forked from OSchip/llvm-project
487 lines
15 KiB
C++
487 lines
15 KiB
C++
//===-- sanitizer_posix_libcdep.cc ----------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file is shared between AddressSanitizer and ThreadSanitizer
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// run-time libraries and implements libc-dependent POSIX-specific functions
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// from sanitizer_libc.h.
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//===----------------------------------------------------------------------===//
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#include "sanitizer_platform.h"
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#if SANITIZER_POSIX
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#include "sanitizer_common.h"
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#include "sanitizer_flags.h"
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#include "sanitizer_platform_limits_netbsd.h"
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#include "sanitizer_platform_limits_openbsd.h"
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#include "sanitizer_platform_limits_posix.h"
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#include "sanitizer_platform_limits_solaris.h"
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#include "sanitizer_posix.h"
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#include "sanitizer_procmaps.h"
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#include <errno.h>
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#include <fcntl.h>
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#include <pthread.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <sys/mman.h>
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#include <sys/resource.h>
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#include <sys/stat.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <unistd.h>
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#if SANITIZER_FREEBSD
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// The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
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// that, it was never implemented. So just define it to zero.
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#undef MAP_NORESERVE
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#define MAP_NORESERVE 0
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#endif
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typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
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namespace __sanitizer {
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u32 GetUid() {
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return getuid();
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}
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uptr GetThreadSelf() {
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return (uptr)pthread_self();
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}
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void ReleaseMemoryPagesToOS(uptr beg, uptr end) {
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uptr page_size = GetPageSizeCached();
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uptr beg_aligned = RoundUpTo(beg, page_size);
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uptr end_aligned = RoundDownTo(end, page_size);
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if (beg_aligned < end_aligned)
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// In the default Solaris compilation environment, madvise() is declared
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// to take a caddr_t arg; casting it to void * results in an invalid
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// conversion error, so use char * instead.
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madvise((char *)beg_aligned, end_aligned - beg_aligned,
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SANITIZER_MADVISE_DONTNEED);
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}
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bool NoHugePagesInRegion(uptr addr, uptr size) {
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#ifdef MADV_NOHUGEPAGE // May not be defined on old systems.
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return madvise((char *)addr, size, MADV_NOHUGEPAGE) == 0;
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#else
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return true;
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#endif // MADV_NOHUGEPAGE
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}
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bool DontDumpShadowMemory(uptr addr, uptr length) {
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#if defined(MADV_DONTDUMP)
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return madvise((char *)addr, length, MADV_DONTDUMP) == 0;
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#elif defined(MADV_NOCORE)
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return madvise((char *)addr, length, MADV_NOCORE) == 0;
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#else
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return true;
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#endif // MADV_DONTDUMP
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}
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static rlim_t getlim(int res) {
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rlimit rlim;
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CHECK_EQ(0, getrlimit(res, &rlim));
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return rlim.rlim_cur;
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}
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static void setlim(int res, rlim_t lim) {
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struct rlimit rlim;
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if (getrlimit(res, const_cast<struct rlimit *>(&rlim))) {
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Report("ERROR: %s getrlimit() failed %d\n", SanitizerToolName, errno);
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Die();
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}
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rlim.rlim_cur = lim;
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if (setrlimit(res, const_cast<struct rlimit *>(&rlim))) {
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Report("ERROR: %s setrlimit() failed %d\n", SanitizerToolName, errno);
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Die();
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}
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}
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void DisableCoreDumperIfNecessary() {
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if (common_flags()->disable_coredump) {
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setlim(RLIMIT_CORE, 0);
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}
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}
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bool StackSizeIsUnlimited() {
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rlim_t stack_size = getlim(RLIMIT_STACK);
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return (stack_size == RLIM_INFINITY);
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}
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void SetStackSizeLimitInBytes(uptr limit) {
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setlim(RLIMIT_STACK, (rlim_t)limit);
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CHECK(!StackSizeIsUnlimited());
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}
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bool AddressSpaceIsUnlimited() {
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rlim_t as_size = getlim(RLIMIT_AS);
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return (as_size == RLIM_INFINITY);
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}
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void SetAddressSpaceUnlimited() {
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setlim(RLIMIT_AS, RLIM_INFINITY);
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CHECK(AddressSpaceIsUnlimited());
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}
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void SleepForSeconds(int seconds) {
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sleep(seconds);
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}
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void SleepForMillis(int millis) {
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usleep(millis * 1000);
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}
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void Abort() {
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#if !SANITIZER_GO
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// If we are handling SIGABRT, unhandle it first.
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// TODO(vitalybuka): Check if handler belongs to sanitizer.
