1 //===-- sanitizer_linux_libcdep.cpp ---------------------------------------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file is shared between AddressSanitizer and ThreadSanitizer
10 // run-time libraries and implements linux-specific functions from
12 //===----------------------------------------------------------------------===//
14 #include "sanitizer_platform.h"
16 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
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"
33 #define _RTLD_SOURCE // for __lwp_gettcb_fast() / __lwp_getprivate_fast()
36 #include <dlfcn.h> // for dlsym()
41 #include <sys/resource.h>
45 #define ElfW(type) Elf_##type
49 #include <pthread_np.h>
51 #include <osreldate.h>
53 #include <sys/sysctl.h>
54 #define pthread_getattr_np pthread_attr_get_np
55 // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
56 // that, it was never implemented. So just define it to zero.
58 #define MAP_NORESERVE 0
59 extern const Elf_Auxinfo *__elf_aux_vector;
63 #include <sys/sysctl.h>
75 #include <android/api-level.h>
76 #if !defined(CPU_COUNT) && !defined(__aarch64__)
79 struct __sanitizer::linux_dirent {
82 unsigned short d_reclen;
88 #if !SANITIZER_ANDROID
93 namespace __sanitizer {
95 SANITIZER_WEAK_ATTRIBUTE int
96 real_sigaction(int signum, const void *act, void *oldact);
98 int internal_sigaction(int signum, const void *act, void *oldact) {
101 return real_sigaction(signum, act, oldact);
103 return sigaction(signum, (const struct sigaction *)act,
104 (struct sigaction *)oldact);
107 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
108 uptr *stack_bottom) {
111 if (at_initialization) {
112 // This is the main thread. Libpthread may not be initialized yet.
114 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
116 // Find the mapping that contains a stack variable.
117 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
118 if (proc_maps.Error()) {
119 *stack_top = *stack_bottom = 0;
122 MemoryMappedSegment segment;
124 while (proc_maps.Next(&segment)) {
125 if ((uptr)&rl < segment.end) break;
126 prev_end = segment.end;
128 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end);
130 // Get stacksize from rlimit, but clip it so that it does not overlap
131 // with other mappings.
132 uptr stacksize = rl.rlim_cur;
133 if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end;
134 // When running with unlimited stack size, we still want to set some limit.
135 // The unlimited stack size is caused by 'ulimit -s unlimited'.
136 // Also, for some reason, GNU make spawns subprocesses with unlimited stack.
137 if (stacksize > kMaxThreadStackSize)
138 stacksize = kMaxThreadStackSize;
139 *stack_top = segment.end;
140 *stack_bottom = segment.end - stacksize;
144 void *stackaddr = nullptr;
145 #if SANITIZER_SOLARIS
147 CHECK_EQ(thr_stksegment(&ss), 0);
148 stacksize = ss.ss_size;
149 stackaddr = (char *)ss.ss_sp - stacksize;
150 #else // !SANITIZER_SOLARIS
152 pthread_attr_init(&attr);
153 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
154 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize);
155 pthread_attr_destroy(&attr);
156 #endif // SANITIZER_SOLARIS
158 *stack_top = (uptr)stackaddr + stacksize;
159 *stack_bottom = (uptr)stackaddr;
163 bool SetEnv(const char *name, const char *value) {
164 void *f = dlsym(RTLD_NEXT, "setenv");
167 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite);
169 CHECK_EQ(sizeof(setenv_f), sizeof(f));
170 internal_memcpy(&setenv_f, &f, sizeof(f));
171 return setenv_f(name, value, 1) == 0;
175 __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor,
177 #ifdef _CS_GNU_LIBC_VERSION
179 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
180 if (len >= sizeof(buf))
183 static const char kGLibC[] = "glibc ";
184 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0)
186 const char *p = buf + sizeof(kGLibC) - 1;
187 *major = internal_simple_strtoll(p, &p, 10);
188 *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0;
189 *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0;
196 // True if we can use dlpi_tls_data. glibc before 2.25 may leave NULL (BZ
197 // #19826) so dlpi_tls_data cannot be used.
