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"
32 #define _RTLD_SOURCE // for __lwp_gettcb_fast() / __lwp_getprivate_fast()
35 #include <dlfcn.h> // for dlsym()
40 #include <sys/resource.h>
44 #define ElfW(type) Elf_##type
48 #include <pthread_np.h>
50 #include <osreldate.h>
52 #include <sys/sysctl.h>
53 #define pthread_getattr_np pthread_attr_get_np
54 // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
55 // that, it was never implemented. So just define it to zero.
57 #define MAP_NORESERVE 0
61 #include <sys/sysctl.h>
72 #include <android/api-level.h>
73 #if !defined(CPU_COUNT) && !defined(__aarch64__)
76 struct __sanitizer::linux_dirent {
79 unsigned short d_reclen;
85 #if !SANITIZER_ANDROID
90 namespace __sanitizer {
92 SANITIZER_WEAK_ATTRIBUTE int
93 real_sigaction(int signum, const void *act, void *oldact);
95 int internal_sigaction(int signum, const void *act, void *oldact) {
98 return real_sigaction(signum, act, oldact);
100 return sigaction(signum, (const struct sigaction *)act,
101 (struct sigaction *)oldact);
104 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
105 uptr *stack_bottom) {
108 if (at_initialization) {
109 // This is the main thread. Libpthread may not be initialized yet.
111 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
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;
119 MemoryMappedSegment segment;
121 while (proc_maps.Next(&segment)) {
122 if ((uptr)&rl < segment.end) break;
123 prev_end = segment.end;
125 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end);
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;
141 void *stackaddr = nullptr;
142 #if SANITIZER_SOLARIS
144 CHECK_EQ(thr_stksegment(&ss), 0);
145 stacksize = ss.ss_size;
146 stackaddr = (char *)ss.ss_sp - stacksize;
147 #else // !SANITIZER_SOLARIS
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
155 *stack_top = (uptr)stackaddr + stacksize;
156 *stack_bottom = (uptr)stackaddr;
160 bool SetEnv(const char *name, const char *value) {
161 void *f = dlsym(RTLD_NEXT, "setenv");
164 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite);
166 CHECK_EQ(sizeof(setenv_f), sizeof(f));
167 internal_memcpy(&setenv_f, &f, sizeof(f));
168 return setenv_f(name, value, 1) == 0;
172 __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor,
174 #ifdef _CS_GNU_LIBC_VERSION
176 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
177 if (len >= sizeof(buf))
180 static const char kGLibC[] = "glibc ";
181 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0)
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;
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.
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;
201 #if SANITIZER_GLIBC && !SANITIZER_GO
202 __attribute__((unused)) static size_t g_tls_size;
204 int major, minor, patch;
205 g_use_dlpi_tls_data =
206 GetLibcVersion(&major, &minor, &patch) && major == 2 && minor >= 25;
208 #if defined(__aarch64__) || defined(__x86_64__) || defined(__powerpc64__)
209 void *get_tls_static_info = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
211 ((void (*)(size_t *, size_t *))get_tls_static_info)(&g_tls_size, &tls_align);
215 void InitTlsSize() { }
216 #endif // SANITIZER_GLIBC && !SANITIZER_GO
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_ANDROID && !SANITIZER_GO
222 // sizeof(struct pthread) from glibc.
223 static atomic_uintptr_t thread_descriptor_size;
225 static uptr ThreadDescriptorSizeFallback() {
227 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__)
231 if (GetLibcVersion(&major, &minor, &patch) && major == 2) {
232 /* sizeof(struct pthread) values from various glibc versions. */
234 val = 1728; // Assume only one particular version for x32.
235 // For ARM sizeof(struct pthread) changed in Glibc 2.23.
