Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

src: remap invalid file descriptors using dup2 #44461

Merged
merged 1 commit into from Oct 26, 2022
Merged

src: remap invalid file descriptors using dup2 #44461

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
25 changes: 23 additions & 2 deletions src/node.cc
View file
Open in desktop
Expand Up @@ -608,11 +608,32 @@ static void PlatformInit(ProcessInitializationFlags::Flags flags) {
for (auto& s : stdio) {
const int fd = &s - stdio;
if (fstat(fd, &s.stat) == 0) continue;

// Anything but EBADF means something is seriously wrong. We don't
// have to special-case EINTR, fstat() is not interruptible.
if (errno != EBADF) ABORT();
if (fd != open("/dev/null", O_RDWR)) ABORT();
if (fstat(fd, &s.stat) != 0) ABORT();

// If EBADF (file descriptor doesn't exist), open /dev/null and duplicate
// its file descriptor to the invalid file descriptor. Make sure *that*
// file descriptor is valid. POSIX doesn't guarantee the next file
// descriptor open(2) gives us is the lowest available number anymore in
// POSIX.1-2017, which is why dup2(2) is needed.
int null_fd;

do {
null_fd = open("/dev/null", O_RDWR);
} while (null_fd < 0 && errno == EINTR);

if (null_fd != fd) {
int err;

do {
err = dup2(null_fd, fd);
} while (err < 0 && errno == EINTR);
CHECK_EQ(err, 0);
}

if (fstat(fd, &s.stat) < 0) ABORT();
}
}

Expand Down