1//===-- sanitizer_linux_libcdep.cpp ---------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file is shared between AddressSanitizer and ThreadSanitizer
10// run-time libraries and implements linux-specific functions from
11// sanitizer_libc.h.
12//===----------------------------------------------------------------------===//
13
14#include "sanitizer_platform.h"
15
16#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
17 SANITIZER_SOLARIS
18
19#include "sanitizer_allocator_internal.h"
20#include "sanitizer_atomic.h"
21#include "sanitizer_common.h"
22#include "sanitizer_file.h"
23#include "sanitizer_flags.h"
24#include "sanitizer_freebsd.h"
25#include "sanitizer_getauxval.h"
26#include "sanitizer_glibc_version.h"
27#include "sanitizer_linux.h"
28#include "sanitizer_placement_new.h"
29#include "sanitizer_procmaps.h"
30#include "sanitizer_solaris.h"
31
32#if SANITIZER_NETBSD
33#define _RTLD_SOURCE // for __lwp_gettcb_fast() / __lwp_getprivate_fast()
34#endif
35
36#include <dlfcn.h> // for dlsym()
37#include <link.h>
38#include <pthread.h>
39#include <signal.h>
40#include <sys/mman.h>
41#include <sys/resource.h>
42#include <syslog.h>
43
44#if !defined(ElfW)
45#define ElfW(type) Elf_##type
46#endif
47
48#if SANITIZER_FREEBSD
49#include <pthread_np.h>
50#include <osreldate.h>
51#include <sys/sysctl.h>
52#define pthread_getattr_np pthread_attr_get_np
53// The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
54// that, it was never implemented. So just define it to zero.
55#undef MAP_NORESERVE
56#define MAP_NORESERVE 0
57#endif
58
59#if SANITIZER_NETBSD
60#include <sys/sysctl.h>
61#include <sys/tls.h>
62#include <lwp.h>
63#endif
64
65#if SANITIZER_SOLARIS
66#include <stddef.h>
67#include <stdlib.h>
68#include <thread.h>
69#endif
70
71#if SANITIZER_ANDROID
72#include <android/api-level.h>
73#if !defined(CPU_COUNT) && !defined(__aarch64__)
74#include <dirent.h>
75#include <fcntl.h>
76struct __sanitizer::linux_dirent {
77 long d_ino;
78 off_t d_off;
79 unsigned short d_reclen;
80 char d_name[];
81};
82#endif
83#endif
84
85#if !SANITIZER_ANDROID
86#include <elf.h>
87#include <unistd.h>
88#endif
89
90namespace __sanitizer {
91
92SANITIZER_WEAK_ATTRIBUTE int
93real_sigaction(int signum, const void *act, void *oldact);
94
95int internal_sigaction(int signum, const void *act, void *oldact) {
96#if !SANITIZER_GO
97 if (&real_sigaction)
98 return real_sigaction(signum, act, oldact);
99#endif
100 return sigaction(signum, (const struct sigaction *)act,
101 (struct sigaction *)oldact);
102}
103
104void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
105 uptr *stack_bottom) {
106 CHECK(stack_top);
107 CHECK(stack_bottom);
108 if (at_initialization) {
109 // This is the main thread. Libpthread may not be initialized yet.
110 struct rlimit rl;
111 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
112
113 // Find the mapping that contains a stack variable.
114 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
115 if (proc_maps.Error()) {
116 *stack_top = *stack_bottom = 0;
117 return;
118 }
119 MemoryMappedSegment segment;
120 uptr prev_end = 0;
121 while (proc_maps.Next(&segment)) {
122 if ((uptr)&rl < segment.end) break;
123 prev_end = segment.end;
124 }
125 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end);
126
127 // Get stacksize from rlimit, but clip it so that it does not overlap
128 // with other mappings.
129 uptr stacksize = rl.rlim_cur;
130 if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end;
131 // When running with unlimited stack size, we still want to set some limit.
132 // The unlimited stack size is caused by 'ulimit -s unlimited'.
133 // Also, for some reason, GNU make spawns subprocesses with unlimited stack.
134 if (stacksize > kMaxThreadStackSize)
135 stacksize = kMaxThreadStackSize;
136 *stack_top = segment.end;
137 *stack_bottom = segment.end - stacksize;
138 return;
139 }
140 uptr stacksize = 0;
141 void *stackaddr = nullptr;
142#if SANITIZER_SOLARIS
143 stack_t ss;
144 CHECK_EQ(thr_stksegment(&ss), 0);
145 stacksize = ss.ss_size;
146 stackaddr = (char *)ss.ss_sp - stacksize;
147#else // !SANITIZER_SOLARIS
148 pthread_attr_t attr;
149 pthread_attr_init(&attr);
150 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
151 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize);
152 pthread_attr_destroy(&attr);
153#endif // SANITIZER_SOLARIS
154
155 *stack_top = (uptr)stackaddr + stacksize;
156 *stack_bottom = (uptr)stackaddr;
157}
158
159#if !SANITIZER_GO
160bool SetEnv(const char *name, const char *value) {
161 void *f = dlsym(RTLD_NEXT, "setenv");
162 if (!f)
163 return false;
164 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite);
165 setenv_ft setenv_f;
166 CHECK_EQ(sizeof(setenv_f), sizeof(f));
167 internal_memcpy(&setenv_f, &f, sizeof(f));
168 return setenv_f(name, value, 1) == 0;
169}
170#endif
171
172__attribute__((unused)) static bool GetLibcVersion(int *major, int *minor,
173 int *patch) {
174#ifdef _CS_GNU_LIBC_VERSION
175 char buf[64];
176 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
177 if (len >= sizeof(buf))
178 return false;
179 buf[len] = 0;
180 static const char kGLibC[] = "glibc ";
181 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0)
182 return false;
183 const char *p = buf + sizeof(kGLibC) - 1;
184 *major = internal_simple_strtoll(p, &p, 10);
185 *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0;
186 *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0;
187 return true;
188#else
189 return false;
190#endif
191}
192
193// True if we can use dlpi_tls_data. glibc before 2.25 may leave NULL (BZ
194// #19826) so dlpi_tls_data cannot be used.
