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//===-- sanitizer_posix_libcdep.cc ----------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is shared between AddressSanitizer and ThreadSanitizer
// run-time libraries and implements libc-dependent POSIX-specific functions
// from sanitizer_libc.h.
//===----------------------------------------------------------------------===//
#include "sanitizer_platform.h"
#if SANITIZER_POSIX
#include "sanitizer_common.h"
#include "sanitizer_flags.h"
#include "sanitizer_platform_limits_posix.h"
#include "sanitizer_stacktrace.h"
#include <errno.h>
#include <pthread.h>
#include <signal.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
namespace __sanitizer {
u32 GetUid() {
return getuid();
}
uptr GetThreadSelf() {
return (uptr)pthread_self();
}
void FlushUnneededShadowMemory(uptr addr, uptr size) {
madvise((void*)addr, size, MADV_DONTNEED);
}
static rlim_t getlim(int res) {
rlimit rlim;
CHECK_EQ(0, getrlimit(res, &rlim));
return rlim.rlim_cur;
}
static void setlim(int res, rlim_t lim) {
// The following magic is to prevent clang from replacing it with memset.
volatile struct rlimit rlim;
rlim.rlim_cur = lim;
rlim.rlim_max = lim;
if (setrlimit(res, (struct rlimit*)&rlim)) {
Report("ERROR: %s setrlimit() failed %d\n", SanitizerToolName, errno);
Die();
}
}
void DisableCoreDumperIfNecessary() {
if (common_flags()->disable_coredump) {
setlim(RLIMIT_CORE, 0);
}
}
bool StackSizeIsUnlimited() {
rlim_t stack_size = getlim(RLIMIT_STACK);
return (stack_size == RLIM_INFINITY);
}
void SetStackSizeLimitInBytes(uptr limit) {
setlim(RLIMIT_STACK, (rlim_t)limit);
CHECK(!StackSizeIsUnlimited());
}
bool AddressSpaceIsUnlimited() {
rlim_t as_size = getlim(RLIMIT_AS);
return (as_size == RLIM_INFINITY);
}
void SetAddressSpaceUnlimited() {
setlim(RLIMIT_AS, RLIM_INFINITY);
CHECK(AddressSpaceIsUnlimited());
}
void SleepForSeconds(int seconds) {
sleep(seconds);
}
void SleepForMillis(int millis) {
usleep(millis * 1000);
}
void Abort() {
abort();
}
int Atexit(void (*function)(void)) {
#ifndef SANITIZER_GO
return atexit(function);
#else
return 0;
#endif
}
int internal_isatty(fd_t fd) {
return isatty(fd);
}
#ifndef SANITIZER_GO
// TODO(glider): different tools may require different altstack size.
static const uptr kAltStackSize = SIGSTKSZ * 4; // SIGSTKSZ is not enough.
void SetAlternateSignalStack() {
stack_t altstack, oldstack;
CHECK_EQ(0, sigaltstack(0, &oldstack));
// If the alternate stack is already in place, do nothing.
// Android always sets an alternate stack, but it's too small for us.
if (!SANITIZER_ANDROID && !(oldstack.ss_flags & SS_DISABLE)) return;
// TODO(glider): the mapped stack should have the MAP_STACK flag in the
// future. It is not required by man 2 sigaltstack now (they're using
// malloc()).
void* base = MmapOrDie(kAltStackSize, __func__);
altstack.ss_sp = (char*) base;
altstack.ss_flags = 0;
altstack.ss_size = kAltStackSize;
CHECK_EQ(0, sigaltstack(&altstack, 0));
}
void UnsetAlternateSignalStack() {
stack_t altstack, oldstack;
altstack.ss_sp = 0;
altstack.ss_flags = SS_DISABLE;
altstack.ss_size = kAltStackSize; // Some sane value required on Darwin.
CHECK_EQ(0, sigaltstack(&altstack, &oldstack));
UnmapOrDie(oldstack.ss_sp, oldstack.ss_size);
}
typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
static void MaybeInstallSigaction(int signum,
SignalHandlerType handler) {
if (!IsDeadlySignal(signum))
return;
struct sigaction sigact;
internal_memset(&sigact, 0, sizeof(sigact));
sigact.sa_sigaction = (sa_sigaction_t)handler;
// Do not block the signal from being received in that signal's handler.
// Clients are responsible for handling this correctly.
sigact.sa_flags = SA_SIGINFO | SA_NODEFER;
if (common_flags()->use_sigaltstack) sigact.sa_flags |= SA_ONSTACK;
CHECK_EQ(0, internal_sigaction(signum, &sigact, 0));
VReport(1, "Installed the sigaction for signal %d\n", signum);
}
void InstallDeadlySignalHandlers(SignalHandlerType handler) {
// Set the alternate signal stack for the main thread.
// This will cause SetAlternateSignalStack to be called twice, but the stack
// will be actually set only once.
if (common_flags()->use_sigaltstack) SetAlternateSignalStack();
MaybeInstallSigaction(SIGSEGV, handler);
MaybeInstallSigaction(SIGBUS, handler);
}
#endif // SANITIZER_GO
bool IsAccessibleMemoryRange(uptr beg, uptr size) {
uptr page_size = GetPageSizeCached();
// Checking too large memory ranges is slow.
CHECK_LT(size, page_size * 10);
int sock_pair[2];
if (pipe(sock_pair))
return false;
uptr bytes_written =
internal_write(sock_pair[1], reinterpret_cast<void *>(beg), size);
int write_errno;
bool result;
if (internal_iserror(bytes_written, &write_errno)) {
CHECK_EQ(EFAULT, write_errno);
result = false;
} else {
result = (bytes_written == size);
}
internal_close(sock_pair[0]);
internal_close(sock_pair[1]);
return result;
}
} // namespace __sanitizer
#endif // SANITIZER_POSIX
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