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author | Lennart Poettering <lennart@poettering.net> | 2023-03-21 14:34:44 +0100 |
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committer | Daan De Meyer <daan.j.demeyer@gmail.com> | 2023-03-21 20:51:55 +0100 |
commit | 42db4a8db704592866ccc96c4a068b1537b1dde8 (patch) | |
tree | 0785d8863cdb64a8343ad7343111f6fbfb2f8cf8 /src/basic/fd-util.c | |
parent | 1c2e550ec43226c2904df3304e3fe362e5b38671 (diff) | |
download | systemd-42db4a8db704592866ccc96c4a068b1537b1dde8.tar.gz |
fd-util: make sure fd_reopen() works with AT_FDCWD systematically
Prompted by:
https://github.com/systemd/systemd/pull/26827#pullrequestreview-1341171981
Diffstat (limited to 'src/basic/fd-util.c')
-rw-r--r-- | src/basic/fd-util.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/src/basic/fd-util.c b/src/basic/fd-util.c index d729643265..5eb43e1f81 100644 --- a/src/basic/fd-util.c +++ b/src/basic/fd-util.c @@ -744,23 +744,29 @@ finish: int fd_reopen(int fd, int flags) { int new_fd, r; + assert(fd >= 0 || fd == AT_FDCWD); + /* Reopens the specified fd with new flags. This is useful for convert an O_PATH fd into a regular one, or to * turn O_RDWR fds into O_RDONLY fds. * * This doesn't work on sockets (since they cannot be open()ed, ever). * - * This implicitly resets the file read index to 0. */ + * This implicitly resets the file read index to 0. + * + * If AT_FDCWD is specified as file descriptor gets an fd to the current cwd */ - if (FLAGS_SET(flags, O_DIRECTORY)) { + if (FLAGS_SET(flags, O_DIRECTORY) || fd == AT_FDCWD) { /* If we shall reopen the fd as directory we can just go via "." and thus bypass the whole * magic /proc/ directory, and make ourselves independent of that being mounted. */ - new_fd = openat(fd, ".", flags); + new_fd = openat(fd, ".", flags | O_DIRECTORY); if (new_fd < 0) return -errno; return new_fd; } + assert(fd >= 0); + new_fd = open(FORMAT_PROC_FD_PATH(fd), flags); if (new_fd < 0) { if (errno != ENOENT) |