Commit Graph

264 Commits

Author SHA1 Message Date
Linus Torvalds
f632a8170a Driver Core and debugfs changes for 5.3-rc1
Here is the "big" driver core and debugfs changes for 5.3-rc1
 
 It's a lot of different patches, all across the tree due to some api
 changes and lots of debugfs cleanups.  Because of this, there is going
 to be some merge issues with your tree at the moment, I'll follow up
 with the expected resolutions to make it easier for you.
 
 Other than the debugfs cleanups, in this set of changes we have:
 	- bus iteration function cleanups (will cause build warnings
 	  with s390 and coresight drivers in your tree)
 	- scripts/get_abi.pl tool to display and parse Documentation/ABI
 	  entries in a simple way
 	- cleanups to Documenatation/ABI/ entries to make them parse
 	  easier due to typos and other minor things
 	- default_attrs use for some ktype users
 	- driver model documentation file conversions to .rst
 	- compressed firmware file loading
 	- deferred probe fixes
 
 All of these have been in linux-next for a while, with a bunch of merge
 issues that Stephen has been patient with me for.  Other than the merge
 issues, functionality is working properly in linux-next :)
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core and debugfs updates from Greg KH:
 "Here is the "big" driver core and debugfs changes for 5.3-rc1

  It's a lot of different patches, all across the tree due to some api
  changes and lots of debugfs cleanups.

  Other than the debugfs cleanups, in this set of changes we have:

   - bus iteration function cleanups

   - scripts/get_abi.pl tool to display and parse Documentation/ABI
     entries in a simple way

   - cleanups to Documenatation/ABI/ entries to make them parse easier
     due to typos and other minor things

   - default_attrs use for some ktype users

   - driver model documentation file conversions to .rst

   - compressed firmware file loading

   - deferred probe fixes

  All of these have been in linux-next for a while, with a bunch of
  merge issues that Stephen has been patient with me for"

* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
  debugfs: make error message a bit more verbose
  orangefs: fix build warning from debugfs cleanup patch
  ubifs: fix build warning after debugfs cleanup patch
  driver: core: Allow subsystems to continue deferring probe
  drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
  arch_topology: Remove error messages on out-of-memory conditions
  lib: notifier-error-inject: no need to check return value of debugfs_create functions
  swiotlb: no need to check return value of debugfs_create functions
  ceph: no need to check return value of debugfs_create functions
  sunrpc: no need to check return value of debugfs_create functions
  ubifs: no need to check return value of debugfs_create functions
  orangefs: no need to check return value of debugfs_create functions
  nfsd: no need to check return value of debugfs_create functions
  lib: 842: no need to check return value of debugfs_create functions
  debugfs: provide pr_fmt() macro
  debugfs: log errors when something goes wrong
  drivers: s390/cio: Fix compilation warning about const qualifiers
  drivers: Add generic helper to match by of_node
  driver_find_device: Unify the match function with class_find_device()
  bus_find_device: Unify the match callback with class_find_device
  ...
2019-07-12 12:24:03 -07:00
Greg Kroah-Hartman
c33d442328 debugfs: make error message a bit more verbose
When a file/directory is already present in debugfs, and it is attempted
to be created again, be more specific about what file/directory is being
created and where it is trying to be created to give a bit more help to
developers to figure out the problem.

Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20190706154256.GA2683@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-08 10:44:57 +02:00
Greg Kroah-Hartman
d03ae4778b debugfs: provide pr_fmt() macro
Use a common "debugfs: " prefix for all pr_* calls in a single place.

Cc: Mark Brown <broonie@kernel.org>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20190703071653.2799-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03 16:55:52 +02:00
Greg Kroah-Hartman
43e23b6c0b debugfs: log errors when something goes wrong
As it is not recommended that debugfs calls be checked, it was pointed
out that major errors should still be logged somewhere so that
developers and users have a chance to figure out what went wrong.  To
help with this, error logging has been added to the debugfs core so that
it is not needed to be present in every individual file that calls
debugfs.

Reported-by: Mark Brown <broonie@kernel.org>
Reported-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20190703071653.2799-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03 16:55:51 +02:00
Amir Goldstein
6679ea6dea debugfs: call fsnotify_{unlink,rmdir}() hooks
This will allow generating fsnotify delete events after the
fsnotify_nameremove() hook is removed from d_delete().

