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>
49 #include <osreldate.h>
50 #include <sys/sysctl.h>
51 #define pthread_getattr_np pthread_attr_get_np
52 // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
53 // that, it was never implemented. So just define it to zero.
55 #define MAP_NORESERVE 0
59 #include <sys/sysctl.h>
70 #include <android/api-level.h>
71 #if !defined(CPU_COUNT) && !defined(__aarch64__)
74 struct __sanitizer::linux_dirent {
77 unsigned short d_reclen;
83 #if !SANITIZER_ANDROID
88 namespace __sanitizer {
90 SANITIZER_WEAK_ATTRIBUTE int
91 real_sigaction(int signum, const void *act, void *oldact);
93 int internal_sigaction(int signum, const void *act, void *oldact) {
96 return real_sigaction(signum, act, oldact);
98 return sigaction(signum, (const struct sigaction *)act,
99 (struct sigaction *)oldact);
102 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
103 uptr *stack_bottom) {
106 if (at_initialization) {
107 // This is the main thread. Libpthread may not be initialized yet.
109 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
111 // Find the mapping that contains a stack variable.
112 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
113 if (proc_maps.Error()) {
114 *stack_top = *stack_bottom = 0;
117 MemoryMappedSegment segment;
119 while (proc_maps.Next(&segment)) {
120 if ((uptr)&rl < segment.end) break;
121 prev_end = segment.end;
123 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end);
125 // Get stacksize from rlimit, but clip it so that it does not overlap
126 // with other mappings.
127 uptr stacksize = rl.rlim_cur;
128 if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end;
129 // When running with unlimited stack size, we still want to set some limit.
130 // The unlimited stack size is caused by 'ulimit -s unlimited'.
131 // Also, for some reason, GNU make spawns subprocesses with unlimited stack.
132 if (stacksize > kMaxThreadStackSize)
133 stacksize = kMaxThreadStackSize;
134 *stack_top = segment.end;
135 *stack_bottom = segment.end - stacksize;
139 void *stackaddr = nullptr;
140 #if SANITIZER_SOLARIS
142 CHECK_EQ(thr_stksegment(&ss), 0);
143 stacksize = ss.ss_size;
144 stackaddr = (char *)ss.ss_sp - stacksize;
145 #else // !SANITIZER_SOLARIS
147 pthread_attr_init(&attr);
148 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
149 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize);
150 pthread_attr_destroy(&attr);
151 #endif // SANITIZER_SOLARIS
153 *stack_top = (uptr)stackaddr + stacksize;
154 *stack_bottom = (uptr)stackaddr;
158 bool SetEnv(const char *name, const char *value) {
159 void *f = dlsym(RTLD_NEXT, "setenv");
162 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite);
164 CHECK_EQ(sizeof(setenv_f), sizeof(f));
165 internal_memcpy(&setenv_f, &f, sizeof(f));
166 return setenv_f(name, value, 1) == 0;
170 __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor,
172 #ifdef _CS_GNU_LIBC_VERSION
174 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
175 if (len >= sizeof(buf))
178 static const char kGLibC[] = "glibc ";
179 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0)
181 const char *p = buf + sizeof(kGLibC) - 1;
182 *major = internal_simple_strtoll(p, &p, 10);
183 *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0;
184 *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0;
191 // True if we can use dlpi_tls_data. glibc before 2.25 may leave NULL (BZ
192 // #19826) so dlpi_tls_data cannot be used.