236 else if (SANITIZER_ARM)
237 val = minor <= 22 ? 1120 : 1216;
239 val = FIRST_32_SECOND_64(1104, 1696);
241 val = FIRST_32_SECOND_64(1120, 1728);
243 val = FIRST_32_SECOND_64(1136, 1728);
245 val = FIRST_32_SECOND_64(1136, 1712);
246 else if (minor == 10)
247 val = FIRST_32_SECOND_64(1168, 1776);
248 else if (minor == 11 || (minor == 12 && patch == 1))
249 val = FIRST_32_SECOND_64(1168, 2288);
250 else if (minor <= 14)
251 val = FIRST_32_SECOND_64(1168, 2304);
252 else if (minor < 32) // Unknown version
253 val = FIRST_32_SECOND_64(1216, 2304);
255 val = FIRST_32_SECOND_64(1344, 2496);
257 #elif defined(__s390__) || defined(__sparc__)
258 // The size of a prefix of TCB including pthread::{specific_1stblock,specific}
259 // suffices. Just return offsetof(struct pthread, specific_used), which hasn't
260 // changed since 2007-05. Technically this applies to i386/x86_64 as well but
261 // we call _dl_get_tls_static_info and need the precise size of struct
263 return FIRST_32_SECOND_64(524, 1552);
264 #elif defined(__mips__)
265 // TODO(sagarthakur): add more values as per different glibc versions.
266 val = FIRST_32_SECOND_64(1152, 1776);
267 #elif SANITIZER_RISCV64
271 if (GetLibcVersion(&major, &minor, &patch) && major == 2) {
272 // TODO: consider adding an optional runtime check for an unknown (untested)
274 if (minor <= 28) // WARNING: the highest tested version is 2.29
275 val = 1772; // no guarantees for this one
276 else if (minor <= 31)
277 val = 1772; // tested against glibc 2.29, 2.31
279 val = 1936; // tested against glibc 2.32
282 #elif defined(__aarch64__)
283 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22.
285 #elif defined(__powerpc64__)
286 val = 1776; // from glibc.ppc64le 2.20-8.fc21
291 uptr ThreadDescriptorSize() {
292 uptr val = atomic_load_relaxed(&thread_descriptor_size);
295 // _thread_db_sizeof_pthread is a GLIBC_PRIVATE symbol that is exported in
296 // glibc 2.34 and later.
297 if (unsigned *psizeof = static_cast<unsigned *>(
298 dlsym(RTLD_DEFAULT, "_thread_db_sizeof_pthread")))
301 val = ThreadDescriptorSizeFallback();
302 atomic_store_relaxed(&thread_descriptor_size, val);
306 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64
307 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb
308 // head structure. It lies before the static tls blocks.
309 static uptr TlsPreTcbSize() {
310 #if defined(__mips__)
311 const uptr kTcbHead = 16; // sizeof (tcbhead_t)
312 #elif defined(__powerpc64__)
313 const uptr kTcbHead = 88; // sizeof (tcbhead_t)
314 #elif SANITIZER_RISCV64
315 const uptr kTcbHead = 16; // sizeof (tcbhead_t)
317 const uptr kTlsAlign = 16;
318 const uptr kTlsPreTcbSize =
319 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign);
320 return kTlsPreTcbSize;
326 uptr begin, end, align;
328 bool operator<(const TlsBlock &rhs) const { return begin < rhs.begin; }
333 extern "C" uptr __tls_get_offset(void *arg);
335 static uptr TlsGetOffset(uptr ti_module, uptr ti_offset) {
336 // The __tls_get_offset ABI requires %r12 to point to GOT and %r2 to be an
337 // offset of a struct tls_index inside GOT. We don't possess either of the
338 // two, so violate the letter of the "ELF Handling For Thread-Local
339 // Storage" document and assume that the implementation just dereferences
341 uptr tls_index[2] = {ti_module, ti_offset};
342 register uptr r2 asm("2") = 0;
343 register void *r12 asm("12") = tls_index;
344 asm("basr %%r14, %[__tls_get_offset]"
346 : [__tls_get_offset] "r"(__tls_get_offset), "r"(r12)
347 : "memory", "cc", "0", "1", "3", "4", "5", "14");
351 extern "C" void *__tls_get_addr(size_t *);
354 static int CollectStaticTlsBlocks(struct dl_phdr_info *info, size_t size,
356 if (!info->dlpi_tls_modid)
358 uptr begin = (uptr)info->dlpi_tls_data;
359 if (!g_use_dlpi_tls_data) {
360 // Call __tls_get_addr as a fallback. This forces TLS allocation on glibc
363 begin = (uptr)__builtin_thread_pointer() +
364 TlsGetOffset(info->dlpi_tls_modid, 0);
366 size_t mod_and_off[2] = {info->dlpi_tls_modid, 0};
367 begin = (uptr)__tls_get_addr(mod_and_off);
370 for (unsigned i = 0; i != info->dlpi_phnum; ++i)
371 if (info->dlpi_phdr[i].p_type == PT_TLS) {
372 static_cast<InternalMmapVector<TlsBlock> *>(data)->push_back(
373 TlsBlock{begin, begin + info->dlpi_phdr[i].p_memsz,
374 info->dlpi_phdr[i].p_align, info->dlpi_tls_modid});
380 __attribute__((unused)) static void GetStaticTlsBoundary(uptr *addr, uptr *size,
382 InternalMmapVector<TlsBlock> ranges;
383 dl_iterate_phdr(CollectStaticTlsBlocks, &ranges);
384 uptr len = ranges.size();
385 Sort(ranges.begin(), len);
386 // Find the range with tls_modid=1. For glibc, because libc.so uses PT_TLS,
387 // this module is guaranteed to exist and is one of the initially loaded
390 while (one != len && ranges[one].tls_modid != 1) ++one;
392 // This may happen with musl if no module uses PT_TLS.