195//
196// musl before 1.2.3 and FreeBSD as of 12.2 incorrectly set dlpi_tls_data to
197// the TLS initialization image
198// https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=254774
199__attribute__((unused)) static int g_use_dlpi_tls_data;
200
201#if SANITIZER_GLIBC && !SANITIZER_GO
202__attribute__((unused)) static size_t g_tls_size;
203void InitTlsSize() {
204 int major, minor, patch;
205 g_use_dlpi_tls_data =
206 GetLibcVersion(&major, &minor, &patch) && major == 2 && minor >= 25;
207
208#if defined(__aarch64__) || defined(__x86_64__) || defined(__powerpc64__)
209 void *get_tls_static_info = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
210 size_t tls_align;
211 ((void (*)(size_t *, size_t *))get_tls_static_info)(&g_tls_size, &tls_align);
212#endif
213}
214#else
215void InitTlsSize() { }
216#endif // SANITIZER_GLIBC && !SANITIZER_GO
217
218// On glibc x86_64, ThreadDescriptorSize() needs to be precise due to the usage
219// of g_tls_size. On other targets, ThreadDescriptorSize() is only used by lsan
220// to get the pointer to thread-specific data keys in the thread control block.
221#if (SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_SOLARIS) && \
222 !SANITIZER_ANDROID && !SANITIZER_GO
223// sizeof(struct pthread) from glibc.
224static atomic_uintptr_t thread_descriptor_size;
225
226static uptr ThreadDescriptorSizeFallback() {
227 uptr val = 0;
228#if defined(__x86_64__) || defined(__i386__) || defined(__arm__)
229 int major;
230 int minor;
231 int patch;
232 if (GetLibcVersion(&major, &minor, &patch) && major == 2) {
233 /* sizeof(struct pthread) values from various glibc versions. */
234 if (SANITIZER_X32)
235 val = 1728; // Assume only one particular version for x32.
236 // For ARM sizeof(struct pthread) changed in Glibc 2.23.
237 else if (SANITIZER_ARM)
238 val = minor <= 22 ? 1120 : 1216;
239 else if (minor <= 3)
240 val = FIRST_32_SECOND_64(1104, 1696);
241 else if (minor == 4)
242 val = FIRST_32_SECOND_64(1120, 1728);
243 else if (minor == 5)
244 val = FIRST_32_SECOND_64(1136, 1728);
245 else if (minor <= 9)
246 val = FIRST_32_SECOND_64(1136, 1712);
247 else if (minor == 10)
248 val = FIRST_32_SECOND_64(1168, 1776);
249 else if (minor == 11 || (minor == 12 && patch == 1))
250 val = FIRST_32_SECOND_64(1168, 2288);
251 else if (minor <= 14)
252 val = FIRST_32_SECOND_64(1168, 2304);
253 else if (minor < 32) // Unknown version
254 val = FIRST_32_SECOND_64(1216, 2304);
255 else // minor == 32
256 val = FIRST_32_SECOND_64(1344, 2496);
257 }
258#elif defined(__s390__) || defined(__sparc__)
259 // The size of a prefix of TCB including pthread::{specific_1stblock,specific}
260 // suffices. Just return offsetof(struct pthread, specific_used), which hasn't
261 // changed since 2007-05. Technically this applies to i386/x86_64 as well but
262 // we call _dl_get_tls_static_info and need the precise size of struct
263 // pthread.
264 return FIRST_32_SECOND_64(524, 1552);
265#elif defined(__mips__)
266 // TODO(sagarthakur): add more values as per different glibc versions.
267 val = FIRST_32_SECOND_64(1152, 1776);
268#elif SANITIZER_RISCV64
269 int major;
270 int minor;
271 int patch;
272 if (GetLibcVersion(&major, &minor, &patch) && major == 2) {
273 // TODO: consider adding an optional runtime check for an unknown (untested)
274 // glibc version
275 if (minor <= 28) // WARNING: the highest tested version is 2.29
276 val = 1772; // no guarantees for this one
277 else if (minor <= 31)
278 val = 1772; // tested against glibc 2.29, 2.31
279 else
280 val = 1936; // tested against glibc 2.32
281 }
282
283#elif defined(__aarch64__)
284 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22.
