1
2 /*--------------------------------------------------------------------*/
3 /*--- Process-related libc stuff. m_libcproc.c ---*/
4 /*--------------------------------------------------------------------*/
5
6 /*
7 This file is part of Valgrind, a dynamic binary instrumentation
8 framework.
9
10 Copyright (C) 2000-2017 Julian Seward
11 jseward@acm.org
12
13 This program is free software; you can redistribute it and/or
14 modify it under the terms of the GNU General Public License as
15 published by the Free Software Foundation; either version 2 of the
16 License, or (at your option) any later version.
17
18 This program is distributed in the hope that it will be useful, but
19 WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 General Public License for more details.
22
23 You should have received a copy of the GNU General Public License
24 along with this program; if not, write to the Free Software
25 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26 02111-1307, USA.
27
28 The GNU General Public License is contained in the file COPYING.
29 */
30
31 #include "pub_core_basics.h"
32 #include "pub_core_machine.h" // For VG_(machine_get_VexArchInfo)
33 #include "pub_core_vki.h"
34 #include "pub_core_vkiscnums.h"
35 #include "pub_core_libcbase.h"
36 #include "pub_core_libcassert.h"
37 #include "pub_core_libcfile.h"
38 #include "pub_core_libcprint.h"
39 #include "pub_core_libcproc.h"
40 #include "pub_core_libcsignal.h"
41 #include "pub_core_seqmatch.h"
42 #include "pub_core_mallocfree.h"
43 #include "pub_core_syscall.h"
44 #include "pub_core_xarray.h"
45 #include "pub_core_clientstate.h"
46
47 #if defined(VGO_darwin)
48 /* --- !!! --- EXTERNAL HEADERS start --- !!! --- */
49 #include <mach/mach.h> /* mach_thread_self */
50 /* --- !!! --- EXTERNAL HEADERS end --- !!! --- */
51 #endif
52
53 /* IMPORTANT: on Darwin it is essential to use the _nocancel versions
54 of syscalls rather than the vanilla version, if a _nocancel version
55 is available. See docs/internals/Darwin-notes.txt for the reason
56 why. */
57
58 /* ---------------------------------------------------------------------
59 Command line and environment stuff
60 ------------------------------------------------------------------ */
61
62 /* As deduced from sp_at_startup, the client's argc, argv[] and
63 envp[] as extracted from the client's stack at startup-time. */
64 HChar** VG_(client_envp) = NULL;
65
66 /* Path to library directory */
67 const HChar *VG_(libdir) = VG_LIBDIR;
68
69 const HChar *VG_(LD_PRELOAD_var_name) =
70 #if defined(VGO_linux) || defined(VGO_solaris)
71 "LD_PRELOAD";
72 #elif defined(VGO_darwin)
73 "DYLD_INSERT_LIBRARIES";
74 #else
75 # error Unknown OS
76 #endif
77
78 /* We do getenv without libc's help by snooping around in
79 VG_(client_envp) as determined at startup time. */
VG_(getenv)80 HChar *VG_(getenv)(const HChar *varname)
81 {
82 Int i, n;
83 vg_assert( VG_(client_envp) );
84 n = VG_(strlen)(varname);
85 for (i = 0; VG_(client_envp)[i] != NULL; i++) {
86 HChar* s = VG_(client_envp)[i];
87 if (VG_(strncmp)(varname, s, n) == 0 && s[n] == '=') {
88 return & s[n+1];
89 }
90 }
91 return NULL;
92 }
93
94 /* If free_fn is not NULL, it is called on "unset" environment variable. */
VG_(env_unsetenv)95 void VG_(env_unsetenv) ( HChar **env, const HChar *varname,
96 void (*free_fn) (void *) )
97 {
98 HChar **from, **to;
99 vg_assert(env);
100 vg_assert(varname);
101 to = NULL;
102 Int len = VG_(strlen)(varname);
103
104 for (from = to = env; from && *from; from++) {
105 if (!(VG_(strncmp)(varname, *from, len) == 0 && (*from)[len] == '=')) {
106 *to = *from;
107 to++;
108 } else if (free_fn != NULL) {
109 free_fn(*from);
110 }
111 }
112 *to = *from;
113 }
114
115 /* set the environment; returns the old env if a new one was allocated */
VG_(env_setenv)116 HChar **VG_(env_setenv) ( HChar ***envp, const HChar* varname,
117 const HChar *val )
118 {
119 HChar **env = (*envp);
120 HChar **cpp;
121 Int len = VG_(strlen)(varname);
122 HChar *valstr = VG_(malloc)("libcproc.es.1", len + VG_(strlen)(val) + 2);
123 HChar **oldenv = NULL;
124
125 VG_(sprintf)(valstr, "%s=%s", varname, val);
126
127 for (cpp = env; cpp && *cpp; cpp++) {
128 if (VG_(strncmp)(varname, *cpp, len) == 0 && (*cpp)[len] == '=') {
129 *cpp = valstr;
130 return oldenv;
131 }
132 }
133
134 if (env == NULL) {
135 env = VG_(malloc)("libcproc.es.2", sizeof(HChar *) * 2);
136 env[0] = valstr;
137 env[1] = NULL;
138
139 *envp = env;
140
141 } else {
142 Int envlen = (cpp-env) + 2;
143 HChar **newenv = VG_(malloc)("libcproc.es.3", envlen * sizeof(HChar *));
144
145 for (cpp = newenv; *env; )
146 *cpp++ = *env++;
147 *cpp++ = valstr;
148 *cpp++ = NULL;
149
150 oldenv = *envp;
151
152 *envp = newenv;
153 }
154
155 return oldenv;
156 }
157
158
159 /* Walk through a colon-separated environment variable, and remove the
160 entries which match remove_pattern. It slides everything down over
161 the removed entries, and pads the remaining space with '\0'. It
162 modifies the entries in place (in the client address space), but it
163 shouldn't matter too much, since we only do this just before an
164 execve().
