Fri, 03 Apr 2020 14:14:26 +0100
8076475: Misuses of strncpy/strncat
Summary: Various small fixes around strncpy and strncat
Reviewed-by: andrew
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 "libproc_impl.h"
26 static const char* alt_root = NULL;
27 static int alt_root_len = -1;
29 #define SA_ALTROOT "SA_ALTROOT"
31 off_t ltell(int fd) {
32 return lseek(fd, 0, SEEK_CUR);
33 }
35 static void init_alt_root() {
36 if (alt_root_len == -1) {
37 alt_root = getenv(SA_ALTROOT);
38 if (alt_root) {
39 alt_root_len = strlen(alt_root);
40 } else {
41 alt_root_len = 0;
42 }
43 }
44 }
46 int pathmap_open(const char* name) {
47 int fd;
48 char alt_path[PATH_MAX + 1];
50 init_alt_root();
52 if (alt_root_len > 0) {
53 strcpy(alt_path, alt_root);
54 strcat(alt_path, name);
55 fd = open(alt_path, O_RDONLY);
56 if (fd >= 0) {
57 print_debug("path %s substituted for %s\n", alt_path, name);
58 return fd;
59 }
61 if (strrchr(name, '/')) {
62 strcpy(alt_path, alt_root);
63 strcat(alt_path, strrchr(name, '/'));
64 fd = open(alt_path, O_RDONLY);
65 if (fd >= 0) {
66 print_debug("path %s substituted for %s\n", alt_path, name);
67 return fd;
68 }
69 }
70 } else {
71 fd = open(name, O_RDONLY);
72 if (fd >= 0) {
73 return fd;
74 }
75 }
76 return -1;
77 }
79 static bool _libsaproc_debug;
81 void print_debug(const char* format,...) {
82 if (_libsaproc_debug) {
83 va_list alist;
85 va_start(alist, format);
86 fputs("libsaproc DEBUG: ", stderr);
87 vfprintf(stderr, format, alist);
88 va_end(alist);
89 }
90 }
92 void print_error(const char* format,...) {
93 va_list alist;
94 va_start(alist, format);
95 fputs("ERROR: ", stderr);
96 vfprintf(stderr, format, alist);
97 va_end(alist);
98 }
100 bool is_debug() {
101 return _libsaproc_debug;
102 }
104 #ifdef __APPLE__
105 // get arch offset in file
106 bool get_arch_off(int fd, cpu_type_t cputype, off_t *offset) {
107 struct fat_header fatheader;
108 struct fat_arch fatarch;
109 off_t img_start = 0;
111 off_t pos = ltell(fd);
112 if (read(fd, (void *)&fatheader, sizeof(struct fat_header)) != sizeof(struct fat_header)) {
113 return false;
114 }
115 if (fatheader.magic == FAT_CIGAM) {
116 int i;
117 for (i = 0; i < ntohl(fatheader.nfat_arch); i++) {
118 if (read(fd, (void *)&fatarch, sizeof(struct fat_arch)) != sizeof(struct fat_arch)) {
119 return false;
120 }
121 if (ntohl(fatarch.cputype) == cputype) {
122 print_debug("fat offset=%x\n", ntohl(fatarch.offset));
123 img_start = ntohl(fatarch.offset);
124 break;
125 }
126 }
127 if (img_start == 0) {
128 return false;
129 }
130 }
131 lseek(fd, pos, SEEK_SET);
132 *offset = img_start;
133 return true;
134 }
136 bool is_macho_file(int fd) {
137 mach_header_64 fhdr;
138 off_t x86_64_off;
140 if (fd < 0) {
141 print_debug("Invalid file handle passed to is_macho_file\n");
142 return false;
143 }
145 off_t pos = ltell(fd);
146 // check fat header
147 if (!get_arch_off(fd, CPU_TYPE_X86_64, &x86_64_off)) {
148 print_debug("failed to get fat header\n");
149 return false;
150 }
151 lseek(fd, x86_64_off, SEEK_SET);
152 if (read(fd, (void *)&fhdr, sizeof(mach_header_64)) != sizeof(mach_header_64)) {
153 return false;
154 }
155 lseek(fd, pos, SEEK_SET); // restore
156 print_debug("fhdr.magic %x\n", fhdr.magic);
157 return (fhdr.magic == MH_MAGIC_64 || fhdr.magic == MH_CIGAM_64);
158 }
160 #endif //__APPLE__
162 // initialize libproc
163 bool init_libproc(bool debug) {
164 _libsaproc_debug = debug;
165 #ifndef __APPLE__