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if (GetHandleSignalMode(SIGABRT) != kHandleSignalNo) {
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struct sigaction sigact;
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internal_memset(&sigact, 0, sizeof(sigact));
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sigact.sa_sigaction = (sa_sigaction_t)SIG_DFL;
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internal_sigaction(SIGABRT, &sigact, nullptr);
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}
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#endif
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abort();
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}
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int Atexit(void (*function)(void)) {
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#if !SANITIZER_GO
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return atexit(function);
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#else
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return 0;
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#endif
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}
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bool SupportsColoredOutput(fd_t fd) {
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return isatty(fd) != 0;
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}
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#if !SANITIZER_GO
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// TODO(glider): different tools may require different altstack size.
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static const uptr kAltStackSize = SIGSTKSZ * 4; // SIGSTKSZ is not enough.
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void SetAlternateSignalStack() {
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stack_t altstack, oldstack;
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CHECK_EQ(0, sigaltstack(nullptr, &oldstack));
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// If the alternate stack is already in place, do nothing.
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// Android always sets an alternate stack, but it's too small for us.
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if (!SANITIZER_ANDROID && !(oldstack.ss_flags & SS_DISABLE)) return;
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// TODO(glider): the mapped stack should have the MAP_STACK flag in the
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// future. It is not required by man 2 sigaltstack now (they're using
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// malloc()).
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void* base = MmapOrDie(kAltStackSize, __func__);
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altstack.ss_sp = (char*) base;
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altstack.ss_flags = 0;
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altstack.ss_size = kAltStackSize;
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CHECK_EQ(0, sigaltstack(&altstack, nullptr));
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}
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void UnsetAlternateSignalStack() {
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stack_t altstack, oldstack;
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altstack.ss_sp = nullptr;
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altstack.ss_flags = SS_DISABLE;
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altstack.ss_size = kAltStackSize; // Some sane value required on Darwin.
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CHECK_EQ(0, sigaltstack(&altstack, &oldstack));
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UnmapOrDie(oldstack.ss_sp, oldstack.ss_size);
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}
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static void MaybeInstallSigaction(int signum,
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SignalHandlerType handler) {
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if (GetHandleSignalMode(signum) == kHandleSignalNo) return;
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struct sigaction sigact;
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internal_memset(&sigact, 0, sizeof(sigact));
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sigact.sa_sigaction = (sa_sigaction_t)handler;
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// Do not block the signal from being received in that signal's handler.
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// Clients are responsible for handling this correctly.
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sigact.sa_flags = SA_SIGINFO | SA_NODEFER;
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if (common_flags()->use_sigaltstack) sigact.sa_flags |= SA_ONSTACK;
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CHECK_EQ(0, internal_sigaction(signum, &sigact, nullptr));
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VReport(1, "Installed the sigaction for signal %d\n", signum);
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}
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void InstallDeadlySignalHandlers(SignalHandlerType handler) {
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// Set the alternate signal stack for the main thread.
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// This will cause SetAlternateSignalStack to be called twice, but the stack
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// will be actually set only once.
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if (common_flags()->use_sigaltstack) SetAlternateSignalStack();
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MaybeInstallSigaction(SIGSEGV, handler);
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MaybeInstallSigaction(SIGBUS, handler);
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MaybeInstallSigaction(SIGABRT, handler);
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MaybeInstallSigaction(SIGFPE, handler);
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MaybeInstallSigaction(SIGILL, handler);
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MaybeInstallSigaction(SIGTRAP, handler);
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}
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bool SignalContext::IsStackOverflow() const {
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// Access at a reasonable offset above SP, or slightly below it (to account
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// for x86_64 or PowerPC redzone, ARM push of multiple registers, etc) is
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// probably a stack overflow.
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#ifdef __s390__
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// On s390, the fault address in siginfo points to start of the page, not
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// to the precise word that was accessed. Mask off the low bits of sp to
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// take it into account.
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bool IsStackAccess = addr >= (sp & ~0xFFF) && addr < sp + 0xFFFF;
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#else
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// Let's accept up to a page size away from top of stack. Things like stack
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// probing can trigger accesses with such large offsets.
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bool IsStackAccess = addr + GetPageSizeCached() > sp && addr < sp + 0xFFFF;
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#endif
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#if __powerpc__
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// Large stack frames can be allocated with e.g.
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// lis r0,-10000
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// stdux r1,r1,r0 # store sp to [sp-10000] and update sp by -10000
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// If the store faults then sp will not have been updated, so test above
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// will not work, because the fault address will be more than just "slightly"
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// below sp.
