asan_linux.cc revision def1be9b7ef4091ce465c0fbfb26cdb52128ade8 
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
15#include "sanitizer_common/sanitizer_platform.h"
16#if SANITIZER_LINUX
17
18#include "asan_interceptors.h"
19#include "asan_internal.h"
20#include "asan_thread.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 !SANITIZER_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 SANITIZER_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# elif defined(__powerpc__) || defined(__powerpc64__)
72  ucontext_t *ucontext = (ucontext_t*)context;
73  *pc = ucontext->uc_mcontext.regs->nip;
74  *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
75  // The powerpc{,64}-linux ABIs do not specify r31 as the frame
76  // pointer, but GCC always uses r31 when we need a frame pointer.
77  *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
78# elif defined(__sparc__)
79  ucontext_t *ucontext = (ucontext_t*)context;
80  uptr *stk_ptr;
81# if defined (__arch64__)
82  *pc = ucontext->uc_mcontext.mc_gregs[MC_PC];
83  *sp = ucontext->uc_mcontext.mc_gregs[MC_O6];
84  stk_ptr = (uptr *) (*sp + 2047);
85  *bp = stk_ptr[15];
86# else
87  *pc = ucontext->uc_mcontext.gregs[REG_PC];
88  *sp = ucontext->uc_mcontext.gregs[REG_O6];
89  stk_ptr = (uptr *) *sp;
90  *bp = stk_ptr[15];
91# endif
92#else
93# error "Unsupported arch"
94#endif
95}
96
97bool AsanInterceptsSignal(int signum) {
98  return signum == SIGSEGV && flags()->handle_segv;
99}
100
101void AsanPlatformThreadInit() {
102  // Nothing here for now.
103}
104
105void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp, bool fast) {
106#if defined(__arm__) || \
107    defined(__powerpc__) || defined(__powerpc64__) || \
108    defined(__sparc__)
109  fast = false;
110#endif
111  if (!fast)
112    return stack->SlowUnwindStack(pc, max_s);
113  stack->size = 0;
114  stack->trace[0] = pc;
115  if (max_s > 1) {
116    stack->max_size = max_s;
117    if (!asan_inited) return;
118    if (AsanThread *t = GetCurrentThread())
119      stack->FastUnwindStack(pc, bp, t->stack_top(), t->stack_bottom());
120  }
121}
122
123#if !SANITIZER_ANDROID
124void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
125  ucontext_t *ucp = (ucontext_t*)context;
126  *stack = (uptr)ucp->uc_stack.ss_sp;
127  *ssize = ucp->uc_stack.ss_size;
128}
129#else
130void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
131  UNIMPLEMENTED();
132}
133#endif
134
135}  // namespace __asan
136
137#endif  // __linux__
138