199 // musl before 1.2.3 and FreeBSD as of 12.2 incorrectly set dlpi_tls_data to
200 // the TLS initialization image
201 // https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=254774
202 __attribute__((unused)) static int g_use_dlpi_tls_data;
204 #if SANITIZER_GLIBC && !SANITIZER_GO
205 __attribute__((unused)) static size_t g_tls_size;
207 int major, minor, patch;
208 g_use_dlpi_tls_data =
209 GetLibcVersion(&major, &minor, &patch) && major == 2 && minor >= 25;
211 #if defined(__aarch64__) || defined(__x86_64__) || defined(__powerpc64__) || \
212 defined(__loongarch__)
213 void *get_tls_static_info = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
215 ((void (*)(size_t *, size_t *))get_tls_static_info)(&g_tls_size, &tls_align);
219 void InitTlsSize() { }
220 #endif // SANITIZER_GLIBC && !SANITIZER_GO
222 // On glibc x86_64, ThreadDescriptorSize() needs to be precise due to the usage
223 // of g_tls_size. On other targets, ThreadDescriptorSize() is only used by lsan
224 // to get the pointer to thread-specific data keys in the thread control block.
225 #if (SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_SOLARIS) && \
226 !SANITIZER_ANDROID && !SANITIZER_GO
227 // sizeof(struct pthread) from glibc.
228 static atomic_uintptr_t thread_descriptor_size;
230 static uptr ThreadDescriptorSizeFallback() {
232 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__)
236 if (GetLibcVersion(&major, &minor, &patch) && major == 2) {
237 /* sizeof(struct pthread) values from various glibc versions. */
239 val = 1728; // Assume only one particular version for x32.
240 // For ARM sizeof(struct pthread) changed in Glibc 2.23.
241 else if (SANITIZER_ARM)
242 val = minor <= 22 ? 1120 : 1216;
244 val = FIRST_32_SECOND_64(1104, 1696);
246 val = FIRST_32_SECOND_64(1120, 1728);
248 val = FIRST_32_SECOND_64(1136, 1728);
250 val = FIRST_32_SECOND_64(1136, 1712);
251 else if (minor == 10)
252 val = FIRST_32_SECOND_64(1168, 1776);
253 else if (minor == 11 || (minor == 12 && patch == 1))
254 val = FIRST_32_SECOND_64(1168, 2288);
255 else if (minor <= 14)
256 val = FIRST_32_SECOND_64(1168, 2304);
257 else if (minor < 32) // Unknown version
258 val = FIRST_32_SECOND_64(1216, 2304);
260 val = FIRST_32_SECOND_64(1344, 2496);
262 #elif defined(__s390__) || defined(__sparc__)
263 // The size of a prefix of TCB including pthread::{specific_1stblock,specific}
264 // suffices. Just return offsetof(struct pthread, specific_used), which hasn't
265 // changed since 2007-05. Technically this applies to i386/x86_64 as well but
266 // we call _dl_get_tls_static_info and need the precise size of struct
268 return FIRST_32_SECOND_64(524, 1552);
269 #elif defined(__mips__)
270 // TODO(sagarthakur): add more values as per different glibc versions.
271 val = FIRST_32_SECOND_64(1152, 1776);
272 #elif SANITIZER_LOONGARCH64
273 val = 1856; // from glibc 2.36
274 #elif SANITIZER_RISCV64
278 if (GetLibcVersion(&major, &minor, &patch) && major == 2) {
279 // TODO: consider adding an optional runtime check for an unknown (untested)
281 if (minor <= 28) // WARNING: the highest tested version is 2.29
282 val = 1772; // no guarantees for this one
283 else if (minor <= 31)
284 val = 1772; // tested against glibc 2.29, 2.31
286 val = 1936; // tested against glibc 2.32
289 #elif defined(__aarch64__)
290 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22.
292 #elif defined(__powerpc64__)
293 val = 1776; // from glibc.ppc64le 2.20-8.fc21
298 uptr ThreadDescriptorSize() {
299 uptr val = atomic_load_relaxed(&thread_descriptor_size);
302 // _thread_db_sizeof_pthread is a GLIBC_PRIVATE symbol that is exported in
303 // glibc 2.34 and later.
304 if (unsigned *psizeof = static_cast<unsigned *>(
305 dlsym(RTLD_DEFAULT, "_thread_db_sizeof_pthread")))
308 val = ThreadDescriptorSizeFallback();
309 atomic_store_relaxed(&thread_descriptor_size, val);
313 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 || \
314 SANITIZER_LOONGARCH64
315 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb
316 // head structure. It lies before the static tls blocks.