165
166 This is also careful to mop up any excess ':'s, since empty strings
167 delimited by ':' are considered to be '.' in a path.
168 */
mash_colon_env(HChar * varp,const HChar * remove_pattern)169 static void mash_colon_env(HChar *varp, const HChar *remove_pattern)
170 {
171 HChar *const start = varp;
172 HChar *entry_start = varp;
173 HChar *output = varp;
174
175 if (varp == NULL)
176 return;
177
178 while(*varp) {
179 if (*varp == ':') {
180 HChar prev;
181 Bool match;
182
183 /* This is a bit subtle: we want to match against the entry
184 we just copied, because it may have overlapped with
185 itself, junking the original. */
186
187 prev = *output;
188 *output = '\0';
189
190 match = VG_(string_match)(remove_pattern, entry_start);
191
192 *output = prev;
193
194 if (match) {
195 output = entry_start;
196 varp++; /* skip ':' after removed entry */
197 } else
198 entry_start = output+1; /* entry starts after ':' */
199 }
200
201 if (*varp)
202 *output++ = *varp++;
203 }
204
205 /* make sure last entry is nul terminated */
206 *output = '\0';
207
208 /* match against the last entry */
209 if (VG_(string_match)(remove_pattern, entry_start)) {
210 output = entry_start;
211 if (output > start) {
212 /* remove trailing ':' */
213 output--;
214 vg_assert(*output == ':');
215 }
216 }
217
218 /* pad out the left-overs with '\0' */
219 while(output < varp)
220 *output++ = '\0';
221 }
222
223
224 /* Removes all the Valgrind-added stuff from the passed environment. Used
225 when starting child processes, so they don't see that added stuff.
226 If the ro_strings option is set to True then all strings referenced by envp
227 are considered read-only, which means they will be duplicated before they
228 are modified.
229 If free_fn is not NULL, it is called on "unset" environment variables. */
VG_(env_remove_valgrind_env_stuff)230 void VG_(env_remove_valgrind_env_stuff)(HChar** envp, Bool ro_strings,
231 void (*free_fn) (void *) )
232 {
233 Int i;
234 HChar* ld_preload_str = NULL;
235 HChar* ld_library_path_str = NULL;
236 HChar* dyld_insert_libraries_str = NULL;
237 HChar* buf;
238
239 // Find LD_* variables
240 // DDD: should probably conditionally compiled some of this:
241 // - LD_LIBRARY_PATH is universal?
242 // - LD_PRELOAD is on Linux, not on Darwin, not sure about AIX
243 // - DYLD_INSERT_LIBRARIES and DYLD_SHARED_REGION are Darwin-only
244 for (i = 0; envp[i] != NULL; i++) {
245 if (VG_(strncmp)(envp[i], "LD_PRELOAD=", 11) == 0) {
246 if (ro_strings)
247 envp[i] = VG_(strdup)("libcproc.erves.1", envp[i]);
248 ld_preload_str = &envp[i][11];
249 }
250 if (VG_(strncmp)(envp[i], "LD_LIBRARY_PATH=", 16) == 0) {
251 if (ro_strings)
252 envp[i] = VG_(strdup)("libcproc.erves.2", envp[i]);
253 ld_library_path_str = &envp[i][16];
254 }
255 if (VG_(strncmp)(envp[i], "DYLD_INSERT_LIBRARIES=", 22) == 0) {
256 if (ro_strings)
257 envp[i] = VG_(strdup)("libcproc.erves.3", envp[i]);
258 dyld_insert_libraries_str = &envp[i][22];
259 }
260 }
261
262 buf = VG_(malloc)("libcproc.erves.4", VG_(strlen)(VG_(libdir)) + 20);
263
264 // Remove Valgrind-specific entries from LD_*.
265 VG_(sprintf)(buf, "%s*/vgpreload_*.so", VG_(libdir));
266 mash_colon_env(ld_preload_str, buf);
267 mash_colon_env(dyld_insert_libraries_str, buf);
268 VG_(sprintf)(buf, "%s*", VG_(libdir));
269 mash_colon_env(ld_library_path_str, buf);
270
271 // Remove VALGRIND_LAUNCHER variable.
272 VG_(env_unsetenv)(envp, VALGRIND_LAUNCHER, free_fn);
273
274 // Remove DYLD_SHARED_REGION variable.
275 VG_(env_unsetenv)(envp, "DYLD_SHARED_REGION", free_fn);
276
277 // XXX if variable becomes empty, remove it completely?
278
279 VG_(free)(buf);
280 }
281
282 /* Resolves filename of VG_(cl_exec_fd) and copies it to the buffer.