166 // initialize the thread_db library
167 if (td_init() != TD_OK) {
168 print_debug("libthread_db's td_init failed\n");
169 return false;
170 }
171 #endif // __APPLE__
172 return true;
173 }
175 void destroy_lib_info(struct ps_prochandle* ph) {
176 lib_info* lib = ph->libs;
177 while (lib) {
178 lib_info* next = lib->next;
179 if (lib->symtab) {
180 destroy_symtab(lib->symtab);
181 }
182 free(lib);
183 lib = next;
184 }
185 }
187 void destroy_thread_info(struct ps_prochandle* ph) {
188 sa_thread_info* thr = ph->threads;
189 while (thr) {
190 sa_thread_info* n = thr->next;
191 free(thr);
192 thr = n;
193 }
194 }
196 // ps_prochandle cleanup
197 void Prelease(struct ps_prochandle* ph) {
198 // do the "derived class" clean-up first
199 ph->ops->release(ph);
200 destroy_lib_info(ph);
201 destroy_thread_info(ph);
202 free(ph);
203 }
205 lib_info* add_lib_info(struct ps_prochandle* ph, const char* libname, uintptr_t base) {
206 return add_lib_info_fd(ph, libname, -1, base);
207 }
209 lib_info* add_lib_info_fd(struct ps_prochandle* ph, const char* libname, int fd, uintptr_t base) {
210 lib_info* newlib;
211 print_debug("add_lib_info_fd %s\n", libname);
213 if ( (newlib = (lib_info*) calloc(1, sizeof(struct lib_info))) == NULL) {
214 print_debug("can't allocate memory for lib_info\n");
215 return NULL;
216 }
218 if (strlen(libname) >= sizeof(newlib->name)) {
219 print_debug("libname %s too long\n", libname);
220 return NULL;
221 }
222 strcpy(newlib->name, libname);
224 newlib->base = base;
226 if (fd == -1) {
227 if ( (newlib->fd = pathmap_open(newlib->name)) < 0) {
228 print_debug("can't open shared object %s\n", newlib->name);
229 free(newlib);
230 return NULL;
231 }
232 } else {
233 newlib->fd = fd;
234 }
236 #ifdef __APPLE__
237 // check whether we have got an Macho file.
238 if (is_macho_file(newlib->fd) == false) {
239 close(newlib->fd);
240 free(newlib);
241 print_debug("not a mach-o file\n");
242 return NULL;
243 }
244 #else
245 // check whether we have got an ELF file. /proc/<pid>/map
246 // gives out all file mappings and not just shared objects
247 if (is_elf_file(newlib->fd) == false) {
248 close(newlib->fd);
249 free(newlib);
250 return NULL;
251 }
252 #endif // __APPLE__
254 newlib->symtab = build_symtab(newlib->fd);
255 if (newlib->symtab == NULL) {
256 print_debug("symbol table build failed for %s\n", newlib->name);
257 } else {
258 print_debug("built symbol table for %s\n", newlib->name);
259 }
261 // even if symbol table building fails, we add the lib_info.
262 // This is because we may need to read from the ELF file or MachO file for core file
263 // address read functionality. lookup_symbol checks for NULL symtab.
264 if (ph->libs) {
265 ph->lib_tail->next = newlib;
266 ph->lib_tail = newlib;
267 } else {
268 ph->libs = ph->lib_tail = newlib;
269 }
270 ph->num_libs++;
271 return newlib;
272 }
274 // lookup for a specific symbol
275 uintptr_t lookup_symbol(struct ps_prochandle* ph, const char* object_name,
276 const char* sym_name) {
277 // ignore object_name. search in all libraries
278 // FIXME: what should we do with object_name?? The library names are obtained
279 // by parsing /proc/<pid>/maps, which may not be the same as object_name.
280 // What we need is a utility to map object_name to real file name, something
281 // dlopen() does by looking at LD_LIBRARY_PATH and /etc/ld.so.cache. For
282 // now, we just ignore object_name and do a global search for the symbol.
