| //===-- asan_posix.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. |
| //===----------------------------------------------------------------------===// |
| |
| #include "sanitizer_common/sanitizer_platform.h" |
| #if SANITIZER_LINUX || SANITIZER_MAC |
| |
| #include "asan_internal.h" |
| #include "asan_interceptors.h" |
| #include "asan_mapping.h" |
| #include "asan_report.h" |
| #include "asan_stack.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_EQ(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_EQ(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_EQ(0, sigaltstack(&altstack, 0)); |
| if (flags()->verbosity > 0) { |
| Report("Alternative stack for T%d set: [%p,%p)\n", |
| 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_EQ(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_EQ(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); |
| } |
| |
| void PlatformTSDDtor(void *tsd) { |
| AsanThreadContext *context = (AsanThreadContext*)tsd; |
| if (context->destructor_iterations > 1) { |
| context->destructor_iterations--; |
| CHECK_EQ(0, pthread_setspecific(tsd_key, tsd)); |
| return; |
| } |
| AsanThread::TSDDtor(tsd); |
| } |
| } // namespace __asan |
| |
| #endif // SANITIZER_LINUX || SANITIZER_MAC |