283 Buffer must not be NULL and buf_size must be at least 1.
284 If buffer is not large enough it is terminated with '\0' only
285 when 'terminate_with_NUL == True'. */
VG_(client_fname)286 void VG_(client_fname)(HChar *buffer, SizeT buf_size, Bool terminate_with_NUL)
287 {
288 vg_assert(buffer != NULL);
289 vg_assert(buf_size >= 1);
290
291 const HChar *name;
292 if (VG_(resolve_filename)(VG_(cl_exec_fd), &name)) {
293 const HChar *n = name + VG_(strlen)(name) - 1;
294
295 while (n > name && *n != '/')
296 n--;
297 if (n != name)
298 n++;
299
300 VG_(strncpy)(buffer, n, buf_size);
301 if (terminate_with_NUL)
302 buffer[buf_size - 1] = '\0';
303 } else {
304 buffer[0] = '\0';
305 }
306 }
307
add_string(HChar * buffer,SizeT * buf_size,const HChar * string)308 static Bool add_string(HChar *buffer, SizeT *buf_size, const HChar *string)
309 {
310 SizeT len = VG_(strlen)(string);
311 VG_(strncat)(buffer, string, *buf_size);
312 if (len >= *buf_size - 1) {
313 *buf_size = 0;
314 return False;
315 } else {
316 *buf_size -= len;
317 return True;
318 }
319 }
320
321 /* Concatenates client exename and command line arguments into
322 the buffer. Buffer must not be NULL and buf_size must be
323 at least 1. Buffer is always terminated with '\0'. */
VG_(client_cmd_and_args)324 void VG_(client_cmd_and_args)(HChar *buffer, SizeT buf_size)
325 {
326 vg_assert(buffer != NULL);
327 vg_assert(buf_size >= 1);
328
329 buffer[0] = '\0';
330
331 if (add_string(buffer, &buf_size, VG_(args_the_exename)) == False)
332 return;
333
334 Int i;
335 for (i = 0; i < VG_(sizeXA)(VG_(args_for_client)); i++) {
336 if (add_string(buffer, &buf_size, " ") == False)
337 return;
338
339 HChar *arg = *(HChar **) VG_(indexXA)(VG_(args_for_client), i);
340 if (add_string(buffer, &buf_size, arg) == False)
341 return;
342 }
343 }
344
345 /* ---------------------------------------------------------------------
346 Various important syscall wrappers
347 ------------------------------------------------------------------ */
348
VG_(waitpid)349 Int VG_(waitpid)(Int pid, Int *status, Int options)
350 {
351 # if defined(VGO_linux)
352 SysRes res = VG_(do_syscall4)(__NR_wait4,
353 pid, (UWord)status, options, 0);
354 return sr_isError(res) ? -1 : sr_Res(res);
355 # elif defined(VGO_darwin)
356 SysRes res = VG_(do_syscall4)(__NR_wait4_nocancel,
357 pid, (UWord)status, options, 0);
358 return sr_isError(res) ? -1 : sr_Res(res);
359 # elif defined(VGO_solaris)
360 SysRes res;
361 vki_idtype_t idtype;
362 vki_id_t id;
363 vki_siginfo_t info;
364
365 /* We need to do a lot of work here. */
366
367 if (pid > 0) {
368 idtype = VKI_P_PID;
369 id = pid;
370 }
371 else if (pid < -1) {
372 idtype = VKI_P_PGID;
373 id = -pid;
374 }
375 else if (pid == -1) {
376 idtype = VKI_P_ALL;
377 id = 0;
378 }
379 else {
380 idtype = VKI_P_PGID;
381 res = VG_(do_syscall0)(__NR_getpid);
382 id = sr_ResHI(res);
383 }
384
385 options |= VKI_WEXITED | VKI_WTRAPPED;
386
387 res = VG_(do_syscall4)(__NR_waitsys, idtype, id, (UWord)&info, options);
388 if (sr_isError(res))
389 return -1;
390
391 if (status) {
392 Int s = info.si_status & 0xff;
393
394 switch (info.si_code) {
395 case VKI_CLD_EXITED:
396 s <<= 8;
397 break;
398 case VKI_CLD_DUMPED:
399 s |= VKI_WCOREFLG;
400 break;
401 case VKI_CLD_KILLED:
402 break;
403 case VKI_CLD_TRAPPED:
404 case VKI_CLD_STOPPED:
405 s <<= 8;
406 s |= VKI_WSTOPFLG;
407 break;
408 case VKI_CLD_CONTINUED:
409 s = VKI_WCONTFLG;
410 break;
411 }
412 *status = s;
413 }
414
415 return info.si_pid;
416 # else
417 # error Unknown OS
418 # endif
419 }
420
421 /* clone the environment */
VG_(env_clone)422 HChar **VG_(env_clone) ( HChar **oldenv )
423 {
424 HChar **oldenvp;
425 HChar **newenvp;
426 HChar **newenv;
427 Int envlen;
428
429 vg_assert(oldenv);
430 for (oldenvp = oldenv; oldenvp && *oldenvp; oldenvp++);
431
432 envlen = oldenvp - oldenv + 1;
433
434 newenv = VG_(malloc)("libcproc.ec.1", envlen * sizeof(HChar *));
435
436 oldenvp = oldenv;
437 newenvp = newenv;
438
439 while (oldenvp && *oldenvp) {
440 *newenvp++ = *oldenvp++;
441 }
442
443 *newenvp = *oldenvp;
444
445 return newenv;
446 }
447
VG_(execv)448 void VG_(execv) ( const HChar* filename, const HChar** argv )
449 {
450 HChar** envp;
451 SysRes res;
452
453 envp = VG_(env_clone)(VG_(client_envp));
454 VG_(env_remove_valgrind_env_stuff)( envp, True /*ro_strings*/, NULL );
455
456 res = VG_(do_syscall3)(__NR_execve,
457 (UWord)filename, (UWord)argv, (UWord)envp);
458
459 VG_(printf)("EXEC failed, errno = %lld\n", (Long)sr_Err(res));
460 }
461
462 /* Spawns a new child. Uses either spawn syscall or fork+execv combo. */
VG_(spawn)463 Int VG_(spawn) ( const HChar *filename, const HChar **argv )
464 {
465 vg_assert(filename != NULL);
466 vg_assert(argv != NULL);
467
468 # if defined(VGO_solaris) && defined(SOLARIS_SPAWN_SYSCALL)
469 HChar **envp = VG_(env_clone)(VG_(client_envp));
470 for (HChar **p = envp; *p != NULL; p++) {
471 *p = VG_(strdup)("libcproc.s.1", *p);
472 }
473 VG_(env_remove_valgrind_env_stuff)(envp, /* ro_strings */ False, VG_(free));
474
475 /* Now combine argv and argp into argenv. */
476 SizeT argenv_size = 1 + 1;
477 for (const HChar **p = argv; *p != NULL; p++) {
478 argenv_size += VG_(strlen)(*p) + 2;
479 }
480 for (HChar **p = envp; *p != NULL; p++) {
481 argenv_size += VG_(strlen)(*p) + 2;
482 }
483