194 // musl before 1.2.3 and FreeBSD as of 12.2 incorrectly set dlpi_tls_data to
195 // the TLS initialization image
196 // https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=254774
197 __attribute__((unused)) static int g_use_dlpi_tls_data;
199 #if SANITIZER_GLIBC && !SANITIZER_GO
200 __attribute__((unused)) static size_t g_tls_size;
202 int major, minor, patch;
203 g_use_dlpi_tls_data =
204 GetLibcVersion(&major, &minor, &patch) && major == 2 && minor >= 25;
206 #if defined(__aarch64__) || defined(__x86_64__) || defined(__powerpc64__)
207 void *get_tls_static_info = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
209 ((void (*)(size_t *, size_t *))get_tls_static_info)(&g_tls_size, &tls_align);
213 void InitTlsSize() { }
214 #endif // SANITIZER_GLIBC && !SANITIZER_GO
216 // On glibc x86_64, ThreadDescriptorSize() needs to be precise due to the usage
217 // of g_tls_size. On other targets, ThreadDescriptorSize() is only used by lsan
218 // to get the pointer to thread-specific data keys in the thread control block.
219 #if (SANITIZER_FREEBSD || SANITIZER_LINUX) && !SANITIZER_ANDROID
220 // sizeof(struct pthread) from glibc.
221 static atomic_uintptr_t thread_descriptor_size;
223 uptr ThreadDescriptorSize() {
224 uptr val = atomic_load_relaxed(&thread_descriptor_size);
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
289 atomic_store_relaxed(&thread_descriptor_size, val);
293 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64
294 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb
295 // head structure. It lies before the static tls blocks.
296 static uptr TlsPreTcbSize() {
297 #if defined(__mips__)
298 const uptr kTcbHead = 16; // sizeof (tcbhead_t)
299 #elif defined(__powerpc64__)
300 const uptr kTcbHead = 88; // sizeof (tcbhead_t)
301 #elif SANITIZER_RISCV64
302 const uptr kTcbHead = 16; // sizeof (tcbhead_t)
304 const uptr kTlsAlign = 16;
305 const uptr kTlsPreTcbSize =
306 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign);
307 return kTlsPreTcbSize;
314 uptr begin, end, align;
316 bool operator<(const TlsBlock &rhs) const { return begin < rhs.begin; }
321 extern "C" uptr __tls_get_offset(void *arg);
323 static uptr TlsGetOffset(uptr ti_module, uptr ti_offset) {
324 // The __tls_get_offset ABI requires %r12 to point to GOT and %r2 to be an
325 // offset of a struct tls_index inside GOT. We don't possess either of the
326 // two, so violate the letter of the "ELF Handling For Thread-Local
327 // Storage" document and assume that the implementation just dereferences
329 uptr tls_index[2] = {ti_module, ti_offset};
330 register uptr r2 asm("2") = 0;
331 register void *r12 asm("12") = tls_index;
332 asm("basr %%r14, %[__tls_get_offset]"
334 : [__tls_get_offset] "r"(__tls_get_offset), "r"(r12)
335 : "memory", "cc", "0", "1", "3", "4", "5", "14");
339 extern "C" void *__tls_get_addr(size_t *);
342 static int CollectStaticTlsBlocks(struct dl_phdr_info *info, size_t size,
344 if (!info->dlpi_tls_modid)
346 uptr begin = (uptr)info->dlpi_tls_data;
347 if (!g_use_dlpi_tls_data) {
348 // Call __tls_get_addr as a fallback. This forces TLS allocation on glibc
351 begin = (uptr)__builtin_thread_pointer() +
352 TlsGetOffset(info->dlpi_tls_modid, 0);
354 size_t mod_and_off[2] = {info->dlpi_tls_modid, 0};
355 begin = (uptr)__tls_get_addr(mod_and_off);
358 for (unsigned i = 0; i != info->dlpi_phnum; ++i)
359 if (info->dlpi_phdr[i].p_type == PT_TLS) {
360 static_cast<InternalMmapVector<TlsBlock> *>(data)->push_back(
361 TlsBlock{begin, begin + info->dlpi_phdr[i].p_memsz,
362 info->dlpi_phdr[i].p_align, info->dlpi_tls_modid});
368 __attribute__((unused)) static void GetStaticTlsBoundary(uptr *addr, uptr *size,
370 InternalMmapVector<TlsBlock> ranges;
371 dl_iterate_phdr(CollectStaticTlsBlocks, &ranges);
372 uptr len = ranges.size();
373 Sort(ranges.begin(), len);
374 // Find the range with tls_modid=1. For glibc, because libc.so uses PT_TLS,
375 // this module is guaranteed to exist and is one of the initially loaded
378 while (one != len && ranges[one].tls_modid != 1) ++one;
380 // This may happen with musl if no module uses PT_TLS.
