gecko-dev/widget/LSBUtils.cpp
Kris Maglione c15ee94ddc Bug 1475612: Fix double file close on background thread. r=erahm
LSBUtils closes a file descriptor twice, once with fclose and then again with
close. It also does this on a background thread, during startup, which means
it tends to race with main thread code which opens files.

This patch fixes that, and also removes a work-around for the issue in the
MemMapSnapshot code.

MozReview-Commit-ID: JdDHt9ayFEl

--HG--
extra : rebase_source : 2000ede41108d6312734d8df7db98272b33528fa
extra : amend_source : 1443a596fab3e3126a22d44787adaf5e12e4587c
2018-07-12 23:13:04 -07:00

79 lines
1.9 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "LSBUtils.h"
#include <unistd.h>
#include "base/process_util.h"
#include "mozilla/FileUtils.h"
namespace mozilla {
namespace widget {
namespace lsb {
static const char* gLsbReleasePath = "/usr/bin/lsb_release";
bool
GetLSBRelease(nsACString& aDistributor,
nsACString& aDescription,
nsACString& aRelease,
nsACString& aCodename)
{
if (access(gLsbReleasePath, R_OK) != 0)
return false;
int pipefd[2];
if (pipe(pipefd) == -1) {
NS_WARNING("pipe() failed!");
return false;
}
std::vector<std::string> argv = {
gLsbReleasePath, "-idrc"
};
base::LaunchOptions options;
options.fds_to_remap.push_back({ pipefd[1], STDOUT_FILENO });
options.wait = true;
base::ProcessHandle process;
bool ok = base::LaunchApp(argv, options, &process);
close(pipefd[1]);
if (!ok) {
NS_WARNING("Failed to spawn lsb_release!");
close(pipefd[0]);
return false;
}
ScopedCloseFile stream(fdopen(pipefd[0], "r"));
if (!stream) {
NS_WARNING("Could not wrap fd!");
close(pipefd[0]);
return false;
}
char dist[256], desc[256], release[256], codename[256];
if (fscanf(stream, "Distributor ID:\t%255[^\n]\n"
"Description:\t%255[^\n]\n"
"Release:\t%255[^\n]\n"
"Codename:\t%255[^\n]\n",
dist, desc, release, codename) != 4)
{
NS_WARNING("Failed to parse lsb_release!");
return false;
}
aDistributor.Assign(dist);
aDescription.Assign(desc);
aRelease.Assign(release);
aCodename.Assign(codename);
return true;
}
} // namespace lsb
} // namespace widget
} // namespace mozilla