libsanitizer/asan/asan_linux.cc

   1 //===-- asan_linux.cc -----------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of AddressSanitizer, an address sanity checker.
   9 //
  10 // Linux-specific details.
  11 //===----------------------------------------------------------------------===//
  12 #ifdef __linux__
  13
  14 #include "asan_interceptors.h"
  15 #include "asan_internal.h"
  16 #include "asan_thread.h"
  17 #include "asan_thread_registry.h"
  18 #include "sanitizer_common/sanitizer_libc.h"
  19 #include "sanitizer_common/sanitizer_procmaps.h"
  20
  21 #include <sys/time.h>
  22 #include <sys/resource.h>
  23 #include <sys/mman.h>
  24 #include <sys/syscall.h>
  25 #include <sys/types.h>
  26 #include <fcntl.h>
  27 #include <pthread.h>
  28 #include <stdio.h>
  29 #include <unistd.h>
  30 #include <unwind.h>
  31
  32 #if !ASAN_ANDROID
  33 // FIXME: where to get ucontext on Android?
  34 #include <sys/ucontext.h>
  35 #endif
  36
  37 extern "C" void* _DYNAMIC;
  38
  39 namespace __asan {
  40
  41 void MaybeReexec() {
  42   // No need to re-exec on Linux.
  43 }
  44
  45 void *AsanDoesNotSupportStaticLinkage() {
  46   // This will fail to link with -static.
  47   return &_DYNAMIC;  // defined in link.h
  48 }
  49
  50 void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
  51 #if ASAN_ANDROID
  52   *pc = *sp = *bp = 0;
  53 #elif defined(__arm__)
  54   ucontext_t *ucontext = (ucontext_t*)context;
  55   *pc = ucontext->uc_mcontext.arm_pc;
  56   *bp = ucontext->uc_mcontext.arm_fp;
  57   *sp = ucontext->uc_mcontext.arm_sp;
  58 # elif defined(__x86_64__)
  59   ucontext_t *ucontext = (ucontext_t*)context;
  60   *pc = ucontext->uc_mcontext.gregs[REG_RIP];
  61   *bp = ucontext->uc_mcontext.gregs[REG_RBP];
  62   *sp = ucontext->uc_mcontext.gregs[REG_RSP];
  63 # elif defined(__i386__)
  64   ucontext_t *ucontext = (ucontext_t*)context;
  65   *pc = ucontext->uc_mcontext.gregs[REG_EIP];
  66   *bp = ucontext->uc_mcontext.gregs[REG_EBP];
  67   *sp = ucontext->uc_mcontext.gregs[REG_ESP];
  68 # elif defined(__powerpc__) || defined(__powerpc64__)
  69   ucontext_t *ucontext = (ucontext_t*)context;
  70   *pc = ucontext->uc_mcontext.regs->nip;
  71   *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
  72   // The powerpc{,64}-linux ABIs do not specify r31 as the frame
  73   // pointer, but GCC always uses r31 when we need a frame pointer.
  74   *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
  75 # elif defined(__sparc__)
  76   ucontext_t *ucontext = (ucontext_t*)context;
  77   uptr *stk_ptr;
  78 # if defined (__arch64__)
  79   *pc = ucontext->uc_mcontext.mc_gregs[MC_PC];
  80   *sp = ucontext->uc_mcontext.mc_gregs[MC_O6];
  81   stk_ptr = (uptr *) (*sp + 2047);
  82   *bp = stk_ptr[15];
  83 # else
  84   *pc = ucontext->uc_mcontext.gregs[REG_PC];
  85   *sp = ucontext->uc_mcontext.gregs[REG_O6];
  86   stk_ptr = (uptr *) *sp;
  87   *bp = stk_ptr[15];
  88 # endif
  89 #else
  90 # error "Unsupported arch"
  91 #endif
  92 }
  93
  94 bool AsanInterceptsSignal(int signum) {
  95   return signum == SIGSEGV && flags()->handle_segv;
  96 }
  97
  98 void AsanPlatformThreadInit() {
  99   // Nothing here for now.
 100 }
 101
 102 void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp, bool fast) {
 103 #if defined(__arm__) || \
 104     defined(__powerpc__) || defined(__powerpc64__) || \
 105     defined(__sparc__)
 106   fast = false;
 107 #endif
 108   if (!fast)
 109     return stack->SlowUnwindStack(pc, max_s);
 110   stack->size = 0;
 111   stack->trace[0] = pc;
 112   if (max_s > 1) {
 113     stack->max_size = max_s;
 114     if (!asan_inited) return;
 115     if (AsanThread *t = asanThreadRegistry().GetCurrent())
 116       stack->FastUnwindStack(pc, bp, t->stack_top(), t->stack_bottom());
 117   }
 118 }
 119
 120 #if !ASAN_ANDROID
 121 void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
 122   ucontext_t *ucp = (ucontext_t*)context;
 123   *stack = (uptr)ucp->uc_stack.ss_sp;
 124   *ssize = ucp->uc_stack.ss_size;
 125 }
 126 #else
 127 void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
 128   UNIMPLEMENTED();
 129 }
 130 #endif
 131
 132 }  // namespace __asan
 133
 134 #endif  // __linux__