285 val = 1776;
286#elif defined(__powerpc64__)
287 val = 1776; // from glibc.ppc64le 2.20-8.fc21
288#endif
289 return val;
290}
291
292uptr ThreadDescriptorSize() {
293 uptr val = atomic_load_relaxed(&thread_descriptor_size);
294 if (val)
295 return val;
296 // _thread_db_sizeof_pthread is a GLIBC_PRIVATE symbol that is exported in
297 // glibc 2.34 and later.
298 if (unsigned *psizeof = static_cast<unsigned *>(
299 dlsym(RTLD_DEFAULT, "_thread_db_sizeof_pthread")))
300 val = *psizeof;
301 if (!val)
302 val = ThreadDescriptorSizeFallback();
303 atomic_store_relaxed(&thread_descriptor_size, val);
304 return val;
305}
306
307#if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64
308// TlsPreTcbSize includes size of struct pthread_descr and size of tcb
309// head structure. It lies before the static tls blocks.
310static uptr TlsPreTcbSize() {
311#if defined(__mips__)
312 const uptr kTcbHead = 16; // sizeof (tcbhead_t)
313#elif defined(__powerpc64__)
314 const uptr kTcbHead = 88; // sizeof (tcbhead_t)
315#elif SANITIZER_RISCV64
316 const uptr kTcbHead = 16; // sizeof (tcbhead_t)
317#endif
318 const uptr kTlsAlign = 16;
319 const uptr kTlsPreTcbSize =
320 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign);
321 return kTlsPreTcbSize;
322}
323#endif
324
325namespace {
326struct TlsBlock {
327 uptr begin, end, align;
328 size_t tls_modid;
329 bool operator<(const TlsBlock &rhs) const { return begin < rhs.begin; }
330};
331} // namespace
332
333#ifdef __s390__
334extern "C" uptr __tls_get_offset(void *arg);
335
336static uptr TlsGetOffset(uptr ti_module, uptr ti_offset) {
337 // The __tls_get_offset ABI requires %r12 to point to GOT and %r2 to be an
338 // offset of a struct tls_index inside GOT. We don't possess either of the
339 // two, so violate the letter of the "ELF Handling For Thread-Local
340 // Storage" document and assume that the implementation just dereferences
341 // %r2 + %r12.
342 uptr tls_index[2] = {ti_module, ti_offset};
343 register uptr r2 asm("2") = 0;
344 register void *r12 asm("12") = tls_index;
345 asm("basr %%r14, %[__tls_get_offset]"
346 : "+r"(r2)
347 : [__tls_get_offset] "r"(__tls_get_offset), "r"(r12)
348 : "memory", "cc", "0", "1", "3", "4", "5", "14");
349 return r2;
350}
351#else
352extern "C" void *__tls_get_addr(size_t *);
353#endif
354
355static size_t main_tls_modid;
356
357static int CollectStaticTlsBlocks(struct dl_phdr_info *info, size_t size,
358 void *data) {
359 size_t tls_modid;
360#if SANITIZER_SOLARIS
361 // dlpi_tls_modid is only available since Solaris 11.4 SRU 10. Use
362 // dlinfo(RTLD_DI_LINKMAP) instead which works on all of Solaris 11.3,
363 // 11.4, and Illumos. The tlsmodid of the executable was changed to 1 in
364 // 11.4 to match other implementations.
365 if (size >= offsetof(dl_phdr_info_test, dlpi_tls_modid))
366 main_tls_modid = 1;
367 else
368 main_tls_modid = 0;
369 g_use_dlpi_tls_data = 0;
370 Rt_map *map;
371 dlinfo(RTLD_SELF, RTLD_DI_LINKMAP, &map);
372 tls_modid = map->rt_tlsmodid;
373#else
374 main_tls_modid = 1;
375 tls_modid = info->dlpi_tls_modid;
376#endif
377
378 if (tls_modid < main_tls_modid)
379 return 0;
380 uptr begin;
381#if !SANITIZER_SOLARIS
382 begin = (uptr)info->dlpi_tls_data;
383#endif
384 if (!g_use_dlpi_tls_data) {
385 // Call __tls_get_addr as a fallback. This forces TLS allocation on glibc
386 // and FreeBSD.
387#ifdef __s390__
388 begin = (uptr)__builtin_thread_pointer() +
389 TlsGetOffset(tls_modid, 0);
390#else
391 size_t mod_and_off[2] = {tls_modid, 0};
392 begin = (uptr)__tls_get_addr(mod_and_off);
393#endif
394 }
395 for (unsigned i = 0; i != info->dlpi_phnum; ++i)
396 if (info->dlpi_phdr[i].p_type == PT_TLS) {
397 static_cast<InternalMmapVector<TlsBlock> *>(data)->push_back(
398 TlsBlock{begin, begin + info->dlpi_phdr[i].p_memsz,
399 info->dlpi_phdr[i].p_align, tls_modid});
400 break;
401 }
402 return 0;
403}
404
405__attribute__((unused)) static void GetStaticTlsBoundary(uptr *addr, uptr *size,
406 uptr *align) {
407 InternalMmapVector<TlsBlock> ranges;
408 dl_iterate_phdr(CollectStaticTlsBlocks, &ranges);
409 uptr len = ranges.size();
410 Sort(ranges.begin(), len);
411 // Find the range with tls_modid == main_tls_modid. For glibc, because
412 // libc.so uses PT_TLS, this module is guaranteed to exist and is one of
413 // the initially loaded modules.
