//===-- sanitizer_linux_libcdep.cpp ---------------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // // This file is shared between AddressSanitizer and ThreadSanitizer // run-time libraries and implements linux-specific functions from // sanitizer_libc.h. //===----------------------------------------------------------------------===// #include "sanitizer_platform.h" #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \ SANITIZER_SOLARIS #include "sanitizer_allocator_internal.h" #include "sanitizer_atomic.h" #include "sanitizer_common.h" #include "sanitizer_file.h" #include "sanitizer_flags.h" #include "sanitizer_freebsd.h" #include "sanitizer_getauxval.h" #include "sanitizer_glibc_version.h" #include "sanitizer_linux.h" #include "sanitizer_placement_new.h" #include "sanitizer_procmaps.h" #include "sanitizer_solaris.h" #if SANITIZER_NETBSD #define _RTLD_SOURCE // for __lwp_gettcb_fast() / __lwp_getprivate_fast() #endif #include // for dlsym() #include #include #include #include #include #include #if !defined(ElfW) #define ElfW(type) Elf_##type #endif #if SANITIZER_FREEBSD #include #include #include #define pthread_getattr_np pthread_attr_get_np // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before // that, it was never implemented. So just define it to zero. #undef MAP_NORESERVE #define MAP_NORESERVE 0 #endif #if SANITIZER_NETBSD #include #include #include #endif #if SANITIZER_SOLARIS #include #include #include #endif #if SANITIZER_ANDROID #include #if !defined(CPU_COUNT) && !defined(__aarch64__) #include #include struct __sanitizer::linux_dirent { long d_ino; off_t d_off; unsigned short d_reclen; char d_name[]; }; #endif #endif #if !SANITIZER_ANDROID #include #include #endif namespace __sanitizer { SANITIZER_WEAK_ATTRIBUTE int real_sigaction(int signum, const void *act, void *oldact); int internal_sigaction(int signum, const void *act, void *oldact) { #if !SANITIZER_GO if (&real_sigaction) return real_sigaction(signum, act, oldact); #endif return sigaction(signum, (const struct sigaction *)act, (struct sigaction *)oldact); } void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top, uptr *stack_bottom) { CHECK(stack_top); CHECK(stack_bottom); if (at_initialization) { // This is the main thread. Libpthread may not be initialized yet. struct rlimit rl; CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0); // Find the mapping that contains a stack variable. MemoryMappingLayout proc_maps(/*cache_enabled*/true); if (proc_maps.Error()) { *stack_top = *stack_bottom = 0; return; } MemoryMappedSegment segment; uptr prev_end = 0; while (proc_maps.Next(&segment)) { if ((uptr)&rl < segment.end) break; prev_end = segment.end; } CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end); // Get stacksize from rlimit, but clip it so that it does not overlap // with other mappings. uptr stacksize = rl.rlim_cur; if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end; // When running with unlimited stack size, we still want to set some limit. // The unlimited stack size is caused by 'ulimit -s unlimited'. // Also, for some reason, GNU make spawns subprocesses with unlimited stack. if (stacksize > kMaxThreadStackSize) stacksize = kMaxThreadStackSize; *stack_top = segment.end; *stack_bottom = segment.end - stacksize; return; } uptr stacksize = 0; void *stackaddr = nullptr; #if SANITIZER_SOLARIS stack_t ss; CHECK_EQ(thr_stksegment(&ss), 0); stacksize = ss.ss_size; stackaddr = (char *)ss.ss_sp - stacksize; #else // !SANITIZER_SOLARIS pthread_attr_t attr; pthread_attr_init(&attr); CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); my_pthread_attr_getstack(&attr, &stackaddr, &stacksize); pthread_attr_destroy(&attr); #endif // SANITIZER_SOLARIS *stack_top = (uptr)stackaddr + stacksize; *stack_bottom = (uptr)stackaddr; } #if !SANITIZER_GO bool SetEnv(const char *name, const char *value) { void *f = dlsym(RTLD_NEXT, "setenv"); if (!f) return false; typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); setenv_ft setenv_f; CHECK_EQ(sizeof(setenv_f), sizeof(f)); internal_memcpy(&setenv_f, &f, sizeof(f)); return setenv_f(name, value, 1) == 0; } #endif __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor, int *patch) { #ifdef _CS_GNU_LIBC_VERSION char buf[64]; uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf)); if (len >= sizeof(buf)) return false; buf[len] = 0; static const char kGLibC[] = "glibc "; if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0) return false; const char *p = buf + sizeof(kGLibC) - 1; *major = internal_simple_strtoll(p, &p, 10); *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; return true; #else return false; #endif } // True if we can use dlpi_tls_data. glibc before 2.25 may leave NULL (BZ // #19826) so dlpi_tls_data cannot be used. // // musl before 1.2.3 and FreeBSD as of 12.2 incorrectly set dlpi_tls_data to // the TLS initialization image // https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=254774 __attribute__((unused)) static int g_use_dlpi_tls_data; #if SANITIZER_GLIBC && !SANITIZER_GO __attribute__((unused)) static size_t g_tls_size; void InitTlsSize() { int major, minor, patch; g_use_dlpi_tls_data = GetLibcVersion(&major, &minor, &patch) && major == 2 && minor >= 25; #if defined(__aarch64__) || defined(__x86_64__) || defined(__powerpc64__) void *get_tls_static_info = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); size_t tls_align; ((void (*)(size_t *, size_t *))get_tls_static_info)(&g_tls_size, &tls_align); #endif } #else void InitTlsSize() { } #endif // SANITIZER_GLIBC && !SANITIZER_GO // On glibc x86_64, ThreadDescriptorSize() needs to be precise due to the usage // of g_tls_size. On other targets, ThreadDescriptorSize() is only used by lsan // to get the pointer to thread-specific data keys in the thread control block. #if (SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_SOLARIS) && \ !SANITIZER_ANDROID && !SANITIZER_GO // sizeof(struct pthread) from glibc. static atomic_uintptr_t thread_descriptor_size; static uptr ThreadDescriptorSizeFallback() { uptr val = 0; #if defined(__x86_64__) || defined(__i386__) || defined(__arm__) int major; int minor; int patch; if (GetLibcVersion(&major, &minor, &patch) && major == 2) { /* sizeof(struct pthread) values from various glibc versions. */ if (SANITIZER_X32) val = 1728; // Assume only one particular version for x32. // For ARM sizeof(struct pthread) changed in Glibc 2.23. else if (SANITIZER_ARM) val = minor <= 22 ? 1120 : 1216; else if (minor <= 3) val = FIRST_32_SECOND_64(1104, 1696); else if (minor == 4) val = FIRST_32_SECOND_64(1120, 1728); else if (minor == 5) val = FIRST_32_SECOND_64(1136, 1728); else if (minor <= 9) val = FIRST_32_SECOND_64(1136, 1712); else if (minor == 10) val = FIRST_32_SECOND_64(1168, 1776); else if (minor == 11 || (minor == 12 && patch == 1)) val = FIRST_32_SECOND_64(1168, 2288); else if (minor <= 14) val = FIRST_32_SECOND_64(1168, 2304); else if (minor < 32) // Unknown version val = FIRST_32_SECOND_64(1216, 2304); else // minor == 32 val = FIRST_32_SECOND_64(1344, 2496); } #elif defined(__s390__) || defined(__sparc__) // The size of a prefix of TCB including pthread::{specific_1stblock,specific} // suffices. Just return offsetof(struct pthread, specific_used), which hasn't // changed since 2007-05. Technically this applies to i386/x86_64 as well but // we call _dl_get_tls_static_info and need the precise size of struct // pthread. return FIRST_32_SECOND_64(524, 1552); #elif defined(__mips__) // TODO(sagarthakur): add more values as per different glibc versions. val = FIRST_32_SECOND_64(1152, 1776); #elif SANITIZER_RISCV64 int major; int minor; int patch; if (GetLibcVersion(&major, &minor, &patch) && major == 2) { // TODO: consider adding an optional runtime check for an unknown (untested) // glibc version if (minor <= 28) // WARNING: the highest tested version is 2.29 val = 1772; // no guarantees for this one else if (minor <= 31) val = 1772; // tested against glibc 2.29, 2.31 else val = 1936; // tested against glibc 2.32 } #elif defined(__aarch64__) // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. val = 1776; #elif defined(__powerpc64__) val = 1776; // from glibc.ppc64le 2.20-8.fc21 #endif return val; } uptr ThreadDescriptorSize() { uptr val = atomic_load_relaxed(&thread_descriptor_size); if (val) return val; // _thread_db_sizeof_pthread is a GLIBC_PRIVATE symbol that is exported in // glibc 2.34 and later. if (unsigned *psizeof = static_cast( dlsym(RTLD_DEFAULT, "_thread_db_sizeof_pthread"))) val = *psizeof; if (!val) val = ThreadDescriptorSizeFallback(); atomic_store_relaxed(&thread_descriptor_size, val); return val; } #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb // head structure. It lies before the static tls blocks. static uptr TlsPreTcbSize() { #if defined(__mips__) const uptr kTcbHead = 16; // sizeof (tcbhead_t) #elif defined(__powerpc64__) const uptr kTcbHead = 88; // sizeof (tcbhead_t) #elif SANITIZER_RISCV64 const uptr kTcbHead = 16; // sizeof (tcbhead_t) #endif const uptr kTlsAlign = 16; const uptr kTlsPreTcbSize = RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign); return kTlsPreTcbSize; } #endif namespace { struct TlsBlock { uptr begin, end, align; size_t tls_modid; bool operator<(const TlsBlock &rhs) const { return begin < rhs.begin; } }; } // namespace #ifdef __s390__ extern "C" uptr __tls_get_offset(void *arg); static uptr TlsGetOffset(uptr ti_module, uptr ti_offset) { // The __tls_get_offset ABI requires %r12 to point to GOT and %r2 to be an // offset of a struct tls_index inside GOT. We don't possess either of the // two, so violate the letter of the "ELF Handling For Thread-Local // Storage" document and assume that the implementation just dereferences // %r2 + %r12. uptr tls_index[2] = {ti_module, ti_offset}; register uptr r2 asm("2") = 0; register void *r12 asm("12") = tls_index; asm("basr %%r14, %[__tls_get_offset]" : "+r"(r2) : [__tls_get_offset] "r"(__tls_get_offset), "r"(r12) : "memory", "cc", "0", "1", "3", "4", "5", "14"); return r2; } #else extern "C" void *__tls_get_addr(size_t *); #endif static size_t main_tls_modid; static int CollectStaticTlsBlocks(struct dl_phdr_info *info, size_t size, void *data) { size_t tls_modid; #if SANITIZER_SOLARIS // dlpi_tls_modid is only available since Solaris 11.4 SRU 10. Use // dlinfo(RTLD_DI_LINKMAP) instead which works on all of Solaris 11.3, // 11.4, and Illumos. The tlsmodid of the executable was changed to 1 in // 11.4 to match other implementations. if (size >= offsetof(dl_phdr_info_test, dlpi_tls_modid)) main_tls_modid = 1; else main_tls_modid = 0; g_use_dlpi_tls_data = 0; Rt_map *map; dlinfo(RTLD_SELF, RTLD_DI_LINKMAP, &map); tls_modid = map->rt_tlsmodid; #else main_tls_modid = 1; tls_modid = info->dlpi_tls_modid; #endif if (tls_modid < main_tls_modid) return 0; uptr begin; #if !SANITIZER_SOLARIS begin = (uptr)info->dlpi_tls_data; #endif if (!g_use_dlpi_tls_data) { // Call __tls_get_addr as a fallback. This forces TLS allocation on glibc // and FreeBSD. #ifdef __s390__ begin = (uptr)__builtin_thread_pointer() + TlsGetOffset(tls_modid, 0); #else size_t mod_and_off[2] = {tls_modid, 0}; begin = (uptr)__tls_get_addr(mod_and_off); #endif } for (unsigned i = 0; i != info->dlpi_phnum; ++i) if (info->dlpi_phdr[i].p_type == PT_TLS) { static_cast *>(data)->push_back( TlsBlock{begin, begin + info->dlpi_phdr[i].p_memsz, info->dlpi_phdr[i].p_align, tls_modid}); break; } return 0; } __attribute__((unused)) static void GetStaticTlsBoundary(uptr *addr, uptr *size, uptr *align) { InternalMmapVector ranges; dl_iterate_phdr(CollectStaticTlsBlocks, &ranges); uptr len = ranges.size(); Sort(ranges.begin(), len); // Find the range with tls_modid == main_tls_modid. For