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 || \
17 SANITIZER_OPENBSD || SANITIZER_SOLARIS
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"
31 #include <dlfcn.h> // for dlsym()
35 #include <sys/resource.h>
39 #define ElfW(type) Elf_##type
43 #include <pthread_np.h>
44 #include <osreldate.h>
45 #include <sys/sysctl.h>
46 #define pthread_getattr_np pthread_attr_get_np
50 #include <pthread_np.h>
51 #include <sys/sysctl.h>
55 #include <sys/sysctl.h>
66 #include <android/api-level.h>
67 #if !defined(CPU_COUNT) && !defined(__aarch64__)
70 struct __sanitizer::linux_dirent {
73 unsigned short d_reclen;
79 #if !SANITIZER_ANDROID
84 namespace __sanitizer {
86 SANITIZER_WEAK_ATTRIBUTE int
87 real_sigaction(int signum, const void *act, void *oldact);
89 int internal_sigaction(int signum, const void *act, void *oldact) {
92 return real_sigaction(signum, act, oldact);
94 return sigaction(signum, (const struct sigaction *)act,
95 (struct sigaction *)oldact);
98 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
102 if (at_initialization) {
103 // This is the main thread. Libpthread may not be initialized yet.
105 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
107 // Find the mapping that contains a stack variable.
108 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
109 if (proc_maps.Error()) {
110 *stack_top = *stack_bottom = 0;
113 MemoryMappedSegment segment;
115 while (proc_maps.Next(&segment)) {
116 if ((uptr)&rl < segment.end) break;
117 prev_end = segment.end;
119 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end);
121 // Get stacksize from rlimit, but clip it so that it does not overlap
122 // with other mappings.
123 uptr stacksize = rl.rlim_cur;
124 if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end;
125 // When running with unlimited stack size, we still want to set some limit.
126 // The unlimited stack size is caused by 'ulimit -s unlimited'.
127 // Also, for some reason, GNU make spawns subprocesses with unlimited stack.
128 if (stacksize > kMaxThreadStackSize)
129 stacksize = kMaxThreadStackSize;
130 *stack_top = segment.end;
131 *stack_bottom = segment.end - stacksize;
135 void *stackaddr = nullptr;
136 #if SANITIZER_SOLARIS
138 CHECK_EQ(thr_stksegment(&ss), 0);
139 stacksize = ss.ss_size;
140 stackaddr = (char *)ss.ss_sp - stacksize;
141 #elif SANITIZER_OPENBSD
143 CHECK_EQ(pthread_stackseg_np(pthread_self(), &sattr), 0);
144 stackaddr = sattr.ss_sp;
145 stacksize = sattr.ss_size;
146 #else // !SANITIZER_SOLARIS
148 pthread_attr_init(&attr);
149 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
150 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize);
151 pthread_attr_destroy(&attr);
152 #endif // SANITIZER_SOLARIS
154 *stack_top = (uptr)stackaddr + stacksize;
155 *stack_bottom = (uptr)stackaddr;
159 bool SetEnv(const char *name, const char *value) {
160 void *f = dlsym(RTLD_NEXT, "setenv");
163 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite);
165 CHECK_EQ(sizeof(setenv_f), sizeof(f));
166 internal_memcpy(&setenv_f, &f, sizeof(f));
167 return setenv_f(name, value, 1) == 0;
171 __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor,
173 #ifdef _CS_GNU_LIBC_VERSION
175 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
176 if (len >= sizeof(buf))
179 static const char kGLibC[] = "glibc ";
180 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0)
182 const char *p = buf + sizeof(kGLibC) - 1;
183 *major = internal_simple_strtoll(p, &p, 10);
184 *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0;
185 *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0;
192 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO && \
193 !SANITIZER_NETBSD && !SANITIZER_OPENBSD && !SANITIZER_SOLARIS
194 static uptr g_tls_size;
197 # define CHECK_GET_TLS_STATIC_INFO_VERSION (!__GLIBC_PREREQ(2, 27))
199 # define CHECK_GET_TLS_STATIC_INFO_VERSION 0
202 #if CHECK_GET_TLS_STATIC_INFO_VERSION
203 # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall))
205 # define DL_INTERNAL_FUNCTION
209 struct GetTlsStaticInfoCall {
210 typedef void (*get_tls_func)(size_t*, size_t*);
212 struct GetTlsStaticInfoRegparmCall {
213 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION;
216 template <typename T>
217 void CallGetTls(void* ptr, size_t* size, size_t* align) {
218 typename T::get_tls_func get_tls;
219 CHECK_EQ(sizeof(get_tls), sizeof(ptr));
220 internal_memcpy(&get_tls, &ptr, sizeof(ptr));
221 CHECK_NE(get_tls, 0);
222 get_tls(size, align);
225 bool CmpLibcVersion(int major, int minor, int patch) {
229 if (!GetLibcVersion(&ma, &mi, &pa))
245 // all current supported platforms have 16 bytes stack alignment
246 const size_t kStackAlign = 16;
247 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
249 size_t tls_align = 0;
250 // On i?86, _dl_get_tls_static_info used to be internal_function, i.e.