317 static uptr TlsPreTcbSize() {
318 #if defined(__mips__)
319 const uptr kTcbHead = 16; // sizeof (tcbhead_t)
320 #elif defined(__powerpc64__)
321 const uptr kTcbHead = 88; // sizeof (tcbhead_t)
322 #elif SANITIZER_RISCV64
323 const uptr kTcbHead = 16; // sizeof (tcbhead_t)
324 #elif SANITIZER_LOONGARCH64
325 const uptr kTcbHead = 16; // sizeof (tcbhead_t)
327 const uptr kTlsAlign = 16;
328 const uptr kTlsPreTcbSize =
329 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign);
330 return kTlsPreTcbSize;
336 uptr begin, end, align;
338 bool operator<(const TlsBlock &rhs) const { return begin < rhs.begin; }
343 extern "C" uptr __tls_get_offset(void *arg);
345 static uptr TlsGetOffset(uptr ti_module, uptr ti_offset) {
346 // The __tls_get_offset ABI requires %r12 to point to GOT and %r2 to be an
347 // offset of a struct tls_index inside GOT. We don't possess either of the
348 // two, so violate the letter of the "ELF Handling For Thread-Local
349 // Storage" document and assume that the implementation just dereferences
351 uptr tls_index[2] = {ti_module, ti_offset};
352 register uptr r2 asm("2") = 0;
353 register void *r12 asm("12") = tls_index;
354 asm("basr %%r14, %[__tls_get_offset]"
356 : [__tls_get_offset] "r"(__tls_get_offset), "r"(r12)
357 : "memory", "cc", "0", "1", "3", "4", "5", "14");
361 extern "C" void *__tls_get_addr(size_t *);
364 static size_t main_tls_modid;
366 static int CollectStaticTlsBlocks(struct dl_phdr_info *info, size_t size,
369 #if SANITIZER_SOLARIS
370 // dlpi_tls_modid is only available since Solaris 11.4 SRU 10. Use
371 // dlinfo(RTLD_DI_LINKMAP) instead which works on all of Solaris 11.3,
372 // 11.4, and Illumos. The tlsmodid of the executable was changed to 1 in
373 // 11.4 to match other implementations.
374 if (size >= offsetof(dl_phdr_info_test, dlpi_tls_modid))
378 g_use_dlpi_tls_data = 0;
380 dlinfo(RTLD_SELF, RTLD_DI_LINKMAP, &map);
381 tls_modid = map->rt_tlsmodid;
384 tls_modid = info->dlpi_tls_modid;
387 if (tls_modid < main_tls_modid)
390 #if !SANITIZER_SOLARIS
391 begin = (uptr)info->dlpi_tls_data;
393 if (!g_use_dlpi_tls_data) {
394 // Call __tls_get_addr as a fallback. This forces TLS allocation on glibc
397 begin = (uptr)__builtin_thread_pointer() +
398 TlsGetOffset(tls_modid, 0);
400 size_t mod_and_off[2] = {tls_modid, 0};
401 begin = (uptr)__tls_get_addr(mod_and_off);
404 for (unsigned i = 0; i != info->dlpi_phnum; ++i)
405 if (info->dlpi_phdr[i].p_type == PT_TLS) {
406 static_cast<InternalMmapVector<TlsBlock> *>(data)->push_back(
407 TlsBlock{begin, begin + info->dlpi_phdr[i].p_memsz,
408 info->dlpi_phdr[i].p_align, tls_modid});
414 __attribute__((unused)) static void GetStaticTlsBoundary(uptr *addr, uptr *size,
416 InternalMmapVector<TlsBlock> ranges;
417 dl_iterate_phdr(CollectStaticTlsBlocks, &ranges);
418 uptr len = ranges.size();
419 Sort(ranges.begin(), len);
420 // Find the range with tls_modid == main_tls_modid. For glibc, because
421 // libc.so uses PT_TLS, this module is guaranteed to exist and is one of
422 // the initially loaded modules.
424 while (one != len && ranges[one].tls_modid != main_tls_modid) ++one;
426 // This may happen with musl if no module uses PT_TLS.