398 // Find the maximum consecutive ranges. We consider two modules consecutive if
399 // the gap is smaller than the alignment. The dynamic loader places static TLS
400 // blocks this way not to waste space.
402 *align = ranges[l].align;
403 while (l != 0 && ranges[l].begin < ranges[l - 1].end + ranges[l - 1].align)
404 *align = Max(*align, ranges[--l].align);
406 while (r != len && ranges[r].begin < ranges[r - 1].end + ranges[r - 1].align)
407 *align = Max(*align, ranges[r++].align);
408 *addr = ranges[l].begin;
409 *size = ranges[r - 1].end - ranges[l].begin;
411 #endif // (x86_64 || i386 || mips || ...) && (SANITIZER_FREEBSD ||
412 // SANITIZER_LINUX) && !SANITIZER_ANDROID && !SANITIZER_GO
415 static struct tls_tcb * ThreadSelfTlsTcb() {
416 struct tls_tcb *tcb = nullptr;
417 #ifdef __HAVE___LWP_GETTCB_FAST
418 tcb = (struct tls_tcb *)__lwp_gettcb_fast();
419 #elif defined(__HAVE___LWP_GETPRIVATE_FAST)
420 tcb = (struct tls_tcb *)__lwp_getprivate_fast();
426 return (uptr)ThreadSelfTlsTcb()->tcb_pthread;
429 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) {
430 const Elf_Phdr *hdr = info->dlpi_phdr;
431 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum;
433 for (; hdr != last_hdr; ++hdr) {
434 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) {
435 *(uptr*)data = hdr->p_memsz;
441 #endif // SANITIZER_NETBSD
443 #if SANITIZER_ANDROID
444 // Bionic provides this API since S.
445 extern "C" SANITIZER_WEAK_ATTRIBUTE void __libc_get_static_tls_bounds(void **,
450 static void GetTls(uptr *addr, uptr *size) {
451 #if SANITIZER_ANDROID
452 if (&__libc_get_static_tls_bounds) {
455 __libc_get_static_tls_bounds(&start_addr, &end_addr);
456 *addr = reinterpret_cast<uptr>(start_addr);
458 reinterpret_cast<uptr>(end_addr) - reinterpret_cast<uptr>(start_addr);
463 #elif SANITIZER_GLIBC && defined(__x86_64__)
464 // For aarch64 and x86-64, use an O(1) approach which requires relatively
465 // precise ThreadDescriptorSize. g_tls_size was initialized in InitTlsSize.
466 asm("mov %%fs:16,%0" : "=r"(*addr));
469 *addr += ThreadDescriptorSize();
470 #elif SANITIZER_GLIBC && defined(__aarch64__)
471 *addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) -
472 ThreadDescriptorSize();
473 *size = g_tls_size + ThreadDescriptorSize();
474 #elif SANITIZER_GLIBC && defined(__powerpc64__)
475 // Workaround for glibc<2.25(?). 2.27 is known to not need this.
477 asm("addi %0,13,-0x7000" : "=r"(tp));
478 const uptr pre_tcb_size = TlsPreTcbSize();
479 *addr = tp - pre_tcb_size;
480 *size = g_tls_size + pre_tcb_size;
481 #elif SANITIZER_FREEBSD || SANITIZER_LINUX
483 GetStaticTlsBoundary(addr, size, &align);
484 #if defined(__x86_64__) || defined(__i386__) || defined(__s390__) || \
486 if (SANITIZER_GLIBC) {
487 #if defined(__x86_64__) || defined(__i386__)
488 align = Max<uptr>(align, 64);
490 align = Max<uptr>(align, 16);
493 const uptr tp = RoundUpTo(*addr + *size, align);
495 // lsan requires the range to additionally cover the static TLS surplus
496 // (elf/dl-tls.c defines 1664). Otherwise there may be false positives for
497 // allocations only referenced by tls in dynamically loaded modules.