glibc, because // libc.so uses PT_TLS, this module is guaranteed to exist and is one of // the initially loaded modules. uptr one = 0; while (one != len && ranges[one].tls_modid != main_tls_modid) ++one; if (one == len) { // This may happen with musl if no module uses PT_TLS. *addr = 0; *size = 0; *align = 1; return; } // Find the maximum consecutive ranges. We consider two modules consecutive if // the gap is smaller than the alignment of the latter range. The dynamic // loader places static TLS blocks this way not to waste space. uptr l = one; *align = ranges[l].align; while (l != 0 && ranges[l].begin < ranges[l - 1].end + ranges[l].align) *align = Max(*align, ranges[--l].align); uptr r = one + 1; while (r != len && ranges[r].begin < ranges[r - 1].end + ranges[r].align) *align = Max(*align, ranges[r++].align); *addr = ranges[l].begin; *size = ranges[r - 1].end - ranges[l].begin; } #endif // (x86_64 || i386 || mips || ...) && (SANITIZER_FREEBSD || // SANITIZER_LINUX) && !SANITIZER_ANDROID && !SANITIZER_GO #if SANITIZER_NETBSD static struct tls_tcb * ThreadSelfTlsTcb() { struct tls_tcb *tcb = nullptr; #ifdef __HAVE___LWP_GETTCB_FAST tcb = (struct tls_tcb *)__lwp_gettcb_fast(); #elif defined(__HAVE___LWP_GETPRIVATE_FAST) tcb = (struct tls_tcb *)__lwp_getprivate_fast(); #endif return tcb; } uptr ThreadSelf() { return (uptr)ThreadSelfTlsTcb()->tcb_pthread; } int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) { const Elf_Phdr *hdr = info->dlpi_phdr; const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum; for (; hdr != last_hdr; ++hdr) { if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) { *(uptr*)data = hdr->p_memsz; break; } } return 0; } #endif // SANITIZER_NETBSD #if SANITIZER_ANDROID // Bionic provides this API since S. extern "C" SANITIZER_WEAK_ATTRIBUTE void __libc_get_static_tls_bounds(void **, void **); #endif #if !SANITIZER_GO static void GetTls(uptr *addr, uptr *size) { #if SANITIZER_ANDROID if (&__libc_get_static_tls_bounds) { void *start_addr; void *end_addr; __libc_get_static_tls_bounds(&start_addr, &end_addr); *addr = reinterpret_cast(start_addr); *size = reinterpret_cast(end_addr) - reinterpret_cast(start_addr); } else { *addr = 0; *size = 0; } #elif SANITIZER_GLIBC && defined(__x86_64__) // For aarch64 and x86-64, use an O(1) approach which requires relatively // precise ThreadDescriptorSize. g_tls_size was initialized in InitTlsSize. # if SANITIZER_X32 asm("mov %%fs:8,%0" : "=r"(*addr)); # else asm("mov %%fs:16,%0" : "=r"(*addr)); # endif *size = g_tls_size; *addr -= *size; *addr += ThreadDescriptorSize(); #elif SANITIZER_GLIBC && defined(__aarch64__) *addr = reinterpret_cast(__builtin_thread_pointer()) - ThreadDescriptorSize(); *size = g_tls_size + ThreadDescriptorSize(); #elif SANITIZER_GLIBC && defined(__powerpc64__) // Workaround for glibc<2.25(?). 2.27 is known to not need this. uptr tp; asm("addi %0,13,-0x7000" : "=r"(tp)); const uptr pre_tcb_size = TlsPreTcbSize(); *addr = tp - pre_tcb_size; *size = g_tls_size + pre_tcb_size; #elif SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_SOLARIS uptr align; GetStaticTlsBoundary(addr, size, &align); #if defined(__x86_64__) || defined(__i386__) || defined(__s390__) || \ defined(__sparc__) if (SANITIZER_GLIBC) { #if defined(__x86_64__) || defined(__i386__) align = Max(align, 64); #else align = Max(align, 16); #endif } const uptr tp = RoundUpTo(*addr + *size, align); // lsan requires the range to additionally cover the static TLS surplus // (elf/dl-tls.c defines 1664). Otherwise there may be false positives for // allocations only referenced by tls in dynamically loaded modules. if (SANITIZER_GLIBC) *size += 1644; else if (SANITIZER_FREEBSD) *size += 128; // RTLD_STATIC_TLS_EXTRA // Extend the range to include the thread control block. On glibc, lsan needs // the range to include pthread::{specific_1stblock,specific} so that // allocations only referenced