Commit Graph

72 Commits

Author SHA1 Message Date
Linus Torvalds
266d17a8c0 Merge tag 'driver-core-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
 "Here is the set of driver core changes for 5.18-rc1.

  Not much here, primarily it was a bunch of cleanups and small updates:

   - kobj_type cleanups for default_groups

   - documentation updates

   - firmware loader minor changes

   - component common helper added and take advantage of it in many
     drivers (the largest part of this pull request).

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (54 commits)
  Documentation: update stable review cycle documentation
  drivers/base/dd.c : Remove the initial value of the global variable
  Documentation: update stable tree link
  Documentation: add link to stable release candidate tree
  devres: fix typos in comments
  Documentation: add note block surrounding security patch note
  samples/kobject: Use sysfs_emit instead of sprintf
  base: soc: Make soc_device_match() simpler and easier to read
  driver core: dd: fix return value of __setup handler
  driver core: Refactor sysfs and drv/bus remove hooks
  driver core: Refactor multiple copies of device cleanup
  scripts: get_abi.pl: Fix typo in help message
  kernfs: fix typos in comments
  kernfs: remove unneeded #if 0 guard
  ALSA: hda/realtek: Make use of the helper component_compare_dev_name
  video: omapfb: dss: Make use of the helper component_compare_dev
  power: supply: ab8500: Make use of the helper component_compare_dev
  ASoC: codecs: wcd938x: Make use of the helper component_compare/release_of
  iommu/mediatek: Make use of the helper component_compare/release_of
  drm: of: Make use of the helper component_release_of
  ...
2022-03-28 12:41:28 -07:00
Anthony Iliopoulos
8f2d116045 devtmpfs: drop redundant fs parameters from internal fs
The internal_fs_type is mounted via vfs_kernel_mount() and is never
registered as a filesystem, thus specifying the parameters is redundant
as those params will not be validated by fs_validate_description().

Both {shmem,ramfs}_fs_parameters are anyway validated when those
respective filesystems are first registered, so there is no reason to
pass them to devtmpfs too, drop them.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Anthony Iliopoulos <ailiop@suse.com>
Link: https://lore.kernel.org/r/20220119220248.32225-1-ailiop@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-04 15:38:01 +01:00
Christoph Hellwig
322cbb50de block: remove genhd.h
There is no good reason to keep genhd.h separate from the main blkdev.h
header that includes it.  So fold the contents of genhd.h into blkdev.h
and remove genhd.h entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220124093913.742411-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02 07:49:59 -07:00
NeilBrown
a6097180d8 devtmpfs regression fix: reconfigure on each mount
Prior to Linux v5.4 devtmpfs used mount_single() which treats the given
mount options as "remount" options, so it updates the configuration of
the single super_block on each mount.

Since that was changed, the mount options used for devtmpfs are ignored.
This is a regression which affect systemd - which mounts devtmpfs with
"-o mode=755,size=4m,nr_inodes=1m".

This patch restores the "remount" effect by calling reconfigure_single()

Fixes: d401727ea0 ("devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()")
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-17 09:40:29 +02:00
Kees Cook
28f0c335dd devtmpfs: mount with noexec and nosuid
devtmpfs is writable. Add the noexec and nosuid as default mount flags
to prevent code execution from /dev. The systems who don't use systemd
and who rely on CONFIG_DEVTMPFS_MOUNT=y are the ones to be protected by
this patch. Other systems are fine with the udev solution.

No sane program should be relying on executing from /dev. So this patch
reduces the attack surface. It doesn't prevent any specific attack, but
it reduces the possibility that someone can use /dev as a place to put
executable code. Chrome OS has been carrying this patch for several
years. It seems trivial and simple solution to improve the protection of
/dev when CONFIG_DEVTMPFS_MOUNT=y.

Original patch:
https://lore.kernel.org/lkml/20121120215059.GA1859@www.outflux.net/

Cc: ellyjones@chromium.org
Cc: Kay Sievers <kay@vrfy.org>
Cc: Roland Eggner <edvx1@systemanalysen.net>
Co-developed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/YcMfDOyrg647RCmd@debian-BULLSEYE-live-builder-AMD64
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:54:42 +01:00
Rasmus Villemoes
01085e24ff devtmpfs: actually reclaim some init memory
Currently gcc seems to inline devtmpfs_setup() into devtmpfsd(), so
its memory footprint isn't reclaimed as intended. Mark it noinline to
make sure it gets put in .init.text.

While here, setup_done can also be put in .init.data: After complete()
releases the internal spinlock, the completion object is never touched
again by that thread, and the waiting thread doesn't proceed until it
observes ->done while holding that spinlock.