414 uptr one = 0;
415 while (one != len && ranges[one].tls_modid != main_tls_modid) ++one;
416 if (one == len) {
417 // This may happen with musl if no module uses PT_TLS.
418 *addr = 0;
419 *size = 0;
420 *align = 1;
421 return;
422 }
423 // Find the maximum consecutive ranges. We consider two modules consecutive if
424 // the gap is smaller than the alignment of the latter range. The dynamic
425 // loader places static TLS blocks this way not to waste space.
426 uptr l = one;
427 *align = ranges[l].align;
428 while (l != 0 && ranges[l].begin < ranges[l - 1].end + ranges[l].align)
429 *align = Max(*align, ranges[--l].align);
430 uptr r = one + 1;
431 while (r != len && ranges[r].begin < ranges[r - 1].end + ranges[r].align)
432 *align = Max(*align, ranges[r++].align);
433 *addr = ranges[l].begin;
434 *size = ranges[r - 1].end - ranges[l].begin;
435}
436#endif // (x86_64 || i386 || mips || ...) && (SANITIZER_FREEBSD ||
437 // SANITIZER_LINUX) && !SANITIZER_ANDROID && !SANITIZER_GO
438
439#if SANITIZER_NETBSD
440static struct tls_tcb * ThreadSelfTlsTcb() {
441 struct tls_tcb *tcb = nullptr;
442#ifdef __HAVE___LWP_GETTCB_FAST
443 tcb = (struct tls_tcb *)__lwp_gettcb_fast();
444#elif defined(__HAVE___LWP_GETPRIVATE_FAST)
445 tcb = (struct tls_tcb *)__lwp_getprivate_fast();
446#endif
447 return tcb;
448}
449
450uptr ThreadSelf() {
451 return (uptr)ThreadSelfTlsTcb()->tcb_pthread;
452}
453
454int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) {
455 const Elf_Phdr *hdr = info->dlpi_phdr;
456 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum;
457
458 for (; hdr != last_hdr; ++hdr) {
459 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) {
460 *(uptr*)data = hdr->p_memsz;
461 break;
462 }
463 }
464 return 0;
465}
466#endif // SANITIZER_NETBSD
467
468#if SANITIZER_ANDROID
469// Bionic provides this API since S.
470extern "C" SANITIZER_WEAK_ATTRIBUTE void __libc_get_static_tls_bounds(void **,
471 void **);
472#endif
473
474#if !SANITIZER_GO
475static void GetTls(uptr *addr, uptr *size) {
476#if SANITIZER_ANDROID
477 if (&__libc_get_static_tls_bounds) {
478 void *start_addr;
479 void *end_addr;
480 __libc_get_static_tls_bounds(&start_addr, &end_addr);
481 *addr = reinterpret_cast<uptr>(start_addr);
482 *size =
483 reinterpret_cast<uptr>(end_addr) - reinterpret_cast<uptr>(start_addr);
484 } else {
485 *addr = 0;
486 *size = 0;
487 }
488#elif SANITIZER_GLIBC && defined(__x86_64__)
489 // For aarch64 and x86-64, use an O(1) approach which requires relatively
490 // precise ThreadDescriptorSize. g_tls_size was initialized in InitTlsSize.
491# if SANITIZER_X32
492 asm("mov %%fs:8,%0" : "=r"(*addr));
493# else
494 asm("mov %%fs:16,%0" : "=r"(*addr));
495# endif
496 *size = g_tls_size;
497 *addr -= *size;
498 *addr += ThreadDescriptorSize();
499#elif SANITIZER_GLIBC && defined(__aarch64__)
500 *addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) -
501 ThreadDescriptorSize();
502 *size = g_tls_size + ThreadDescriptorSize();
503#elif SANITIZER_GLIBC && defined(__powerpc64__)
504 // Workaround for glibc<2.25(?). 2.27 is known to not need this.
505 uptr tp;
506 asm("addi %0,13,-0x7000" : "=r"(tp));
507 const uptr pre_tcb_size = TlsPreTcbSize();
508 *addr = tp - pre_tcb_size;
509 *size = g_tls_size + pre_tcb_size;
510#elif SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_SOLARIS
511 uptr align;
512 GetStaticTlsBoundary(addr, size, &align);
513#if defined(__x86_64__) || defined(__i386__) || defined(__s390__) || \
514 defined(__sparc__)
515 if (SANITIZER_GLIBC) {
516#if defined(__x86_64__) || defined(__i386__)
517 align = Max<uptr>(align, 64);
518#else
519 align = Max<uptr>(align, 16);
520#endif
521 }
522 const uptr tp = RoundUpTo(*addr + *size, align);
523
524 // lsan requires the range to additionally cover the static TLS surplus
525 // (elf/dl-tls.c defines 1664). Otherwise there may be false positives for
526 // allocations only referenced by tls in dynamically loaded modules.