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2019-06-20 14:47:09 +02:00
Amir Goldstein
823e545c02 debugfs: simplify __debugfs_remove_file()
Move simple_unlink()+d_delete() from __debugfs_remove_file() into
caller __debugfs_remove() and rename helper for post remove file to
__debugfs_file_removed().

This will simplify adding fsnotify_unlink() hook.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2019-06-20 14:46:42 +02:00
Greg Kroah-Hartman
c9c2c27d7c debugfs: make debugfs_create_u32_array() return void
The single user of debugfs_create_u32_array() does not care about the
return value of it, so make it return void as there is no need to do
anything with the return value.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-03 16:34:27 +02:00
Thomas Gleixner
ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Linus Torvalds
d27fb65bc2 Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc dcache updates from Al Viro:
 "Most of this pile is putting name length into struct name_snapshot and
  making use of it.

  The beginning of this series ("ovl_lookup_real_one(): don't bother
  with strlen()") ought to have been split in two (separate switch of
  name_snapshot to struct qstr from overlayfs reaping the trivial
  benefits of that), but I wanted to avoid a rebase - by the time I'd
  spotted that it was (a) in -next and (b) close to 5.1-final ;-/"

* 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  audit_compare_dname_path(): switch to const struct qstr *
  audit_update_watch(): switch to const struct qstr *
  inotify_handle_event(): don't bother with strlen()
  fsnotify: switch send_to_group() and ->handle_event to const struct qstr *
  fsnotify(): switch to passing const struct qstr * for file_name
  switch fsnotify_move() to passing const struct qstr * for old_name
  ovl_lookup_real_one(): don't bother with strlen()
  sysv: bury the broken "quietly truncate the long filenames" logics
  nsfs: unobfuscate
  unexport d_alloc_pseudo()
2019-05-07 20:03:32 -07:00
Linus Torvalds
cf482a49af Driver core/kobject patches for 5.2-rc1
Here is the "big" set of driver core patches for 5.2-rc1
 
 There are a number of ACPI patches in here as well, as Rafael said they
 should go through this tree due to the driver core changes they
 required.  They have all been acked by the ACPI developers.
 
 There are also a number of small subsystem-specific changes in here, due
 to some changes to the kobject core code.  Those too have all been acked
 by the various subsystem maintainers.
 
 As for content, it's pretty boring outside of the ACPI changes:
   - spdx cleanups
   - kobject documentation updates
   - default attribute groups for kobjects
   - other minor kobject/driver core fixes
 
 All have been in linux-next for a while with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core/kobject updates from Greg KH:
 "Here is the "big" set of driver core patches for 5.2-rc1

  There are a number of ACPI patches in here as well, as Rafael said
  they should go through this tree due to the driver core changes they
  required. They have all been acked by the ACPI developers.

  There are also a number of small subsystem-specific changes in here,
  due to some changes to the kobject core code. Those too have all been
  acked by the various subsystem maintainers.

  As for content, it's pretty boring outside of the ACPI changes:
   - spdx cleanups
   - kobject documentation updates
   - default attribute groups for kobjects
   - other minor kobject/driver core fixes

  All have been in linux-next for a while with no reported issues"

* tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (47 commits)
  kobject: clean up the kobject add documentation a bit more
  kobject: Fix kernel-doc comment first line
  kobject: Remove docstring reference to kset
  firmware_loader: Fix a typo ("syfs" -> "sysfs")
  kobject: fix dereference before null check on kobj
  Revert "driver core: platform: Fix the usage of platform device name(pdev->name)"
  init/config: Do not select BUILD_BIN2C for IKCONFIG
  Provide in-kernel headers to make extending kernel easier
  kobject: Improve doc clarity kobject_init_and_add()
  kobject: Improve docs for kobject_add/del
  driver core: platform: Fix the usage of platform device name(pdev->name)
  livepatch: Replace klp_ktype_patch's default_attrs with groups
  cpufreq: schedutil: Replace default_attrs field with groups
  padata: Replace padata_attr_type default_attrs field with groups
  irqdesc: Replace irq_kobj_type's default_attrs field with groups
  net-sysfs: Replace ktype default_attrs field with groups
  block: Replace all ktype default_attrs with groups
  samples/kobject: Replace foo_ktype's default_attrs field with groups
  kobject: Add support for default attribute groups to kobj_type
  driver core: Postpone DMA tear-down until after devres release for probe failure
  ...
2019-05-07 13:01:40 -07:00
Al Viro
6234ddf429 debugfs: switch to ->free_inode()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-01 22:43:24 -04:00
Al Viro
f4ec3a3d43 switch fsnotify_move() to passing const struct qstr * for old_name
note that in the second (RENAME_EXCHANGE) call of fsnotify_move() in
vfs_rename() the old_dentry->d_name is guaranteed to be unchanged
throughout the evaluation of fsnotify_move() (by the fact that the
parent directory is locked exclusive), so we don't need to fetch
old_dentry->d_name.name in the caller.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-26 13:22:05 -04:00
Al Viro
230c6402b1 ovl_lookup_real_one(): don't bother with strlen()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-26 13:13:33 -04:00
Ronald Tschalär
9abb24990a debugfs: update documented return values of debugfs helpers
Since commit ff9fb72bc0 ("debugfs: return error values, not NULL")
these helper functions do not return NULL anymore (with the exception
of debugfs_create_u32_array()).

Fixes: ff9fb72bc0 ("debugfs: return error values, not NULL")
Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 11:56:50 +02:00
Al Viro
93b919da64 debugfs: fix use-after-free on symlink traversal
symlink body shouldn't be freed without an RCU delay.  Switch debugfs to
->destroy_inode() and use of call_rcu(); free both the inode and symlink
body in the callback.  Similar to solution for bpf, only here it's even
more obvious that ->evict_inode() can be dropped.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-01 00:31:02 -04:00
Greg Kroah-Hartman
9481caf39b Merge 5.0-rc6 into driver-core-next
We need the debugfs fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-11 09:09:02 +01:00
Greg Kroah-Hartman
37ea7b630a debugfs: debugfs_lookup() should return NULL if not found
Lots of callers of debugfs_lookup() were just checking NULL to see if
the file/directory was found or not.  By changing this in ff9fb72bc0
("debugfs: return error values, not NULL") we caused some subsystems to
easily crash.

Fixes: ff9fb72bc0 ("debugfs: return error values, not NULL")
Reported-by: syzbot+b382ba6a802a3d242790@syzkaller.appspotmail.com
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-30 12:39:49 +01:00
Greg Kroah-Hartman
ff9fb72bc0 debugfs: return error values, not NULL
When an error happens, debugfs should return an error pointer value, not
NULL.  This will prevent the totally theoretical error where a debugfs
call fails due to lack of memory, returning NULL, and that dentry value
is then passed to another debugfs call, which would end up succeeding,
creating a file at the root of the debugfs tree, but would then be
impossible to remove (because you can not remove the directory NULL).

So, to make everyone happy, always return errors, this makes the users
of debugfs much simpler (they do not have to ever check the return
value), and everyone can rest easy.

Reported-by: Gary R Hook <ghook@amd.com>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Michal Hocko <mhocko@kernel.org>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-29 21:28:35 +01:00
Greg Kroah-Hartman
d88c93f090 debugfs: fix debugfs_rename parameter checking
debugfs_rename() needs to check that the dentries passed into it really
are valid, as sometimes they are not (i.e. if the return value of
another debugfs call is passed into this one.)  So fix this up by
properly checking if the two parent directories are errors (they are
allowed to be NULL), and if the dentry to rename is not NULL or an
error.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-25 12:56:32 +01:00
Sergey Senozhatsky
0eeb27311f debugfs: debugfs_use_start/finish do not exist anymore
debugfs_use_file_start() and debugfs_use_file_finish() do not exist
since commit c9afbec270 ("debugfs: purge obsolete SRCU based removal
protection"); tweak debugfs_create_file_unsafe() comment.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-22 10:30:35 +01:00
Linus Torvalds
f5b7769eb0 Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent"
This reverts commit 95cde3c599.

The commit had good intentions, but it breaks kvm-tool and qemu-kvm.

With it in place, "lkvm run" just fails with

  Error: KVM_CREATE_VM ioctl
  Warning: Failed init: kvm__init

which isn't a wonderful error message, but bisection pinpointed the
problematic commit.