386 // Find the maximum consecutive ranges. We consider two modules consecutive if
387 // the gap is smaller than the alignment. The dynamic loader places static TLS
388 // blocks this way not to waste space.
390 *align = ranges[l].align;
391 while (l != 0 && ranges[l].begin < ranges[l - 1].end + ranges[l - 1].align)
392 *align = Max(*align, ranges[--l].align);
394 while (r != len && ranges[r].begin < ranges[r - 1].end + ranges[r - 1].align)
395 *align = Max(*align, ranges[r++].align);
396 *addr = ranges[l].begin;
397 *size = ranges[r - 1].end - ranges[l].begin;
399 #endif // !SANITIZER_GO
400 #endif // (x86_64 || i386 || mips || ...) && (SANITIZER_FREEBSD ||
401 // SANITIZER_LINUX) && !SANITIZER_ANDROID
404 static struct tls_tcb * ThreadSelfTlsTcb() {
405 struct tls_tcb *tcb = nullptr;
406 #ifdef __HAVE___LWP_GETTCB_FAST
407 tcb = (struct tls_tcb *)__lwp_gettcb_fast();
408 #elif defined(__HAVE___LWP_GETPRIVATE_FAST)
409 tcb = (struct tls_tcb *)__lwp_getprivate_fast();
415 return (uptr)ThreadSelfTlsTcb()->tcb_pthread;
418 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) {
419 const Elf_Phdr *hdr = info->dlpi_phdr;
420 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum;
422 for (; hdr != last_hdr; ++hdr) {
423 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) {
424 *(uptr*)data = hdr->p_memsz;
430 #endif // SANITIZER_NETBSD
432 #if SANITIZER_ANDROID
433 // Bionic provides this API since S.
434 extern "C" SANITIZER_WEAK_ATTRIBUTE void __libc_get_static_tls_bounds(void **,
439 static void GetTls(uptr *addr, uptr *size) {
440 #if SANITIZER_ANDROID
441 if (&__libc_get_static_tls_bounds) {
444 __libc_get_static_tls_bounds(&start_addr, &end_addr);
445 *addr = reinterpret_cast<uptr>(start_addr);
447 reinterpret_cast<uptr>(end_addr) - reinterpret_cast<uptr>(start_addr);
452 #elif SANITIZER_GLIBC && defined(__x86_64__)
453 // For aarch64 and x86-64, use an O(1) approach which requires relatively
454 // precise ThreadDescriptorSize. g_tls_size was initialized in InitTlsSize.
455 asm("mov %%fs:16,%0" : "=r"(*addr));
458 *addr += ThreadDescriptorSize();
459 #elif SANITIZER_GLIBC && defined(__aarch64__)
460 *addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) -
461 ThreadDescriptorSize();
462 *size = g_tls_size + ThreadDescriptorSize();
463 #elif SANITIZER_GLIBC && defined(__powerpc64__)
464 // Workaround for glibc<2.25(?). 2.27 is known to not need this.
466 asm("addi %0,13,-0x7000" : "=r"(tp));
467 const uptr pre_tcb_size = TlsPreTcbSize();
468 *addr = tp - pre_tcb_size;
469 *size = g_tls_size + pre_tcb_size;
470 #elif SANITIZER_FREEBSD || SANITIZER_LINUX
472 GetStaticTlsBoundary(addr, size, &align);
473 #if defined(__x86_64__) || defined(__i386__) || defined(__s390__) || \
475 if (SANITIZER_GLIBC) {
476 #if defined(__x86_64__) || defined(__i386__)
477 align = Max<uptr>(align, 64);
479 align = Max<uptr>(align, 16);
482 const uptr tp = RoundUpTo(*addr + *size, align);
484 // lsan requires the range to additionally cover the static TLS surplus
485 // (elf/dl-tls.c defines 1664). Otherwise there may be false positives for
486 // allocations only referenced by tls in dynamically loaded modules.