284 lib_info* lib = ph->libs;
285 while (lib) {
286 if (lib->symtab) {
287 uintptr_t res = search_symbol(lib->symtab, lib->base, sym_name, NULL);
288 if (res) return res;
289 }
290 lib = lib->next;
291 }
293 print_debug("lookup failed for symbol '%s' in obj '%s'\n",
294 sym_name, object_name);
295 return (uintptr_t) NULL;
296 }
298 const char* symbol_for_pc(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* poffset) {
299 const char* res = NULL;
300 lib_info* lib = ph->libs;
301 while (lib) {
302 if (lib->symtab && addr >= lib->base) {
303 res = nearest_symbol(lib->symtab, addr - lib->base, poffset);
304 if (res) return res;
305 }
306 lib = lib->next;
307 }
308 return NULL;
309 }
311 // add a thread to ps_prochandle
312 sa_thread_info* add_thread_info(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) {
313 sa_thread_info* newthr;
314 if ( (newthr = (sa_thread_info*) calloc(1, sizeof(sa_thread_info))) == NULL) {
315 print_debug("can't allocate memory for thread_info\n");
316 return NULL;
317 }
319 // initialize thread info
320 newthr->pthread_id = pthread_id;
321 newthr->lwp_id = lwp_id;
323 // add new thread to the list
324 newthr->next = ph->threads;
325 ph->threads = newthr;
326 ph->num_threads++;
327 return newthr;
328 }
330 #ifndef __APPLE__
331 // struct used for client data from thread_db callback
332 struct thread_db_client_data {
333 struct ps_prochandle* ph;
334 thread_info_callback callback;
335 };
337 // callback function for libthread_db
338 static int thread_db_callback(const td_thrhandle_t *th_p, void *data) {
339 struct thread_db_client_data* ptr = (struct thread_db_client_data*) data;
340 td_thrinfo_t ti;
341 td_err_e err;
343 memset(&ti, 0, sizeof(ti));
344 err = td_thr_get_info(th_p, &ti);
345 if (err != TD_OK) {
346 print_debug("libthread_db : td_thr_get_info failed, can't get thread info\n");
347 return err;
348 }
350 print_debug("thread_db : pthread %d (lwp %d)\n", ti.ti_tid, ti.ti_lid);
352 if (ptr->callback(ptr->ph, (pthread_t)ti.ti_tid, ti.ti_lid) != true)
353 return TD_ERR;
355 return TD_OK;
356 }
358 // read thread_info using libthread_db
359 bool read_thread_info(struct ps_prochandle* ph, thread_info_callback cb) {
360 struct thread_db_client_data mydata;
361 td_thragent_t* thread_agent = NULL;
362 if (td_ta_new(ph, &thread_agent) != TD_OK) {
363 print_debug("can't create libthread_db agent\n");
364 return false;
365 }
367 mydata.ph = ph;
368 mydata.callback = cb;
370 // we use libthread_db iterator to iterate thru list of threads.
371 if (td_ta_thr_iter(thread_agent, thread_db_callback, &mydata,
372 TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
373 TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS) != TD_OK) {
374 td_ta_delete(thread_agent);
375 return false;
376 }
378 // delete thread agent
379 td_ta_delete(thread_agent);
380 return true;
381 }
383 #endif // __APPLE__
385 // get number of threads
386 int get_num_threads(struct ps_prochandle* ph) {
387 return ph->num_threads;
388 }
390 // get lwp_id of n'th thread
391 lwpid_t get_lwp_id(struct ps_prochandle* ph, int index) {
392 int count = 0;
393 sa_thread_info* thr = ph->threads;
394 while (thr) {
395 if (count == index) {
396 return thr->lwp_id;
397 }
398 count++;
399 thr = thr->next;
400 }
401 return 0;
402 }
404 #ifdef __APPLE__
405 // set lwp_id of n'th thread
406 bool set_lwp_id(struct ps_prochandle* ph, int index, lwpid_t lwpid) {
407 int count = 0;
408 sa_thread_info* thr = ph->threads;
409 while (thr) {
410 if (count == index) {
411 thr->lwp_id = lwpid;
412 return true;
413 }
414 count++;
415 thr = thr->next;
416 }
417 return false;
418 }
420 // get regs of n-th thread, only used in fillThreads the first time called
421 bool get_nth_lwp_regs(struct ps_prochandle* ph, int index, struct reg* regs) {
422 int count = 0;
423 sa_thread_info* thr = ph->threads;
424 while (thr) {
425 if (count == index) {
426 break;
427 }
428 count++;
429 thr = thr->next;
