Mercurial > hg > truffle
annotate agent/src/os/bsd/ps_proc.c @ 13163:1baa169508f5
made DebugScope be AutoCloseable so that try-with-resource can be used to more cleanly manage scopes
author | Doug Simon <doug.simon@oracle.com> |
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date | Mon, 25 Nov 2013 18:42:51 +0100 |
parents | 1a04de1aaedb |
children |
rev | line source |
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3960 | 1 /* |
8058 | 2 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. |
3960 | 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 | |
25 #include <limits.h> | |
26 #include <stdio.h> | |
27 #include <stdlib.h> | |
28 #include <string.h> | |
29 #include <errno.h> | |
30 #include <sys/types.h> | |
31 #include <sys/wait.h> | |
32 #include <sys/ptrace.h> | |
33 #include <sys/param.h> | |
34 #include <sys/user.h> | |
35 #include <elf.h> | |
36 #include <sys/elf_common.h> | |
37 #include <sys/link_elf.h> | |
38 #include <libutil.h> | |
39 #include "libproc_impl.h" | |
40 #include "elfmacros.h" | |
41 | |
42 // This file has the libproc implementation specific to live process | |
43 // For core files, refer to ps_core.c | |
44 | |
45 static inline uintptr_t align(uintptr_t ptr, size_t size) { | |
46 return (ptr & ~(size - 1)); | |
47 } | |
48 | |
49 // --------------------------------------------- | |
50 // ptrace functions | |
51 // --------------------------------------------- | |
52 | |
53 // read "size" bytes of data from "addr" within the target process. | |
54 // unlike the standard ptrace() function, process_read_data() can handle | |
55 // unaligned address - alignment check, if required, should be done | |
56 // before calling process_read_data. | |
57 | |
58 static bool process_read_data(struct ps_prochandle* ph, uintptr_t addr, char *buf, size_t size) { | |
59 int rslt; | |
60 size_t i, words; | |
61 uintptr_t end_addr = addr + size; | |
62 uintptr_t aligned_addr = align(addr, sizeof(int)); | |
63 | |
64 if (aligned_addr != addr) { | |
65 char *ptr = (char *)&rslt; | |
66 errno = 0; | |
67 rslt = ptrace(PT_READ_D, ph->pid, (caddr_t) aligned_addr, 0); | |
68 if (errno) { | |
69 print_debug("ptrace(PT_READ_D, ..) failed for %d bytes @ %lx\n", size, addr); | |
70 return false; | |
71 } | |
72 for (; aligned_addr != addr; aligned_addr++, ptr++); | |
73 for (; ((intptr_t)aligned_addr % sizeof(int)) && aligned_addr < end_addr; | |
74 aligned_addr++) | |
75 *(buf++) = *(ptr++); | |
76 } | |
77 | |
78 words = (end_addr - aligned_addr) / sizeof(int); | |
79 | |
80 // assert((intptr_t)aligned_addr % sizeof(int) == 0); | |
81 for (i = 0; i < words; i++) { | |
82 errno = 0; | |
83 rslt = ptrace(PT_READ_D, ph->pid, (caddr_t) aligned_addr, 0); | |
84 if (errno) { | |
85 print_debug("ptrace(PT_READ_D, ..) failed for %d bytes @ %lx\n", size, addr); | |
86 return false; | |
87 } | |
88 *(int *)buf = rslt; | |
89 buf += sizeof(int); | |
90 aligned_addr += sizeof(int); | |
91 } | |
92 | |
93 if (aligned_addr != end_addr) { | |
94 char *ptr = (char *)&rslt; | |
95 errno = 0; | |
96 rslt = ptrace(PT_READ_D, ph->pid, (caddr_t) aligned_addr, 0); | |
97 if (errno) { | |
98 print_debug("ptrace(PT_READ_D, ..) failed for %d bytes @ %lx\n", size, addr); | |
99 return false; | |
100 } | |
101 for (; aligned_addr != end_addr; aligned_addr++) | |
102 *(buf++) = *(ptr++); | |
103 } | |
104 return true; | |
105 } | |
106 | |
107 // null implementation for write | |
108 static bool process_write_data(struct ps_prochandle* ph, | |
109 uintptr_t addr, const char *buf , size_t size) { | |
110 return false; | |
111 } | |
112 | |
113 // "user" should be a pointer to a reg | |
114 static bool process_get_lwp_regs(struct ps_prochandle* ph, pid_t pid, struct reg *user) { | |
115 // we have already attached to all thread 'pid's, just use ptrace call | |