489 else if (SANITIZER_FREEBSD)
490 *size += 128; // RTLD_STATIC_TLS_EXTRA
492 // Extend the range to include the thread control block. On glibc, lsan needs
493 // the range to include pthread::{specific_1stblock,specific} so that
494 // allocations only referenced by pthread_setspecific can be scanned. This may
495 // underestimate by at most TLS_TCB_ALIGN-1 bytes but it should be fine
496 // because the number of bytes after pthread::specific is larger.
497 *addr = tp - RoundUpTo(*size, align);
498 *size = tp - *addr + ThreadDescriptorSize();
502 else if (SANITIZER_FREEBSD)
503 *size += 128; // RTLD_STATIC_TLS_EXTRA
504 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64
505 const uptr pre_tcb_size = TlsPreTcbSize();
506 *addr -= pre_tcb_size;
507 *size += pre_tcb_size;
509 // arm and aarch64 reserve two words at TP, so this underestimates the range.
510 // However, this is sufficient for the purpose of finding the pointers to
511 // thread-specific data keys.
512 const uptr tcb_size = ThreadDescriptorSize();
517 #elif SANITIZER_NETBSD
518 struct tls_tcb * const tcb = ThreadSelfTlsTcb();
522 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program).
523 // ld.elf_so hardcodes the index 1.
524 dl_iterate_phdr(GetSizeFromHdr, size);
527 // The block has been found and tcb_dtv[1] contains the base address
528 *addr = (uptr)tcb->tcb_dtv[1];
531 #elif SANITIZER_SOLARIS
543 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
546 GetTls(&addr, &size);
554 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
555 uptr *tls_addr, uptr *tls_size) {
557 // Stub implementation for Go.
558 *stk_addr = *stk_size = *tls_addr = *tls_size = 0;
560 GetTls(tls_addr, tls_size);
562 uptr stack_top, stack_bottom;
563 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
564 *stk_addr = stack_bottom;
565 *stk_size = stack_top - stack_bottom;
568 // If stack and tls intersect, make them non-intersecting.
569 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
570 if (*stk_addr + *stk_size < *tls_addr + *tls_size)
571 *tls_size = *stk_addr + *stk_size - *tls_addr;
572 *stk_size = *tls_addr - *stk_addr;
578 #if !SANITIZER_FREEBSD
579 typedef ElfW(Phdr) Elf_Phdr;
580 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2
581 #define Elf_Phdr XElf32_Phdr
582 #define dl_phdr_info xdl_phdr_info
583 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b))
584 #endif // !SANITIZER_FREEBSD
586 struct DlIteratePhdrData {
587 InternalMmapVectorNoCtor<LoadedModule> *modules;
591 static int AddModuleSegments(const char *module_name, dl_phdr_info *info,
592 InternalMmapVectorNoCtor<LoadedModule> *modules) {
593 if (module_name[0] == '\0')
595 LoadedModule cur_module;
596 cur_module.set(module_name, info->dlpi_addr);
597 for (int i = 0; i < (int)info->dlpi_phnum; i++) {
598 const Elf_Phdr *phdr = &info->dlpi_phdr[i];
599 if (phdr->p_type == PT_LOAD) {
600 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
601 uptr cur_end = cur_beg + phdr->p_memsz;
602 bool executable = phdr->p_flags & PF_X;
603 bool writable = phdr->p_flags & PF_W;
604 cur_module.addAddressRange(cur_beg, cur_end, executable,
608 modules->push_back(cur_module);
612 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
613 DlIteratePhdrData *data = (DlIteratePhdrData *)arg;
615 InternalMmapVector<char> module_name(kMaxPathLength);
617 // First module is the binary itself.