432 // Find the maximum consecutive ranges. We consider two modules consecutive if
433 // the gap is smaller than the alignment of the latter range. The dynamic
434 // loader places static TLS blocks this way not to waste space.
436 *align = ranges[l].align;
437 while (l != 0 && ranges[l].begin < ranges[l - 1].end + ranges[l].align)
438 *align = Max(*align, ranges[--l].align);
440 while (r != len && ranges[r].begin < ranges[r - 1].end + ranges[r].align)
441 *align = Max(*align, ranges[r++].align);
442 *addr = ranges[l].begin;
443 *size = ranges[r - 1].end - ranges[l].begin;
445 #endif // (x86_64 || i386 || mips || ...) && (SANITIZER_FREEBSD ||
446 // SANITIZER_LINUX) && !SANITIZER_ANDROID && !SANITIZER_GO
449 static struct tls_tcb * ThreadSelfTlsTcb() {
450 struct tls_tcb *tcb = nullptr;
451 #ifdef __HAVE___LWP_GETTCB_FAST
452 tcb = (struct tls_tcb *)__lwp_gettcb_fast();
453 #elif defined(__HAVE___LWP_GETPRIVATE_FAST)
454 tcb = (struct tls_tcb *)__lwp_getprivate_fast();
460 return (uptr)ThreadSelfTlsTcb()->tcb_pthread;
463 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) {
464 const Elf_Phdr *hdr = info->dlpi_phdr;
465 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum;
467 for (; hdr != last_hdr; ++hdr) {
468 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) {
469 *(uptr*)data = hdr->p_memsz;
475 #endif // SANITIZER_NETBSD
477 #if SANITIZER_ANDROID
478 // Bionic provides this API since S.
479 extern "C" SANITIZER_WEAK_ATTRIBUTE void __libc_get_static_tls_bounds(void **,
484 static void GetTls(uptr *addr, uptr *size) {
485 #if SANITIZER_ANDROID
486 if (&__libc_get_static_tls_bounds) {
489 __libc_get_static_tls_bounds(&start_addr, &end_addr);
490 *addr = reinterpret_cast<uptr>(start_addr);
492 reinterpret_cast<uptr>(end_addr) - reinterpret_cast<uptr>(start_addr);
497 #elif SANITIZER_GLIBC && defined(__x86_64__)
498 // For aarch64 and x86-64, use an O(1) approach which requires relatively
499 // precise ThreadDescriptorSize. g_tls_size was initialized in InitTlsSize.
501 asm("mov %%fs:8,%0" : "=r"(*addr));
503 asm("mov %%fs:16,%0" : "=r"(*addr));
507 *addr += ThreadDescriptorSize();
508 #elif SANITIZER_GLIBC && defined(__aarch64__)
509 *addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) -
510 ThreadDescriptorSize();
511 *size = g_tls_size + ThreadDescriptorSize();
512 #elif SANITIZER_GLIBC && defined(__loongarch__)
514 *addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) -
515 ThreadDescriptorSize();
517 asm("or %0,$tp,$zero" : "=r"(*addr));
518 *addr -= ThreadDescriptorSize();
520 *size = g_tls_size + ThreadDescriptorSize();
521 #elif SANITIZER_GLIBC && defined(__powerpc64__)
522 // Workaround for glibc<2.25(?). 2.27 is known to not need this.
524 asm("addi %0,13,-0x7000" : "=r"(tp));
525 const uptr pre_tcb_size = TlsPreTcbSize();
526 *addr = tp - pre_tcb_size;
527 *size = g_tls_size + pre_tcb_size;
528 #elif SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_SOLARIS
530 GetStaticTlsBoundary(addr, size, &align);
531 #if defined(__x86_64__) || defined(__i386__) || defined(__s390__) || \
533 if (SANITIZER_GLIBC) {
534 #if defined(__x86_64__) || defined(__i386__)
535 align = Max<uptr>(align, 64);
537 align = Max<uptr>(align, 16);
540 const uptr tp = RoundUpTo(*addr + *size, align);
542 // lsan requires the range to additionally cover the static TLS surplus
543 // (elf/dl-tls.c defines 1664). Otherwise there may be false positives for
544 // allocations only referenced by tls in dynamically loaded modules.
