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// Copyright (c) 2006, 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.
// minidump_file_writer.cc: Minidump file writer implementation.
//
// See minidump_file_writer.h for documentation.
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "minidump_file_writer-inl.h"
#include "common/linux/linux_libc_support.h"
#include "common/string_conversion.h"
#if defined(__linux__) && __linux__
#include "third_party/lss/linux_syscall_support.h"
#endif
#if defined(__ANDROID__)
#include <errno.h>
namespace {
bool g_need_ftruncate_workaround = false;
bool g_checked_need_ftruncate_workaround = false;
void CheckNeedsFTruncateWorkAround(int file) {
if (g_checked_need_ftruncate_workaround) {
return;
}
g_checked_need_ftruncate_workaround = true;
// Attempt an idempotent truncate that chops off nothing and see if we
// run into any sort of errors.
off_t offset = sys_lseek(file, 0, SEEK_END);
if (offset == -1) {
// lseek failed. Don't apply work around. It's unlikely that we can write
// to a minidump with either method.
return;
}
int result = ftruncate(file, offset);
if (result == -1 && errno == EACCES) {
// It very likely that we are running into the kernel bug in M devices.
// We are going to deploy the workaround for writing minidump files
// without uses of ftruncate(). This workaround should be fine even
// for kernels without the bug.
g_need_ftruncate_workaround = true;
}
}
bool NeedsFTruncateWorkAround() {
return g_need_ftruncate_workaround;
}
} // namespace
#endif // defined(__ANDROID__)
namespace google_breakpad {
const MDRVA MinidumpFileWriter::kInvalidMDRVA = static_cast<MDRVA>(-1);
MinidumpFileWriter::MinidumpFileWriter()
: file_(-1),
close_file_when_destroyed_(true),
position_(0),
size_(0) {
}
MinidumpFileWriter::~MinidumpFileWriter() {
if (close_file_when_destroyed_)
Close();
}
bool MinidumpFileWriter::Open(const char *path) {
assert(file_ == -1);
#if defined(__linux__) && __linux__
file_ = sys_open(path, O_WRONLY | O_CREAT | O_EXCL, 0600);
#else
file_ = open(path, O_WRONLY | O_CREAT | O_EXCL, 0600);
#endif
return file_ != -1;
}
void MinidumpFileWriter::SetFile(const int file) {
assert(file_ == -1);
file_ = file;
close_file_when_destroyed_ = false;
#if defined(__ANDROID__)
CheckNeedsFTruncateWorkAround(file);
#endif
}
bool MinidumpFileWriter::Close() {
bool result = true;
if (file_ != -1) {
#if defined(__ANDROID__)
if (!NeedsFTruncateWorkAround() && ftruncate(file_, position_)) {
return false;
}
#else
if (ftruncate(file_, position_)) {
return false;
}
#endif
#if defined(__linux__) && __linux__
result = (sys_close(file_) == 0);
#else
result = (close(file_) == 0);
#endif
file_ = -1;
}
return result;
}
bool MinidumpFileWriter::CopyStringToMDString(const wchar_t *str,
unsigned int length,
TypedMDRVA<MDString> *mdstring) {
bool result = true;
if (sizeof(wchar_t) == sizeof(uint16_t)) {
// Shortcut if wchar_t is the same size as MDString's buffer
result = mdstring->Copy(str, mdstring->get()->length);
} else {
uint16_t out[2];
int out_idx = 0;
// Copy the string character by character
while (length && result) {
UTF32ToUTF16Char(*str, out);
if (!out[0])
return false;
// Process one character at a time
--length;
++str;
// Append the one or two UTF-16 characters. The first one will be non-
// zero, but the second one may be zero, depending on the conversion from
// UTF-32.
int out_count = out[1] ? 2 : 1;
size_t out_size = sizeof(uint16_t) * out_count;
result = mdstring->CopyIndexAfterObject(out_idx, out, out_size);
out_idx += out_count;
}
}
return result;
}
bool MinidumpFileWriter::CopyStringToMDString(const char *str,
unsigned int length,
TypedMDRVA<MDString> *mdstring) {
bool result = true;
uint16_t out[2];
int out_idx = 0;
// Copy the string character by character
while (length && result) {
int conversion_count = UTF8ToUTF16Char(str, length, out);
if (!conversion_count)
return false;
// Move the pointer along based on the nubmer of converted characters
length -= conversion_count;
str += conversion_count;
// Append the one or two UTF-16 characters
int out_count = out[1] ? 2 : 1;
size_t out_size = sizeof(uint16_t) * out_count;
result = mdstring->CopyIndexAfterObject(out_idx, out, out_size);
out_idx += out_count;
}
return result;
}
unsigned int MinidumpFileWriter::CalculateNumOfU16s(const wchar_t *str, unsigned int length) {
if (sizeof(wchar_t) == sizeof(uint16_t)) {
// Shortcut if wchar_t is the same size as MDString's buffer
return length;
} else {
uint16_t out[2];
unsigned int num_of_u16s = 0;
// Copy the string character by character
while (length) {
UTF32ToUTF16Char(*str, out);
if (!out[0])
return false;
// Process one character at a time
--length;
++str;
// Count the number of UTF-16 characters needed for every wchar_t
// and add it to the total.