484 HChar *argenv = VG_(malloc)("libcproc.s.2", argenv_size);
485 HChar *current = argenv;
486 # define COPY_CHAR_TO_ARGENV(dst, character) \
487 do { \
488 *(dst) = character; \
489 (dst) += 1; \
490 } while (0)
491 # define COPY_STRING_TO_ARGENV(dst, src) \
492 do { \
493 COPY_CHAR_TO_ARGENV(dst, '\1'); \
494 SizeT src_len = VG_(strlen)((src)) + 1; \
495 VG_(memcpy)((dst), (src), src_len); \
496 (dst) += src_len; \
497 } while (0)
498
499 for (const HChar **p = argv; *p != NULL; p++) {
500 COPY_STRING_TO_ARGENV(current, *p);
501 }
502 COPY_CHAR_TO_ARGENV(current, '\0');
503 for (HChar **p = envp; *p != NULL; p++) {
504 COPY_STRING_TO_ARGENV(current, *p);
505 }
506 COPY_CHAR_TO_ARGENV(current, '\0');
507 vg_assert(current == argenv + argenv_size);
508 # undef COPY_CHAR_TO_ARGENV
509 # undef COPY_STRING_TOARGENV
510
511 SysRes res = VG_(do_syscall5)(__NR_spawn, (UWord) filename, (UWord) NULL, 0,
512 (UWord) argenv, argenv_size);
513
514 VG_(free)(argenv);
515 for (HChar **p = envp; *p != NULL; p++) {
516 VG_(free)(*p);
517 }
518 VG_(free)(envp);
519
520 if (sr_isError(res))
521 return -1;
522 return sr_Res(res);
523
524 # else
525
526 Int pid = VG_(fork)();
527 if (pid < 0)
528 return -1;
529 if (pid == 0) {
530 /* child */
531 VG_(execv)(argv[0], argv);
532
533 /* If we're still alive here, execv failed. */
534 VG_(exit)(1);
535 } else {
536 return pid;
537 }
538 # endif /* VGO_solaris && SOLARIS_SPAWN_SYSCALL */
539 }
540
541 /* Return -1 if error, else 0. NOTE does not indicate return code of
542 child! */
VG_(system)543 Int VG_(system) ( const HChar* cmd )
544 {
545 Int pid;
546 if (cmd == NULL)
547 return 1;
548
549 const HChar *argv[4] = { "/bin/sh", "-c", cmd, 0 };
550 pid = VG_(spawn)(argv[0], argv);
551 if (pid < 0)
552 return -1;
553
554 vg_assert(pid > 0);
555 /* parent */
556 /* We have to set SIGCHLD to its default behaviour in order that
557 VG_(waitpid) works (at least on AIX). According to the Linux
558 man page for waitpid:
559
560 POSIX.1-2001 specifies that if the disposition of SIGCHLD is
561 set to SIG_IGN or the SA_NOCLDWAIT flag is set for SIGCHLD
562 (see sigaction(2)), then children that terminate do not
563 become zombies and a call to wait() or waitpid() will block
564 until all children have terminated, and then fail with errno
565 set to ECHILD. (The original POSIX standard left the
566 behaviour of setting SIGCHLD to SIG_IGN unspecified.)
567 */
568 Int ir, zzz;
569 vki_sigaction_toK_t sa, sa2;
570 vki_sigaction_fromK_t saved_sa;
571 VG_(memset)( &sa, 0, sizeof(sa) );
572 VG_(sigemptyset)(&sa.sa_mask);
573 sa.ksa_handler = VKI_SIG_DFL;
574 sa.sa_flags = 0;
575 ir = VG_(sigaction)(VKI_SIGCHLD, &sa, &saved_sa);
576 vg_assert(ir == 0);
577
578 zzz = VG_(waitpid)(pid, NULL, 0);
579
580 VG_(convert_sigaction_fromK_to_toK)( &saved_sa, &sa2 );
581 ir = VG_(sigaction)(VKI_SIGCHLD, &sa2, NULL);
582 vg_assert(ir == 0);
583 return zzz == -1 ? -1 : 0;
584 }
585
VG_(sysctl)586 Int VG_(sysctl)(Int *name, UInt namelen, void *oldp, SizeT *oldlenp, void *newp, SizeT newlen)
587 {
588 SysRes res;
589 # if defined(VGO_darwin)
590 res = VG_(do_syscall6)(__NR___sysctl,
591 (UWord)name, namelen, (UWord)oldp, (UWord)oldlenp, (UWord)newp, newlen);
592 # else
593 res = VG_(mk_SysRes_Error)(VKI_ENOSYS);
594 # endif
595 return sr_isError(res) ? -1 : sr_Res(res);
596 }
597
598 /* ---------------------------------------------------------------------
599 Resource limits
600 ------------------------------------------------------------------ */
601
602 /* Support for getrlimit. */
VG_(getrlimit)603 Int VG_(getrlimit) (Int resource, struct vki_rlimit *rlim)
604 {
605 SysRes res = VG_(mk_SysRes_Error)(VKI_ENOSYS);
606 /* res = getrlimit( resource, rlim ); */
607 # ifdef __NR_ugetrlimit
608 res = VG_(do_syscall2)(__NR_ugetrlimit, resource, (UWord)rlim);
609 # endif
610 if (sr_isError(res) && sr_Err(res) == VKI_ENOSYS)
611 res = VG_(do_syscall2)(__NR_getrlimit, resource, (UWord)rlim);
612 return sr_isError(res) ? -1 : sr_Res(res);
613 }
614
615
616 /* Support for setrlimit. */
VG_(setrlimit)617 Int VG_(setrlimit) (Int resource, const struct vki_rlimit *rlim)
618 {
619 SysRes res;
620 /* res = setrlimit( resource, rlim ); */
621 res = VG_(do_syscall2)(__NR_setrlimit, resource, (UWord)rlim);
622 return sr_isError(res) ? -1 : sr_Res(res);
623 }
624
625 /* Support for prctl. */
VG_(prctl)626 Int VG_(prctl) (Int option,
627 ULong arg2, ULong arg3, ULong arg4, ULong arg5)
628 {
629 SysRes res = VG_(mk_SysRes_Error)(VKI_ENOSYS);
630 # if defined(VGO_linux)
631 /* res = prctl( option, arg2, arg3, arg4, arg5 ); */
632 res = VG_(do_syscall5)(__NR_prctl, (UWord) option,
633 (UWord) arg2, (UWord) arg3, (UWord) arg4,
634 (UWord) arg5);
635 # endif
636
637 return sr_isError(res) ? -1 : sr_Res(res);
638 }
639
640 /* ---------------------------------------------------------------------
641 pids, etc
642 ------------------------------------------------------------------ */
643
VG_(gettid)644 Int VG_(gettid)(void)
645 {
646 # if defined(VGO_linux)
647 SysRes res = VG_(do_syscall0)(__NR_gettid);
648
649 if (sr_isError(res) && sr_Res(res) == VKI_ENOSYS) {
650 HChar pid[16];
651 /*
652 * The gettid system call does not exist. The obvious assumption
653 * to make at this point would be that we are running on an older
654 * system where the getpid system call actually returns the ID of
655 * the current thread.