547 else if (SANITIZER_FREEBSD)
548 *size += 128; // RTLD_STATIC_TLS_EXTRA
550 // Extend the range to include the thread control block. On glibc, lsan needs
551 // the range to include pthread::{specific_1stblock,specific} so that
552 // allocations only referenced by pthread_setspecific can be scanned. This may
553 // underestimate by at most TLS_TCB_ALIGN-1 bytes but it should be fine
554 // because the number of bytes after pthread::specific is larger.
555 *addr = tp - RoundUpTo(*size, align);
556 *size = tp - *addr + ThreadDescriptorSize();
560 else if (SANITIZER_FREEBSD)
561 *size += 128; // RTLD_STATIC_TLS_EXTRA
562 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64
563 const uptr pre_tcb_size = TlsPreTcbSize();
564 *addr -= pre_tcb_size;
565 *size += pre_tcb_size;
567 // arm and aarch64 reserve two words at TP, so this underestimates the range.
568 // However, this is sufficient for the purpose of finding the pointers to
569 // thread-specific data keys.
570 const uptr tcb_size = ThreadDescriptorSize();
575 #elif SANITIZER_NETBSD
576 struct tls_tcb * const tcb = ThreadSelfTlsTcb();
580 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program).
581 // ld.elf_so hardcodes the index 1.
582 dl_iterate_phdr(GetSizeFromHdr, size);
585 // The block has been found and tcb_dtv[1] contains the base address
586 *addr = (uptr)tcb->tcb_dtv[1];
597 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
600 GetTls(&addr, &size);
608 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
609 uptr *tls_addr, uptr *tls_size) {
611 // Stub implementation for Go.
612 *stk_addr = *stk_size = *tls_addr = *tls_size = 0;
614 GetTls(tls_addr, tls_size);
616 uptr stack_top, stack_bottom;
617 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
618 *stk_addr = stack_bottom;
619 *stk_size = stack_top - stack_bottom;
622 // If stack and tls intersect, make them non-intersecting.
623 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
624 if (*stk_addr + *stk_size < *tls_addr + *tls_size)
625 *tls_size = *stk_addr + *stk_size - *tls_addr;
626 *stk_size = *tls_addr - *stk_addr;
632 #if !SANITIZER_FREEBSD
633 typedef ElfW(Phdr) Elf_Phdr;
634 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2
635 #define Elf_Phdr XElf32_Phdr
636 #define dl_phdr_info xdl_phdr_info
637 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b))
638 #endif // !SANITIZER_FREEBSD
640 struct DlIteratePhdrData {
641 InternalMmapVectorNoCtor<LoadedModule> *modules;
645 static int AddModuleSegments(const char *module_name, dl_phdr_info *info,
646 InternalMmapVectorNoCtor<LoadedModule> *modules) {
647 if (module_name[0] == '\0')
649 LoadedModule cur_module;
650 cur_module.set(module_name, info->dlpi_addr);
651 for (int i = 0; i < (int)info->dlpi_phnum; i++) {
652 const Elf_Phdr *phdr = &info->dlpi_phdr[i];
653 if (phdr->p_type == PT_LOAD) {
654 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
655 uptr cur_end = cur_beg + phdr->p_memsz;
656 bool executable = phdr->p_flags & PF_X;
657 bool writable = phdr->p_flags & PF_W;
658 cur_module.addAddressRange(cur_beg, cur_end, executable,
660 } else if (phdr->p_type == PT_NOTE) {
661 # ifdef NT_GNU_BUILD_ID
663 while (off + sizeof(ElfW(Nhdr)) < phdr->p_memsz) {
664 auto *nhdr = reinterpret_cast<const ElfW(Nhdr) *>(info->dlpi_addr +
665 phdr->p_vaddr + off);
666 constexpr auto kGnuNamesz = 4; // "GNU" with NUL-byte.