527 if (SANITIZER_GLIBC)
528 *size += 1644;
529 else if (SANITIZER_FREEBSD)
530 *size += 128; // RTLD_STATIC_TLS_EXTRA
531
532 // Extend the range to include the thread control block. On glibc, lsan needs
533 // the range to include pthread::{specific_1stblock,specific} so that
534 // allocations only referenced by pthread_setspecific can be scanned. This may
535 // underestimate by at most TLS_TCB_ALIGN-1 bytes but it should be fine
536 // because the number of bytes after pthread::specific is larger.
537 *addr = tp - RoundUpTo(*size, align);
538 *size = tp - *addr + ThreadDescriptorSize();
539#else
540 if (SANITIZER_GLIBC)
541 *size += 1664;
542 else if (SANITIZER_FREEBSD)
543 *size += 128; // RTLD_STATIC_TLS_EXTRA
544#if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64
545 const uptr pre_tcb_size = TlsPreTcbSize();
546 *addr -= pre_tcb_size;
547 *size += pre_tcb_size;
548#else
549 // arm and aarch64 reserve two words at TP, so this underestimates the range.
550 // However, this is sufficient for the purpose of finding the pointers to
551 // thread-specific data keys.
552 const uptr tcb_size = ThreadDescriptorSize();
553 *addr -= tcb_size;
554 *size += tcb_size;
555#endif
556#endif
557#elif SANITIZER_NETBSD
558 struct tls_tcb * const tcb = ThreadSelfTlsTcb();
559 *addr = 0;
560 *size = 0;
561 if (tcb != 0) {
562 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program).
563 // ld.elf_so hardcodes the index 1.
564 dl_iterate_phdr(GetSizeFromHdr, size);
565
566 if (*size != 0) {
567 // The block has been found and tcb_dtv[1] contains the base address
568 *addr = (uptr)tcb->tcb_dtv[1];
569 }
570 }
571#error "Unknown OS"
572#endif
573}
574#endif
575
576#if !SANITIZER_GO
577uptr GetTlsSize() {
578#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
579 SANITIZER_SOLARIS
580 uptr addr, size;
581 GetTls(&addr, &size);
582 return size;
583#else
584 return 0;
585#endif
586}
587#endif
588
589void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
590 uptr *tls_addr, uptr *tls_size) {
591#if SANITIZER_GO
592 // Stub implementation for Go.
593 *stk_addr = *stk_size = *tls_addr = *tls_size = 0;
594#else
595 GetTls(tls_addr, tls_size);
596
597 uptr stack_top, stack_bottom;
598 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
599 *stk_addr = stack_bottom;
600 *stk_size = stack_top - stack_bottom;
601
602 if (!main) {
603 // If stack and tls intersect, make them non-intersecting.
604 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
605 if (*stk_addr + *stk_size < *tls_addr + *tls_size)
606 *tls_size = *stk_addr + *stk_size - *tls_addr;
607 *stk_size = *tls_addr - *stk_addr;
608 }
609 }
610#endif
611}
612
613#if !SANITIZER_FREEBSD
614typedef ElfW(Phdr) Elf_Phdr;
615#elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2
616#define Elf_Phdr XElf32_Phdr
617#define dl_phdr_info xdl_phdr_info
618#define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b))
619#endif // !SANITIZER_FREEBSD
620
621struct DlIteratePhdrData {
622 InternalMmapVectorNoCtor<LoadedModule> *modules;
623 bool first;
624};
625
626static int AddModuleSegments(const char *module_name, dl_phdr_info *info,
627 InternalMmapVectorNoCtor<LoadedModule> *modules) {
628 if (module_name[0] == '\0')
629 return 0;
630 LoadedModule cur_module;
631 cur_module.set(module_name, info->dlpi_addr);
632 for (int i = 0; i < (int)info->dlpi_phnum; i++) {
633 const Elf_Phdr *phdr = &info->dlpi_phdr[i];
634 if (phdr->p_type == PT_LOAD) {
635 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
636 uptr cur_end = cur_beg + phdr->p_memsz;
637 bool executable = phdr->p_flags & PF_X;
638 bool writable = phdr->p_flags & PF_W;
639 cur_module.addAddressRange(cur_beg, cur_end, executable,
640 writable);
641 } else if (phdr->p_type == PT_NOTE) {
642# ifdef NT_GNU_BUILD_ID
643 uptr off = 0;
644 while (off + sizeof(ElfW(Nhdr)) < phdr->p_memsz) {
645 auto *nhdr = reinterpret_cast<const ElfW(Nhdr) *>(info->dlpi_addr +
646 phdr->p_vaddr + off);
647 constexpr auto kGnuNamesz = 4; // "GNU" with NUL-byte.
648 static_assert(kGnuNamesz % 4 == 0, "kGnuNameSize is aligned to 4.");
649 if (nhdr->n_type == NT_GNU_BUILD_ID && nhdr->n_namesz == kGnuNamesz) {
650 if (off + sizeof(ElfW(Nhdr)) + nhdr->n_namesz + nhdr->n_descsz >
651 phdr->p_memsz) {
652 // Something is very wrong, bail out instead of reading potentially
653 // arbitrary memory.
