1 //===-- asan_posix.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 15 #include "sanitizer_common/sanitizer_platform.h" 16 #if SANITIZER_POSIX 17 18 #include "asan_internal.h" 19 #include "asan_interceptors.h" 20 #include "asan_mapping.h" 21 #include "asan_report.h" 22 #include "asan_stack.h" 23 #include "sanitizer_common/sanitizer_libc.h" 24 #include "sanitizer_common/sanitizer_posix.h" 25 #include "sanitizer_common/sanitizer_procmaps.h" 26 27 #include <pthread.h> 28 #include <signal.h> 29 #include <stdlib.h> 30 #include <sys/time.h> 31 #include <sys/resource.h> 32 #include <unistd.h> 33 34 namespace __asan { 35 36 void AsanOnDeadlySignal(int signo, void *siginfo, void *context) { 37 ScopedDeadlySignal signal_scope(GetCurrentThread()); 38 int code = (int)((siginfo_t*)siginfo)->si_code; 39 // Write the first message using the bullet-proof write. 40 if (18 != internal_write(2, "ASAN:DEADLYSIGNAL\n", 18)) Die(); 41 SignalContext sig = SignalContext::Create(siginfo, context); 42 43 // Access at a reasonable offset above SP, or slightly below it (to account 44 // for x86_64 or PowerPC redzone, ARM push of multiple registers, etc) is 45 // probably a stack overflow. 46 bool IsStackAccess = sig.addr + 512 > sig.sp && sig.addr < sig.sp + 0xFFFF; 47 48 #if __powerpc__ 49 // Large stack frames can be allocated with e.g. 50 // lis r0,-10000 51 // stdux r1,r1,r0 # store sp to [sp-10000] and update sp by -10000 52 // If the store faults then sp will not have been updated, so test above 53 // will not work, becase the fault address will be more than just "slightly" 54 // below sp. 55 if (!IsStackAccess && IsAccessibleMemoryRange(sig.pc, 4)) { 56 u32 inst = *(unsigned *)sig.pc; 57 u32 ra = (inst >> 16) & 0x1F; 58 u32 opcd = inst >> 26; 59 u32 xo = (inst >> 1) & 0x3FF; 60 // Check for store-with-update to sp. The instructions we accept are: 61 // stbu rs,d(ra) stbux rs,ra,rb 62 // sthu rs,d(ra) sthux rs,ra,rb 63 // stwu rs,d(ra) stwux rs,ra,rb 64 // stdu rs,ds(ra) stdux rs,ra,rb 65 // where ra is r1 (the stack pointer). 66 if (ra == 1 && 67 (opcd == 39 || opcd == 45 || opcd == 37 || opcd == 62 || 68 (opcd == 31 && (xo == 247 || xo == 439 || xo == 183 || xo == 181)))) 69 IsStackAccess = true; 70 } 71 #endif // __powerpc__ 72 73 // We also check si_code to filter out SEGV caused by something else other 74 // then hitting the guard page or unmapped memory, like, for example, 75 // unaligned memory access. 76 if (IsStackAccess && (code == si_SEGV_MAPERR || code == si_SEGV_ACCERR)) 77 ReportStackOverflow(sig); 78 else if (signo == SIGFPE) 79 ReportDeadlySignal("FPE", sig); 80 else if (signo == SIGILL) 81 ReportDeadlySignal("ILL", sig); 82 else 83 ReportDeadlySignal("SEGV", sig); 84 } 85 86 // ---------------------- TSD ---------------- {{{1 87 88 static pthread_key_t tsd_key; 89 static bool tsd_key_inited = false; 90 void AsanTSDInit(void (*destructor)(void *tsd)) { 91 CHECK(!tsd_key_inited); 92 tsd_key_inited = true; 93 CHECK_EQ(0, pthread_key_create(&tsd_key, destructor)); 94 } 95 96 void *AsanTSDGet() { 97 CHECK(tsd_key_inited); 98 return pthread_getspecific(tsd_key); 99 } 100 101 void AsanTSDSet(void *tsd) { 102 CHECK(tsd_key_inited); 103 pthread_setspecific(tsd_key, tsd); 104 } 105 106 void PlatformTSDDtor(void *tsd) { 107 AsanThreadContext *context = (AsanThreadContext*)tsd; 108 if (context->destructor_iterations > 1) { 109 context->destructor_iterations--; 110 CHECK_EQ(0, pthread_setspecific(tsd_key, tsd)); 111 return; 112 } 113 AsanThread::TSDDtor(tsd); 114 } 115 } // namespace __asan 116 117 #endif // SANITIZER_POSIX 118