656 *
657 * Unfortunately it seems that there are some systems with a kernel
658 * where getpid has been changed to return the ID of the thread group
659 * leader but where the gettid system call has not yet been added.
660 *
661 * So instead of calling getpid here we use readlink to see where
662 * the /proc/self link is pointing...
663 */
664
665 # if defined(VGP_arm64_linux)
666 res = VG_(do_syscall4)(__NR_readlinkat, VKI_AT_FDCWD,
667 (UWord)"/proc/self",
668 (UWord)pid, sizeof(pid));
669 # else
670 res = VG_(do_syscall3)(__NR_readlink, (UWord)"/proc/self",
671 (UWord)pid, sizeof(pid));
672 # endif
673 if (!sr_isError(res) && sr_Res(res) > 0) {
674 HChar* s;
675 pid[sr_Res(res)] = '\0';
676 res = VG_(mk_SysRes_Success)( VG_(strtoll10)(pid, &s) );
677 if (*s != '\0') {
678 VG_(message)(Vg_DebugMsg,
679 "Warning: invalid file name linked to by /proc/self: %s\n",
680 pid);
681 }
682 }
683 }
684
685 return sr_Res(res);
686
687 # elif defined(VGO_darwin)
688 // Darwin's gettid syscall is something else.
689 // Use Mach thread ports for lwpid instead.
690 return mach_thread_self();
691
692 # elif defined(VGO_solaris)
693 SysRes res = VG_(do_syscall0)(__NR_lwp_self);
694 return sr_Res(res);
695
696 # else
697 # error "Unknown OS"
698 # endif
699 }
700
701 /* You'd be amazed how many places need to know the current pid. */
VG_(getpid)702 Int VG_(getpid) ( void )
703 {
704 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */
705 return sr_Res( VG_(do_syscall0)(__NR_getpid) );
706 }
707
VG_(getpgrp)708 Int VG_(getpgrp) ( void )
709 {
710 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */
711 # if defined(VGP_arm64_linux)
712 return sr_Res( VG_(do_syscall1)(__NR_getpgid, 0) );
713 # elif defined(VGO_linux) || defined(VGO_darwin)
714 return sr_Res( VG_(do_syscall0)(__NR_getpgrp) );
715 # elif defined(VGO_solaris)
716 /* Uses the shared pgrpsys syscall, 0 for the getpgrp variant. */
717 return sr_Res( VG_(do_syscall1)(__NR_pgrpsys, 0) );
718 # else
719 # error Unknown OS
720 # endif
721 }
722
VG_(getppid)723 Int VG_(getppid) ( void )
724 {
725 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */
726 # if defined(VGO_linux) || defined(VGO_darwin)
727 return sr_Res( VG_(do_syscall0)(__NR_getppid) );
728 # elif defined(VGO_solaris)
729 /* Uses the shared getpid/getppid syscall, val2 contains a parent pid. */
730 return sr_ResHI( VG_(do_syscall0)(__NR_getpid) );
731 # else
732 # error Unknown OS
733 # endif
734 }
735
VG_(geteuid)736 Int VG_(geteuid) ( void )
737 {
738 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */
739 # if defined(VGO_linux) || defined(VGO_darwin)
740 {
741 # if defined(__NR_geteuid32)
742 // We use the 32-bit version if it's supported. Otherwise, IDs greater
743 // than 65536 cause problems, as bug #151209 showed.
744 return sr_Res( VG_(do_syscall0)(__NR_geteuid32) );
745 # else
746 return sr_Res( VG_(do_syscall0)(__NR_geteuid) );
747 # endif
748 }
749 # elif defined(VGO_solaris)
750 /* Uses the shared getuid/geteuid syscall, val2 contains the effective
751 uid. */
752 return sr_ResHI( VG_(do_syscall0)(__NR_getuid) );
753 # else
754 # error Unknown OS
755 # endif
756 }
757
VG_(getegid)758 Int VG_(getegid) ( void )
759 {
760 # if defined(VGO_linux) || defined(VGO_darwin)
761 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */
762 # if defined(__NR_getegid32)
763 // We use the 32-bit version if it's supported. Otherwise, IDs greater
764 // than 65536 cause problems, as bug #151209 showed.
