linux-toradex.git/include/linux/file.h, branch v5.10-rc3

fs: Expand __receive_fd() to accept existing fd

2020-07-13T18:03:45+00:00

Expand __receive_fd() with support for replace_fd() for the coming seccomp
"addfd" ioctl(). Add new wrapper receive_fd_replace() for the new behavior
and update existing wrappers to retain old behavior.

Thanks to Colin Ian King  for pointing out an
uninitialized variable exposure in an earlier version of this patch.

Cc: Alexander Viro 
Cc: Dmitry Kadashev 
Cc: Jens Axboe 
Cc: Arnd Bergmann 
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Sargun Dhillon 
Acked-by: Christian Brauner 
Signed-off-by: Kees Cook

fs: Add receive_fd() wrapper for __receive_fd()

2020-07-13T18:03:44+00:00

For both pidfd and seccomp, the __user pointer is not used. Update
__receive_fd() to make writing to ufd optional via a NULL check. However,
for the receive_fd_user() wrapper, ufd is NULL checked so an -EFAULT
can be returned to avoid changing the SCM_RIGHTS interface behavior. Add
new wrapper receive_fd() for pidfd and seccomp that does not use the ufd
argument. For the new helper, the allocated fd needs to be returned on
success. Update the existing callers to handle it.

Cc: Alexander Viro 
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Sargun Dhillon 
Acked-by: Christian Brauner 
Signed-off-by: Kees Cook

fs: Move __scm_install_fd() to __receive_fd()

2020-07-13T18:03:44+00:00

In preparation for users of the "install a received file" logic outside
of net/ (pidfd and seccomp), relocate and rename __scm_install_fd() from
net/core/scm.c to __receive_fd() in fs/file.c, and provide a wrapper
named receive_fd_user(), as future patches will change the interface
to __receive_fd().

Additionally add a comment to fd_install() as a counterpoint to how
__receive_fd() interacts with fput().

Cc: Alexander Viro 
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Cc: Dmitry Kadashev 
Cc: Jens Axboe 
Cc: Arnd Bergmann 
Cc: Sargun Dhillon 
Cc: Ido Schimmel 
Cc: Ioana Ciornei 
Cc: linux-fsdevel@vger.kernel.org
Cc: netdev@vger.kernel.org
Reviewed-by: Sargun Dhillon 
Acked-by: Christian Brauner 
Signed-off-by: Kees Cook

sysctl: remove all extern declaration from sysctl.c

2020-04-27T06:06:53+00:00

Extern declarations in .c files are a bad style and can lead to
mismatches.  Use existing definitions in headers where they exist,
and otherwise move the external declarations to suitable header
files.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro

io_uring: make sure openat/openat2 honor rlimit nofile

2020-03-20T14:47:27+00:00

Dmitry reports that a test case shows that io_uring isn't honoring a
modified rlimit nofile setting. get_unused_fd_flags() checks the task
signal->rlimi[] for the limits. As this isn't easily inheritable,
provide a __get_unused_fd_flags() that takes the value instead. Then we
can grab it when the request is prepared (from the original task), and
pass that in when we do the async part part of the open.

Reported-by: Dmitry Kadashev 
Tested-by: Dmitry Kadashev 
Acked-by: David S. Miller 
Signed-off-by: Jens Axboe

vfs, fdtable: Add fget_task helper

2020-01-13T20:48:42+00:00

This introduces a function which can be used to fetch a file, given an
arbitrary task. As long as the user holds a reference (refcnt) to the
task_struct it is safe to call, and will either return NULL on failure,
or a pointer to the file, with a refcnt.

This patch is based on Oleg Nesterov's (cf. [1]) patch from September
2018.

[1]: Link: https://lore.kernel.org/r/20180915160423.GA31461@redhat.com

Signed-off-by: Sargun Dhillon 
Suggested-by: Oleg Nesterov 
Acked-by: Christian Brauner 
Reviewed-by: Arnd Bergmann 
Link: https://lore.kernel.org/r/20200107175927.4558-2-sargun@sargun.me
Signed-off-by: Christian Brauner

fs: add fget_many() and fput_many()

2019-02-28T15:24:23+00:00

Some uses cases repeatedly get and put references to the same file, but
the only exposed interface is doing these one at the time. As each of
these entail an atomic inc or dec on a shared structure, that cost can
add up.

Add fget_many(), which works just like fget(), except it takes an
argument for how many references to get on the file. Ditto fput_many(),
which can drop an arbitrary number of references to a file.

Reviewed-by: Hannes Reinecke 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

make alloc_file() static

2018-07-12T14:04:29+00:00

Acked-by: Linus Torvalds 
Signed-off-by: Al Viro

new helper: alloc_file_clone()

2018-07-12T14:04:28+00:00

alloc_file_clone(old_file, mode, ops): create a new struct file with
->f_path equal to that of old_file.  pipe converted.

Acked-by: Linus Torvalds 
Signed-off-by: Al Viro

new wrapper: alloc_file_pseudo()

2018-07-12T14:04:23+00:00

takes inode, vfsmount, name, O_... flags and file_operations and
either returns a new struct file (in which case inode reference we
held is consumed) or returns ERR_PTR(), in which case no refcounts
are altered.

converted aio_private_file() and sock_alloc_file() to it

Acked-by: Linus Torvalds 
Signed-off-by: Al Viro