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// Linux-specific details. 13//===----------------------------------------------------------------------===// 14#ifdef __linux__ 15 16#include "asan_interceptors.h" 17#include "asan_internal.h" 18#include "asan_lock.h" 19#include "asan_thread.h" 20#include "asan_thread_registry.h" 21#include "sanitizer_common/sanitizer_libc.h" 22#include "sanitizer_common/sanitizer_procmaps.h" 23 24#include <sys/time.h> 25#include <sys/resource.h> 26#include <sys/mman.h> 27#include <sys/syscall.h> 28#include <sys/types.h> 29#include <fcntl.h> 30#include <pthread.h> 31#include <stdio.h> 32#include <unistd.h> 33#include <unwind.h> 34 35#if !ASAN_ANDROID 36// FIXME: where to get ucontext on Android? 37#include <sys/ucontext.h> 38#endif 39 40extern "C" void* _DYNAMIC; 41 42namespace __asan { 43 44void MaybeReexec() { 45 // No need to re-exec on Linux. 46} 47 48void *AsanDoesNotSupportStaticLinkage() { 49 // This will fail to link with -static. 50 return &_DYNAMIC; // defined in link.h 51} 52 53void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) { 54#if ASAN_ANDROID 55 *pc = *sp = *bp = 0; 56#elif defined(__arm__) 57 ucontext_t *ucontext = (ucontext_t*)context; 58 *pc = ucontext->uc_mcontext.arm_pc; 59 *bp = ucontext->uc_mcontext.arm_fp; 60 *sp = ucontext->uc_mcontext.arm_sp; 61# elif defined(__x86_64__) 62 ucontext_t *ucontext = (ucontext_t*)context; 63 *pc = ucontext->uc_mcontext.gregs[REG_RIP]; 64 *bp = ucontext->uc_mcontext.gregs[REG_RBP]; 65 *sp = ucontext->uc_mcontext.gregs[REG_RSP]; 66# elif defined(__i386__) 67 ucontext_t *ucontext = (ucontext_t*)context; 68 *pc = ucontext->uc_mcontext.gregs[REG_EIP]; 69 *bp = ucontext->uc_mcontext.gregs[REG_EBP]; 70 *sp = ucontext->uc_mcontext.gregs[REG_ESP]; 71#else 72# error "Unsupported arch" 73#endif 74} 75 76bool AsanInterceptsSignal(int signum) { 77 return signum == SIGSEGV && flags()->handle_segv; 78} 79 80void AsanPlatformThreadInit() { 81 // Nothing here for now. 82} 83 84AsanLock::AsanLock(LinkerInitialized) { 85 // We assume that pthread_mutex_t initialized to all zeroes is a valid 86 // unlocked mutex. We can not use PTHREAD_MUTEX_INITIALIZER as it triggers 87 // a gcc warning: 88 // extended initializer lists only available with -std=c++0x or -std=gnu++0x 89} 90 91void AsanLock::Lock() { 92 CHECK(sizeof(pthread_mutex_t) <= sizeof(opaque_storage_)); 93 pthread_mutex_lock((pthread_mutex_t*)&opaque_storage_); 94 CHECK(!owner_); 95 owner_ = (uptr)pthread_self(); 96} 97 98void AsanLock::Unlock() { 99 CHECK(owner_ == (uptr)pthread_self()); 100 owner_ = 0; 101 pthread_mutex_unlock((pthread_mutex_t*)&opaque_storage_); 102} 103 104#ifdef __arm__ 105#define UNWIND_STOP _URC_END_OF_STACK 106#define UNWIND_CONTINUE _URC_NO_REASON 107#else 108#define UNWIND_STOP _URC_NORMAL_STOP 109#define UNWIND_CONTINUE _URC_NO_REASON 110#endif 111 112uptr Unwind_GetIP(struct _Unwind_Context *ctx) { 113#ifdef __arm__ 114 uptr val; 115 _Unwind_VRS_Result res = _Unwind_VRS_Get(ctx, _UVRSC_CORE, 116 15 /* r15 = PC */, _UVRSD_UINT32, &val); 117 CHECK(res == _UVRSR_OK && "_Unwind_VRS_Get failed"); 118 // Clear the Thumb bit. 119 return val & ~(uptr)1; 120#else 121 return _Unwind_GetIP(ctx); 122#endif 123} 124 125_Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, 126 void *param) { 127 StackTrace *b = (StackTrace*)param; 128 CHECK(b->size < b->max_size); 129 uptr pc = Unwind_GetIP(ctx); 130 b->trace[b->size++] = pc; 131 if (b->size == b->max_size) return UNWIND_STOP; 132 return UNWIND_CONTINUE; 133} 134 135void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp) { 136 stack->size = 0; 137 stack->trace[0] = pc; 138 if ((max_s) > 1) { 139 stack->max_size = max_s; 140#ifdef __arm__ 141 _Unwind_Backtrace(Unwind_Trace, stack); 142#else 143 if (!asan_inited) return; 144 if (AsanThread *t = asanThreadRegistry().GetCurrent()) 145 stack->FastUnwindStack(pc, bp, t->stack_top(), t->stack_bottom()); 146#endif 147 } 148} 149 150} // namespace __asan 151 152#endif // __linux__ 153