by pthread_setspecific can be scanned. This may // underestimate by at most TLS_TCB_ALIGN-1 bytes but it should be fine // because the number of bytes after pthread::specific is larger. *addr = tp - RoundUpTo(*size, align); *size = tp - *addr + ThreadDescriptorSize(); #else if (SANITIZER_GLIBC) *size += 1664; else if (SANITIZER_FREEBSD) *size += 128; // RTLD_STATIC_TLS_EXTRA #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 const uptr pre_tcb_size = TlsPreTcbSize(); *addr -= pre_tcb_size; *size += pre_tcb_size; #else // arm and aarch64 reserve two words at TP, so this underestimates the range. // However, this is sufficient for the purpose of finding the pointers to // thread-specific data keys. const uptr tcb_size = ThreadDescriptorSize(); *addr -= tcb_size; *size += tcb_size; #endif #endif #elif SANITIZER_NETBSD struct tls_tcb * const tcb = ThreadSelfTlsTcb(); *addr = 0; *size = 0; if (tcb != 0) { // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program). // ld.elf_so hardcodes the index 1. dl_iterate_phdr(GetSizeFromHdr, size); if (*size != 0) { // The block has been found and tcb_dtv[1] contains the base address *addr = (uptr)tcb->tcb_dtv[1]; } } #error "Unknown OS" #endif } #endif #if !SANITIZER_GO uptr GetTlsSize() { #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \ SANITIZER_SOLARIS uptr addr, size; GetTls(&addr, &size); return size; #else return 0; #endif } #endif void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, uptr *tls_addr, uptr *tls_size) { #if SANITIZER_GO // Stub implementation for Go. *stk_addr = *stk_size = *tls_addr = *tls_size = 0; #else GetTls(tls_addr, tls_size); uptr stack_top, stack_bottom; GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); *stk_addr = stack_bottom; *stk_size = stack_top - stack_bottom; if (!main) { // If stack and tls intersect, make them non-intersecting. if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { if (*stk_addr + *stk_size < *tls_addr + *tls_size) *tls_size = *stk_addr + *stk_size - *tls_addr; *stk_size = *tls_addr - *stk_addr; } } #endif } #if !SANITIZER_FREEBSD typedef ElfW(Phdr) Elf_Phdr; #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2 #define Elf_Phdr XElf32_Phdr #define dl_phdr_info xdl_phdr_info #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b)) #endif // !SANITIZER_FREEBSD struct DlIteratePhdrData { InternalMmapVectorNoCtor *modules; bool first; }; static int AddModuleSegments(const char *module_name, dl_phdr_info *info, InternalMmapVectorNoCtor *modules) { if (module_name[0] == '\0') return 0; LoadedModule cur_module; cur_module.set(module_name, info->dlpi_addr); for (int i = 0; i < (int)info->dlpi_phnum; i++) { const Elf_Phdr *phdr = &info->dlpi_phdr[i]; if (phdr->p_type == PT_LOAD) { uptr cur_beg = info->dlpi_addr + phdr->p_vaddr; uptr cur_end = cur_beg + phdr->p_memsz; bool executable = phdr->p_flags & PF_X; bool writable = phdr->p_flags & PF_W; cur_module.addAddressRange(cur_beg, cur_end, executable, writable); } else if (phdr->p_type == PT_NOTE) { # ifdef NT_GNU_BUILD_ID uptr off = 0; while (off + sizeof(ElfW(Nhdr)) < phdr->p_memsz) { auto *nhdr = reinterpret_cast(info->dlpi_addr + phdr->p_vaddr + off); constexpr auto kGnuNamesz = 4; // "GNU" with NUL-byte. static_assert(kGnuNamesz % 4 == 0, "kGnuNameSize is aligned to 4."); if (nhdr->n_type == NT_GNU_BUILD_ID && nhdr->n_namesz == kGnuNamesz) { if (off + sizeof(ElfW(Nhdr)) + nhdr->n_namesz + nhdr->n_descsz > phdr->p_memsz) { // Something is very wrong, bail out instead of reading potentially // arbitrary memory. break; } const char *name = reinterpret_cast(nhdr) + sizeof(*nhdr); if (internal_memcmp(name, "GNU", 3) == 0) { const char *value = reinterpret_cast(nhdr) + sizeof(*nhdr) + kGnuNamesz; cur_module.setUuid(value, nhdr->n_descsz); break; } } off += sizeof(*nhdr) + RoundUpTo(nhdr->n_namesz, 4) + RoundUpTo(nhdr->n_descsz, 4); } # endif } } modules->push_back(cur_module); return 