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if (!IsStackAccess && IsAccessibleMemoryRange(pc, 4)) {
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u32 inst = *(unsigned *)pc;
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u32 ra = (inst >> 16) & 0x1F;
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u32 opcd = inst >> 26;
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u32 xo = (inst >> 1) & 0x3FF;
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// Check for store-with-update to sp. The instructions we accept are:
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// stbu rs,d(ra) stbux rs,ra,rb
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// sthu rs,d(ra) sthux rs,ra,rb
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// stwu rs,d(ra) stwux rs,ra,rb
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// stdu rs,ds(ra) stdux rs,ra,rb
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// where ra is r1 (the stack pointer).
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if (ra == 1 &&
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(opcd == 39 || opcd == 45 || opcd == 37 || opcd == 62 ||
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(opcd == 31 && (xo == 247 || xo == 439 || xo == 183 || xo == 181))))
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IsStackAccess = true;
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}
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#endif // __powerpc__
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// We also check si_code to filter out SEGV caused by something else other
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// then hitting the guard page or unmapped memory, like, for example,
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// unaligned memory access.
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auto si = static_cast<const siginfo_t *>(siginfo);
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return IsStackAccess &&
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(si->si_code == si_SEGV_MAPERR || si->si_code == si_SEGV_ACCERR);
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}
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#endif // SANITIZER_GO
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bool IsAccessibleMemoryRange(uptr beg, uptr size) {
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uptr page_size = GetPageSizeCached();
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// Checking too large memory ranges is slow.
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CHECK_LT(size, page_size * 10);
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int sock_pair[2];
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if (pipe(sock_pair))
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return false;
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uptr bytes_written =
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internal_write(sock_pair[1], reinterpret_cast<void *>(beg), size);
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int write_errno;
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bool result;
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if (internal_iserror(bytes_written, &write_errno)) {
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CHECK_EQ(EFAULT, write_errno);
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result = false;
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} else {
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result = (bytes_written == size);
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}
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internal_close(sock_pair[0]);
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internal_close(sock_pair[1]);
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return result;
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}
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void PlatformPrepareForSandboxing(__sanitizer_sandbox_arguments *args) {
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// Some kinds of sandboxes may forbid filesystem access, so we won't be able
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// to read the file mappings from /proc/self/maps. Luckily, neither the
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// process will be able to load additional libraries, so it's fine to use the
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// cached mappings.
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MemoryMappingLayout::CacheMemoryMappings();
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}
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bool MmapFixedNoReserve(uptr fixed_addr, uptr size, const char *name) {
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size = RoundUpTo(size, GetPageSizeCached());
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fixed_addr = RoundDownTo(fixed_addr, GetPageSizeCached());
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uptr p = MmapNamed((void *)fixed_addr, size, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE | MAP_ANON, name);
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int reserrno;
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if (internal_iserror(p, &reserrno)) {
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Report("ERROR: %s failed to "
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"allocate 0x%zx (%zd) bytes at address %zx (errno: %d)\n",
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SanitizerToolName, size, size, fixed_addr, reserrno);
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return false;
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}
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IncreaseTotalMmap(size);
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return true;
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}
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uptr ReservedAddressRange::Init(uptr size, const char *name, uptr fixed_addr) {
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base_ = fixed_addr ? MmapFixedNoAccess(fixed_addr, size, name)
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: MmapNoAccess(size);
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size_ = size;
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name_ = name;
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(void)os_handle_; // unsupported
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return reinterpret_cast<uptr>(base_);
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}
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// Uses fixed_addr for now.
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// Will use offset instead once we've implemented this function for real.
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uptr ReservedAddressRange::Map(uptr fixed_addr, uptr size, const char *name) {
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return reinterpret_cast<uptr>(
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MmapFixedOrDieOnFatalError(fixed_addr, size, name));
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}
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uptr ReservedAddressRange::MapOrDie(uptr fixed_addr, uptr size,
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const char *name) {
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return reinterpret_cast<uptr>(MmapFixedOrDie(fixed_addr, size, name));
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}
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void ReservedAddressRange::Unmap(uptr addr, uptr size) {
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CHECK_LE(size, size_);
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if (addr == reinterpret_cast<uptr>(base_))
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// If we unmap the whole range, just null out the base.
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base_ = (size == size_) ? nullptr : reinterpret_cast<void*>(addr + size);
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else
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CHECK_EQ(addr + size, reinterpret_cast<uptr>(base_) + size_);
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size_ -= size;
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UnmapOrDie(reinterpret_cast<void*>(addr), size);
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}
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void *MmapFixedNoAccess(uptr fixed_addr, uptr size, const char *name) {
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return (void *)MmapNamed((void *)fixed_addr, size, PROT_NONE,
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MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE | MAP_ANON,
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name);
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}
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void *MmapNoAccess(uptr size) {
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unsigned flags = MAP_PRIVATE | MAP_ANON | MAP_NORESERVE;
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return (void *)internal_mmap(nullptr, size, PROT_NONE, flags, -1, 0);
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}
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// This function is defined elsewhere if we intercepted pthread_attr_getstack.