116 // to get regset now. Note that we don't cache regset upfront for processes. | |
117 if (ptrace(PT_GETREGS, pid, (caddr_t) user, 0) < 0) { | |
118 print_debug("ptrace(PTRACE_GETREGS, ...) failed for lwp %d\n", pid); | |
119 return false; | |
120 } | |
121 return true; | |
122 } | |
123 | |
124 // fill in ptrace_lwpinfo for lid | |
125 static bool process_get_lwp_info(struct ps_prochandle *ph, lwpid_t lwp_id, void *linfo) { | |
126 errno = 0; | |
127 ptrace(PT_LWPINFO, lwp_id, linfo, sizeof(struct ptrace_lwpinfo)); | |
128 | |
129 return (errno == 0)? true: false; | |
130 } | |
131 | |
8058 | 132 static bool ptrace_continue(pid_t pid, int signal) { |
133 // pass the signal to the process so we don't swallow it | |
13002
1a04de1aaedb
8026950: Nits in agent ps_proc.c file breaks compilation of open hotspot
dsamersoff
parents:
8058
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changeset
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134 if (ptrace(PT_CONTINUE, pid, NULL, signal) < 0) { |
8058 | 135 print_debug("ptrace(PTRACE_CONT, ..) failed for %d\n", pid); |
136 return false; | |
137 } | |
138 return true; | |
139 } | |
140 | |
141 // waits until the ATTACH has stopped the process | |
142 // by signal SIGSTOP | |
143 static bool ptrace_waitpid(pid_t pid) { | |
144 int ret; | |
145 int status; | |
146 do { | |
147 // Wait for debuggee to stop. | |
148 ret = waitpid(pid, &status, 0); | |
149 if (ret >= 0) { | |
150 if (WIFSTOPPED(status)) { | |
151 // Any signal will stop the thread, make sure it is SIGSTOP. Otherwise SIGSTOP | |
152 // will still be pending and delivered when the process is DETACHED and the process | |
153 // will go to sleep. | |
154 if (WSTOPSIG(status) == SIGSTOP) { | |
155 // Debuggee stopped by SIGSTOP. | |
156 return true; | |
157 } | |
158 if (!ptrace_continue(pid, WSTOPSIG(status))) { | |
159 print_error("Failed to correctly attach to VM. VM might HANG! [PTRACE_CONT failed, stopped by %d]\n", WSTOPSIG(status)); | |
160 return false; | |
161 } | |
162 } else { | |
163 print_debug("waitpid(): Child process exited/terminated (status = 0x%x)\n", status); | |
164 return false; | |
165 } | |
166 } else { | |
167 switch (errno) { | |
168 case EINTR: | |
169 continue; | |
170 break; | |
171 case ECHILD: | |
172 print_debug("waitpid() failed. Child process pid (%d) does not exist \n", pid); | |
173 break; | |
174 case EINVAL: | |
175 print_debug("waitpid() failed. Invalid options argument.\n"); | |
176 break; | |
177 default: | |
178 print_debug("waitpid() failed. Unexpected error %d\n",errno); | |
179 } | |
180 return false; | |
181 } | |
182 } while(true); | |
183 } | |
184 | |
3960 | 185 // attach to a process/thread specified by "pid" |
186 static bool ptrace_attach(pid_t pid) { | |
187 if (ptrace(PT_ATTACH, pid, NULL, 0) < 0) { | |
188 print_debug("ptrace(PTRACE_ATTACH, ..) failed for %d\n", pid); | |
189 return false; | |
190 } else { | |
8058 | 191 return ptrace_waitpid(pid); |
3960 | 192 } |
193 } | |
194 | |
195 // ------------------------------------------------------- | |
196 // functions for obtaining library information | |
197 // ------------------------------------------------------- | |
198 | |
199 // callback for read_thread_info | |
200 static bool add_new_thread(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) { | |
201 return add_thread_info(ph, pthread_id, lwp_id) != NULL; | |
202 } | |
203 | |
204 #if defined(__FreeBSD__) && __FreeBSD_version < 701000 | |
205 /* | |
206 * TEXT_START_ADDR from binutils/ld/emulparams/<arch_spec>.sh | |
207 * Not the most robust but good enough. | |
208 */ | |
209 | |
210 #if defined(amd64) || defined(x86_64) | |
211 #define TEXT_START_ADDR 0x400000 | |
212 #elif defined(i386) | |
213 #define TEXT_START_ADDR 0x8048000 | |
