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| author |   Maarten Lankhorst <maarten.lankhorst@linux.intel.com> | 2024-05-28 22:21:34 +0200 |
|---|---|---|
| committer | Maarten Lankhorst <maarten.lankhorst@linux.intel.com> | 2024-05-28 22:21:34 +0200 |
| commit | f73a058be5d70dd81a43f16b2bbff4b1576a7af8 (patch) | |
| tree | b7959c01cf7a5d95c7c4d5b61929ff9123370322 /fs/fcntl.c | |
| parent | dma-buf: handle testing kthreads creation failure (diff) | |
| parent | Merge tag 'drm-misc-fixes-2024-05-23' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes (diff) | |
| download | wireguard-linux-f73a058be5d70dd81a43f16b2bbff4b1576a7af8.tar.xz wireguard-linux-f73a058be5d70dd81a43f16b2bbff4b1576a7af8.zip | |
Merge remote-tracking branch 'drm/drm-fixes' into drm-misc-fixes
v6.10-rc1 is released, forward from v6.9
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Diffstat (limited to 'fs/fcntl.c')
| -rw-r--r-- | fs/fcntl.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c index 54cc85d3338e..300e5d9ad913 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -327,6 +327,22 @@ static long fcntl_set_rw_hint(struct file *file, unsigned int cmd, return 0; } +/* Is the file descriptor a dup of the file? */ +static long f_dupfd_query(int fd, struct file *filp) +{ + CLASS(fd_raw, f)(fd); + + /* + * We can do the 'fdput()' immediately, as the only thing that + * matters is the pointer value which isn't changed by the fdput. + * + * Technically we didn't need a ref at all, and 'fdget()' was + * overkill, but given our lockless file pointer lookup, the + * alternatives are complicated. + */ + return f.file == filp; +} + static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, struct file *filp) { @@ -342,6 +358,9 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, case F_DUPFD_CLOEXEC: err = f_dupfd(argi, filp, O_CLOEXEC); break; + case F_DUPFD_QUERY: + err = f_dupfd_query(argi, filp); + break; case F_GETFD: err = get_close_on_exec(fd) ? FD_CLOEXEC : 0; break; @@ -446,6 +465,7 @@ static int check_fcntl_cmd(unsigned cmd) switch (cmd) { case F_DUPFD: case F_DUPFD_CLOEXEC: + case F_DUPFD_QUERY: case F_GETFD: case F_SETFD: case F_GETFL: |