765 return sr_Res( VG_(do_syscall0)(__NR_getegid32) );
766 # else
767 return sr_Res( VG_(do_syscall0)(__NR_getegid) );
768 # endif
769
770 # elif defined(VGO_solaris)
771 /* Uses the shared getgid/getegid syscall, val2 contains the effective
772 gid. */
773 return sr_ResHI( VG_(do_syscall0)(__NR_getgid) );
774 # else
775 # error Unknown OS
776 # endif
777 }
778
779 /* Get supplementary groups into list[0 .. size-1]. Returns the
780 number of groups written, or -1 if error. Note that in order to be
781 portable, the groups are 32-bit unsigned ints regardless of the
782 platform.
783 As a special case, if size == 0 the function returns the number of
784 groups leaving list untouched. */
VG_(getgroups)785 Int VG_(getgroups)( Int size, UInt* list )
786 {
787 if (size < 0) return -1;
788
789 # if defined(VGP_x86_linux) || defined(VGP_ppc32_linux) \
790 || defined(VGP_mips64_linux)
791 Int i;
792 SysRes sres;
793 UShort list16[size];
794 sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list16);
795 if (sr_isError(sres))
796 return -1;
797 if (size != 0) {
798 for (i = 0; i < sr_Res(sres); i++)
799 list[i] = (UInt)list16[i];
800 }
801 return sr_Res(sres);
802
803 # elif defined(VGP_amd64_linux) || defined(VGP_arm_linux) \
804 || defined(VGP_ppc64be_linux) || defined(VGP_ppc64le_linux) \
805 || defined(VGO_darwin) || defined(VGP_s390x_linux) \
806 || defined(VGP_mips32_linux) || defined(VGP_arm64_linux) \
807 || defined(VGO_solaris)
808 SysRes sres;
809 sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list);
810 if (sr_isError(sres))
811 return -1;
812 return sr_Res(sres);
813
814 # else
815 # error "VG_(getgroups): needs implementation on this platform"
816 # endif
817 }
818
819 /* ---------------------------------------------------------------------
820 Process tracing
821 ------------------------------------------------------------------ */
822
VG_(ptrace)823 Int VG_(ptrace) ( Int request, Int pid, void *addr, void *data )
824 {
825 SysRes res;
826 # if defined(VGO_linux) || defined(VGO_darwin)
827 res = VG_(do_syscall4)(__NR_ptrace, request, pid, (UWord)addr, (UWord)data);
828 # elif defined(VGO_solaris)
829 /* There is no ptrace syscall on Solaris. Such requests has to be
830 implemented using the /proc interface. Callers of VG_(ptrace) should
831 ensure that this function is not reached on Solaris, i.e. they must
832 provide a special code for Solaris for whatever feature they provide. */
833 I_die_here;
834 # else
835 # error Unknown OS
836 # endif
837 if (sr_isError(res))
838 return -1;
839 return sr_Res(res);
840 }
841
842 /* ---------------------------------------------------------------------
843 Fork
844 ------------------------------------------------------------------ */
845
VG_(fork)846 Int VG_(fork) ( void )
847 {
848 # if defined(VGP_arm64_linux)
849 SysRes res;
850 res = VG_(do_syscall5)(__NR_clone, VKI_SIGCHLD,
851 (UWord)NULL, (UWord)NULL, (UWord)NULL, (UWord)NULL);
852 if (sr_isError(res))
853 return -1;
854 return sr_Res(res);
855
856 # elif defined(VGO_linux)
857 SysRes res;
858 res = VG_(do_syscall0)(__NR_fork);
859 if (sr_isError(res))
860 return -1;
861 return sr_Res(res);
862
863 # elif defined(VGO_darwin)
864 SysRes res;
865 res = VG_(do_syscall0)(__NR_fork); /* __NR_fork is UX64 */
866 if (sr_isError(res))
867 return -1;
868 /* on success: wLO = child pid; wHI = 1 for child, 0 for parent */
869 if (sr_ResHI(res) != 0) {
870 return 0; /* this is child: return 0 instead of child pid */
871 }
872 return sr_Res(res);
873
874 # elif defined(VGO_solaris)
875 /* Using fork() on Solaris is not really the best thing to do. Solaris
876 does not do memory overcommitment so fork() can fail if there is not
877 enough memory to copy the current process into a new one.
878 Prefer to use VG_(spawn)() over VG_(fork)() + VG_(execv)(). */
879 SysRes res;
880 res = VG_(do_syscall2)(__NR_forksys, 0 /*subcode (fork)*/, 0 /*flags*/);
881 if (sr_isError(res))
882 return -1;
883 /* On success:
884 val = a pid of the child in the parent, a pid of the parent in the
885 child,
886 val2 = 0 in the parent process, 1 in the child process. */
887 if (sr_ResHI(res) != 0) {
888 return 0;
889 }
890 return sr_Res(res);
891
892 # else
893 # error "Unknown OS"
894 # endif
895 }
896
897 /* ---------------------------------------------------------------------
898 Timing stuff
899 ------------------------------------------------------------------ */
900
VG_(read_millisecond_timer)901 UInt VG_(read_millisecond_timer) ( void )
902 {
903 /* 'now' and 'base' are in microseconds */
904 static ULong base = 0;
905 ULong now;
906
907 # if defined(VGO_linux) || defined(VGO_solaris)
908 { SysRes res;
909 struct vki_timespec ts_now;
910 res = VG_(do_syscall2)(__NR_clock_gettime, VKI_CLOCK_MONOTONIC,
911 (UWord)&ts_now);
912 if (sr_isError(res) == 0) {
913 now = ts_now.tv_sec * 1000000ULL + ts_now.tv_nsec / 1000;
914 } else {
915 struct vki_timeval tv_now;
916 /* Note: On Solaris, this syscall takes only one parameter but the
917 extra dummy one does not cause any harm. */
918 res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL);
919 vg_assert(! sr_isError(res));
920 now = tv_now.tv_sec * 1000000ULL + tv_now.tv_usec;
921 }
922 }
923
924 # elif defined(VGO_darwin)
925 // Weird: it seems that gettimeofday() doesn't fill in the timeval, but
926 // rather returns the tv_sec as the low 32 bits of the result and the
927 // tv_usec as the high 32 bits of the result. (But the timeval cannot be
928 // NULL!) See bug 200990.