430 }
431 if (thr != NULL) {
432 memcpy(regs, &thr->regs, sizeof(struct reg));
433 return true;
434 }
435 return false;
436 }
438 #endif // __APPLE__
440 // get regs for a given lwp
441 bool get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id, struct reg* regs) {
442 return ph->ops->get_lwp_regs(ph, lwp_id, regs);
443 }
445 // get number of shared objects
446 int get_num_libs(struct ps_prochandle* ph) {
447 return ph->num_libs;
448 }
450 // get name of n'th solib
451 const char* get_lib_name(struct ps_prochandle* ph, int index) {
452 int count = 0;
453 lib_info* lib = ph->libs;
454 while (lib) {
455 if (count == index) {
456 return lib->name;
457 }
458 count++;
459 lib = lib->next;
460 }
461 return NULL;
462 }
464 // get base address of a lib
465 uintptr_t get_lib_base(struct ps_prochandle* ph, int index) {
466 int count = 0;
467 lib_info* lib = ph->libs;
468 while (lib) {
469 if (count == index) {
470 return lib->base;
471 }
472 count++;
473 lib = lib->next;
474 }
475 return (uintptr_t)NULL;
476 }
478 bool find_lib(struct ps_prochandle* ph, const char *lib_name) {
479 lib_info *p = ph->libs;
480 while (p) {
481 if (strcmp(p->name, lib_name) == 0) {
482 return true;
483 }
484 p = p->next;
485 }
486 return false;
487 }
489 //--------------------------------------------------------------------------
490 // proc service functions
492 // ps_pglobal_lookup() looks up the symbol sym_name in the symbol table
493 // of the load object object_name in the target process identified by ph.
494 // It returns the symbol's value as an address in the target process in
495 // *sym_addr.
497 ps_err_e ps_pglobal_lookup(struct ps_prochandle *ph, const char *object_name,
498 const char *sym_name, psaddr_t *sym_addr) {
499 *sym_addr = (psaddr_t) lookup_symbol(ph, object_name, sym_name);
500 return (*sym_addr ? PS_OK : PS_NOSYM);
501 }
503 // read "size" bytes info "buf" from address "addr"
504 ps_err_e ps_pread(struct ps_prochandle *ph, psaddr_t addr,
505 void *buf, size_t size) {
506 return ph->ops->p_pread(ph, (uintptr_t) addr, buf, size)? PS_OK: PS_ERR;
507 }
509 // write "size" bytes of data to debuggee at address "addr"
510 ps_err_e ps_pwrite(struct ps_prochandle *ph, psaddr_t addr,
511 const void *buf, size_t size) {
512 return ph->ops->p_pwrite(ph, (uintptr_t)addr, buf, size)? PS_OK: PS_ERR;
513 }
515 // fill in ptrace_lwpinfo for lid
516 ps_err_e ps_linfo(struct ps_prochandle *ph, lwpid_t lwp_id, void *linfo) {
517 return ph->ops->get_lwp_info(ph, lwp_id, linfo)? PS_OK: PS_ERR;
518 }
520 // needed for when libthread_db is compiled with TD_DEBUG defined
521 void
522 ps_plog (const char *format, ...)
523 {
524 va_list alist;
526 va_start(alist, format);
527 vfprintf(stderr, format, alist);
528 va_end(alist);
529 }
531 #ifndef __APPLE__
532 // ------------------------------------------------------------------------
533 // Functions below this point are not yet implemented. They are here only
534 // to make the linker happy.
536 ps_err_e ps_lsetfpregs(struct ps_prochandle *ph, lwpid_t lid, const prfpregset_t *fpregs) {
537 print_debug("ps_lsetfpregs not implemented\n");
538 return PS_OK;
539 }
541 ps_err_e ps_lsetregs(struct ps_prochandle *ph, lwpid_t lid, const prgregset_t gregset) {
542 print_debug("ps_lsetregs not implemented\n");
543 return PS_OK;
544 }
546 ps_err_e ps_lgetfpregs(struct ps_prochandle *ph, lwpid_t lid, prfpregset_t *fpregs) {
547 print_debug("ps_lgetfpregs not implemented\n");
548 return PS_OK;
549 }
551 ps_err_e ps_lgetregs(struct ps_prochandle *ph, lwpid_t lid, prgregset_t gregset) {
552 print_debug("ps_lgetfpregs not implemented\n");
553 return PS_OK;
554 }
556 ps_err_e ps_lstop(struct ps_prochandle *ph, lwpid_t lid) {
557 print_debug("ps_lstop not implemented\n");
558 return PS_OK;
559 }
561 ps_err_e ps_pcontinue(struct ps_prochandle *ph) {
562 print_debug("ps_pcontinue not implemented\n");
563 return PS_OK;
564 }
565 #endif // __APPLE__