1 //===-- sanitizer_posix_libcdep.cc ----------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is shared between AddressSanitizer and ThreadSanitizer
11 // run-time libraries and implements libc-dependent POSIX-specific functions
12 // from sanitizer_libc.h.
13 //===----------------------------------------------------------------------===//
15 #include "sanitizer_platform.h"
18 #include "sanitizer_common.h"
19 #include "sanitizer_flags.h"
20 #include "sanitizer_platform_limits_posix.h"
21 #include "sanitizer_stacktrace.h"
28 #include <sys/resource.h>
30 #include <sys/types.h>
33 namespace __sanitizer {
39 uptr GetThreadSelf() {
40 return (uptr)pthread_self();
43 void FlushUnneededShadowMemory(uptr addr, uptr size) {
44 madvise((void*)addr, size, MADV_DONTNEED);
47 static rlim_t getlim(int res) {
49 CHECK_EQ(0, getrlimit(res, &rlim));
53 static void setlim(int res, rlim_t lim) {
54 // The following magic is to prevent clang from replacing it with memset.
55 volatile struct rlimit rlim;
58 if (setrlimit(res, const_cast<struct rlimit *>(&rlim))) {
59 Report("ERROR: %s setrlimit() failed %d\n", SanitizerToolName, errno);
64 void DisableCoreDumperIfNecessary() {
65 if (common_flags()->disable_coredump) {
66 setlim(RLIMIT_CORE, 0);
70 bool StackSizeIsUnlimited() {
71 rlim_t stack_size = getlim(RLIMIT_STACK);
72 return (stack_size == RLIM_INFINITY);
75 void SetStackSizeLimitInBytes(uptr limit) {
76 setlim(RLIMIT_STACK, (rlim_t)limit);
77 CHECK(!StackSizeIsUnlimited());
80 bool AddressSpaceIsUnlimited() {
81 rlim_t as_size = getlim(RLIMIT_AS);
82 return (as_size == RLIM_INFINITY);
85 void SetAddressSpaceUnlimited() {
86 setlim(RLIMIT_AS, RLIM_INFINITY);
87 CHECK(AddressSpaceIsUnlimited());
90 void SleepForSeconds(int seconds) {
94 void SleepForMillis(int millis) {
95 usleep(millis * 1000);
102 int Atexit(void (*function)(void)) {
104 return atexit(function);
110 int internal_isatty(fd_t fd) {
115 // TODO(glider): different tools may require different altstack size.
116 static const uptr kAltStackSize = SIGSTKSZ * 4; // SIGSTKSZ is not enough.
118 void SetAlternateSignalStack() {
119 stack_t altstack, oldstack;
120 CHECK_EQ(0, sigaltstack(0, &oldstack));
121 // If the alternate stack is already in place, do nothing.
122 // Android always sets an alternate stack, but it's too small for us.
123 if (!SANITIZER_ANDROID && !(oldstack.ss_flags & SS_DISABLE)) return;
124 // TODO(glider): the mapped stack should have the MAP_STACK flag in the
125 // future. It is not required by man 2 sigaltstack now (they're using
127 void* base = MmapOrDie(kAltStackSize, __func__);
128 altstack.ss_sp = (char*) base;
129 altstack.ss_flags = 0;
130 altstack.ss_size = kAltStackSize;
131 CHECK_EQ(0, sigaltstack(&altstack, 0));
134 void UnsetAlternateSignalStack() {
135 stack_t altstack, oldstack;
137 altstack.ss_flags = SS_DISABLE;
138 altstack.ss_size = kAltStackSize; // Some sane value required on Darwin.
139 CHECK_EQ(0, sigaltstack(&altstack, &oldstack));
140 UnmapOrDie(oldstack.ss_sp, oldstack.ss_size);
143 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
144 static void MaybeInstallSigaction(int signum,
145 SignalHandlerType handler) {
146 if (!IsDeadlySignal(signum))
148 struct sigaction sigact;
149 internal_memset(&sigact, 0, sizeof(sigact));
150 sigact.sa_sigaction = (sa_sigaction_t)handler;
151 // Do not block the signal from being received in that signal's handler.
152 // Clients are responsible for handling this correctly.
153 sigact.sa_flags = SA_SIGINFO | SA_NODEFER;
154 if (common_flags()->use_sigaltstack) sigact.sa_flags |= SA_ONSTACK;
155 CHECK_EQ(0, internal_sigaction(signum, &sigact, 0));
156 VReport(1, "Installed the sigaction for signal %d\n", signum);
159 void InstallDeadlySignalHandlers(SignalHandlerType handler) {
160 // Set the alternate signal stack for the main thread.
161 // This will cause SetAlternateSignalStack to be called twice, but the stack
162 // will be actually set only once.
163 if (common_flags()->use_sigaltstack) SetAlternateSignalStack();
164 MaybeInstallSigaction(SIGSEGV, handler);
165 MaybeInstallSigaction(SIGBUS, handler);
167 #endif // SANITIZER_GO
169 bool IsAccessibleMemoryRange(uptr beg, uptr size) {
170 uptr page_size = GetPageSizeCached();
171 // Checking too large memory ranges is slow.
172 CHECK_LT(size, page_size * 10);
177 internal_write(sock_pair[1], reinterpret_cast<void *>(beg), size);
180 if (internal_iserror(bytes_written, &write_errno)) {
181 CHECK_EQ(EFAULT, write_errno);
184 result = (bytes_written == size);
186 internal_close(sock_pair[0]);
187 internal_close(sock_pair[1]);
191 } // namespace __sanitizer
193 #endif // SANITIZER_POSIX