618 ReadBinaryNameCached(module_name.data(), module_name.size());
619 return AddModuleSegments(module_name.data(), info, data->modules);
622 if (info->dlpi_name) {
623 InternalScopedString module_name;
624 module_name.append("%s", info->dlpi_name);
625 return AddModuleSegments(module_name.data(), info, data->modules);
631 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
632 extern "C" __attribute__((weak)) int dl_iterate_phdr(
633 int (*)(struct dl_phdr_info *, size_t, void *), void *);
636 static bool requiresProcmaps() {
637 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22
638 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken.
639 // The runtime check allows the same library to work with
640 // both K and L (and future) Android releases.
641 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1;
647 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) {
648 MemoryMappingLayout memory_mapping(/*cache_enabled*/true);
649 memory_mapping.DumpListOfModules(modules);
652 void ListOfModules::init() {
654 if (requiresProcmaps()) {
655 procmapsInit(&modules_);
657 DlIteratePhdrData data = {&modules_, true};
658 dl_iterate_phdr(dl_iterate_phdr_cb, &data);
662 // When a custom loader is used, dl_iterate_phdr may not contain the full
663 // list of modules. Allow callers to fall back to using procmaps.
664 void ListOfModules::fallbackInit() {
665 if (!requiresProcmaps()) {
667 procmapsInit(&modules_);
673 // getrusage does not give us the current RSS, only the max RSS.
674 // Still, this is better than nothing if /proc/self/statm is not available
675 // for some reason, e.g. due to a sandbox.
676 static uptr GetRSSFromGetrusage() {
678 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox.
680 return usage.ru_maxrss << 10; // ru_maxrss is in Kb.
684 if (!common_flags()->can_use_proc_maps_statm)
685 return GetRSSFromGetrusage();
686 fd_t fd = OpenFile("/proc/self/statm", RdOnly);
687 if (fd == kInvalidFd)
688 return GetRSSFromGetrusage();
690 uptr len = internal_read(fd, buf, sizeof(buf) - 1);
695 // The format of the file is:
696 // 1084 89 69 11 0 79 0
697 // We need the second number which is RSS in pages.
699 // Skip the first number.
700 while (*pos >= '0' && *pos <= '9')
703 while (!(*pos >= '0' && *pos <= '9') && *pos != 0)
707 while (*pos >= '0' && *pos <= '9')
708 rss = rss * 10 + *pos++ - '0';
709 return rss * GetPageSizeCached();
712 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as
713 // they allocate memory.
714 u32 GetNumberOfCPUs() {
715 #if SANITIZER_FREEBSD || SANITIZER_NETBSD
718 uptr len = sizeof(ncpu);
721 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0);
723 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__)
724 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't
725 // exist in sched.h. That is the case for toolchains generated with older
727 // This code doesn't work on AArch64 because internal_getdents makes use of
728 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64.
729 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY);
730 if (internal_iserror(fd))
732 InternalMmapVector<u8> buffer(4096);
733 uptr bytes_read = buffer.size();
736 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read];
738 if ((u8 *)entry >= &buffer[bytes_read]) {
739 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(),
741 if (internal_iserror(bytes_read) || !bytes_read)
743 entry = (struct linux_dirent *)buffer.data();
745 d_type = (u8 *)entry + entry->d_reclen - 1;
746 if (d_type >= &buffer[bytes_read] ||
747 (u8 *)&entry->d_name[3] >= &buffer[bytes_read])
749 if (entry->d_ino != 0 && *d_type == DT_DIR) {
750 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' &&
751 entry->d_name[2] == 'u' &&
752 entry->d_name[3] >= '0' && entry->d_name[3] <= '9')
755 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen);
759 #elif SANITIZER_SOLARIS
760 return sysconf(_SC_NPROCESSORS_ONLN);
763 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0);
764 return CPU_COUNT(&CPUs);
770 #if SANITIZER_ANDROID
771 static atomic_uint8_t android_log_initialized;
773 void AndroidLogInit() {
774 openlog(GetProcessName(), 0, LOG_USER);
775 atomic_store(&android_log_initialized, 1, memory_order_release);
778 static bool ShouldLogAfterPrintf() {
779 return atomic_load(&android_log_initialized, memory_order_acquire);
782 extern "C" SANITIZER_WEAK_ATTRIBUTE
783 int async_safe_write_log(int pri, const char* tag, const char* msg);
784 extern "C" SANITIZER_WEAK_ATTRIBUTE
785 int __android_log_write(int prio, const char* tag, const char* msg);
787 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime.