251 // __attribute__((regparm(3), stdcall)) before glibc 2.27 and is normal
252 // function in 2.27 and later.
253 if (CHECK_GET_TLS_STATIC_INFO_VERSION && !CmpLibcVersion(2, 27, 0))
254 CallGetTls<GetTlsStaticInfoRegparmCall>(get_tls_static_info_ptr,
255 &tls_size, &tls_align);
257 CallGetTls<GetTlsStaticInfoCall>(get_tls_static_info_ptr,
258 &tls_size, &tls_align);
259 if (tls_align < kStackAlign)
260 tls_align = kStackAlign;
261 g_tls_size = RoundUpTo(tls_size, tls_align);
264 void InitTlsSize() { }
265 #endif // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO &&
266 // !SANITIZER_NETBSD && !SANITIZER_SOLARIS
268 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) || \
269 defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__) || \
270 defined(__arm__)) && \
271 SANITIZER_LINUX && !SANITIZER_ANDROID
272 // sizeof(struct pthread) from glibc.
273 static atomic_uintptr_t thread_descriptor_size;
275 uptr ThreadDescriptorSize() {
276 uptr val = atomic_load_relaxed(&thread_descriptor_size);
279 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__)
283 if (GetLibcVersion(&major, &minor, &patch) && major == 2) {
284 /* sizeof(struct pthread) values from various glibc versions. */
286 val = 1728; // Assume only one particular version for x32.
287 // For ARM sizeof(struct pthread) changed in Glibc 2.23.
288 else if (SANITIZER_ARM)
289 val = minor <= 22 ? 1120 : 1216;
291 val = FIRST_32_SECOND_64(1104, 1696);
293 val = FIRST_32_SECOND_64(1120, 1728);
295 val = FIRST_32_SECOND_64(1136, 1728);
297 val = FIRST_32_SECOND_64(1136, 1712);
298 else if (minor == 10)
299 val = FIRST_32_SECOND_64(1168, 1776);
300 else if (minor == 11 || (minor == 12 && patch == 1))
301 val = FIRST_32_SECOND_64(1168, 2288);
302 else if (minor <= 14)
303 val = FIRST_32_SECOND_64(1168, 2304);
305 val = FIRST_32_SECOND_64(1216, 2304);
307 #elif defined(__mips__)
308 // TODO(sagarthakur): add more values as per different glibc versions.
309 val = FIRST_32_SECOND_64(1152, 1776);
310 #elif defined(__aarch64__)
311 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22.
313 #elif defined(__powerpc64__)
314 val = 1776; // from glibc.ppc64le 2.20-8.fc21
315 #elif defined(__s390__)
316 val = FIRST_32_SECOND_64(1152, 1776); // valid for glibc 2.22
319 atomic_store_relaxed(&thread_descriptor_size, val);
323 // The offset at which pointer to self is located in the thread descriptor.
324 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16);
326 uptr ThreadSelfOffset() {
327 return kThreadSelfOffset;
330 #if defined(__mips__) || defined(__powerpc64__)
331 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb
332 // head structure. It lies before the static tls blocks.
333 static uptr TlsPreTcbSize() {
334 # if defined(__mips__)
335 const uptr kTcbHead = 16; // sizeof (tcbhead_t)
336 # elif defined(__powerpc64__)
337 const uptr kTcbHead = 88; // sizeof (tcbhead_t)
339 const uptr kTlsAlign = 16;
340 const uptr kTlsPreTcbSize =
341 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign);
342 return kTlsPreTcbSize;
348 # if defined(__i386__)
349 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
350 # elif defined(__x86_64__)
351 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
352 # elif defined(__mips__)
353 // MIPS uses TLS variant I. The thread pointer (in hardware register $29)
354 // points to the end of the TCB + 0x7000. The pthread_descr structure is
355 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the
356 // TCB and the size of pthread_descr.