214 #else | |
215 #error TEXT_START_ADDR not defined | |
216 #endif | |
217 | |
218 #define BUF_SIZE (PATH_MAX + NAME_MAX + 1) | |
219 | |
220 uintptr_t linkmap_addr(struct ps_prochandle *ph) { | |
221 uintptr_t ehdr_addr, phdr_addr, dyn_addr, dmap_addr, lmap_addr; | |
222 ELF_EHDR ehdr; | |
223 ELF_PHDR *phdrs, *phdr; | |
224 ELF_DYN *dyns, *dyn; | |
225 struct r_debug dmap; | |
226 unsigned long hdrs_size; | |
227 unsigned int i; | |
228 | |
229 /* read ELF_EHDR at TEXT_START_ADDR and validate */ | |
230 | |
231 ehdr_addr = (uintptr_t)TEXT_START_ADDR; | |
232 | |
233 if (process_read_data(ph, ehdr_addr, (char *)&ehdr, sizeof(ehdr)) != true) { | |
234 print_debug("process_read_data failed for ehdr_addr %p\n", ehdr_addr); | |
235 return (0); | |
236 } | |
237 | |
238 if (!IS_ELF(ehdr) || | |
239 ehdr.e_ident[EI_CLASS] != ELF_TARG_CLASS || | |
240 ehdr.e_ident[EI_DATA] != ELF_TARG_DATA || | |
241 ehdr.e_ident[EI_VERSION] != EV_CURRENT || | |
242 ehdr.e_phentsize != sizeof(ELF_PHDR) || | |
243 ehdr.e_version != ELF_TARG_VER || | |
244 ehdr.e_machine != ELF_TARG_MACH) { | |
245 print_debug("not an ELF_EHDR at %p\n", ehdr_addr); | |
246 return (0); | |
247 } | |
248 | |
249 /* allocate space for all ELF_PHDR's and read */ | |
250 | |
251 phdr_addr = ehdr_addr + ehdr.e_phoff; | |
252 hdrs_size = ehdr.e_phnum * sizeof(ELF_PHDR); | |
253 | |
254 if ((phdrs = malloc(hdrs_size)) == NULL) | |
255 return (0); | |
256 | |
257 if (process_read_data(ph, phdr_addr, (char *)phdrs, hdrs_size) != true) { | |
258 print_debug("process_read_data failed for phdr_addr %p\n", phdr_addr); | |
259 return (0); | |
260 } | |
261 | |
262 /* find PT_DYNAMIC section */ | |
263 | |
264 for (i = 0, phdr = phdrs; i < ehdr.e_phnum; i++, phdr++) { | |
265 if (phdr->p_type == PT_DYNAMIC) | |
266 break; | |
267 } | |
268 | |
269 if (i >= ehdr.e_phnum) { | |
270 print_debug("PT_DYNAMIC section not found!\n"); | |
271 free(phdrs); | |
272 return (0); | |
273 } | |
274 | |
275 /* allocate space and read in ELF_DYN headers */ | |
276 | |
277 dyn_addr = phdr->p_vaddr; | |
278 hdrs_size = phdr->p_memsz; | |
279 free(phdrs); | |
280 | |
281 if ((dyns = malloc(hdrs_size)) == NULL) | |
282 return (0); | |
283 | |
284 if (process_read_data(ph, dyn_addr, (char *)dyns, hdrs_size) != true) { | |
285 print_debug("process_read_data failed for dyn_addr %p\n", dyn_addr); | |
286 free(dyns); | |
287 return (0); | |
288 } | |
289 | |
290 /* find DT_DEBUG */ | |
291 | |
292 dyn = dyns; | |
293 while (dyn->d_tag != DT_DEBUG && dyn->d_tag != DT_NULL) { | |
294 dyn++; | |
295 } | |
296 | |
297 if (dyn->d_tag != DT_DEBUG) { | |
298 print_debug("failed to find DT_DEBUG\n"); | |
299 free(dyns); | |
300 return (0); | |
301 } | |
302 | |
303 /* read struct r_debug into dmap */ | |
304 | |
305 dmap_addr = (uintptr_t)dyn->d_un.d_ptr; | |
306 free(dyns); | |
307 | |
308 if (process_read_data(ph, dmap_addr, (char *)&dmap, sizeof(dmap)) != true) { | |
309 print_debug("process_read_data failed for dmap_addr %p\n", dmap_addr); | |
310 return (0); | |
311 } | |
312 | |
313 lmap_addr = (uintptr_t)dmap.r_map; | |
314 | |
315 return (lmap_addr); | |
316 } | |
317 #endif // __FreeBSD__ && __FreeBSD_version < 701000 | |
318 | |
319 static bool read_lib_info(struct ps_prochandle* ph) { | |
320 #if defined(__FreeBSD__) && __FreeBSD_version >= 701000 | |
321 struct kinfo_vmentry *freep, *kve; | |
322 int i, cnt; | |
323 | |
324 freep = kinfo_getvmmap(ph->pid, &cnt); | |
325 if (freep == NULL) { | |
326 print_debug("can't get vm map for pid\n", ph->pid); | |
327 return false; | |
328 } | |
329 | |
330 for (i = 0; i < cnt; i++) { | |
331 kve = &freep[i]; | |
332 if ((kve->kve_flags & KVME_FLAG_COW) && | |
333 kve->kve_path != NULL && | |
334 strlen(kve->kve_path) > 0) { | |
335 | |
336 if (find_lib(ph, kve->kve_path) == false) { | |