667 static_assert(kGnuNamesz % 4 == 0, "kGnuNameSize is aligned to 4.");
668 if (nhdr->n_type == NT_GNU_BUILD_ID && nhdr->n_namesz == kGnuNamesz) {
669 if (off + sizeof(ElfW(Nhdr)) + nhdr->n_namesz + nhdr->n_descsz >
671 // Something is very wrong, bail out instead of reading potentially
676 reinterpret_cast<const char *>(nhdr) + sizeof(*nhdr);
677 if (internal_memcmp(name, "GNU", 3) == 0) {
678 const char *value = reinterpret_cast<const char *>(nhdr) +
679 sizeof(*nhdr) + kGnuNamesz;
680 cur_module.setUuid(value, nhdr->n_descsz);
684 off += sizeof(*nhdr) + RoundUpTo(nhdr->n_namesz, 4) +
685 RoundUpTo(nhdr->n_descsz, 4);
690 modules->push_back(cur_module);
694 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
695 DlIteratePhdrData *data = (DlIteratePhdrData *)arg;
697 InternalMmapVector<char> module_name(kMaxPathLength);
699 // First module is the binary itself.
700 ReadBinaryNameCached(module_name.data(), module_name.size());
701 return AddModuleSegments(module_name.data(), info, data->modules);
704 if (info->dlpi_name) {
705 InternalScopedString module_name;
706 module_name.append("%s", info->dlpi_name);
707 return AddModuleSegments(module_name.data(), info, data->modules);
713 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
714 extern "C" __attribute__((weak)) int dl_iterate_phdr(
715 int (*)(struct dl_phdr_info *, size_t, void *), void *);
718 static bool requiresProcmaps() {
719 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22
720 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken.
721 // The runtime check allows the same library to work with
722 // both K and L (and future) Android releases.
723 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1;
729 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) {
730 MemoryMappingLayout memory_mapping(/*cache_enabled*/true);
731 memory_mapping.DumpListOfModules(modules);
734 void ListOfModules::init() {
736 if (requiresProcmaps()) {
737 procmapsInit(&modules_);
739 DlIteratePhdrData data = {&modules_, true};
740 dl_iterate_phdr(dl_iterate_phdr_cb, &data);
744 // When a custom loader is used, dl_iterate_phdr may not contain the full
745 // list of modules. Allow callers to fall back to using procmaps.
746 void ListOfModules::fallbackInit() {
747 if (!requiresProcmaps()) {
749 procmapsInit(&modules_);
755 // getrusage does not give us the current RSS, only the max RSS.
756 // Still, this is better than nothing if /proc/self/statm is not available
757 // for some reason, e.g. due to a sandbox.
758 static uptr GetRSSFromGetrusage() {
760 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox.
762 return usage.ru_maxrss << 10; // ru_maxrss is in Kb.
766 if (!common_flags()->can_use_proc_maps_statm)
767 return GetRSSFromGetrusage();
768 fd_t fd = OpenFile("/proc/self/statm", RdOnly);
769 if (fd == kInvalidFd)
770 return GetRSSFromGetrusage();
772 uptr len = internal_read(fd, buf, sizeof(buf) - 1);
777 // The format of the file is:
778 // 1084 89 69 11 0 79 0
779 // We need the second number which is RSS in pages.
781 // Skip the first number.
782 while (*pos >= '0' && *pos <= '9')
785 while (!(*pos >= '0' && *pos <= '9') && *pos != 0)
789 while (*pos >= '0' && *pos <= '9')
790 rss = rss * 10 + *pos++ - '0';
791 return rss * GetPageSizeCached();
794 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as
795 // they allocate memory.
796 u32 GetNumberOfCPUs() {
797 #if SANITIZER_FREEBSD || SANITIZER_NETBSD
800 uptr len = sizeof(ncpu);
803 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0);
805 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__)
806 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't
807 // exist in sched.h. That is the case for toolchains generated with older
809 // This code doesn't work on AArch64 because internal_getdents makes use of
810 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64.
811 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY);
812 if (internal_iserror(fd))
814 InternalMmapVector<u8> buffer(4096);
815 uptr bytes_read = buffer.size();
818 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read];
820 if ((u8 *)entry >= &buffer[bytes_read]) {
821 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(),
823 if (internal_iserror(bytes_read) || !bytes_read)
825 entry = (struct linux_dirent *)buffer.data();
827 d_type = (u8 *)entry + entry->d_reclen - 1;
828 if (d_type >= &buffer[bytes_read] ||
829 (u8 *)&entry->d_name[3] >= &buffer[bytes_read])
831 if (entry->d_ino != 0 && *d_type == DT_DIR) {
832 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' &&
833 entry->d_name[2] == 'u' &&
834 entry->d_name[3] >= '0' && entry->d_name[3] <= '9')
837 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen);
841 #elif SANITIZER_SOLARIS
842 return sysconf(_SC_NPROCESSORS_ONLN);
845 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0);
846 return CPU_COUNT(&CPUs);
852 #if SANITIZER_ANDROID
853 static atomic_uint8_t android_log_initialized;
855 void AndroidLogInit() {
856 openlog(GetProcessName(), 0, LOG_USER);
857 atomic_store(&android_log_initialized, 1, memory_order_release);
860 static bool ShouldLogAfterPrintf() {
861 return atomic_load(&android_log_initialized, memory_order_acquire);
864 extern "C" SANITIZER_WEAK_ATTRIBUTE
865 int async_safe_write_log(int pri, const char* tag, const char* msg);
866 extern "C" SANITIZER_WEAK_ATTRIBUTE
867 int __android_log_write(int prio, const char* tag, const char* msg);
869 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime.