654 break;
655 }
656 const char *name =
657 reinterpret_cast<const char *>(nhdr) + sizeof(*nhdr);
658 if (internal_memcmp(name, "GNU", 3) == 0) {
659 const char *value = reinterpret_cast<const char *>(nhdr) +
660 sizeof(*nhdr) + kGnuNamesz;
661 cur_module.setUuid(value, nhdr->n_descsz);
662 break;
663 }
664 }
665 off += sizeof(*nhdr) + RoundUpTo(nhdr->n_namesz, 4) +
666 RoundUpTo(nhdr->n_descsz, 4);
667 }
668# endif
669 }
670 }
671 modules->push_back(cur_module);
672 return 0;
673}
674
675static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
676 DlIteratePhdrData *data = (DlIteratePhdrData *)arg;
677 if (data->first) {
678 InternalMmapVector<char> module_name(kMaxPathLength);
679 data->first = false;
680 // First module is the binary itself.
681 ReadBinaryNameCached(module_name.data(), module_name.size());
682 return AddModuleSegments(module_name.data(), info, data->modules);
683 }
684
685 if (info->dlpi_name) {
686 InternalScopedString module_name;
687 module_name.append("%s", info->dlpi_name);
688 return AddModuleSegments(module_name.data(), info, data->modules);
689 }
690
691 return 0;
692}
693
694#if SANITIZER_ANDROID && __ANDROID_API__ < 21
695extern "C" __attribute__((weak)) int dl_iterate_phdr(
696 int (*)(struct dl_phdr_info *, size_t, void *), void *);
697#endif
698
699static bool requiresProcmaps() {
700#if SANITIZER_ANDROID && __ANDROID_API__ <= 22
701 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken.
702 // The runtime check allows the same library to work with
703 // both K and L (and future) Android releases.
704 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1;
705#else
706 return false;
707#endif
708}
709
710static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) {
711 MemoryMappingLayout memory_mapping(/*cache_enabled*/true);
712 memory_mapping.DumpListOfModules(modules);
713}
714
715void ListOfModules::init() {
716 clearOrInit();
717 if (requiresProcmaps()) {
718 procmapsInit(&modules_);
719 } else {
720 DlIteratePhdrData data = {&modules_, true};
721 dl_iterate_phdr(dl_iterate_phdr_cb, &data);
722 }
723}
724
725// When a custom loader is used, dl_iterate_phdr may not contain the full
726// list of modules. Allow callers to fall back to using procmaps.
727void ListOfModules::fallbackInit() {
728 if (!requiresProcmaps()) {
729 clearOrInit();
730 procmapsInit(&modules_);
731 } else {
732 clear();
733 }
734}
735
736// getrusage does not give us the current RSS, only the max RSS.
737// Still, this is better than nothing if /proc/self/statm is not available
738// for some reason, e.g. due to a sandbox.
739static uptr GetRSSFromGetrusage() {
740 struct rusage usage;
741 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox.
742 return 0;
743 return usage.ru_maxrss << 10; // ru_maxrss is in Kb.
744}
745
746uptr GetRSS() {
747 if (!common_flags()->can_use_proc_maps_statm)
748 return GetRSSFromGetrusage();
749 fd_t fd = OpenFile("/proc/self/statm", RdOnly);
750 if (fd == kInvalidFd)
751 return GetRSSFromGetrusage();
752 char buf[64];
753 uptr len = internal_read(fd, buf, sizeof(buf) - 1);
754 internal_close(fd);
755 if ((sptr)len <= 0)
756 return 0;
757 buf[len] = 0;
758 // The format of the file is:
759 // 1084 89 69 11 0 79 0
760 // We need the second number which is RSS in pages.
761 char *pos = buf;
762 // Skip the first number.
763 while (*pos >= '0' && *pos <= '9')
764 pos++;
765 // Skip whitespaces.
766 while (!(*pos >= '0' && *pos <= '9') && *pos != 0)
767 pos++;
768 // Read the number.
769 uptr rss = 0;
770 while (*pos >= '0' && *pos <= '9')
771 rss = rss * 10 + *pos++ - '0';
772 return rss * GetPageSizeCached();
773}
774
775// sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as
776// they allocate memory.
777u32 GetNumberOfCPUs() {
778#if SANITIZER_FREEBSD || SANITIZER_NETBSD
779 u32 ncpu;
780 int req[2];
781 uptr len = sizeof(ncpu);
782 req[0] = CTL_HW;
783 req[1] = HW_NCPU;
784 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0);
785 return ncpu;
786#elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__)
787 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't
788 // exist in sched.h. That is the case for toolchains generated with older
789 // NDKs.
790 // This code doesn't work on AArch64 because internal_getdents makes use of
791 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64.
