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// Copyright (c) 2011, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// memory_mapped_file.cc: Implement google_breakpad::MemoryMappedFile.
// See memory_mapped_file.h for details.
#include "common/linux/memory_mapped_file.h"
#include <fcntl.h>
#include <sys/mman.h>
#if defined(__ANDROID__)
#include <sys/stat.h>
#endif
#include <unistd.h>
#include "common/memory_range.h"
#include "third_party/lss/linux_syscall_support.h"
namespace google_breakpad {
MemoryMappedFile::MemoryMappedFile() {}
MemoryMappedFile::MemoryMappedFile(const char* path, size_t offset) {
Map(path, offset);
}
MemoryMappedFile::~MemoryMappedFile() {
Unmap();
}
bool MemoryMappedFile::Map(const char* path, size_t offset) {
Unmap();
int fd = sys_open(path, O_RDONLY, 0);
if (fd == -1) {
return false;
}
#if defined(__x86_64__) || defined(__aarch64__)
struct kernel_stat st;
if (sys_fstat(fd, &st) == -1 || st.st_size < 0) {
#else
struct kernel_stat64 st;
if (sys_fstat64(fd, &st) == -1 || st.st_size < 0) {
#endif
sys_close(fd);
return false;
}
// Strangely file size can be negative, but we check above that it is not.
size_t file_len = static_cast<size_t>(st.st_size);
// If the file does not extend beyond the offset, simply use an empty
// MemoryRange and return true. Don't bother to call mmap()
// even though mmap() can handle an empty file on some platforms.
if (offset >= file_len) {
sys_close(fd);
return true;
}
#if defined(__x86_64__) || defined(__aarch64__)
void* data = sys_mmap(NULL, file_len, PROT_READ, MAP_PRIVATE, fd, offset);
#else
if ((offset & 4095) != 0) {
// Not page aligned.
sys_close(fd);
return false;
}
void* data = sys_mmap2(
NULL, file_len, PROT_READ, MAP_PRIVATE, fd, offset >> 12);
#endif
sys_close(fd);
if (data == MAP_FAILED) {
return false;
}
content_.Set(data, file_len - offset);
return true;
}
void MemoryMappedFile::Unmap() {
if (content_.data()) {
sys_munmap(const_cast<uint8_t*>(content_.data()), content_.length());
content_.Set(NULL, 0);
}
}
} // namespace google_breakpad
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