2946cd7010
to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
108 lines
2.9 KiB
C++
108 lines
2.9 KiB
C++
//===- FuzzerShmemPosix.cpp - Posix shared memory ---------------*- C++ -* ===//
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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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// SharedMemoryRegion
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//===----------------------------------------------------------------------===//
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#include "FuzzerDefs.h"
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#if LIBFUZZER_POSIX
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#include "FuzzerIO.h"
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#include "FuzzerShmem.h"
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#include <errno.h>
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#include <fcntl.h>
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#include <semaphore.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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namespace fuzzer {
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std::string SharedMemoryRegion::Path(const char *Name) {
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return DirPlusFile(TmpDir(), Name);
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}
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std::string SharedMemoryRegion::SemName(const char *Name, int Idx) {
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std::string Res(Name);
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// When passing a name without a leading <slash> character to
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// sem_open, the behaviour is unspecified in POSIX. Add a leading
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// <slash> character for the name if there is no such one.
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if (!Res.empty() && Res[0] != '/')
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Res.insert(Res.begin(), '/');
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return Res + (char)('0' + Idx);
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}
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bool SharedMemoryRegion::Map(int fd) {
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Data =
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(uint8_t *)mmap(0, kShmemSize, PROT_WRITE | PROT_READ, MAP_SHARED, fd, 0);
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if (Data == (uint8_t*)-1)
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return false;
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return true;
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}
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bool SharedMemoryRegion::Create(const char *Name) {
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int fd = open(Path(Name).c_str(), O_CREAT | O_RDWR, 0777);
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if (fd < 0) return false;
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if (ftruncate(fd, kShmemSize) < 0) return false;
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if (!Map(fd))
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return false;
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for (int i = 0; i < 2; i++) {
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sem_unlink(SemName(Name, i).c_str());
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Semaphore[i] = sem_open(SemName(Name, i).c_str(), O_CREAT, 0644, 0);
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if (Semaphore[i] == SEM_FAILED)
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return false;
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}
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IAmServer = true;
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return true;
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}
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bool SharedMemoryRegion::Open(const char *Name) {
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int fd = open(Path(Name).c_str(), O_RDWR);
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if (fd < 0) return false;
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struct stat stat_res;
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if (0 != fstat(fd, &stat_res))
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return false;
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assert(stat_res.st_size == kShmemSize);
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if (!Map(fd))
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return false;
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for (int i = 0; i < 2; i++) {
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Semaphore[i] = sem_open(SemName(Name, i).c_str(), 0);
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if (Semaphore[i] == SEM_FAILED)
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return false;
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}
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IAmServer = false;
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return true;
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}
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bool SharedMemoryRegion::Destroy(const char *Name) {
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return 0 == unlink(Path(Name).c_str());
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}
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void SharedMemoryRegion::Post(int Idx) {
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assert(Idx == 0 || Idx == 1);
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sem_post((sem_t*)Semaphore[Idx]);
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}
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void SharedMemoryRegion::Wait(int Idx) {
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assert(Idx == 0 || Idx == 1);
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for (int i = 0; i < 10 && sem_wait((sem_t*)Semaphore[Idx]); i++) {
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// sem_wait may fail if interrupted by a signal.
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sleep(i);
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if (i)
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Printf("%s: sem_wait[%d] failed %s\n", i < 9 ? "WARNING" : "ERROR", i,
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strerror(errno));
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if (i == 9) abort();
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}
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}
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} // namespace fuzzer
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#endif // LIBFUZZER_POSIX
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