This is now the same pattern as for kthreadd_done in init/main.c:
complete() is done in a __ref function, while the corresponding
wait_for_completion() is in an __init function.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/r/20210312103027.2701413-2-linux@rasmusvillemoes.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-23 14:57:35 +01:00
Rasmus Villemoes
38f087de89 devtmpfs: fix placement of complete() call
Calling complete() from within the __init function is wrong -
theoretically, the init process could proceed all the way to freeing
the init mem before the devtmpfsd thread gets to execute the return
instruction in devtmpfs_setup().

In practice, it seems to be harmless as gcc inlines devtmpfs_setup()
into devtmpfsd(). So the calls of the __init functions init_chdir()
etc. actually happen from devtmpfs_setup(), but the __ref on that one
silences modpost (it's all right, because those calls happen before
the complete()). But it does make the __init annotation of the setup
function moot, which we'll fix in a subsequent patch.

Fixes: bcbacc4909 ("devtmpfs: refactor devtmpfsd()")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/r/20210312103027.2701413-1-linux@rasmusvillemoes.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-23 14:57:35 +01:00
Christian Brauner
6521f89170 namei: prepare for idmapped mounts
The various vfs_*() helpers are called by filesystems or by the vfs
itself to perform core operations such as create, link, mkdir, mknod, rename,
rmdir, tmpfile and unlink. Enable them to handle idmapped mounts. If the
inode is accessed through an idmapped mount map it into the
mount's user namespace and pass it down. Afterwards the checks and
operations are identical to non-idmapped mounts. If the initial user
namespace is passed nothing changes so non-idmapped mounts will see
identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-15-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:18 +01:00
Christian Brauner
2f221d6f7b attr: handle idmapped mounts
When file attributes are changed most filesystems rely on the
setattr_prepare(), setattr_copy(), and notify_change() helpers for
initialization and permission checking. Let them handle idmapped mounts.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.

Helpers that perform checks on the ia_uid and ia_gid fields in struct
iattr assume that ia_uid and ia_gid are intended values and have already
been mapped correctly at the userspace-kernelspace boundary as we
already do today. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-8-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:16 +01:00
Christoph Hellwig
4b7ca5014c init: add an init_chroot helper
Add a simple helper to chroot with a kernel space file name and switch
the early init code over to it.  Remove the now unused ksys_chroot.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-31 08:17:52 +02:00
Christoph Hellwig
db63f1e315 init: add an init_chdir helper
Add a simple helper to chdir with a kernel space file name and switch
the early init code over to it.  Remove the now unused ksys_chdir.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-31 08:17:52 +02:00
Christoph Hellwig
c60166f042 init: add an init_mount helper
Like do_mount, but takes a kernel pointer for the destination path.
Switch over the mounts in the init code and devtmpfs to it, which
just happen to work due to the implicit set_fs(KERNEL_DS) during early
init right now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-31 08:17:51 +02:00
Christoph Hellwig
bcbacc4909 devtmpfs: refactor devtmpfsd()
Split the main worker loop into a separate function.  This allows
devtmpfsd_setup to be marked __init, which will allows us to call
__init routines for the setup work.  devtmpfѕ itself needs a __ref
marker for that to work, and a comment explaining why it works.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-31 08:17:51 +02:00
Linus Torvalds
c9d35ee049 Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs file system parameter updates from Al Viro:
 "Saner fs_parser.c guts and data structures. The system-wide registry
  of syntax types (string/enum/int32/oct32/.../etc.) is gone and so is
  the horror switch() in fs_parse() that would have to grow another case
  every time something got added to that system-wide registry.

  New syntax types can be added by filesystems easily now, and their
  namespace is that of functions - not of system-wide enum members. IOW,
  they can be shared or kept private and if some turn out to be widely
  useful, we can make them common library helpers, etc., without having
  to do anything whatsoever to fs_parse() itself.

  And we already get that kind of requests - the thing that finally
  pushed me into doing that was "oh, and let's add one for timeouts -
  things like 15s or 2h". If some filesystem really wants that, let them
  do it. Without somebody having to play gatekeeper for the variants
  blessed by direct support in fs_parse(), TYVM.

