1 /*
2 * Copyright (c) 2003, 2006, 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,
20 * CA 94065 USA or visit www.oracle.com if you need additional information or
21 * have any 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
182 // even if symbol table building fails, we add the lib_info.
183 // This is because we may need to read from the ELF file for core file
184 // address read functionality. lookup_symbol checks for NULL symtab.
185 if (ph->libs) {
186 ph->lib_tail->next = newlib;
187 ph->lib_tail = newlib;
188 } else {
189 ph->libs = ph->lib_tail = newlib;
190 }
191 ph->num_libs++;
192
193 return newlib;
194 }
195
196 // lookup for a specific symbol
197 uintptr_t lookup_symbol(struct ps_prochandle* ph, const char* object_name,
198 const char* sym_name) {
199 // ignore object_name. search in all libraries
200 // FIXME: what should we do with object_name?? The library names are obtained
201 // by parsing /proc/<pid>/maps, which may not be the same as object_name.
202 // What we need is a utility to map object_name to real file name, something
203 // dlopen() does by looking at LD_LIBRARY_PATH and /etc/ld.so.cache. For
204 // now, we just ignore object_name and do a global search for the symbol.
205
206 lib_info* lib = ph->libs;
207 while (lib) {
208 if (lib->symtab) {
209 uintptr_t res = search_symbol(lib->symtab, lib->base, sym_name, NULL);
210 if (res) return res;
211 }
212 lib = lib->next;
213 }
214
215 print_debug("lookup failed for symbol '%s' in obj '%s'\n",
216 sym_name, object_name);
217 return (uintptr_t) NULL;
218 }
219
220
221 const char* symbol_for_pc(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* poffset) {
222 const char* res = NULL;
223 lib_info* lib = ph->libs;
224 while (lib) {
225 if (lib->symtab && addr >= lib->base) {
226 res = nearest_symbol(lib->symtab, addr - lib->base, poffset);
227 if (res) return res;
228 }
229 lib = lib->next;
230 }
231 return NULL;
232 }
233
234 // add a thread to ps_prochandle
235 thread_info* add_thread_info(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) {
236 thread_info* newthr;
237 if ( (newthr = (thread_info*) calloc(1, sizeof(thread_info))) == NULL) {
238 print_debug("can't allocate memory for thread_info\n");
239 return NULL;
240 }
241
242 // initialize thread info
243 newthr->pthread_id = pthread_id;
244 newthr->lwp_id = lwp_id;
245
246 // add new thread to the list
247 newthr->next = ph->threads;
248 ph->threads = newthr;
249 ph->num_threads++;
250 return newthr;
251 }
252
253
254 // struct used for client data from thread_db callback
255 struct thread_db_client_data {
256 struct ps_prochandle* ph;
257 thread_info_callback callback;
258 };
259
260 // callback function for libthread_db
261 static int thread_db_callback(const td_thrhandle_t *th_p, void *data) {
262 struct thread_db_client_data* ptr = (struct thread_db_client_data*) data;
263 td_thrinfo_t ti;
264 td_err_e err;
265
266 memset(&ti, 0, sizeof(ti));
267 err = td_thr_get_info(th_p, &ti);
268 if (err != TD_OK) {
269 print_debug("libthread_db : td_thr_get_info failed, can't get thread info\n");
270 return err;
271 }
272
273 print_debug("thread_db : pthread %d (lwp %d)\n", ti.ti_tid, ti.ti_lid);
274
275 if (ptr->callback(ptr->ph, ti.ti_tid, ti.ti_lid) != true)
276 return TD_ERR;
277
278 return TD_OK;
279 }
280
281 // read thread_info using libthread_db
282 bool read_thread_info(struct ps_prochandle* ph, thread_info_callback cb) {
283 struct thread_db_client_data mydata;
284 td_thragent_t* thread_agent = NULL;
285 if (td_ta_new(ph, &thread_agent) != TD_OK) {
286 print_debug("can't create libthread_db agent\n");
287 return false;
288 }
289
290 mydata.ph = ph;
291 mydata.callback = cb;
292
293 // we use libthread_db iterator to iterate thru list of threads.