500 else if (SANITIZER_FREEBSD)
501 *size += 128; // RTLD_STATIC_TLS_EXTRA
503 // Extend the range to include the thread control block. On glibc, lsan needs
504 // the range to include pthread::{specific_1stblock,specific} so that
505 // allocations only referenced by pthread_setspecific can be scanned. This may
506 // underestimate by at most TLS_TCB_ALIGN-1 bytes but it should be fine
507 // because the number of bytes after pthread::specific is larger.
508 *addr = tp - RoundUpTo(*size, align);
509 *size = tp - *addr + ThreadDescriptorSize();
513 else if (SANITIZER_FREEBSD)
514 *size += 128; // RTLD_STATIC_TLS_EXTRA
515 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64
516 const uptr pre_tcb_size = TlsPreTcbSize();
517 *addr -= pre_tcb_size;
518 *size += pre_tcb_size;
520 // arm and aarch64 reserve two words at TP, so this underestimates the range.
521 // However, this is sufficient for the purpose of finding the pointers to
522 // thread-specific data keys.
523 const uptr tcb_size = ThreadDescriptorSize();
528 #elif SANITIZER_NETBSD
529 struct tls_tcb * const tcb = ThreadSelfTlsTcb();
533 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program).
534 // ld.elf_so hardcodes the index 1.
535 dl_iterate_phdr(GetSizeFromHdr, size);
538 // The block has been found and tcb_dtv[1] contains the base address
539 *addr = (uptr)tcb->tcb_dtv[1];
542 #elif SANITIZER_SOLARIS
554 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
557 GetTls(&addr, &size);
565 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
566 uptr *tls_addr, uptr *tls_size) {
568 // Stub implementation for Go.
569 *stk_addr = *stk_size = *tls_addr = *tls_size = 0;
571 GetTls(tls_addr, tls_size);
573 uptr stack_top, stack_bottom;
574 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
575 *stk_addr = stack_bottom;
576 *stk_size = stack_top - stack_bottom;
579 // If stack and tls intersect, make them non-intersecting.
580 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
581 if (*stk_addr + *stk_size < *tls_addr + *tls_size)
582 *tls_size = *stk_addr + *stk_size - *tls_addr;
583 *stk_size = *tls_addr - *stk_addr;
589 #if !SANITIZER_FREEBSD
590 typedef ElfW(Phdr) Elf_Phdr;
591 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2
592 #define Elf_Phdr XElf32_Phdr
593 #define dl_phdr_info xdl_phdr_info
594 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b))
595 #endif // !SANITIZER_FREEBSD
597 struct DlIteratePhdrData {
598 InternalMmapVectorNoCtor<LoadedModule> *modules;
602 static int AddModuleSegments(const char *module_name, dl_phdr_info *info,
603 InternalMmapVectorNoCtor<LoadedModule> *modules) {
604 if (module_name[0] == '\0')
606 LoadedModule cur_module;
607 cur_module.set(module_name, info->dlpi_addr);
608 for (int i = 0; i < (int)info->dlpi_phnum; i++) {
609 const Elf_Phdr *phdr = &info->dlpi_phdr[i];
610 if (phdr->p_type == PT_LOAD) {
611 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
612 uptr cur_end = cur_beg + phdr->p_memsz;
613 bool executable = phdr->p_flags & PF_X;
614 bool writable = phdr->p_flags & PF_W;
615 cur_module.addAddressRange(cur_beg, cur_end, executable,
617 } else if (phdr->p_type == PT_NOTE) {
618 # ifdef NT_GNU_BUILD_ID
620 while (off + sizeof(ElfW(Nhdr)) < phdr->p_memsz) {
621 auto *nhdr = reinterpret_cast<const ElfW(Nhdr) *>(info->dlpi_addr +
622 phdr->p_vaddr + off);
623 constexpr auto kGnuNamesz = 4; // "GNU" with NUL-byte.