357 const uptr kTlsTcbOffset = 0x7000;
359 asm volatile(".set push;\
362 .set pop" : "=r" (thread_pointer));
363 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize();
364 # elif defined(__aarch64__) || defined(__arm__)
365 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) -
366 ThreadDescriptorSize();
367 # elif defined(__s390__)
368 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer());
369 # elif defined(__powerpc64__)
370 // PPC64LE uses TLS variant I. The thread pointer (in GPR 13)
371 // points to the end of the TCB + 0x7000. The pthread_descr structure is
372 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the
373 // TCB and the size of pthread_descr.
374 const uptr kTlsTcbOffset = 0x7000;
376 asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset));
377 descr_addr = thread_pointer - TlsPreTcbSize();
379 # error "unsupported CPU arch"
383 #endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX
385 #if SANITIZER_FREEBSD
386 static void **ThreadSelfSegbase() {
388 # if defined(__i386__)
389 // sysarch(I386_GET_GSBASE, segbase);
390 __asm __volatile("mov %%gs:0, %0" : "=r" (segbase));
391 # elif defined(__x86_64__)
392 // sysarch(AMD64_GET_FSBASE, segbase);
393 __asm __volatile("movq %%fs:0, %0" : "=r" (segbase));
395 # error "unsupported CPU arch"
401 return (uptr)ThreadSelfSegbase()[2];
403 #endif // SANITIZER_FREEBSD
406 static struct tls_tcb * ThreadSelfTlsTcb() {
407 return (struct tls_tcb *)_lwp_getprivate();
411 return (uptr)ThreadSelfTlsTcb()->tcb_pthread;
414 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) {
415 const Elf_Phdr *hdr = info->dlpi_phdr;
416 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum;
418 for (; hdr != last_hdr; ++hdr) {
419 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) {
420 *(uptr*)data = hdr->p_memsz;
426 #endif // SANITIZER_NETBSD
429 static void GetTls(uptr *addr, uptr *size) {
430 #if SANITIZER_LINUX && !SANITIZER_ANDROID
431 # if defined(__x86_64__) || defined(__i386__) || defined(__s390__)
432 *addr = ThreadSelf();
433 *size = GetTlsSize();
435 *addr += ThreadDescriptorSize();
436 # elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__) \
438 *addr = ThreadSelf();
439 *size = GetTlsSize();
444 #elif SANITIZER_FREEBSD
445 void** segbase = ThreadSelfSegbase();
450 // tls_size = round(tls_static_space, tcbalign);
452 // dtv[2] = segbase - tls_static_space;
453 void **dtv = (void**) segbase[1];
454 *addr = (uptr) dtv[2];
455 *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]);
457 #elif SANITIZER_NETBSD
458 struct tls_tcb * const tcb = ThreadSelfTlsTcb();
462 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program).
463 // ld.elf_so hardcodes the index 1.
464 dl_iterate_phdr(GetSizeFromHdr, size);
467 // The block has been found and tcb_dtv[1] contains the base address
468 *addr = (uptr)tcb->tcb_dtv[1];
471 #elif SANITIZER_OPENBSD
474 #elif SANITIZER_ANDROID
477 #elif SANITIZER_SOLARIS
489 #if SANITIZER_FREEBSD || SANITIZER_ANDROID || SANITIZER_NETBSD || \
490 SANITIZER_OPENBSD || SANITIZER_SOLARIS
492 GetTls(&addr, &size);
494 #elif defined(__mips__) || defined(__powerpc64__)
495 return RoundUpTo(g_tls_size + TlsPreTcbSize(), 16);
502 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
503 uptr *tls_addr, uptr *tls_size) {
505 // Stub implementation for Go.
506 *stk_addr = *stk_size = *tls_addr = *tls_size = 0;
508 GetTls(tls_addr, tls_size);
510 uptr stack_top, stack_bottom;
511 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
512 *stk_addr = stack_bottom;
513 *stk_size = stack_top - stack_bottom;
516 // If stack and tls intersect, make them non-intersecting.