870 #define SANITIZER_ANDROID_LOG_INFO 4
872 // async_safe_write_log is a new public version of __libc_write_log that is
873 // used behind syslog. It is preferable to syslog as it will not do any dynamic
874 // memory allocation or formatting.
875 // If the function is not available, syslog is preferred for L+ (it was broken
876 // pre-L) as __android_log_write triggers a racey behavior with the strncpy
877 // interceptor. Fallback to __android_log_write pre-L.
878 void WriteOneLineToSyslog(const char *s) {
879 if (&async_safe_write_log) {
880 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s);
881 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) {
882 syslog(LOG_INFO, "%s", s);
884 CHECK(&__android_log_write);
885 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s);
889 extern "C" SANITIZER_WEAK_ATTRIBUTE
890 void android_set_abort_message(const char *);
892 void SetAbortMessage(const char *str) {
893 if (&android_set_abort_message)
894 android_set_abort_message(str);
897 void AndroidLogInit() {}
899 static bool ShouldLogAfterPrintf() { return true; }
901 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); }
903 void SetAbortMessage(const char *str) {}
904 #endif // SANITIZER_ANDROID
906 void LogMessageOnPrintf(const char *str) {
907 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf())
911 #endif // SANITIZER_LINUX
913 #if SANITIZER_GLIBC && !SANITIZER_GO
914 // glibc crashes when using clock_gettime from a preinit_array function as the
915 // vDSO function pointers haven't been initialized yet. __progname is
916 // initialized after the vDSO function pointers, so if it exists, is not null
917 // and is not empty, we can use clock_gettime.
918 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname;
919 inline bool CanUseVDSO() { return &__progname && __progname && *__progname; }
921 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling
922 // clock_gettime. real_clock_gettime only exists if clock_gettime is
923 // intercepted, so define it weakly and use it if available.
924 extern "C" SANITIZER_WEAK_ATTRIBUTE
925 int real_clock_gettime(u32 clk_id, void *tp);
926 u64 MonotonicNanoTime() {
929 if (&real_clock_gettime)
930 real_clock_gettime(CLOCK_MONOTONIC, &ts);
932 clock_gettime(CLOCK_MONOTONIC, &ts);
934 internal_clock_gettime(CLOCK_MONOTONIC, &ts);
936 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
939 // Non-glibc & Go always use the regular function.
940 u64 MonotonicNanoTime() {
942 clock_gettime(CLOCK_MONOTONIC, &ts);
943 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
945 #endif // SANITIZER_GLIBC && !SANITIZER_GO
948 const char *pathname = "/proc/self/exe";
950 #if SANITIZER_FREEBSD
951 for (const auto *aux = __elf_aux_vector; aux->a_type != AT_NULL; aux++) {
952 if (aux->a_type == AT_EXECPATH) {
953 pathname = static_cast<const char *>(aux->a_un.a_ptr);
957 #elif SANITIZER_NETBSD
958 static const int name[] = {
968 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1)
970 #elif SANITIZER_SOLARIS
971 pathname = getexecname();
972 CHECK_NE(pathname, NULL);
973 #elif SANITIZER_USE_GETAUXVAL
974 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that
975 // rely on that will fail to load shared libraries. Query AT_EXECFN instead.