792 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY);
793 if (internal_iserror(fd))
794 return 0;
795 InternalMmapVector<u8> buffer(4096);
796 uptr bytes_read = buffer.size();
797 uptr n_cpus = 0;
798 u8 *d_type;
799 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read];
800 while (true) {
801 if ((u8 *)entry >= &buffer[bytes_read]) {
802 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(),
803 buffer.size());
804 if (internal_iserror(bytes_read) || !bytes_read)
805 break;
806 entry = (struct linux_dirent *)buffer.data();
807 }
808 d_type = (u8 *)entry + entry->d_reclen - 1;
809 if (d_type >= &buffer[bytes_read] ||
810 (u8 *)&entry->d_name[3] >= &buffer[bytes_read])
811 break;
812 if (entry->d_ino != 0 && *d_type == DT_DIR) {
813 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' &&
814 entry->d_name[2] == 'u' &&
815 entry->d_name[3] >= '0' && entry->d_name[3] <= '9')
816 n_cpus++;
817 }
818 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen);
819 }
820 internal_close(fd);
821 return n_cpus;
822#elif SANITIZER_SOLARIS
823 return sysconf(_SC_NPROCESSORS_ONLN);
824#else
825 cpu_set_t CPUs;
826 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0);
827 return CPU_COUNT(&CPUs);
828#endif
829}
830
831#if SANITIZER_LINUX
832
833#if SANITIZER_ANDROID
834static atomic_uint8_t android_log_initialized;
835
836void AndroidLogInit() {
837 openlog(GetProcessName(), 0, LOG_USER);
838 atomic_store(&android_log_initialized, 1, memory_order_release);
839}
840
841static bool ShouldLogAfterPrintf() {
842 return atomic_load(&android_log_initialized, memory_order_acquire);
843}
844
845extern "C" SANITIZER_WEAK_ATTRIBUTE
846int async_safe_write_log(int pri, const char* tag, const char* msg);
847extern "C" SANITIZER_WEAK_ATTRIBUTE
848int __android_log_write(int prio, const char* tag, const char* msg);
849
850// ANDROID_LOG_INFO is 4, but can't be resolved at runtime.
851#define SANITIZER_ANDROID_LOG_INFO 4
852
853// async_safe_write_log is a new public version of __libc_write_log that is
854// used behind syslog. It is preferable to syslog as it will not do any dynamic
855// memory allocation or formatting.
856// If the function is not available, syslog is preferred for L+ (it was broken
857// pre-L) as __android_log_write triggers a racey behavior with the strncpy
858// interceptor. Fallback to __android_log_write pre-L.
859void WriteOneLineToSyslog(const char *s) {
860 if (&async_safe_write_log) {
861 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s);
862 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) {
863 syslog(LOG_INFO, "%s", s);
864 } else {
865 CHECK(&__android_log_write);
866 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s);
867 }
868}
869
870extern "C" SANITIZER_WEAK_ATTRIBUTE
871void android_set_abort_message(const char *);
872
873void SetAbortMessage(const char *str) {
874 if (&android_set_abort_message)
875 android_set_abort_message(str);
876}
877#else
878void AndroidLogInit() {}
879
880static bool ShouldLogAfterPrintf() { return true; }
881
882void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); }
883
884void SetAbortMessage(const char *str) {}
885#endif // SANITIZER_ANDROID
886
887void LogMessageOnPrintf(const char *str) {
888 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf())
889 WriteToSyslog(str);
890}
891
892#endif // SANITIZER_LINUX
893
894#if SANITIZER_GLIBC && !SANITIZER_GO
895// glibc crashes when using clock_gettime from a preinit_array function as the
896// vDSO function pointers haven't been initialized yet. __progname is
897// initialized after the vDSO function pointers, so if it exists, is not null
898// and is not empty, we can use clock_gettime.
899extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname;
900inline bool CanUseVDSO() { return &__progname && __progname && *__progname; }
901
902// MonotonicNanoTime is a timing function that can leverage the vDSO by calling
903// clock_gettime. real_clock_gettime only exists if clock_gettime is
904// intercepted, so define it weakly and use it if available.
905extern "C" SANITIZER_WEAK_ATTRIBUTE
906int real_clock_gettime(u32 clk_id, void *tp);
907u64 MonotonicNanoTime() {
908 timespec ts;
909 if (CanUseVDSO()) {
910 if (&real_clock_gettime)
911 real_clock_gettime(CLOCK_MONOTONIC, &ts);
912 else
913 clock_gettime(CLOCK_MONOTONIC, &ts);
914 } else {
915 internal_clock_gettime(CLOCK_MONOTONIC, &ts);
916 }
917 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
918}
919#else
920// Non-glibc & Go always use the regular function.
921u64 MonotonicNanoTime() {
922 timespec ts;
923 clock_gettime(CLOCK_MONOTONIC, &ts);
924 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
925}
926#endif // SANITIZER_GLIBC && !SANITIZER_GO
927
928void ReExec() {
929 const char *pathname = "/proc/self/exe";
930
931#if SANITIZER_NETBSD
932 static const int name[] = {
933 CTL_KERN,
934 KERN_PROC_ARGS,
935 -1,
936 KERN_PROC_PATHNAME,
937 };
938 char path[400];
939 uptr len;
940
941 len = sizeof(path);
942 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1)
943 pathname = path;
944#elif SANITIZER_SOLARIS
945 pathname = getexecname();
946 CHECK_NE(pathname, NULL);
947#elif SANITIZER_USE_GETAUXVAL
948 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that
949 // rely on that will fail to load shared libraries. Query AT_EXECFN instead.