517 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
518 CHECK_GT(*tls_addr + *tls_size, *stk_addr);
519 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size);
520 *stk_size -= *tls_size;
521 *tls_addr = *stk_addr + *stk_size;
527 #if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD
528 typedef ElfW(Phdr) Elf_Phdr;
529 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2
530 #define Elf_Phdr XElf32_Phdr
531 #define dl_phdr_info xdl_phdr_info
532 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b))
533 #endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD
535 struct DlIteratePhdrData {
536 InternalMmapVectorNoCtor<LoadedModule> *modules;
540 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
541 DlIteratePhdrData *data = (DlIteratePhdrData*)arg;
542 InternalScopedString module_name(kMaxPathLength);
545 // First module is the binary itself.
546 ReadBinaryNameCached(module_name.data(), module_name.size());
547 } else if (info->dlpi_name) {
548 module_name.append("%s", info->dlpi_name);
550 if (module_name[0] == '\0')
552 LoadedModule cur_module;
553 cur_module.set(module_name.data(), info->dlpi_addr);
554 for (int i = 0; i < (int)info->dlpi_phnum; i++) {
555 const Elf_Phdr *phdr = &info->dlpi_phdr[i];
556 if (phdr->p_type == PT_LOAD) {
557 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
558 uptr cur_end = cur_beg + phdr->p_memsz;
559 bool executable = phdr->p_flags & PF_X;
560 bool writable = phdr->p_flags & PF_W;
561 cur_module.addAddressRange(cur_beg, cur_end, executable,
565 data->modules->push_back(cur_module);
569 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
570 extern "C" __attribute__((weak)) int dl_iterate_phdr(
571 int (*)(struct dl_phdr_info *, size_t, void *), void *);
574 static bool requiresProcmaps() {
575 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22
576 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken.
577 // The runtime check allows the same library to work with
578 // both K and L (and future) Android releases.
579 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1;
585 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) {
586 MemoryMappingLayout memory_mapping(/*cache_enabled*/true);
587 memory_mapping.DumpListOfModules(modules);
590 void ListOfModules::init() {
592 if (requiresProcmaps()) {
593 procmapsInit(&modules_);
595 DlIteratePhdrData data = {&modules_, true};
596 dl_iterate_phdr(dl_iterate_phdr_cb, &data);
600 // When a custom loader is used, dl_iterate_phdr may not contain the full
601 // list of modules. Allow callers to fall back to using procmaps.
602 void ListOfModules::fallbackInit() {
603 if (!requiresProcmaps()) {
605 procmapsInit(&modules_);
611 // getrusage does not give us the current RSS, only the max RSS.
612 // Still, this is better than nothing if /proc/self/statm is not available
613 // for some reason, e.g. due to a sandbox.
614 static uptr GetRSSFromGetrusage() {
616 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox.
618 return usage.ru_maxrss << 10; // ru_maxrss is in Kb.
622 if (!common_flags()->can_use_proc_maps_statm)
623 return GetRSSFromGetrusage();
624 fd_t fd = OpenFile("/proc/self/statm", RdOnly);
625 if (fd == kInvalidFd)
626 return GetRSSFromGetrusage();
628 uptr len = internal_read(fd, buf, sizeof(buf) - 1);
633 // The format of the file is:
634 // 1084 89 69 11 0 79 0
635 // We need the second number which is RSS in pages.
637 // Skip the first number.
638 while (*pos >= '0' && *pos <= '9')
641 while (!(*pos >= '0' && *pos <= '9') && *pos != 0)
645 while (*pos >= '0' && *pos <= '9')
646 rss = rss * 10 + *pos++ - '0';
647 return rss * GetPageSizeCached();
650 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as
651 // they allocate memory.
652 u32 GetNumberOfCPUs() {
653 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD
656 uptr len = sizeof(ncpu);
659 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0);
661 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__)
662 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't
663 // exist in sched.h. That is the case for toolchains generated with older
665 // This code doesn't work on AArch64 because internal_getdents makes use of
666 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64.