976 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN));
979 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron());
981 CHECK_EQ(internal_iserror(rv, &rverrno), true);
982 Printf("execve failed, errno %d\n", rverrno);
986 void UnmapFromTo(uptr from, uptr to) {
990 uptr res = internal_munmap(reinterpret_cast<void *>(from), to - from);
991 if (UNLIKELY(internal_iserror(res))) {
992 Report("ERROR: %s failed to unmap 0x%zx (%zd) bytes at address %p\n",
993 SanitizerToolName, to - from, to - from, (void *)from);
994 CHECK("unable to unmap" && 0);
998 uptr MapDynamicShadow(uptr shadow_size_bytes, uptr shadow_scale,
999 uptr min_shadow_base_alignment,
1000 UNUSED uptr &high_mem_end) {
1001 const uptr granularity = GetMmapGranularity();
1002 const uptr alignment =
1003 Max<uptr>(granularity << shadow_scale, 1ULL << min_shadow_base_alignment);
1004 const uptr left_padding =
1005 Max<uptr>(granularity, 1ULL << min_shadow_base_alignment);
1007 const uptr shadow_size = RoundUpTo(shadow_size_bytes, granularity);
1008 const uptr map_size = shadow_size + left_padding + alignment;
1010 const uptr map_start = (uptr)MmapNoAccess(map_size);
1011 CHECK_NE(map_start, ~(uptr)0);
1013 const uptr shadow_start = RoundUpTo(map_start + left_padding, alignment);
1015 UnmapFromTo(map_start, shadow_start - left_padding);
1016 UnmapFromTo(shadow_start + shadow_size, map_start + map_size);
1018 return shadow_start;
1021 static uptr MmapSharedNoReserve(uptr addr, uptr size) {
1022 return internal_mmap(
1023 reinterpret_cast<void *>(addr), size, PROT_READ | PROT_WRITE,
1024 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
1027 static uptr MremapCreateAlias(uptr base_addr, uptr alias_addr,
1030 return internal_mremap(reinterpret_cast<void *>(base_addr), 0, alias_size,
1031 MREMAP_MAYMOVE | MREMAP_FIXED,
1032 reinterpret_cast<void *>(alias_addr));
1034 CHECK(false && "mremap is not supported outside of Linux");
1039 static void CreateAliases(uptr start_addr, uptr alias_size, uptr num_aliases) {
1040 uptr total_size = alias_size * num_aliases;
1041 uptr mapped = MmapSharedNoReserve(start_addr, total_size);
1042 CHECK_EQ(mapped, start_addr);
1044 for (uptr i = 1; i < num_aliases; ++i) {
1045 uptr alias_addr = start_addr + i * alias_size;
1046 CHECK_EQ(MremapCreateAlias(start_addr, alias_addr, alias_size), alias_addr);
1050 uptr MapDynamicShadowAndAliases(uptr shadow_size, uptr alias_size,
1051 uptr num_aliases, uptr ring_buffer_size) {
1052 CHECK_EQ(alias_size & (alias_size - 1), 0);
1053 CHECK_EQ(num_aliases & (num_aliases - 1), 0);
1054 CHECK_EQ(ring_buffer_size & (ring_buffer_size - 1), 0);
1056 const uptr granularity = GetMmapGranularity();
1057 shadow_size = RoundUpTo(shadow_size, granularity);
1058 CHECK_EQ(shadow_size & (shadow_size - 1), 0);
1060 const uptr alias_region_size = alias_size * num_aliases;
1061 const uptr alignment =
1062 2 * Max(Max(shadow_size, alias_region_size), ring_buffer_size);
1063 const uptr left_padding = ring_buffer_size;
1065 const uptr right_size = alignment;
1066 const uptr map_size = left_padding + 2 * alignment;
1068 const uptr map_start = reinterpret_cast<uptr>(MmapNoAccess(map_size));
1069 CHECK_NE(map_start, static_cast<uptr>(-1));
1070 const uptr right_start = RoundUpTo(map_start + left_padding, alignment);
1072 UnmapFromTo(map_start, right_start - left_padding);
1073 UnmapFromTo(right_start + right_size, map_start + map_size);
1075 CreateAliases(right_start + right_size / 2, alias_size, num_aliases);
1080 void InitializePlatformCommonFlags(CommonFlags *cf) {
1081 #if SANITIZER_ANDROID
1082 if (&__libc_get_static_tls_bounds == nullptr)
1083 cf->detect_leaks = false;
1087 } // namespace __sanitizer