The problem is almost certainly due to the special kvm debugfs entries
created dynamically by kvm under /sys/kernel/debug/kvm/.  See
kvm_create_vm_debugfs()

Bisected-and-reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Wanpeng Li <kernellwp@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-12 20:52:16 -07:00
Thomas Richter
95cde3c599 debugfs: inode: debugfs_create_dir uses mode permission from parent
Currently function debugfs_create_dir() creates a new
directory in the debugfs (usually mounted /sys/kernel/debug)
with permission rwxr-xr-x. This is hard coded.

Change this to use the parent directory permission.

Output before the patch:
root@s8360047 ~]# tree -dp -L 1 /sys/kernel/debug/
/sys/kernel/debug/
├── [drwxr-xr-x]  bdi
├── [drwxr-xr-x]  block
├── [drwxr-xr-x]  dasd
├── [drwxr-xr-x]  device_component
├── [drwxr-xr-x]  extfrag
├── [drwxr-xr-x]  hid
├── [drwxr-xr-x]  kprobes
├── [drwxr-xr-x]  kvm
├── [drwxr-xr-x]  memblock
├── [drwxr-xr-x]  pm_qos
├── [drwxr-xr-x]  qdio
├── [drwxr-xr-x]  s390
├── [drwxr-xr-x]  s390dbf
└── [drwx------]  tracing

14 directories
[root@s8360047 linux]#

Output after the patch:
[root@s8360047 ~]# tree -dp -L 1 /sys/kernel/debug/
sys/kernel/debug/
├── [drwx------]  bdi
├── [drwx------]  block
├── [drwx------]  dasd
├── [drwx------]  device_component
├── [drwx------]  extfrag
├── [drwx------]  hid
├── [drwx------]  kprobes
├── [drwx------]  kvm
├── [drwx------]  memblock
├── [drwx------]  pm_qos
├── [drwx------]  qdio
├── [drwx------]  s390
├── [drwx------]  s390dbf
└── [drwx------]  tracing