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extern "C" {
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SANITIZER_WEAK_ATTRIBUTE int
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real_pthread_attr_getstack(void *attr, void **addr, size_t *size);
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} // extern "C"
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int my_pthread_attr_getstack(void *attr, void **addr, uptr *size) {
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#if !SANITIZER_GO && !SANITIZER_MAC
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if (&real_pthread_attr_getstack)
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return real_pthread_attr_getstack((pthread_attr_t *)attr, addr,
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(size_t *)size);
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#endif
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return pthread_attr_getstack((pthread_attr_t *)attr, addr, (size_t *)size);
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}
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#if !SANITIZER_GO
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void AdjustStackSize(void *attr_) {
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pthread_attr_t *attr = (pthread_attr_t *)attr_;
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uptr stackaddr = 0;
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uptr stacksize = 0;
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my_pthread_attr_getstack(attr, (void**)&stackaddr, &stacksize);
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// GLibC will return (0 - stacksize) as the stack address in the case when
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// stacksize is set, but stackaddr is not.
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bool stack_set = (stackaddr != 0) && (stackaddr + stacksize != 0);
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// We place a lot of tool data into TLS, account for that.
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const uptr minstacksize = GetTlsSize() + 128*1024;
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if (stacksize < minstacksize) {
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if (!stack_set) {
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if (stacksize != 0) {
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VPrintf(1, "Sanitizer: increasing stacksize %zu->%zu\n", stacksize,
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minstacksize);
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pthread_attr_setstacksize(attr, minstacksize);
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}
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} else {
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Printf("Sanitizer: pre-allocated stack size is insufficient: "
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"%zu < %zu\n", stacksize, minstacksize);
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Printf("Sanitizer: pthread_create is likely to fail.\n");
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}
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}
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}
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#endif // !SANITIZER_GO
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pid_t StartSubprocess(const char *program, const char *const argv[],
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fd_t stdin_fd, fd_t stdout_fd, fd_t stderr_fd) {
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auto file_closer = at_scope_exit([&] {
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if (stdin_fd != kInvalidFd) {
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internal_close(stdin_fd);
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}
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if (stdout_fd != kInvalidFd) {
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internal_close(stdout_fd);
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}
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if (stderr_fd != kInvalidFd) {
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internal_close(stderr_fd);
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}
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});
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int pid = internal_fork();
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if (pid < 0) {
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int rverrno;
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if (internal_iserror(pid, &rverrno)) {
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Report("WARNING: failed to fork (errno %d)\n", rverrno);
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}
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return pid;
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}
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if (pid == 0) {
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// Child subprocess
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if (stdin_fd != kInvalidFd) {
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internal_close(STDIN_FILENO);
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internal_dup2(stdin_fd, STDIN_FILENO);
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internal_close(stdin_fd);
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}
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if (stdout_fd != kInvalidFd) {
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internal_close(STDOUT_FILENO);
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internal_dup2(stdout_fd, STDOUT_FILENO);
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internal_close(stdout_fd);
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}
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if (stderr_fd != kInvalidFd) {
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internal_close(STDERR_FILENO);
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internal_dup2(stderr_fd, STDERR_FILENO);
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internal_close(stderr_fd);
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}
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for (int fd = sysconf(_SC_OPEN_MAX); fd > 2; fd--) internal_close(fd);
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execv(program, const_cast<char **>(&argv[0]));
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internal__exit(1);
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}
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return pid;
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}
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bool IsProcessRunning(pid_t pid) {
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int process_status;
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uptr waitpid_status = internal_waitpid(pid, &process_status, WNOHANG);
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int local_errno;
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if (internal_iserror(waitpid_status, &local_errno)) {
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VReport(1, "Waiting on the process failed (errno %d).\n", local_errno);
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return false;
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}
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return waitpid_status == 0;
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}
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int WaitForProcess(pid_t pid) {
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int process_status;
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uptr waitpid_status = internal_waitpid(pid, &process_status, 0);
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|
int local_errno;
|
|
if (internal_iserror(waitpid_status, &local_errno)) {
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VReport(1, "Waiting on the process failed (errno %d).\n", local_errno);
|
|
return -1;
|
|
}
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|
return process_status;
|
|
}
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bool IsStateDetached(int state) {
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return state == PTHREAD_CREATE_DETACHED;
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|
}
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} // namespace __sanitizer
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#endif // SANITIZER_POSIX
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