788 #define SANITIZER_ANDROID_LOG_INFO 4
790 // async_safe_write_log is a new public version of __libc_write_log that is
791 // used behind syslog. It is preferable to syslog as it will not do any dynamic
792 // memory allocation or formatting.
793 // If the function is not available, syslog is preferred for L+ (it was broken
794 // pre-L) as __android_log_write triggers a racey behavior with the strncpy
795 // interceptor. Fallback to __android_log_write pre-L.
796 void WriteOneLineToSyslog(const char *s) {
797 if (&async_safe_write_log) {
798 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s);
799 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) {
800 syslog(LOG_INFO, "%s", s);
802 CHECK(&__android_log_write);
803 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s);
807 extern "C" SANITIZER_WEAK_ATTRIBUTE
808 void android_set_abort_message(const char *);
810 void SetAbortMessage(const char *str) {
811 if (&android_set_abort_message)
812 android_set_abort_message(str);
815 void AndroidLogInit() {}
817 static bool ShouldLogAfterPrintf() { return true; }
819 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); }
821 void SetAbortMessage(const char *str) {}
822 #endif // SANITIZER_ANDROID
824 void LogMessageOnPrintf(const char *str) {
825 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf())
829 #endif // SANITIZER_LINUX
831 #if SANITIZER_GLIBC && !SANITIZER_GO
832 // glibc crashes when using clock_gettime from a preinit_array function as the
833 // vDSO function pointers haven't been initialized yet. __progname is
834 // initialized after the vDSO function pointers, so if it exists, is not null
835 // and is not empty, we can use clock_gettime.
836 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname;
837 inline bool CanUseVDSO() { return &__progname && __progname && *__progname; }
839 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling
840 // clock_gettime. real_clock_gettime only exists if clock_gettime is
841 // intercepted, so define it weakly and use it if available.
842 extern "C" SANITIZER_WEAK_ATTRIBUTE
843 int real_clock_gettime(u32 clk_id, void *tp);
844 u64 MonotonicNanoTime() {
847 if (&real_clock_gettime)
848 real_clock_gettime(CLOCK_MONOTONIC, &ts);
850 clock_gettime(CLOCK_MONOTONIC, &ts);
852 internal_clock_gettime(CLOCK_MONOTONIC, &ts);
854 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
857 // Non-glibc & Go always use the regular function.
858 u64 MonotonicNanoTime() {
860 clock_gettime(CLOCK_MONOTONIC, &ts);
861 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
863 #endif // SANITIZER_GLIBC && !SANITIZER_GO
866 const char *pathname = "/proc/self/exe";
869 static const int name[] = {
879 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1)
881 #elif SANITIZER_SOLARIS
882 pathname = getexecname();
883 CHECK_NE(pathname, NULL);
884 #elif SANITIZER_USE_GETAUXVAL
885 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that
886 // rely on that will fail to load shared libraries. Query AT_EXECFN instead.