14 directories
[root@s8360047 linux]#

Here is the full diff output done with:
[root@s8360047 ~]# diff -u treefull.before treefull.after |
	sed 's-^- # -' > treefull.diff
 # --- treefull.before	2018-04-27 13:22:04.532824564 +0200
 # +++ treefull.after	2018-04-27 13:24:12.106182062 +0200
 # @@ -1,55 +1,55 @@
 #  /sys/kernel/debug/
 # -├── [drwxr-xr-x]  bdi
 # -│   ├── [drwxr-xr-x]  1:0
 # -│   ├── [drwxr-xr-x]  1:1
 # -│   ├── [drwxr-xr-x]  1:10
 # -│   ├── [drwxr-xr-x]  1:11
 # -│   ├── [drwxr-xr-x]  1:12
 # -│   ├── [drwxr-xr-x]  1:13
 # -│   ├── [drwxr-xr-x]  1:14
 # -│   ├── [drwxr-xr-x]  1:15
 # -│   ├── [drwxr-xr-x]  1:2
 # -│   ├── [drwxr-xr-x]  1:3
 # -│   ├── [drwxr-xr-x]  1:4
 # -│   ├── [drwxr-xr-x]  1:5
 # -│   ├── [drwxr-xr-x]  1:6
 # -│   ├── [drwxr-xr-x]  1:7
 # -│   ├── [drwxr-xr-x]  1:8
 # -│   ├── [drwxr-xr-x]  1:9
 # -│   └── [drwxr-xr-x]  94:0
 # -├── [drwxr-xr-x]  block
 # -├── [drwxr-xr-x]  dasd
 # -│   ├── [drwxr-xr-x]  0.0.e18a
 # -│   ├── [drwxr-xr-x]  dasda
 # -│   └── [drwxr-xr-x]  global
 # -├── [drwxr-xr-x]  device_component
 # -├── [drwxr-xr-x]  extfrag
 # -├── [drwxr-xr-x]  hid
 # -├── [drwxr-xr-x]  kprobes
 # -├── [drwxr-xr-x]  kvm
 # -├── [drwxr-xr-x]  memblock
 # -├── [drwxr-xr-x]  pm_qos
 # -├── [drwxr-xr-x]  qdio
 # -│   └── [drwxr-xr-x]  0.0.f5f2
 # -├── [drwxr-xr-x]  s390
 # -│   └── [drwxr-xr-x]  stsi
 # -├── [drwxr-xr-x]  s390dbf
 # -│   ├── [drwxr-xr-x]  0.0.e18a
 # -│   ├── [drwxr-xr-x]  cio_crw
 # -│   ├── [drwxr-xr-x]  cio_msg
 # -│   ├── [drwxr-xr-x]  cio_trace
 # -│   ├── [drwxr-xr-x]  dasd
 # -│   ├── [drwxr-xr-x]  kvm-trace
 # -│   ├── [drwxr-xr-x]  lgr
 # -│   ├── [drwxr-xr-x]  qdio_0.0.f5f2
 # -│   ├── [drwxr-xr-x]  qdio_error
 # -│   ├── [drwxr-xr-x]  qdio_setup
 # -│   ├── [drwxr-xr-x]  qeth_card_0.0.f5f0
 # -│   ├── [drwxr-xr-x]  qeth_control
 # -│   ├── [drwxr-xr-x]  qeth_msg
 # -│   ├── [drwxr-xr-x]  qeth_setup
 # -│   ├── [drwxr-xr-x]  vmcp
 # -│   └── [drwxr-xr-x]  vmur
 # +├── [drwx------]  bdi
 # +│   ├── [drwx------]  1:0
 # +│   ├── [drwx------]  1:1
 # +│   ├── [drwx------]  1:10
 # +│   ├── [drwx------]  1:11
 # +│   ├── [drwx------]  1:12
 # +│   ├── [drwx------]  1:13
 # +│   ├── [drwx------]  1:14
 # +│   ├── [drwx------]  1:15
 # +│   ├── [drwx------]  1:2
 # +│   ├── [drwx------]  1:3
 # +│   ├── [drwx------]  1:4
 # +│   ├── [drwx------]  1:5
 # +│   ├── [drwx------]  1:6
 # +│   ├── [drwx------]  1:7
 # +│   ├── [drwx------]  1:8
 # +│   ├── [drwx------]  1:9
 # +│   └── [drwx------]  94:0
 # +├── [drwx------]  block
 # +├── [drwx------]  dasd
 # +│   ├── [drwx------]  0.0.e18a
 # +│   ├── [drwx------]  dasda
 # +│   └── [drwx------]  global
 # +├── [drwx------]  device_component
 # +├── [drwx------]  extfrag
 # +├── [drwx------]  hid
 # +├── [drwx------]  kprobes
 # +├── [drwx------]  kvm
 # +├── [drwx------]  memblock
 # +├── [drwx------]  pm_qos
 # +├── [drwx------]  qdio
 # +│   └── [drwx------]  0.0.f5f2
 # +├── [drwx------]  s390
 # +│   └── [drwx------]  stsi
 # +├── [drwx------]  s390dbf
 # +│   ├── [drwx------]  0.0.e18a
 # +│   ├── [drwx------]  cio_crw
 # +│   ├── [drwx------]  cio_msg
 # +│   ├── [drwx------]  cio_trace
 # +│   ├── [drwx------]  dasd
 # +│   ├── [drwx------]  kvm-trace
 # +│   ├── [drwx------]  lgr
 # +│   ├── [drwx------]  qdio_0.0.f5f2
 # +│   ├── [drwx------]  qdio_error
 # +│   ├── [drwx------]  qdio_setup
 # +│   ├── [drwx------]  qeth_card_0.0.f5f0
 # +│   ├── [drwx------]  qeth_control
 # +│   ├── [drwx------]  qeth_msg
 # +│   ├── [drwx------]  qeth_setup
 # +│   ├── [drwx------]  vmcp
 # +│   └── [drwx------]  vmur
 #  └── [drwx------]  tracing
 #      ├── [drwxr-xr-x]  events
 #      │   ├── [drwxr-xr-x]  alarmtimer