624 static_assert(kGnuNamesz % 4 == 0, "kGnuNameSize is aligned to 4.");
625 if (nhdr->n_type == NT_GNU_BUILD_ID && nhdr->n_namesz == kGnuNamesz) {
626 if (off + sizeof(ElfW(Nhdr)) + nhdr->n_namesz + nhdr->n_descsz >
628 // Something is very wrong, bail out instead of reading potentially
633 reinterpret_cast<const char *>(nhdr) + sizeof(*nhdr);
634 if (internal_memcmp(name, "GNU", 3) == 0) {
635 const char *value = reinterpret_cast<const char *>(nhdr) +
636 sizeof(*nhdr) + kGnuNamesz;
637 cur_module.setUuid(value, nhdr->n_descsz);
641 off += sizeof(*nhdr) + RoundUpTo(nhdr->n_namesz, 4) +
642 RoundUpTo(nhdr->n_descsz, 4);
647 modules->push_back(cur_module);
651 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
652 DlIteratePhdrData *data = (DlIteratePhdrData *)arg;
654 InternalMmapVector<char> module_name(kMaxPathLength);
656 // First module is the binary itself.
657 ReadBinaryNameCached(module_name.data(), module_name.size());
658 return AddModuleSegments(module_name.data(), info, data->modules);
661 if (info->dlpi_name) {
662 InternalScopedString module_name;
663 module_name.append("%s", info->dlpi_name);
664 return AddModuleSegments(module_name.data(), info, data->modules);
670 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
671 extern "C" __attribute__((weak)) int dl_iterate_phdr(
672 int (*)(struct dl_phdr_info *, size_t, void *), void *);
675 static bool requiresProcmaps() {
676 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22
677 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken.
678 // The runtime check allows the same library to work with
679 // both K and L (and future) Android releases.
680 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1;
686 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) {
687 MemoryMappingLayout memory_mapping(/*cache_enabled*/true);
688 memory_mapping.DumpListOfModules(modules);
691 void ListOfModules::init() {
693 if (requiresProcmaps()) {
694 procmapsInit(&modules_);
696 DlIteratePhdrData data = {&modules_, true};
697 dl_iterate_phdr(dl_iterate_phdr_cb, &data);
701 // When a custom loader is used, dl_iterate_phdr may not contain the full
702 // list of modules. Allow callers to fall back to using procmaps.
703 void ListOfModules::fallbackInit() {
704 if (!requiresProcmaps()) {
706 procmapsInit(&modules_);
712 // getrusage does not give us the current RSS, only the max RSS.
713 // Still, this is better than nothing if /proc/self/statm is not available
714 // for some reason, e.g. due to a sandbox.
715 static uptr GetRSSFromGetrusage() {
717 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox.
719 return usage.ru_maxrss << 10; // ru_maxrss is in Kb.
723 if (!common_flags()->can_use_proc_maps_statm)
724 return GetRSSFromGetrusage();
725 fd_t fd = OpenFile("/proc/self/statm", RdOnly);
726 if (fd == kInvalidFd)
727 return GetRSSFromGetrusage();
729 uptr len = internal_read(fd, buf, sizeof(buf) - 1);
734 // The format of the file is:
735 // 1084 89 69 11 0 79 0
736 // We need the second number which is RSS in pages.
738 // Skip the first number.
739 while (*pos >= '0' && *pos <= '9')
742 while (!(*pos >= '0' && *pos <= '9') && *pos != 0)
746 while (*pos >= '0' && *pos <= '9')
747 rss = rss * 10 + *pos++ - '0';
748 return rss * GetPageSizeCached();
751 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as
752 // they allocate memory.
753 u32 GetNumberOfCPUs() {
754 #if SANITIZER_FREEBSD || SANITIZER_NETBSD
757 uptr len = sizeof(ncpu);
760 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0);
762 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__)
763 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't
764 // exist in sched.h. That is the case for toolchains generated with older
766 // This code doesn't work on AArch64 because internal_getdents makes use of
767 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64.