887 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN));
890 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron());
892 CHECK_EQ(internal_iserror(rv, &rverrno), true);
893 Printf("execve failed, errno %d\n", rverrno);
897 void UnmapFromTo(uptr from, uptr to) {
901 uptr res = internal_munmap(reinterpret_cast<void *>(from), to - from);
902 if (UNLIKELY(internal_iserror(res))) {
903 Report("ERROR: %s failed to unmap 0x%zx (%zd) bytes at address %p\n",
904 SanitizerToolName, to - from, to - from, (void *)from);
905 CHECK("unable to unmap" && 0);
909 uptr MapDynamicShadow(uptr shadow_size_bytes, uptr shadow_scale,
910 uptr min_shadow_base_alignment,
911 UNUSED uptr &high_mem_end) {
912 const uptr granularity = GetMmapGranularity();
913 const uptr alignment =
914 Max<uptr>(granularity << shadow_scale, 1ULL << min_shadow_base_alignment);
915 const uptr left_padding =
916 Max<uptr>(granularity, 1ULL << min_shadow_base_alignment);
918 const uptr shadow_size = RoundUpTo(shadow_size_bytes, granularity);
919 const uptr map_size = shadow_size + left_padding + alignment;
921 const uptr map_start = (uptr)MmapNoAccess(map_size);
922 CHECK_NE(map_start, ~(uptr)0);
924 const uptr shadow_start = RoundUpTo(map_start + left_padding, alignment);
926 UnmapFromTo(map_start, shadow_start - left_padding);
927 UnmapFromTo(shadow_start + shadow_size, map_start + map_size);
932 static uptr MmapSharedNoReserve(uptr addr, uptr size) {
933 return internal_mmap(
934 reinterpret_cast<void *>(addr), size, PROT_READ | PROT_WRITE,
935 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
938 static uptr MremapCreateAlias(uptr base_addr, uptr alias_addr,
941 return internal_mremap(reinterpret_cast<void *>(base_addr), 0, alias_size,
942 MREMAP_MAYMOVE | MREMAP_FIXED,
943 reinterpret_cast<void *>(alias_addr));
945 CHECK(false && "mremap is not supported outside of Linux");
950 static void CreateAliases(uptr start_addr, uptr alias_size, uptr num_aliases) {
951 uptr total_size = alias_size * num_aliases;
952 uptr mapped = MmapSharedNoReserve(start_addr, total_size);
953 CHECK_EQ(mapped, start_addr);
955 for (uptr i = 1; i < num_aliases; ++i) {
956 uptr alias_addr = start_addr + i * alias_size;
957 CHECK_EQ(MremapCreateAlias(start_addr, alias_addr, alias_size), alias_addr);
961 uptr MapDynamicShadowAndAliases(uptr shadow_size, uptr alias_size,
962 uptr num_aliases, uptr ring_buffer_size) {
963 CHECK_EQ(alias_size & (alias_size - 1), 0);
964 CHECK_EQ(num_aliases & (num_aliases - 1), 0);
965 CHECK_EQ(ring_buffer_size & (ring_buffer_size - 1), 0);
967 const uptr granularity = GetMmapGranularity();
968 shadow_size = RoundUpTo(shadow_size, granularity);
969 CHECK_EQ(shadow_size & (shadow_size - 1), 0);
971 const uptr alias_region_size = alias_size * num_aliases;
972 const uptr alignment =
973 2 * Max(Max(shadow_size, alias_region_size), ring_buffer_size);
974 const uptr left_padding = ring_buffer_size;
976 const uptr right_size = alignment;
977 const uptr map_size = left_padding + 2 * alignment;
979 const uptr map_start = reinterpret_cast<uptr>(MmapNoAccess(map_size));
980 CHECK_NE(map_start, static_cast<uptr>(-1));
981 const uptr right_start = RoundUpTo(map_start + left_padding, alignment);
983 UnmapFromTo(map_start, right_start - left_padding);
984 UnmapFromTo(right_start + right_size, map_start + map_size);
986 CreateAliases(right_start + right_size / 2, alias_size, num_aliases);
991 void InitializePlatformCommonFlags(CommonFlags *cf) {
992 #if SANITIZER_ANDROID
993 if (&__libc_get_static_tls_bounds == nullptr)
994 cf->detect_leaks = false;
998 } // namespace __sanitizer