Fixes: edac65eaf8 ("debugfs: take mode-dependent parts of debugfs_get_inode() into callers")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:48:18 +02:00
Andy Shevchenko
964f8363a1 debugfs: Re-use kstrtobool_from_user()
Re-use kstrtobool_from_user() instead of open coded variant.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:48:18 +02:00
Al Viro
cd1c0c9321 debugfs_lookup(): switch to lookup_one_len_unlocked()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-03-29 15:07:47 -04:00
Linus Torvalds
a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00
Al Viro
cfe39442ab use linux/poll.h instead of asm/poll.h
The only place that has any business including asm/poll.h
is linux/poll.h.  Fortunately, asm/poll.h had only been
included in 3 places beyond that one, and all of them
are trivial to switch to using linux/poll.h.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-02-01 16:23:11 -05:00
Al Viro
076ccb76e1 fs: annotate ->poll() instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27 16:20:05 -05:00
Al Viro
e6c8adca20 anntotate the places where ->poll() return values go
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27 16:19:53 -05:00
Greg Kroah-Hartman
2b2d8788dd debugfs: Remove redundant license text
Now that the SPDX tag is in all debugfs files, that identifies the
license in a specific and legally-defined manner.  So the extra GPL text
wording can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:03 +01:00
Greg Kroah-Hartman
3bce94fd5f debugfs: add SPDX identifiers to all debugfs files
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the debugfs files files with the correct SPDX license identifier
based on the license text in the file itself.  The SPDX identifier is a
legally binding shorthand, which can be used instead of the full boiler
plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:03 +01:00
Nicolai Stange
7d39bc50c4 debugfs: defer debugfs_fsdata allocation to first usage
Currently, __debugfs_create_file allocates one struct debugfs_fsdata
instance for every file created. However, there are potentially many
debugfs file around, most of which are never touched by userspace.

Thus, defer the allocations to the first usage, i.e. to the first
debugfs_file_get().

A dentry's ->d_fsdata starts out to point to the "real", user provided
fops. After a debugfs_fsdata instance has been allocated (and the real
fops pointer has been moved over into its ->real_fops member),
->d_fsdata is changed to point to it from then on. The two cases are
distinguished by setting BIT(0) for the real fops case.

struct debugfs_fsdata's foremost purpose is to track active users and to
make debugfs_remove() block until they are done. Since no debugfs_fsdata
instance means no active users, make debugfs_remove() return immediately
in this case.

Take care of possible races between debugfs_file_get() and
debugfs_remove(): either debugfs_remove() must see a debugfs_fsdata
instance and thus wait for possible active users or debugfs_file_get() must
see a dead dentry and return immediately.

Make a dentry's ->d_release(), i.e. debugfs_release_dentry(), check whether
->d_fsdata is actually a debugfs_fsdata instance before kfree()ing it.

Similarly, make debugfs_real_fops() check whether ->d_fsdata is actually
a debugfs_fsdata instance before returning it, otherwise emit a warning.

The set of possible error codes returned from debugfs_file_get() has grown
from -EIO to -EIO and -ENOMEM. Make open_proxy_open() and full_proxy_open()
pass the -ENOMEM onwards to their callers.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:03 +01:00
Nicolai Stange
154b9d7512 debugfs: call debugfs_real_fops() only after debugfs_file_get()
The current implementation of debugfs_real_fops() relies on a
debugfs_fsdata instance to be installed at ->d_fsdata.

With future patches introducing lazy allocation of these, this requirement
will be guaranteed to be fullfilled only inbetween a
debugfs_file_get()/debugfs_file_put() pair.

The full proxies' fops implemented by debugfs happen to be the only
offenders. Fix them up by moving their debugfs_real_fops() calls past those
to debugfs_file_get().

full_proxy_release() is special as it doesn't invoke debugfs_file_get() at
all. Leave it alone for now.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:03 +01:00
Nicolai Stange
c9afbec270 debugfs: purge obsolete SRCU based removal protection
Purge the SRCU based file removal race protection in favour of the new,
refcount based debugfs_file_get()/debugfs_file_put() API.

Fixes: 49d200deaa ("debugfs: prevent access to removed files' private data")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Nicolai Stange
69d29f9e6a debugfs: convert to debugfs_file_get() and -put()
Convert all calls to the now obsolete debugfs_use_file_start() and
debugfs_use_file_finish() from the debugfs core itself to the new
debugfs_file_get() and debugfs_file_put() API.

Fixes: 49d200deaa ("debugfs: prevent access to removed files' private data")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Nicolai Stange
055ab8e3e3 debugfs: debugfs_real_fops(): drop __must_hold sparse annotation
Currently, debugfs_real_fops() is annotated with a
__must_hold(&debugfs_srcu) sparse annotation.