667 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY);
668 if (internal_iserror(fd))
670 InternalMmapVector<u8> buffer(4096);
671 uptr bytes_read = buffer.size();
674 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read];
676 if ((u8 *)entry >= &buffer[bytes_read]) {
677 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(),
679 if (internal_iserror(bytes_read) || !bytes_read)
681 entry = (struct linux_dirent *)buffer.data();
683 d_type = (u8 *)entry + entry->d_reclen - 1;
684 if (d_type >= &buffer[bytes_read] ||
685 (u8 *)&entry->d_name[3] >= &buffer[bytes_read])
687 if (entry->d_ino != 0 && *d_type == DT_DIR) {
688 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' &&
689 entry->d_name[2] == 'u' &&
690 entry->d_name[3] >= '0' && entry->d_name[3] <= '9')
693 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen);
697 #elif SANITIZER_SOLARIS
698 return sysconf(_SC_NPROCESSORS_ONLN);
701 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0);
702 return CPU_COUNT(&CPUs);
708 # if SANITIZER_ANDROID
709 static atomic_uint8_t android_log_initialized;
711 void AndroidLogInit() {
712 openlog(GetProcessName(), 0, LOG_USER);
713 atomic_store(&android_log_initialized, 1, memory_order_release);
716 static bool ShouldLogAfterPrintf() {
717 return atomic_load(&android_log_initialized, memory_order_acquire);
720 extern "C" SANITIZER_WEAK_ATTRIBUTE
721 int async_safe_write_log(int pri, const char* tag, const char* msg);
722 extern "C" SANITIZER_WEAK_ATTRIBUTE
723 int __android_log_write(int prio, const char* tag, const char* msg);
725 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime.
726 #define SANITIZER_ANDROID_LOG_INFO 4
728 // async_safe_write_log is a new public version of __libc_write_log that is
729 // used behind syslog. It is preferable to syslog as it will not do any dynamic
730 // memory allocation or formatting.
731 // If the function is not available, syslog is preferred for L+ (it was broken
732 // pre-L) as __android_log_write triggers a racey behavior with the strncpy
733 // interceptor. Fallback to __android_log_write pre-L.
734 void WriteOneLineToSyslog(const char *s) {
735 if (&async_safe_write_log) {
736 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s);
737 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) {
738 syslog(LOG_INFO, "%s", s);
740 CHECK(&__android_log_write);
741 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s);
745 extern "C" SANITIZER_WEAK_ATTRIBUTE
746 void android_set_abort_message(const char *);
748 void SetAbortMessage(const char *str) {
749 if (&android_set_abort_message)
750 android_set_abort_message(str);
753 void AndroidLogInit() {}
755 static bool ShouldLogAfterPrintf() { return true; }
757 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); }
759 void SetAbortMessage(const char *str) {}
760 # endif // SANITIZER_ANDROID
762 void LogMessageOnPrintf(const char *str) {
763 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf())
767 #endif // SANITIZER_LINUX
769 #if SANITIZER_LINUX && !SANITIZER_GO
770 // glibc crashes when using clock_gettime from a preinit_array function as the
771 // vDSO function pointers haven't been initialized yet. __progname is
772 // initialized after the vDSO function pointers, so if it exists, is not null
773 // and is not empty, we can use clock_gettime.
774 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname;
775 INLINE bool CanUseVDSO() {
776 // Bionic is safe, it checks for the vDSO function pointers to be initialized.
777 if (SANITIZER_ANDROID)
779 if (&__progname && __progname && *__progname)
784 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling
785 // clock_gettime. real_clock_gettime only exists if clock_gettime is
786 // intercepted, so define it weakly and use it if available.
787 extern "C" SANITIZER_WEAK_ATTRIBUTE
788 int real_clock_gettime(u32 clk_id, void *tp);
789 u64 MonotonicNanoTime() {
792 if (&real_clock_gettime)
793 real_clock_gettime(CLOCK_MONOTONIC, &ts);
795 clock_gettime(CLOCK_MONOTONIC, &ts);
797 internal_clock_gettime(CLOCK_MONOTONIC, &ts);
799 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
802 // Non-Linux & Go always use the syscall.
803 u64 MonotonicNanoTime() {
805 internal_clock_gettime(CLOCK_MONOTONIC, &ts);
806 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
808 #endif // SANITIZER_LINUX && !SANITIZER_GO
810 #if !SANITIZER_OPENBSD
812 const char *pathname = "/proc/self/exe";
815 static const int name[] = {
825 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1)
827 #elif SANITIZER_SOLARIS
828 pathname = getexecname();
829 CHECK_NE(pathname, NULL);
830 #elif SANITIZER_USE_GETAUXVAL
831 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that
832 // rely on that will fail to load shared libraries. Query AT_EXECFN instead.
833 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN));
836 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron());
838 CHECK_EQ(internal_iserror(rv, &rverrno), true);
839 Printf("execve failed, errno %d\n", rverrno);
842 #endif // !SANITIZER_OPENBSD
844 } // namespace __sanitizer