//===-- asan_linux.cc -----------------------------------------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file is a part of AddressSanitizer, an address sanity checker. // // Posix-specific details. //===----------------------------------------------------------------------===// #if defined(__linux__) || defined(__APPLE__) #include "asan_internal.h" #include "asan_interceptors.h" #include "asan_mapping.h" #include "asan_report.h" #include "asan_stack.h" #include "asan_thread_registry.h" #include "sanitizer_common/sanitizer_libc.h" #include "sanitizer_common/sanitizer_procmaps.h" #include <pthread.h> #include <signal.h> #include <stdlib.h> #include <sys/time.h> #include <sys/resource.h> #include <unistd.h> static const uptr kAltStackSize = SIGSTKSZ * 4; // SIGSTKSZ is not enough. namespace __asan { static void MaybeInstallSigaction(int signum, void (*handler)(int, siginfo_t *, void *)) { if (!AsanInterceptsSignal(signum)) return; struct sigaction sigact; REAL(memset)(&sigact, 0, sizeof(sigact)); sigact.sa_sigaction = handler; sigact.sa_flags = SA_SIGINFO; if (flags()->use_sigaltstack) sigact.sa_flags |= SA_ONSTACK; CHECK(0 == REAL(sigaction)(signum, &sigact, 0)); if (flags()->verbosity >= 1) { Report("Installed the sigaction for signal %d\n", signum); } } static void ASAN_OnSIGSEGV(int, siginfo_t *siginfo, void *context) { uptr addr = (uptr)siginfo->si_addr; // Write the first message using the bullet-proof write. if (13 != internal_write(2, "ASAN:SIGSEGV\n", 13)) Die(); uptr pc, sp, bp; GetPcSpBp(context, &pc, &sp, &bp); ReportSIGSEGV(pc, sp, bp, addr); } void SetAlternateSignalStack() { stack_t altstack, oldstack; CHECK(0 == sigaltstack(0, &oldstack)); // If the alternate stack is already in place, do nothing. if ((oldstack.ss_flags & SS_DISABLE) == 0) return; // TODO(glider): the mapped stack should have the MAP_STACK flag in the // future. It is not required by man 2 sigaltstack now (they're using // malloc()). void* base = MmapOrDie(kAltStackSize, __FUNCTION__); altstack.ss_sp = base; altstack.ss_flags = 0; altstack.ss_size = kAltStackSize; CHECK(0 == sigaltstack(&altstack, 0)); if (flags()->verbosity > 0) { Report("Alternative stack for T%d set: [%p,%p)\n", asanThreadRegistry().GetCurrentTidOrInvalid(), altstack.ss_sp, (char*)altstack.ss_sp + altstack.ss_size); } } void UnsetAlternateSignalStack() { stack_t altstack, oldstack; altstack.ss_sp = 0; altstack.ss_flags = SS_DISABLE; altstack.ss_size = 0; CHECK(0 == sigaltstack(&altstack, &oldstack)); UnmapOrDie(oldstack.ss_sp, oldstack.ss_size); } void InstallSignalHandlers() { // Set the alternate signal stack for the main thread. // This will cause SetAlternateSignalStack to be called twice, but the stack // will be actually set only once. if (flags()->use_sigaltstack) SetAlternateSignalStack(); MaybeInstallSigaction(SIGSEGV, ASAN_OnSIGSEGV); MaybeInstallSigaction(SIGBUS, ASAN_OnSIGSEGV); } // ---------------------- TSD ---------------- {{{1 static pthread_key_t tsd_key; static bool tsd_key_inited = false; void AsanTSDInit(void (*destructor)(void *tsd)) { CHECK(!tsd_key_inited); tsd_key_inited = true; CHECK(0 == pthread_key_create(&tsd_key, destructor)); } void *AsanTSDGet() { CHECK(tsd_key_inited); return pthread_getspecific(tsd_key); } void AsanTSDSet(void *tsd) { CHECK(tsd_key_inited); pthread_setspecific(tsd_key, tsd); } } // namespace __asan #endif // __linux__ || __APPLE_