0; } static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { DlIteratePhdrData *data = (DlIteratePhdrData *)arg; if (data->first) { InternalMmapVector module_name(kMaxPathLength); data->first = false; // First module is the binary itself. ReadBinaryNameCached(module_name.data(), module_name.size()); return AddModuleSegments(module_name.data(), info, data->modules); } if (info->dlpi_name) { InternalScopedString module_name; module_name.append("%s", info->dlpi_name); return AddModuleSegments(module_name.data(), info, data->modules); } return 0; } #if SANITIZER_ANDROID && __ANDROID_API__ < 21 extern "C" __attribute__((weak)) int dl_iterate_phdr( int (*)(struct dl_phdr_info *, size_t, void *), void *); #endif static bool requiresProcmaps() { #if SANITIZER_ANDROID && __ANDROID_API__ <= 22 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken. // The runtime check allows the same library to work with // both K and L (and future) Android releases. return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1; #else return false; #endif } static void procmapsInit(InternalMmapVectorNoCtor *modules) { MemoryMappingLayout memory_mapping(/*cache_enabled*/true); memory_mapping.DumpListOfModules(modules); } void ListOfModules::init() { clearOrInit(); if (requiresProcmaps()) { procmapsInit(&modules_); } else { DlIteratePhdrData data = {&modules_, true}; dl_iterate_phdr(dl_iterate_phdr_cb, &data); } } // When a custom loader is used, dl_iterate_phdr may not contain the full // list of modules. Allow callers to fall back to using procmaps. void ListOfModules::fallbackInit() { if (!requiresProcmaps()) { clearOrInit(); procmapsInit(&modules_); } else { clear(); } } // getrusage does not give us the current RSS, only the max RSS. // Still, this is better than nothing if /proc/self/statm is not available // for some reason, e.g. due to a sandbox. static uptr GetRSSFromGetrusage() { struct rusage usage; if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox. return 0; return usage.ru_maxrss << 10; // ru_maxrss is in Kb. } uptr GetRSS() { if (!common_flags()->can_use_proc_maps_statm) return GetRSSFromGetrusage(); fd_t fd = OpenFile("/proc/self/statm", RdOnly); if (fd == kInvalidFd) return GetRSSFromGetrusage(); char buf[64]; uptr len = internal_read(fd, buf, sizeof(buf) - 1); internal_close(fd); if ((sptr)len <= 0) return 0; buf[len] = 0; // The format of the file is: // 1084 89 69 11 0 79 0 // We need the second number which is RSS in pages. char *pos = buf; // Skip the first number. while (*pos >= '0' && *pos <= '9') pos++; // Skip whitespaces. while (!(*pos >= '0' && *pos <= '9') && *pos != 0) pos++; // Read the number. uptr rss = 0; while (*pos >= '0' && *pos <= '9') rss = rss * 10 + *pos++ - '0'; return rss * GetPageSizeCached(); } // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as // they allocate memory. u32 GetNumberOfCPUs() { #if SANITIZER_FREEBSD || SANITIZER_NETBSD u32 ncpu; int req[2]; uptr len = sizeof(ncpu); req[0] = CTL_HW; req[1] = HW_NCPU; CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0); return ncpu; #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__) // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't // exist in sched.h. That is the case for toolchains generated with older // NDKs. // This code doesn't work on AArch64 because internal_getdents makes use of // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64. uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY); if (internal_iserror(fd)) return 0; InternalMmapVector buffer(4096); uptr bytes_read = buffer.size(); uptr n_cpus = 0; u8 *d_type; struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read]; while (true) { if ((u8 *)entry >= &buffer[bytes_read]) { bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(), buffer.size()); if (internal_iserror(bytes_read) || !bytes_read) break; entry = (struct linux_dirent *)buffer.data(); } d_type = (u8 *)entry + entry->d_reclen - 1; if (d_type >= &buffer[bytes_read] || (u8 *)&entry->d_name[3] >= &buffer[bytes_read]) break; if (entry->d_ino != 0 && *d_type == DT_DIR) { if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' && entry->d_name[2] == 'u' && entry->d_name[3] >= '0' && entry->d_name[3] <= '9') n_cpus++; } entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen); } internal_close(fd); return n_cpus; #elif SANITIZER_SOLARIS return sysconf(_SC_NPROCESSORS_ONLN); #else #if defined(CPU_COUNT) cpu_set_t CPUs; CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0); return CPU_COUNT(&CPUs); #else return 1; #endif #endif } #if SANITIZER_LINUX #if SANITIZER_ANDROID static atomic_uint8_t android_log_initialized; void AndroidLogInit() { openlog(GetProcessName(), 0, LOG_USER); atomic_store(&android_log_initialized, 1, memory_order_release); } static bool ShouldLogAfterPrintf() { return atomic_load(&android_log_initialized, memory_order_acquire); } extern "C" SANITIZER_WEAK_ATTRIBUTE int async_safe_write_log(int pri, const char* tag, const char* msg); extern "C" SANITIZER_WEAK_ATTRIBUTE int __android_log_write(int prio, const char* tag, const char* msg); // ANDROID_LOG_INFO is 4, but can't be resolved at runtime. #define SANITIZER_ANDROID_LOG_INFO 4 // async_safe_write_log is a new public version of __libc_write_log that is // used behind syslog. It is preferable to syslog as it will not do any dynamic // memory allocation or formatting. // If the function is not available, syslog is preferred for L+ (it was broken // pre-L) as __android_log_write triggers a racey behavior with the strncpy // interceptor. Fallback to __android_log_write pre-L. void WriteOneLineToSyslog(const char *s) { if (&async_safe_write_log) { async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s); } else if (AndroidGetApiLevel() > ANDROID_KITKAT) { syslog(LOG_INFO, "%s", s); } else { CHECK(&__android_log_write); __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s); } } extern "C" SANITIZER_WEAK_ATTRIBUTE void android_set_abort_message(const char *); void SetAbortMessage(const char *str) { if (&android_set_abort_message) android_set_abort_message(str); } #else void AndroidLogInit() {} static bool ShouldLogAfterPrintf() { return true; } void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); } void SetAbortMessage(const char *str) {} #endif // SANITIZER_ANDROID void LogMessageOnPrintf(const char *str) { if (common_flags()->log_to_syslog && ShouldLogAfterPrintf()) WriteToSyslog(str); } #endif // SANITIZER_LINUX #if SANITIZER_GLIBC && !SANITIZER_GO // glibc crashes when using clock_gettime from a preinit_array function as the // vDSO function pointers haven't been initialized yet. __progname is // initialized after the vDSO function pointers, so if it exists, is not null // and is not empty, we can use clock_gettime. extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname; inline bool CanUseVDSO() { return &__progname && __progname && *__progname; } // MonotonicNanoTime is a timing function that can leverage the vDSO by calling // clock_gettime. real_clock_gettime only exists if clock_gettime is // intercepted, so define it weakly and use it if available. extern "C" SANITIZER_WEAK_ATTRIBUTE int real_clock_gettime(u32 clk_id, void *tp); u64 MonotonicNanoTime() { timespec ts; if (CanUseVDSO()) { if (&real_clock_gettime) real_clock_gettime(CLOCK_MONOTONIC, &ts); else clock_gettime(CLOCK_MONOTONIC, &ts); } else { internal_clock_gettime(CLOCK_MONOTONIC, &ts); } return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; } #else // Non-glibc & Go always use the regular function. u64 MonotonicNanoTime() { timespec ts; clock_gettime(CLOCK_MONOTONIC, &ts); return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; } #endif // SANITIZER_GLIBC && !SANITIZER_GO void ReExec() { const char *pathname = "/proc/self/exe"; #if SANITIZER_NETBSD static