With the conversion of the SRCU based protection of users against
concurrent file removals to a per-file refcount based scheme, this becomes
wrong.

Drop this annotation.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Nicolai Stange
e9117a5a4b debugfs: implement per-file removal protection
Since commit 49d200deaa ("debugfs: prevent access to removed files'
private data"), accesses to a file's private data are protected from
concurrent removal by covering all file_operations with a SRCU read section
and sychronizing with those before returning from debugfs_remove() by means
of synchronize_srcu().

As pointed out by Johannes Berg, there are debugfs files with forever
blocking file_operations. Their corresponding SRCU read side sections would
block any debugfs_remove() forever as well, even unrelated ones. This
results in a livelock. Because a remover can't cancel any indefinite
blocking within foreign files, this is a problem.

Resolve this by introducing support for more granular protection on a
per-file basis.

This is implemented by introducing an  'active_users' refcount_t to the
per-file struct debugfs_fsdata state. At file creation time, it is set to
one and a debugfs_remove() will drop that initial reference. The new
debugfs_file_get() and debugfs_file_put(), intended to be used in place of
former debugfs_use_file_start() and debugfs_use_file_finish(), increment
and decrement it respectively. Once the count drops to zero,
debugfs_file_put() will signal a completion which is possibly being waited
for from debugfs_remove().
Thus, as long as there is a debugfs_file_get() not yet matched by a
corresponding debugfs_file_put() around, debugfs_remove() will block.

Actual users of debugfs_use_file_start() and -finish() will get converted
to the new debugfs_file_get() and debugfs_file_put() by followup patches.

Fixes: 49d200deaa ("debugfs: prevent access to removed files' private data")
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Nicolai Stange
7c8d469877 debugfs: add support for more elaborate ->d_fsdata
Currently, the user provided fops, "real_fops", are stored directly into
->d_fsdata.

In order to be able to store more per-file state and thus prepare for more
granular file removal protection, wrap the real_fops into a dynamically
allocated container struct, debugfs_fsdata.

A struct debugfs_fsdata gets allocated at file creation and freed from the
newly intoduced ->d_release().

Finally, move the implementation of debugfs_real_fops() out of the public
debugfs header such that struct debugfs_fsdata's declaration can be kept
private.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Linus Torvalds
78dcf73421 Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull ->s_options removal from Al Viro:
 "Preparations for fsmount/fsopen stuff (coming next cycle). Everything
  gets moved to explicit ->show_options(), killing ->s_options off +
  some cosmetic bits around fs/namespace.c and friends. Basically, the
  stuff needed to work with fsmount series with minimum of conflicts
  with other work.

  It's not strictly required for this merge window, but it would reduce
  the PITA during the coming cycle, so it would be nice to have those
  bits and pieces out of the way"

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  isofs: Fix isofs_show_options()
  VFS: Kill off s_options and helpers
  orangefs: Implement show_options
  9p: Implement show_options
  isofs: Implement show_options
  afs: Implement show_options
  affs: Implement show_options
  befs: Implement show_options
  spufs: Implement show_options
  bpf: Implement show_options
  ramfs: Implement show_options
  pstore: Implement show_options
  omfs: Implement show_options
  hugetlbfs: Implement show_options
  VFS: Don't use save/replace_mount_options if not using generic_show_options
  VFS: Provide empty name qstr
  VFS: Make get_filesystem() return the affected filesystem
  VFS: Clean up whitespace in fs/namespace.c and fs/super.c
  Provide a function to create a NUL-terminated string from unterminated data
2017-07-15 12:00:42 -07:00
Linus Torvalds
b8d4c1f9f4 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc filesystem updates from Al Viro:
 "Assorted normal VFS / filesystems stuff..."

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  dentry name snapshots
  Make statfs properly return read-only state after emergency remount
  fs/dcache: init in_lookup_hashtable
  minix: Deinline get_block, save 2691 bytes
  fs: Reorder inode_owner_or_capable() to avoid needless
  fs: warn in case userspace lied about modprobe return
2017-07-08 10:50:54 -07:00
Al Viro
49d31c2f38 dentry name snapshots
take_dentry_name_snapshot() takes a safe snapshot of dentry name;
if the name is a short one, it gets copied into caller-supplied
structure, otherwise an extra reference to external name is grabbed
(those are never modified).  In either case the pointer to stable
string is stored into the same structure.

dentry must be held by the caller of take_dentry_name_snapshot(),
but may be freely dropped afterwards - the snapshot will stay
until destroyed by release_dentry_name_snapshot().