950 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN));
951#endif
952
953 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron());
954 int rverrno;
955 CHECK_EQ(internal_iserror(rv, &rverrno), true);
956 Printf("execve failed, errno %d\n", rverrno);
957 Die();
958}
959
960void UnmapFromTo(uptr from, uptr to) {
961 if (to == from)
962 return;
963 CHECK(to >= from);
964 uptr res = internal_munmap(reinterpret_cast<void *>(from), to - from);
965 if (UNLIKELY(internal_iserror(res))) {
966 Report("ERROR: %s failed to unmap 0x%zx (%zd) bytes at address %p\n",
967 SanitizerToolName, to - from, to - from, (void *)from);
968 CHECK("unable to unmap" && 0);
969 }
970}
971
972uptr MapDynamicShadow(uptr shadow_size_bytes, uptr shadow_scale,
973 uptr min_shadow_base_alignment,
974 UNUSED uptr &high_mem_end) {
975 const uptr granularity = GetMmapGranularity();
976 const uptr alignment =
977 Max<uptr>(granularity << shadow_scale, 1ULL << min_shadow_base_alignment);
978 const uptr left_padding =
979 Max<uptr>(granularity, 1ULL << min_shadow_base_alignment);
980
981 const uptr shadow_size = RoundUpTo(shadow_size_bytes, granularity);
982 const uptr map_size = shadow_size + left_padding + alignment;
983
984 const uptr map_start = (uptr)MmapNoAccess(map_size);
985 CHECK_NE(map_start, ~(uptr)0);
986
987 const uptr shadow_start = RoundUpTo(map_start + left_padding, alignment);
988
989 UnmapFromTo(map_start, shadow_start - left_padding);
990 UnmapFromTo(shadow_start + shadow_size, map_start + map_size);
991
992 return shadow_start;
993}
994
995static uptr MmapSharedNoReserve(uptr addr, uptr size) {
996 return internal_mmap(
997 reinterpret_cast<void *>(addr), size, PROT_READ | PROT_WRITE,
998 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
999}
1000
1001static uptr MremapCreateAlias(uptr base_addr, uptr alias_addr,
1002 uptr alias_size) {
1003#if SANITIZER_LINUX
1004 return internal_mremap(reinterpret_cast<void *>(base_addr), 0, alias_size,
1005 MREMAP_MAYMOVE | MREMAP_FIXED,
1006 reinterpret_cast<void *>(alias_addr));
1007#else
1008 CHECK(false && "mremap is not supported outside of Linux");
1009 return 0;
1010#endif
1011}
1012
1013static void CreateAliases(uptr start_addr, uptr alias_size, uptr num_aliases) {
1014 uptr total_size = alias_size * num_aliases;
1015 uptr mapped = MmapSharedNoReserve(start_addr, total_size);
1016 CHECK_EQ(mapped, start_addr);
1017
1018 for (uptr i = 1; i < num_aliases; ++i) {
1019 uptr alias_addr = start_addr + i * alias_size;
1020 CHECK_EQ(MremapCreateAlias(start_addr, alias_addr, alias_size), alias_addr);
1021 }
1022}
1023
1024uptr MapDynamicShadowAndAliases(uptr shadow_size, uptr alias_size,
1025 uptr num_aliases, uptr ring_buffer_size) {
1026 CHECK_EQ(alias_size & (alias_size - 1), 0);
1027 CHECK_EQ(num_aliases & (num_aliases - 1), 0);
1028 CHECK_EQ(ring_buffer_size & (ring_buffer_size - 1), 0);
1029
1030 const uptr granularity = GetMmapGranularity();
1031 shadow_size = RoundUpTo(shadow_size, granularity);
1032 CHECK_EQ(shadow_size & (shadow_size - 1), 0);
1033
1034 const uptr alias_region_size = alias_size * num_aliases;
1035 const uptr alignment =
1036 2 * Max(Max(shadow_size, alias_region_size), ring_buffer_size);
1037 const uptr left_padding = ring_buffer_size;
1038
1039 const uptr right_size = alignment;
1040 const uptr map_size = left_padding + 2 * alignment;
1041
1042 const uptr map_start = reinterpret_cast<uptr>(MmapNoAccess(map_size));
1043 CHECK_NE(map_start, static_cast<uptr>(-1));
1044 const uptr right_start = RoundUpTo(map_start + left_padding, alignment);
1045
1046 UnmapFromTo(map_start, right_start - left_padding);
1047 UnmapFromTo(right_start + right_size, map_start + map_size);
1048
1049 CreateAliases(right_start + right_size / 2, alias_size, num_aliases);
1050
1051 return right_start;
1052}
1053
1054void InitializePlatformCommonFlags(CommonFlags *cf) {
1055#if SANITIZER_ANDROID
1056 if (&__libc_get_static_tls_bounds == nullptr)
1057 cf->detect_leaks = false;
1058#endif
1059}
1060
1061} // namespace __sanitizer
1062
1063#endif
1064

source code of compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp