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 34namespace __asan { 35 36void 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 fd=2, just in case. 40 // It may actually fail to write in case stderr is closed. 41 internal_write(2, "ASAN:DEADLYSIGNAL\n", 18); 42 SignalContext sig = SignalContext::Create(siginfo, context); 43 44 // Access at a reasonable offset above SP, or slightly below it (to account 45 // for x86_64 or PowerPC redzone, ARM push of multiple registers, etc) is 46 // probably a stack overflow. 47#ifdef __s390__ 48 // On s390, the fault address in siginfo points to start of the page, not 49 // to the precise word that was accessed. Mask off the low bits of sp to 50 // take it into account. 51 bool IsStackAccess = sig.addr >= (sig.sp & ~0xFFF) && 52 sig.addr < sig.sp + 0xFFFF; 53#else 54 bool IsStackAccess = sig.addr + 512 > sig.sp && sig.addr < sig.sp + 0xFFFF; 55#endif 56 57#if __powerpc__ 58 // Large stack frames can be allocated with e.g. 59 // lis r0,-10000 60 // stdux r1,r1,r0 # store sp to [sp-10000] and update sp by -10000 61 // If the store faults then sp will not have been updated, so test above 62 // will not work, becase the fault address will be more than just "slightly" 63 // below sp. 64 if (!IsStackAccess && IsAccessibleMemoryRange(sig.pc, 4)) { 65 u32 inst = *(unsigned *)sig.pc; 66 u32 ra = (inst >> 16) & 0x1F; 67 u32 opcd = inst >> 26; 68 u32 xo = (inst >> 1) & 0x3FF; 69 // Check for store-with-update to sp. The instructions we accept are: 70 // stbu rs,d(ra) stbux rs,ra,rb 71 // sthu rs,d(ra) sthux rs,ra,rb 72 // stwu rs,d(ra) stwux rs,ra,rb 73 // stdu rs,ds(ra) stdux rs,ra,rb 74 // where ra is r1 (the stack pointer). 75 if (ra == 1 && 76 (opcd == 39 || opcd == 45 || opcd == 37 || opcd == 62 || 77 (opcd == 31 && (xo == 247 || xo == 439 || xo == 183 || xo == 181)))) 78 IsStackAccess = true; 79 } 80#endif // __powerpc__ 81 82 // We also check si_code to filter out SEGV caused by something else other 83 // then hitting the guard page or unmapped memory, like, for example, 84 // unaligned memory access. 85 if (IsStackAccess && (code == si_SEGV_MAPERR || code == si_SEGV_ACCERR)) 86 ReportStackOverflow(sig); 87 else if (signo == SIGFPE) 88 ReportDeadlySignal("FPE", sig); 89 else if (signo == SIGILL) 90 ReportDeadlySignal("ILL", sig); 91 else 92 ReportDeadlySignal("SEGV", sig); 93} 94 95// ---------------------- TSD ---------------- {{{1 96 97static pthread_key_t tsd_key; 98static bool tsd_key_inited = false; 99void AsanTSDInit(void (*destructor)(void *tsd)) { 100 CHECK(!tsd_key_inited); 101 tsd_key_inited = true; 102 CHECK_EQ(0, pthread_key_create(&tsd_key, destructor)); 103} 104 105void *AsanTSDGet() { 106 CHECK(tsd_key_inited); 107 return pthread_getspecific(tsd_key); 108} 109 110void AsanTSDSet(void *tsd) { 111 CHECK(tsd_key_inited); 112 pthread_setspecific(tsd_key, tsd); 113} 114 115void PlatformTSDDtor(void *tsd) { 116 AsanThreadContext *context = (AsanThreadContext*)tsd; 117 if (context->destructor_iterations > 1) { 118 context->destructor_iterations--; 119 CHECK_EQ(0, pthread_setspecific(tsd_key, tsd)); 120 return; 121 } 122 AsanThread::TSDDtor(tsd); 123} 124} // namespace __asan 125 126#endif // SANITIZER_POSIX 127