929 { SysRes res;
930 struct vki_timeval tv_now = { 0, 0 };
931 res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL);
932 vg_assert(! sr_isError(res));
933 now = sr_Res(res) * 1000000ULL + sr_ResHI(res);
934 }
935
936 # else
937 # error "Unknown OS"
938 # endif
939
940 /* COMMON CODE */
941 if (base == 0)
942 base = now;
943
944 return (now - base) / 1000;
945 }
946
VG_(gettimeofday)947 Int VG_(gettimeofday)(struct vki_timeval *tv, struct vki_timezone *tz)
948 {
949 SysRes res;
950 res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)tv, (UWord)tz);
951
952 if (! sr_isError(res)) return 0;
953
954 /* Make sure, argument values are deterministic upon failure */
955 if (tv) *tv = (struct vki_timeval){ .tv_sec = 0, .tv_usec = 0 };
956 if (tz) *tz = (struct vki_timezone){ .tz_minuteswest = 0, .tz_dsttime = 0 };
957
958 return -1;
959 }
960
961
962 /* ---------------------------------------------------------------------
963 atfork()
964 ------------------------------------------------------------------ */
965
966 struct atfork {
967 vg_atfork_t pre;
968 vg_atfork_t parent;
969 vg_atfork_t child;
970 };
971
972 #define VG_MAX_ATFORK 10
973
974 static struct atfork atforks[VG_MAX_ATFORK];
975 static Int n_atfork = 0;
976
VG_(atfork)977 void VG_(atfork)(vg_atfork_t pre, vg_atfork_t parent, vg_atfork_t child)
978 {
979 Int i;
980
981 for (i = 0; i < n_atfork; i++) {
982 if (atforks[i].pre == pre &&
983 atforks[i].parent == parent &&
984 atforks[i].child == child)
985 return;
986 }
987
988 if (n_atfork >= VG_MAX_ATFORK)
989 VG_(core_panic)(
990 "Too many VG_(atfork) handlers requested: raise VG_MAX_ATFORK");
991
992 atforks[n_atfork].pre = pre;
993 atforks[n_atfork].parent = parent;
994 atforks[n_atfork].child = child;
995
996 n_atfork++;
997 }
998
VG_(do_atfork_pre)999 void VG_(do_atfork_pre)(ThreadId tid)
1000 {
1001 Int i;
1002
1003 for (i = 0; i < n_atfork; i++)
1004 if (atforks[i].pre != NULL)
1005 (*atforks[i].pre)(tid);
1006 }
1007
VG_(do_atfork_parent)1008 void VG_(do_atfork_parent)(ThreadId tid)
1009 {
1010 Int i;
1011
1012 for (i = 0; i < n_atfork; i++)
1013 if (atforks[i].parent != NULL)
1014 (*atforks[i].parent)(tid);
1015 }
1016
VG_(do_atfork_child)1017 void VG_(do_atfork_child)(ThreadId tid)
1018 {
1019 Int i;
1020
1021 for (i = 0; i < n_atfork; i++)
1022 if (atforks[i].child != NULL)
1023 (*atforks[i].child)(tid);
1024 }
1025
1026
1027 /* ---------------------------------------------------------------------
1028 icache invalidation
1029 ------------------------------------------------------------------ */
1030
VG_(invalidate_icache)1031 void VG_(invalidate_icache) ( void *ptr, SizeT nbytes )
1032 {
1033 if (nbytes == 0) return; // nothing to do
1034
1035 // Get cache info
1036 VexArchInfo vai;
1037 VG_(machine_get_VexArchInfo)(NULL, &vai);
1038
1039 // If I-caches are coherent, nothing needs to be done here
1040 if (vai.hwcache_info.icaches_maintain_coherence) return;
1041
1042 # if defined(VGA_ppc32) || defined(VGA_ppc64be) || defined(VGA_ppc64le)
1043 Addr startaddr = (Addr) ptr;
1044 Addr endaddr = startaddr + nbytes;
1045 Addr cls;
1046 Addr addr;
1047
1048 cls = vai.ppc_icache_line_szB;
1049
1050 /* Stay sane .. */
1051 vg_assert(cls == 16 || cls == 32 || cls == 64 || cls == 128);
1052
1053 startaddr &= ~(cls - 1);
1054 for (addr = startaddr; addr < endaddr; addr += cls) {
1055 __asm__ __volatile__("dcbst 0,%0" : : "r" (addr));
1056 }
1057 __asm__ __volatile__("sync");
1058 for (addr = startaddr; addr < endaddr; addr += cls) {
1059 __asm__ __volatile__("icbi 0,%0" : : "r" (addr));
1060 }
1061 __asm__ __volatile__("sync; isync");
1062
1063 # elif defined(VGP_arm_linux)
1064 /* ARM cache flushes are privileged, so we must defer to the kernel. */
1065 Addr startaddr = (Addr) ptr;
1066 Addr endaddr = startaddr + nbytes;
1067 VG_(do_syscall2)(__NR_ARM_cacheflush, startaddr, endaddr);
1068
1069 # elif defined(VGP_arm64_linux)
1070 // This arm64_linux section of this function VG_(invalidate_icache)
1071 // is copied from
1072 // https://github.com/armvixl/vixl/blob/master/src/a64/cpu-a64.cc
1073 // which has the following copyright notice:
1074 /*
1075 Copyright 2013, ARM Limited
1076 All rights reserved.
1077
1078 Redistribution and use in source and binary forms, with or without
1079 modification, are permitted provided that the following conditions are met:
1080
1081 * Redistributions of source code must retain the above copyright notice,
1082 this list of conditions and the following disclaimer.
1083 * Redistributions in binary form must reproduce the above copyright notice,
1084 this list of conditions and the following disclaimer in the documentation
1085 and/or other materials provided with the distribution.
