1 //===-- asan_linux.cc -----------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file is a part of AddressSanitizer, an address sanity checker. 11 // 12 // Posix-specific details. 13 //===----------------------------------------------------------------------===// 14 #if defined(__linux__) || defined(__APPLE__) 15 16 #include "asan_internal.h" 17 #include "asan_interceptors.h" 18 #include "asan_mapping.h" 19 #include "asan_report.h" 20 #include "asan_stack.h" 21 #include "asan_thread_registry.h" 22 #include "sanitizer_common/sanitizer_libc.h" 23 #include "sanitizer_common/sanitizer_procmaps.h" 24 25 #include <pthread.h> 26 #include <signal.h> 27 #include <stdlib.h> 28 #include <sys/time.h> 29 #include <sys/resource.h> 30 #include <unistd.h> 31 32 static const uptr kAltStackSize = SIGSTKSZ * 4; // SIGSTKSZ is not enough. 33 34 namespace __asan { 35 36 static void MaybeInstallSigaction(int signum, 37 void (*handler)(int, siginfo_t *, void *)) { 38 if (!AsanInterceptsSignal(signum)) 39 return; 40 struct sigaction sigact; 41 REAL(memset)(&sigact, 0, sizeof(sigact)); 42 sigact.sa_sigaction = handler; 43 sigact.sa_flags = SA_SIGINFO; 44 if (flags()->use_sigaltstack) sigact.sa_flags |= SA_ONSTACK; 45 CHECK(0 == REAL(sigaction)(signum, &sigact, 0)); 46 if (flags()->verbosity >= 1) { 47 Report("Installed the sigaction for signal %d\n", signum); 48 } 49 } 50 51 static void ASAN_OnSIGSEGV(int, siginfo_t *siginfo, void *context) { 52 uptr addr = (uptr)siginfo->si_addr; 53 // Write the first message using the bullet-proof write. 54 if (13 != internal_write(2, "ASAN:SIGSEGV\n", 13)) Die(); 55 uptr pc, sp, bp; 56 GetPcSpBp(context, &pc, &sp, &bp); 57 ReportSIGSEGV(pc, sp, bp, addr); 58 } 59 60 void SetAlternateSignalStack() { 61 stack_t altstack, oldstack; 62 CHECK(0 == sigaltstack(0, &oldstack)); 63 // If the alternate stack is already in place, do nothing. 64 if ((oldstack.ss_flags & SS_DISABLE) == 0) return; 65 // TODO(glider): the mapped stack should have the MAP_STACK flag in the 66 // future. It is not required by man 2 sigaltstack now (they're using 67 // malloc()). 68 void* base = MmapOrDie(kAltStackSize, __FUNCTION__); 69 altstack.ss_sp = base; 70 altstack.ss_flags = 0; 71 altstack.ss_size = kAltStackSize; 72 CHECK(0 == sigaltstack(&altstack, 0)); 73 if (flags()->verbosity > 0) { 74 Report("Alternative stack for T%d set: [%p,%p)\n", 75 asanThreadRegistry().GetCurrentTidOrInvalid(), 76 altstack.ss_sp, (char*)altstack.ss_sp + altstack.ss_size); 77 } 78 } 79 80 void UnsetAlternateSignalStack() { 81 stack_t altstack, oldstack; 82 altstack.ss_sp = 0; 83 altstack.ss_flags = SS_DISABLE; 84 altstack.ss_size = 0; 85 CHECK(0 == sigaltstack(&altstack, &oldstack)); 86 UnmapOrDie(oldstack.ss_sp, oldstack.ss_size); 87 } 88 89 void InstallSignalHandlers() { 90 // Set the alternate signal stack for the main thread. 91 // This will cause SetAlternateSignalStack to be called twice, but the stack 92 // will be actually set only once. 93 if (flags()->use_sigaltstack) SetAlternateSignalStack(); 94 MaybeInstallSigaction(SIGSEGV, ASAN_OnSIGSEGV); 95 MaybeInstallSigaction(SIGBUS, ASAN_OnSIGSEGV); 96 } 97 98 // ---------------------- TSD ---------------- {{{1 99 100 static pthread_key_t tsd_key; 101 static bool tsd_key_inited = false; 102 void AsanTSDInit(void (*destructor)(void *tsd)) { 103 CHECK(!tsd_key_inited); 104 tsd_key_inited = true; 105 CHECK(0 == pthread_key_create(&tsd_key, destructor)); 106 } 107 108 void *AsanTSDGet() { 109 CHECK(tsd_key_inited); 110 return pthread_getspecific(tsd_key); 111 } 112 113 void AsanTSDSet(void *tsd) { 114 CHECK(tsd_key_inited); 115 pthread_setspecific(tsd_key, tsd); 116 } 117 118 } // namespace __asan 119 120 #endif // __linux__ || __APPLE_ 121