int out_count = out[1] ? 2 : 1;
num_of_u16s += out_count;
}
return num_of_u16s;
}
}
unsigned int MinidumpFileWriter::CalculateNumOfU16s(const char *str, unsigned int length) {
uint16_t out[2];
unsigned int num_of_u16s = 0;
while (length) {
int conversion_count = UTF8ToUTF16Char(str, length, out);
if (!conversion_count) {
break;
}
// Move the pointer along based on the number of converted characters
length -= conversion_count;
str += conversion_count;
// Add one or two to the total
int out_count = out[1] ? 2 : 1;
num_of_u16s += out_count;
}
return num_of_u16s;
}
template <typename CharType>
bool MinidumpFileWriter::WriteStringCore(const CharType *str,
unsigned int length,
MDLocationDescriptor *location) {
assert(str);
assert(location);
// Calculate the mdstring length by either limiting to |length| as passed in
// or by finding the location of the NULL character.
unsigned int mdstring_length = 0;
if (!length)
length = INT_MAX;
for (; mdstring_length < length && str[mdstring_length]; ++mdstring_length)
;
unsigned int num_of_u16s = MinidumpFileWriter::CalculateNumOfU16s(str, mdstring_length);
// Allocate the string buffer
TypedMDRVA<MDString> mdstring(this);
if (!mdstring.AllocateObjectAndArray(num_of_u16s + 1, sizeof(uint16_t)))
return false;
// Set length excluding the NULL and copy the string
mdstring.get()->length =
static_cast<uint32_t>(num_of_u16s * sizeof(uint16_t));
bool result = CopyStringToMDString(str, mdstring_length, &mdstring);
// NULL terminate
if (result) {
uint16_t ch = 0;
result = mdstring.CopyIndexAfterObject(num_of_u16s, &ch, sizeof(ch));
if (result)
*location = mdstring.location();
}
return result;
}
bool MinidumpFileWriter::WriteString(const wchar_t *str, unsigned int length,
MDLocationDescriptor *location) {
return WriteStringCore(str, length, location);
}
bool MinidumpFileWriter::WriteString(const char *str, unsigned int length,
MDLocationDescriptor *location) {
return WriteStringCore(str, length, location);
}
bool MinidumpFileWriter::WriteMemory(const void *src, size_t size,
MDMemoryDescriptor *output) {
assert(src);
assert(output);
UntypedMDRVA mem(this);
if (!mem.Allocate(size))
return false;
if (!mem.Copy(src, mem.size()))
return false;
output->start_of_memory_range = reinterpret_cast<uint64_t>(src);
output->memory = mem.location();
return true;
}
MDRVA MinidumpFileWriter::Allocate(size_t size) {
assert(size);
assert(file_ != -1);
#if defined(__ANDROID__)
if (NeedsFTruncateWorkAround()) {
// If ftruncate() is not available. We simply increase the size beyond the
// current file size. sys_write() will expand the file when data is written
// to it. Because we did not over allocate to fit memory pages, we also
// do not need to ftruncate() the file once we are done.
size_ += size;
// We don't need to seek since the file is unchanged.
MDRVA current_position = position_;
position_ += static_cast<MDRVA>(size);
return current_position;
}
#endif
size_t aligned_size = (size + 7) & ~7; // 64-bit alignment
if (position_ + aligned_size > size_) {
size_t growth = aligned_size;
size_t minimal_growth = getpagesize();
// Ensure that the file grows by at least the size of a memory page
if (growth < minimal_growth)
growth = minimal_growth;
size_t new_size = size_ + growth;
if (ftruncate(file_, new_size) != 0)
return kInvalidMDRVA;
size_ = new_size;
}
MDRVA current_position = position_;
position_ += static_cast<MDRVA>(aligned_size);
return current_position;
}
bool MinidumpFileWriter::Copy(MDRVA position, const void *src, ssize_t size) {
assert(src);
assert(size);
assert(file_ != -1);
// Ensure that the data will fit in the allocated space
if (static_cast<size_t>(size + position) > size_)
return false;
// Seek and write the data
#if defined(__linux__) && __linux__
if (sys_lseek(file_, position, SEEK_SET) == static_cast<off_t>(position)) {
if (sys_write(file_, src, size) == size) {
return true;
}
}
#else
if (lseek(file_, position, SEEK_SET) == static_cast<off_t>(position)) {
if (write(file_, src, size) == size) {
return true;
}
}
#endif
return false;
}
bool UntypedMDRVA::Allocate(size_t size) {
assert(size_ == 0);
size_ = size;
position_ = writer_->Allocate(size_);
return position_ != MinidumpFileWriter::kInvalidMDRVA;
}
bool UntypedMDRVA::Copy(MDRVA pos, const void *src, size_t size) {
assert(src);
assert(size);
assert(pos + size <= position_ + size_);
return writer_->Copy(pos, src, size);
}
} // namespace google_breakpad