768 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY);
769 if (internal_iserror(fd))
771 InternalMmapVector<u8> buffer(4096);
772 uptr bytes_read = buffer.size();
775 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read];
777 if ((u8 *)entry >= &buffer[bytes_read]) {
778 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(),
780 if (internal_iserror(bytes_read) || !bytes_read)
782 entry = (struct linux_dirent *)buffer.data();
784 d_type = (u8 *)entry + entry->d_reclen - 1;
785 if (d_type >= &buffer[bytes_read] ||
786 (u8 *)&entry->d_name[3] >= &buffer[bytes_read])
788 if (entry->d_ino != 0 && *d_type == DT_DIR) {
789 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' &&
790 entry->d_name[2] == 'u' &&
791 entry->d_name[3] >= '0' && entry->d_name[3] <= '9')
794 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen);
798 #elif SANITIZER_SOLARIS
799 return sysconf(_SC_NPROCESSORS_ONLN);
802 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0);
803 return CPU_COUNT(&CPUs);
809 #if SANITIZER_ANDROID
810 static atomic_uint8_t android_log_initialized;
812 void AndroidLogInit() {
813 openlog(GetProcessName(), 0, LOG_USER);
814 atomic_store(&android_log_initialized, 1, memory_order_release);
817 static bool ShouldLogAfterPrintf() {
818 return atomic_load(&android_log_initialized, memory_order_acquire);
821 extern "C" SANITIZER_WEAK_ATTRIBUTE
822 int async_safe_write_log(int pri, const char* tag, const char* msg);
823 extern "C" SANITIZER_WEAK_ATTRIBUTE
824 int __android_log_write(int prio, const char* tag, const char* msg);
826 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime.
827 #define SANITIZER_ANDROID_LOG_INFO 4
829 // async_safe_write_log is a new public version of __libc_write_log that is
830 // used behind syslog. It is preferable to syslog as it will not do any dynamic
831 // memory allocation or formatting.
832 // If the function is not available, syslog is preferred for L+ (it was broken
833 // pre-L) as __android_log_write triggers a racey behavior with the strncpy
834 // interceptor. Fallback to __android_log_write pre-L.
835 void WriteOneLineToSyslog(const char *s) {
836 if (&async_safe_write_log) {
837 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s);
838 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) {
839 syslog(LOG_INFO, "%s", s);
841 CHECK(&__android_log_write);
842 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s);
846 extern "C" SANITIZER_WEAK_ATTRIBUTE
847 void android_set_abort_message(const char *);
849 void SetAbortMessage(const char *str) {
850 if (&android_set_abort_message)
851 android_set_abort_message(str);
854 void AndroidLogInit() {}
856 static bool ShouldLogAfterPrintf() { return true; }
858 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); }
860 void SetAbortMessage(const char *str) {}
861 #endif // SANITIZER_ANDROID
863 void LogMessageOnPrintf(const char *str) {
864 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf())
868 #endif // SANITIZER_LINUX
870 #if SANITIZER_GLIBC && !SANITIZER_GO
871 // glibc crashes when using clock_gettime from a preinit_array function as the
872 // vDSO function pointers haven't been initialized yet. __progname is
873 // initialized after the vDSO function pointers, so if it exists, is not null
874 // and is not empty, we can use clock_gettime.
875 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname;
876 inline bool CanUseVDSO() { return &__progname && __progname && *__progname; }
878 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling
879 // clock_gettime. real_clock_gettime only exists if clock_gettime is
880 // intercepted, so define it weakly and use it if available.
881 extern "C" SANITIZER_WEAK_ATTRIBUTE
882 int real_clock_gettime(u32 clk_id, void *tp);
883 u64 MonotonicNanoTime() {
886 if (&real_clock_gettime)
887 real_clock_gettime(CLOCK_MONOTONIC, &ts);
889 clock_gettime(CLOCK_MONOTONIC, &ts);
891 internal_clock_gettime(CLOCK_MONOTONIC, &ts);
893 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
896 // Non-glibc & Go always use the regular function.
897 u64 MonotonicNanoTime() {
899 clock_gettime(CLOCK_MONOTONIC, &ts);
900 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
902 #endif // SANITIZER_GLIBC && !SANITIZER_GO
905 const char *pathname = "/proc/self/exe";
907 #if SANITIZER_FREEBSD
908 char exe_path[PATH_MAX];
909 if (elf_aux_info(AT_EXECPATH, exe_path, sizeof(exe_path)) == 0) {
910 char link_path[PATH_MAX];
911 if (realpath(exe_path, link_path))
912 pathname = link_path;
914 #elif SANITIZER_NETBSD
915 static const int name[] = {
925 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1)
927 #elif SANITIZER_SOLARIS
928 pathname = getexecname();
929 CHECK_NE(pathname, NULL);
930 #elif SANITIZER_USE_GETAUXVAL
931 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that
932 // rely on that will fail to load shared libraries. Query AT_EXECFN instead.