  Quite a bit of boilerplate is gone. And IMO the data structures make a
  lot more sense now. -200LoC, while we are at it"

* 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (25 commits)
  tmpfs: switch to use of invalfc()
  cgroup1: switch to use of errorfc() et.al.
  procfs: switch to use of invalfc()
  hugetlbfs: switch to use of invalfc()
  cramfs: switch to use of errofc() et.al.
  gfs2: switch to use of errorfc() et.al.
  fuse: switch to use errorfc() et.al.
  ceph: use errorfc() and friends instead of spelling the prefix out
  prefix-handling analogues of errorf() and friends
  turn fs_param_is_... into functions
  fs_parse: handle optional arguments sanely
  fs_parse: fold fs_parameter_desc/fs_parameter_spec
  fs_parser: remove fs_parameter_description name field
  add prefix to fs_context->log
  ceph_parse_param(), ceph_parse_mon_ips(): switch to passing fc_log
  new primitive: __fs_parse()
  switch rbd and libceph to p_log-based primitives
  struct p_log, variants of warnf() et.al. taking that one instead
  teach logfc() to handle prefices, give it saner calling conventions
  get rid of cg_invalf()
  ...
2020-02-08 13:26:41 -08:00
Al Viro
d7167b1499 fs_parse: fold fs_parameter_desc/fs_parameter_spec
The former contains nothing but a pointer to an array of the latter...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:37 -05:00
Rasmus Villemoes
72a9cc952f devtmpfs: factor out common tail of devtmpfs_{create,delete}_node
There's some common boilerplate in devtmpfs_{create,delete}_node, put
that in a little helper.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/r/20200115184154.3492-6-linux@rasmusvillemoes.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22 15:28:15 +01:00
Rasmus Villemoes
fad1db8a35 devtmpfs: initify a bit
devtmpfs_mount() is only called from prepare_namespace() in
init/do_mounts.c, which is an __init function, so devtmpfs_mount() can
also be moved to .init.text.

Then the mount_dev static variable is only referenced from __init
functions (devtmpfs_mount and its initializer function mount_param).

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/r/20200115184154.3492-5-linux@rasmusvillemoes.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22 15:28:15 +01:00
Rasmus Villemoes
21766d11d1 devtmpfs: simplify initialization of mount_dev
Avoid a bit of ifdeffery by using the IS_ENABLED() helper.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/r/20200115184154.3492-4-linux@rasmusvillemoes.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22 15:28:15 +01:00
Rasmus Villemoes
0ff0e95e99 devtmpfs: factor out setup part of devtmpfsd()
Factor out the setup part of devtmpfsd() to make it a bit easier to
see that we always call setup_done() exactly once (provided of course
the kthread is succesfully created).

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/r/20200115184154.3492-3-linux@rasmusvillemoes.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22 15:28:14 +01:00
Rasmus Villemoes
c9d6b287d7 devtmpfs: fix theoretical stale pointer deref in devtmpfsd()
After complete(&setup_done), devtmpfs_init proceeds and may actually
return, invalidating the *err pointer, before devtmpfsd() proceeds to
reading back *err.

This is of course completely theoretical since the error conditions
never trigger in practice, and even if they did, nobody cares about
the exit value from a kernel thread, so it doesn't matter if we happen
to read back some garbage from some other stack frame. Still, this
isn't a pattern that should be copy-pasted, so fix it.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/r/20200115184154.3492-2-linux@rasmusvillemoes.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22 15:28:14 +01:00
Dominik Brodowski
5e787dbf65 devtmpfs: use do_mount() instead of ksys_mount()
In devtmpfs, do_mount() can be called directly instead of complex wrapping
by ksys_mount():
- the first and third arguments are const strings in the kernel,
  and do not need to be copied over from userspace;
- the fifth argument is NULL, and therefore no page needs to be
  copied over from userspace;
- the second and fourth argument are passed through anyway.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2019-12-12 14:49:57 +01:00
David Howells
f32356261d vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API
Convert the ramfs, shmem, tmpfs, devtmpfs and rootfs filesystems to the new
internal mount API as the old one will be obsoleted and removed.  This
allows greater flexibility in communication of mount parameters between
userspace, the VFS and the filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Note that tmpfs is slightly tricky as it can contain embedded commas, so it
can't be trivially split up using strsep() to break on commas in
generic_parse_monolithic().  Instead, tmpfs has to supply its own generic
parser.

However, if tmpfs changes, then devtmpfs and rootfs, which are wrappers
around tmpfs or ramfs, must change too - and thus so must ramfs, so these
had to be converted also.

[AV: rewritten]

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Hugh Dickins <hughd@google.com>
cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-12 21:05:34 -04:00
Al Viro
7e30d2a5eb make shmem_fill_super() static
... have callers use shmem_mount()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-05 14:34:28 -04:00
Al Viro
d401727ea0 devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()
Create an internal-only type matching the current devtmpfs, never
register it and have one kernel-internal mount done.  That thing
gets mounted only once, so it is free to use mount_nodev().

The "public" devtmpfs (the one we do register, and only after
the internal mount of the real thing is done) simply gets and
returns an extra reference to the internal superblock.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-05 14:34:27 -04:00
Al Viro
33488845f2 constify ksys_mount() string arguments
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-04 22:01:59 -04:00