337 lib_info* lib; | |
338 if ((lib = add_lib_info(ph, kve->kve_path, | |
339 (uintptr_t) kve->kve_start)) == NULL) | |
340 continue; // ignore, add_lib_info prints error | |
341 | |
342 // we don't need to keep the library open, symtab is already | |
343 // built. Only for core dump we need to keep the fd open. | |
344 close(lib->fd); | |
345 lib->fd = -1; | |
346 } | |
347 } | |
348 } | |
349 | |
350 free(freep); | |
351 | |
352 return true; | |
353 #else | |
354 char *l_name; | |
355 struct link_map *lmap; | |
356 uintptr_t lmap_addr; | |
357 | |
358 if ((l_name = malloc(BUF_SIZE)) == NULL) | |
359 return false; | |
360 | |
361 if ((lmap = malloc(sizeof(*lmap))) == NULL) { | |
362 free(l_name); | |
363 return false; | |
364 } | |
365 | |
366 lmap_addr = linkmap_addr(ph); | |
367 | |
368 if (lmap_addr == 0) { | |
369 free(l_name); | |
370 free(lmap); | |
371 return false; | |
372 } | |
373 | |
374 do { | |
375 if (process_read_data(ph, lmap_addr, (char *)lmap, sizeof(*lmap)) != true) { | |
376 print_debug("process_read_data failed for lmap_addr %p\n", lmap_addr); | |
377 free (l_name); | |
378 free (lmap); | |
379 return false; | |
380 } | |
381 | |
382 if (process_read_data(ph, (uintptr_t)lmap->l_name, l_name, | |
383 BUF_SIZE) != true) { | |
384 print_debug("process_read_data failed for lmap->l_name %p\n", | |
385 lmap->l_name); | |
386 free (l_name); | |
387 free (lmap); | |
388 return false; | |
389 } | |
390 | |
391 if (find_lib(ph, l_name) == false) { | |
392 lib_info* lib; | |
393 if ((lib = add_lib_info(ph, l_name, | |
394 (uintptr_t) lmap->l_addr)) == NULL) | |
395 continue; // ignore, add_lib_info prints error | |
396 | |
397 // we don't need to keep the library open, symtab is already | |
398 // built. Only for core dump we need to keep the fd open. | |
399 close(lib->fd); | |
400 lib->fd = -1; | |
401 } | |
402 lmap_addr = (uintptr_t)lmap->l_next; | |
403 } while (lmap->l_next != NULL); | |
404 | |
405 free (l_name); | |
406 free (lmap); | |
407 | |
408 return true; | |
409 #endif | |
410 } | |
411 | |
412 // detach a given pid | |
413 static bool ptrace_detach(pid_t pid) { | |
414 if (pid && ptrace(PT_DETACH, pid, (caddr_t)1, 0) < 0) { | |
415 print_debug("ptrace(PTRACE_DETACH, ..) failed for %d\n", pid); | |
416 return false; | |
417 } else { | |
418 return true; | |
419 } | |
420 } | |
421 | |
422 static void process_cleanup(struct ps_prochandle* ph) { | |
423 ptrace_detach(ph->pid); | |
424 } | |
425 | |
426 static ps_prochandle_ops process_ops = { | |
427 .release= process_cleanup, | |
428 .p_pread= process_read_data, | |
429 .p_pwrite= process_write_data, | |
430 .get_lwp_regs= process_get_lwp_regs, | |
431 .get_lwp_info= process_get_lwp_info | |
432 }; | |
433 | |
434 // attach to the process. One and only one exposed stuff | |
435 struct ps_prochandle* Pgrab(pid_t pid) { | |
436 struct ps_prochandle* ph = NULL; | |
437 | |
438 if ( (ph = (struct ps_prochandle*) calloc(1, sizeof(struct ps_prochandle))) == NULL) { | |
439 print_debug("can't allocate memory for ps_prochandle\n"); | |
440 return NULL; | |
441 } | |
442 | |
443 if (ptrace_attach(pid) != true) { | |
444 free(ph); | |
445 return NULL; | |
446 } | |
447 | |
448 // initialize ps_prochandle | |
449 ph->pid = pid; | |
450 | |
451 // initialize vtable | |
452 ph->ops = &process_ops; | |
453 | |
454 // read library info and symbol tables, must do this before attaching threads, | |
455 // as the symbols in the pthread library will be used to figure out | |
456 // the list of threads within the same process. | |
457 if (read_lib_info(ph) != true) { | |
458 ptrace_detach(pid); | |
459 free(ph); | |
460 return NULL; | |
461 } | |
462 | |
463 // read thread info | |
464 read_thread_info(ph, add_new_thread); | |
465 | |
466 return ph; | |
467 } |