const int name[] = { CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME, }; char path[400]; uptr len; len = sizeof(path); if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1) pathname = path; #elif SANITIZER_SOLARIS pathname = getexecname(); CHECK_NE(pathname, NULL); #elif SANITIZER_USE_GETAUXVAL // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that // rely on that will fail to load shared libraries. Query AT_EXECFN instead. pathname = reinterpret_cast(getauxval(AT_EXECFN)); #endif uptr rv = internal_execve(pathname, GetArgv(), GetEnviron()); int rverrno; CHECK_EQ(internal_iserror(rv, &rverrno), true); Printf("execve failed, errno %d\n", rverrno); Die(); } void UnmapFromTo(uptr from, uptr to) { if (to == from) return; CHECK(to >= from); uptr res = internal_munmap(reinterpret_cast(from), to - from); if (UNLIKELY(internal_iserror(res))) { Report("ERROR: %s failed to unmap 0x%zx (%zd) bytes at address %p\n", SanitizerToolName, to - from, to - from, (void *)from); CHECK("unable to unmap" && 0); } } uptr MapDynamicShadow(uptr shadow_size_bytes, uptr shadow_scale, uptr min_shadow_base_alignment, UNUSED uptr &high_mem_end) { const uptr granularity = GetMmapGranularity(); const uptr alignment = Max(granularity << shadow_scale, 1ULL << min_shadow_base_alignment); const uptr left_padding = Max(granularity, 1ULL << min_shadow_base_alignment); const uptr shadow_size = RoundUpTo(shadow_size_bytes, granularity); const uptr map_size = shadow_size + left_padding + alignment; const uptr map_start = (uptr)MmapNoAccess(map_size); CHECK_NE(map_start, ~(uptr)0); const uptr shadow_start = RoundUpTo(map_start + left_padding, alignment); UnmapFromTo(map_start, shadow_start - left_padding); UnmapFromTo(shadow_start + shadow_size, map_start + map_size); return shadow_start; } static uptr MmapSharedNoReserve(uptr addr, uptr size) { return internal_mmap( reinterpret_cast(addr), size, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0); } static uptr MremapCreateAlias(uptr base_addr, uptr alias_addr, uptr alias_size) { #if SANITIZER_LINUX return internal_mremap(reinterpret_cast(base_addr), 0, alias_size, MREMAP_MAYMOVE | MREMAP_FIXED, reinterpret_cast(alias_addr)); #else CHECK(false && "mremap is not supported outside of Linux"); return 0; #endif } static void CreateAliases(uptr start_addr, uptr alias_size, uptr num_aliases) { uptr total_size = alias_size * num_aliases; uptr mapped = MmapSharedNoReserve(start_addr, total_size); CHECK_EQ(mapped, start_addr); for (uptr i = 1; i < num_aliases; ++i) { uptr alias_addr = start_addr + i * alias_size; CHECK_EQ(MremapCreateAlias(start_addr, alias_addr, alias_size), alias_addr); } } uptr MapDynamicShadowAndAliases(uptr shadow_size, uptr alias_size, uptr num_aliases, uptr ring_buffer_size) { CHECK_EQ(alias_size & (alias_size - 1), 0); CHECK_EQ(num_aliases & (num_aliases - 1), 0); CHECK_EQ(ring_buffer_size & (ring_buffer_size - 1), 0); const uptr granularity = GetMmapGranularity(); shadow_size = RoundUpTo(shadow_size, granularity); CHECK_EQ(shadow_size & (shadow_size - 1), 0); const uptr alias_region_size = alias_size * num_aliases; const uptr alignment = 2 * Max(Max(shadow_size, alias_region_size), ring_buffer_size); const uptr left_padding = ring_buffer_size; const uptr right_size = alignment; const uptr map_size = left_padding + 2 * alignment; const uptr map_start = reinterpret_cast(MmapNoAccess(map_size)); CHECK_NE(map_start, static_cast(-1)); const uptr right_start = RoundUpTo(map_start + left_padding, alignment); UnmapFromTo(map_start, right_start - left_padding); UnmapFromTo(right_start + right_size, map_start + map_size); CreateAliases(right_start + right_size / 2, alias_size, num_aliases); return right_start; } void InitializePlatformCommonFlags(CommonFlags *cf) { #if SANITIZER_ANDROID if (&__libc_get_static_tls_bounds == nullptr) cf->detect_leaks = false; #endif } } // namespace __sanitizer #endif