933 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN));
936 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron());
938 CHECK_EQ(internal_iserror(rv, &rverrno), true);
939 Printf("execve failed, errno %d\n", rverrno);
943 void UnmapFromTo(uptr from, uptr to) {
947 uptr res = internal_munmap(reinterpret_cast<void *>(from), to - from);
948 if (UNLIKELY(internal_iserror(res))) {
949 Report("ERROR: %s failed to unmap 0x%zx (%zd) bytes at address %p\n",
950 SanitizerToolName, to - from, to - from, (void *)from);
951 CHECK("unable to unmap" && 0);
955 uptr MapDynamicShadow(uptr shadow_size_bytes, uptr shadow_scale,
956 uptr min_shadow_base_alignment,
957 UNUSED uptr &high_mem_end) {
958 const uptr granularity = GetMmapGranularity();
959 const uptr alignment =
960 Max<uptr>(granularity << shadow_scale, 1ULL << min_shadow_base_alignment);
961 const uptr left_padding =
962 Max<uptr>(granularity, 1ULL << min_shadow_base_alignment);
964 const uptr shadow_size = RoundUpTo(shadow_size_bytes, granularity);
965 const uptr map_size = shadow_size + left_padding + alignment;
967 const uptr map_start = (uptr)MmapNoAccess(map_size);
968 CHECK_NE(map_start, ~(uptr)0);
970 const uptr shadow_start = RoundUpTo(map_start + left_padding, alignment);
972 UnmapFromTo(map_start, shadow_start - left_padding);
973 UnmapFromTo(shadow_start + shadow_size, map_start + map_size);
978 static uptr MmapSharedNoReserve(uptr addr, uptr size) {
979 return internal_mmap(
980 reinterpret_cast<void *>(addr), size, PROT_READ | PROT_WRITE,
981 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
984 static uptr MremapCreateAlias(uptr base_addr, uptr alias_addr,
987 return internal_mremap(reinterpret_cast<void *>(base_addr), 0, alias_size,
988 MREMAP_MAYMOVE | MREMAP_FIXED,
989 reinterpret_cast<void *>(alias_addr));
991 CHECK(false && "mremap is not supported outside of Linux");
996 static void CreateAliases(uptr start_addr, uptr alias_size, uptr num_aliases) {
997 uptr total_size = alias_size * num_aliases;
998 uptr mapped = MmapSharedNoReserve(start_addr, total_size);
999 CHECK_EQ(mapped, start_addr);
1001 for (uptr i = 1; i < num_aliases; ++i) {
1002 uptr alias_addr = start_addr + i * alias_size;
1003 CHECK_EQ(MremapCreateAlias(start_addr, alias_addr, alias_size), alias_addr);
1007 uptr MapDynamicShadowAndAliases(uptr shadow_size, uptr alias_size,
1008 uptr num_aliases, uptr ring_buffer_size) {
1009 CHECK_EQ(alias_size & (alias_size - 1), 0);
1010 CHECK_EQ(num_aliases & (num_aliases - 1), 0);
1011 CHECK_EQ(ring_buffer_size & (ring_buffer_size - 1), 0);
1013 const uptr granularity = GetMmapGranularity();
1014 shadow_size = RoundUpTo(shadow_size, granularity);
1015 CHECK_EQ(shadow_size & (shadow_size - 1), 0);
1017 const uptr alias_region_size = alias_size * num_aliases;
1018 const uptr alignment =
1019 2 * Max(Max(shadow_size, alias_region_size), ring_buffer_size);
1020 const uptr left_padding = ring_buffer_size;
1022 const uptr right_size = alignment;
1023 const uptr map_size = left_padding + 2 * alignment;
1025 const uptr map_start = reinterpret_cast<uptr>(MmapNoAccess(map_size));
1026 CHECK_NE(map_start, static_cast<uptr>(-1));
1027 const uptr right_start = RoundUpTo(map_start + left_padding, alignment);
1029 UnmapFromTo(map_start, right_start - left_padding);
1030 UnmapFromTo(right_start + right_size, map_start + map_size);
1032 CreateAliases(right_start + right_size / 2, alias_size, num_aliases);
1037 void InitializePlatformCommonFlags(CommonFlags *cf) {
1038 #if SANITIZER_ANDROID
1039 if (&__libc_get_static_tls_bounds == nullptr)
1040 cf->detect_leaks = false;
1044 } // namespace __sanitizer