS_OK;
432 }
433
434 ps_err_e ps_lgetfpregs(struct ps_prochandle *ph, lwpid_t lid, prfpregset_t *fpregs) {
435 print_debug("ps_lgetfpregs not implemented\n");
436 return PS_OK;
437 }
438
439 ps_err_e ps_lgetregs(struct ps_prochandle *ph, lwpid_t lid, prgregset_t gregset) {
440 print_debug("ps_lgetfpregs not implemented\n");
441 return PS_OK;
442 }
443
444 ps_err_e ps_lstop(struct ps_prochandle *ph, lwpid_t lid) {
445 print_debug("ps_lstop not implemented\n");
446 return PS_OK;
447 }
448
449 ps_err_e ps_pcontinue(struct ps_prochandle *ph) {
450 print_debug("ps_pcontinue not implemented\n");
451 return PS_OK;
452 }