294 if (td_ta_thr_iter(thread_agent, thread_db_callback, &mydata,
295 TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
296 TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS) != TD_OK) {
297 td_ta_delete(thread_agent);
298 return false;
299 }
300
301 // delete thread agent
302 td_ta_delete(thread_agent);
303 return true;
304 }
305
306
307 // get number of threads
308 int get_num_threads(struct ps_prochandle* ph) {
309 return ph->num_threads;
310 }
311
312 // get lwp_id of n'th thread
313 lwpid_t get_lwp_id(struct ps_prochandle* ph, int index) {
314 int count = 0;
315 thread_info* thr = ph->threads;
316 while (thr) {
317 if (count == index) {
318 return thr->lwp_id;
319 }
320 count++;
321 thr = thr->next;
322 }
323 return -1;
324 }
325
326 // get regs for a given lwp
327 bool get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id, struct user_regs_struct* regs) {
328 return ph->ops->get_lwp_regs(ph, lwp_id, regs);
329 }
330
331 // get number of shared objects
332 int get_num_libs(struct ps_prochandle* ph) {
333 return ph->num_libs;
334 }
335
336 // get name of n'th solib
337 const char* get_lib_name(struct ps_prochandle* ph, int index) {
338 int count = 0;
339 lib_info* lib = ph->libs;
340 while (lib) {
341 if (count == index) {
342 return lib->name;
343 }
344 count++;
345 lib = lib->next;
346 }
347 return NULL;
348 }
349
350 // get base address of a lib
351 uintptr_t get_lib_base(struct ps_prochandle* ph, int index) {
352 int count = 0;
353 lib_info* lib = ph->libs;
354 while (lib) {
355 if (count == index) {
356 return lib->base;
357 }
358 count++;
359 lib = lib->next;
360 }
361 return (uintptr_t)NULL;
362 }
363
364 bool find_lib(struct ps_prochandle* ph, const char *lib_name) {
365 lib_info *p = ph->libs;
366 while (p) {
367 if (strcmp(p->name, lib_name) == 0) {
368 return true;
369 }
370 p = p->next;
371 }
372 return false;
373 }
374
375 //--------------------------------------------------------------------------
376 // proc service functions
377
378 // get process id
379 pid_t ps_getpid(struct ps_prochandle *ph) {
380 return ph->pid;
381 }
382
383 // ps_pglobal_lookup() looks up the symbol sym_name in the symbol table
384 // of the load object object_name in the target process identified by ph.
385 // It returns the symbol's value as an address in the target process in
386 // *sym_addr.
387
388 ps_err_e ps_pglobal_lookup(struct ps_prochandle *ph, const char *object_name,
389 const char *sym_name, psaddr_t *sym_addr) {
390 *sym_addr = (psaddr_t) lookup_symbol(ph, object_name, sym_name);
391 return (*sym_addr ? PS_OK : PS_NOSYM);
392 }
393
394 // read "size" bytes info "buf" from address "addr"
395 ps_err_e ps_pdread(struct ps_prochandle *ph, psaddr_t addr,
396 void *buf, size_t size) {
397 return ph->ops->p_pread(ph, (uintptr_t) addr, buf, size)? PS_OK: PS_ERR;
398 }
399
400 // write "size" bytes of data to debuggee at address "addr"
401 ps_err_e ps_pdwrite(struct ps_prochandle *ph, psaddr_t addr,
402 const void *buf, size_t size) {
403 return ph->ops->p_pwrite(ph, (uintptr_t)addr, buf, size)? PS_OK: PS_ERR;
404 }
405
406 // ------------------------------------------------------------------------
407 // Functions below this point are not yet implemented. They are here only
408 // to make the linker happy.
409
410 ps_err_e ps_lsetfpregs(struct ps_prochandle *ph, lwpid_t lid, const prfpregset_t *fpregs) {
411 print_debug("ps_lsetfpregs not implemented\n");
412 return PS_OK;
413 }
414
415 ps_err_e ps_lsetregs(struct ps_prochandle *ph, lwpid_t lid, const prgregset_t gregset) {
416 print_debug("ps_lsetregs not implemented\n");
417 return PS_OK;
418 }
419
420 ps_err_e ps_lgetfpregs(struct ps_prochandle *ph, lwpid_t lid, prfpregset_t *fpregs) {
421 print_debug("ps_lgetfpregs not implemented\n");
422 return PS_OK;
423 }
424
425 ps_err_e ps_lgetregs(struct ps_prochandle *ph, lwpid_t lid, prgregset_t gregset) {
426 print_debug("ps_lgetfpregs not implemented\n");
427 return PS_OK;
428 }
429
430 // new libthread_db of NPTL seem to require this symbol
431 ps_err_e ps_get_thread_area() {
432 print_debug("ps_get_thread_area not implemented\n");
433 return PS_OK;
434 }