1086 * Neither the name of ARM Limited nor the names of its contributors may be
1087 used to endorse or promote products derived from this software without
1088 specific prior written permission.
1089
1090 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
1091 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
1092 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
1093 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
1094 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
1095 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
1096 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
1097 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
1098 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1099 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1100 */
1101
1102 // Ask what the I and D line sizes are
1103 UInt cache_type_register;
1104 // Copy the content of the cache type register to a core register.
1105 __asm__ __volatile__ ("mrs %[ctr], ctr_el0" // NOLINT
1106 : [ctr] "=r" (cache_type_register));
1107
1108 const Int kDCacheLineSizeShift = 16;
1109 const Int kICacheLineSizeShift = 0;
1110 const UInt kDCacheLineSizeMask = 0xf << kDCacheLineSizeShift;
1111 const UInt kICacheLineSizeMask = 0xf << kICacheLineSizeShift;
1112
1113 // The cache type register holds the size of the I and D caches as a power of
1114 // two.
1115 const UInt dcache_line_size_power_of_two =
1116 (cache_type_register & kDCacheLineSizeMask) >> kDCacheLineSizeShift;
1117 const UInt icache_line_size_power_of_two =
1118 (cache_type_register & kICacheLineSizeMask) >> kICacheLineSizeShift;
1119
1120 const UInt dcache_line_size_ = 4 * (1 << dcache_line_size_power_of_two);
1121 const UInt icache_line_size_ = 4 * (1 << icache_line_size_power_of_two);
1122
1123 Addr start = (Addr)ptr;
1124 // Sizes will be used to generate a mask big enough to cover a pointer.
1125 Addr dsize = (Addr)dcache_line_size_;
1126 Addr isize = (Addr)icache_line_size_;
1127
1128 // Cache line sizes are always a power of 2.
1129 Addr dstart = start & ~(dsize - 1);
1130 Addr istart = start & ~(isize - 1);
1131 Addr end = start + nbytes;
1132
1133 __asm__ __volatile__ (
1134 // Clean every line of the D cache containing the target data.
1135 "0: \n\t"
1136 // dc : Data Cache maintenance
1137 // c : Clean
1138 // va : by (Virtual) Address
1139 // u : to the point of Unification
1140 // The point of unification for a processor is the point by which the
1141 // instruction and data caches are guaranteed to see the same copy of a
1142 // memory location. See ARM DDI 0406B page B2-12 for more information.
1143 "dc cvau, %[dline] \n\t"
1144 "add %[dline], %[dline], %[dsize] \n\t"
1145 "cmp %[dline], %[end] \n\t"
1146 "b.lt 0b \n\t"
1147 // Barrier to make sure the effect of the code above is visible to the rest
1148 // of the world.
1149 // dsb : Data Synchronisation Barrier
1150 // ish : Inner SHareable domain
1151 // The point of unification for an Inner Shareable shareability domain is
1152 // the point by which the instruction and data caches of all the processors
1153 // in that Inner Shareable shareability domain are guaranteed to see the
1154 // same copy of a memory location. See ARM DDI 0406B page B2-12 for more
1155 // information.
1156 "dsb ish \n\t"
1157 // Invalidate every line of the I cache containing the target data.
1158 "1: \n\t"
1159 // ic : instruction cache maintenance
1160 // i : invalidate
1161 // va : by address
1162 // u : to the point of unification
1163 "ic ivau, %[iline] \n\t"
1164 "add %[iline], %[iline], %[isize] \n\t"
1165 "cmp %[iline], %[end] \n\t"
1166 "b.lt 1b \n\t"
1167 // Barrier to make sure the effect of the code above is visible to the rest
1168 // of the world.
1169 "dsb ish \n\t"
1170 // Barrier to ensure any prefetching which happened before this code is
1171 // discarded.
1172 // isb : Instruction Synchronisation Barrier
1173 "isb \n\t"
1174 : [dline] "+r" (dstart),
1175 [iline] "+r" (istart)
1176 : [dsize] "r" (dsize),
1177 [isize] "r" (isize),
1178 [end] "r" (end)
1179 // This code does not write to memory but without the dependency gcc might
1180 // move this code before the code is generated.
1181 : "cc", "memory"
1182 );
1183
1184 # elif defined(VGA_mips32) || defined(VGA_mips64)
1185 SysRes sres = VG_(do_syscall3)(__NR_cacheflush, (UWord) ptr,
1186 (UWord) nbytes, (UWord) 3);
1187 vg_assert( !sr_isError(sres) );
1188
1189 # endif
1190 }
1191
1192
1193 /* ---------------------------------------------------------------------
1194 dcache flushing
1195 ------------------------------------------------------------------ */
1196
VG_(flush_dcache)1197 void VG_(flush_dcache) ( void *ptr, SizeT nbytes )
1198 {
1199 /* Currently this is only required on ARM64. */
1200 # if defined(VGA_arm64)
1201 Addr startaddr = (Addr) ptr;
1202 Addr endaddr = startaddr + nbytes;
1203 Addr cls;
1204 Addr addr;
1205
1206 ULong ctr_el0;
1207 __asm__ __volatile__ ("mrs %0, ctr_el0" : "=r"(ctr_el0));
1208 cls = 4 * (1ULL << (0xF & (ctr_el0 >> 16)));
1209
1210 /* Stay sane .. */
1211 vg_assert(cls == 64 || cls == 128);
1212
1213 startaddr &= ~(cls - 1);
1214 for (addr = startaddr; addr < endaddr; addr += cls) {
1215 __asm__ __volatile__("dc cvau, %0" : : "r" (addr));
1216 }
1217 __asm__ __volatile__("dsb ish");
1218 # endif
1219 }
1220
1221 /*--------------------------------------------------------------------*/
1222 /*--- end ---*/
1223 /*--------------------------------------------------------------------*/
1224