Intended use:
	struct name_snapshot s;

	take_dentry_name_snapshot(&s, dentry);
	...
	access s.name
	...
	release_dentry_name_snapshot(&s);

Replaces fsnotify_oldname_...(), gets used in fsnotify to obtain the name
to pass down with event.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-07 20:09:10 -04:00
David Howells
c3d98ea082 VFS: Don't use save/replace_mount_options if not using generic_show_options
btrfs, debugfs, reiserfs and tracefs call save_mount_options() and reiserfs
calls replace_mount_options(), but they then implement their own
->show_options() methods and don't touch s_options, rendering the saved
options unnecessary.  I'm trying to eliminate s_options to make it easier
to implement a context-based mount where the mount options can be passed
individually over a file descriptor.

Remove the calls to save/replace_mount_options() call in these cases.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Chris Mason <clm@fb.com>
cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Steven Rostedt <rostedt@goodmis.org>
cc: linux-btrfs@vger.kernel.org
cc: reiserfs-devel@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-06 03:31:46 -04:00
Mauro Carvalho Chehab
e1511a840a fs: fix the location of the kernel-api book
The kernel-api book is now part of the core-api. Update its
location.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-05-16 08:44:23 -03:00
Mauro Carvalho Chehab
e1b4fc7add fs: update location of filesystems documentation
The filesystem documentation was moved from DocBook to
Documentation/filesystems/. Update it at the sources.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-05-16 08:44:22 -03:00
Eric Biggers
cda37124f4 fs: constify tree_descr arrays passed to simple_fill_super()
simple_fill_super() is passed an array of tree_descr structures which
describe the files to create in the filesystem's root directory.  Since
these arrays are never modified intentionally, they should be 'const' so
that they are placed in .rodata and benefit from memory protection.
This patch updates the function signature and all users, and also
constifies tree_descr.name.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-26 23:54:06 -04:00
Linus Torvalds
f1ef09fde1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace updates from Eric Biederman:
 "There is a lot here. A lot of these changes result in subtle user
  visible differences in kernel behavior. I don't expect anything will
  care but I will revert/fix things immediately if any regressions show
  up.

  From Seth Forshee there is a continuation of the work to make the vfs
  ready for unpriviled mounts. We had thought the previous changes
  prevented the creation of files outside of s_user_ns of a filesystem,
  but it turns we missed the O_CREAT path. Ooops.

  Pavel Tikhomirov and Oleg Nesterov worked together to fix a long
  standing bug in the implemenation of PR_SET_CHILD_SUBREAPER where only
  children that are forked after the prctl are considered and not
  children forked before the prctl. The only known user of this prctl
  systemd forks all children after the prctl. So no userspace
  regressions will occur. Holding earlier forked children to the same
  rules as later forked children creates a semantic that is sane enough
  to allow checkpoing of processes that use this feature.

  There is a long delayed change by Nikolay Borisov to limit inotify
  instances inside a user namespace.

  Michael Kerrisk extends the API for files used to maniuplate
  namespaces with two new trivial ioctls to allow discovery of the
  hierachy and properties of namespaces.

  Konstantin Khlebnikov with the help of Al Viro adds code that when a
  network namespace exits purges it's sysctl entries from the dcache. As
  in some circumstances this could use a lot of memory.

  Vivek Goyal fixed a bug with stacked filesystems where the permissions
  on the wrong inode were being checked.

  I continue previous work on ptracing across exec. Allowing a file to
  be setuid across exec while being ptraced if the tracer has enough
  credentials in the user namespace, and if the process has CAP_SETUID
  in it's own namespace. Proc files for setuid or otherwise undumpable
  executables are now owned by the root in the user namespace of their
  mm. Allowing debugging of setuid applications in containers to work
  better.

  A bug I introduced with permission checking and automount is now
  fixed. The big change is to mark the mounts that the kernel initiates
  as a result of an automount. This allows the permission checks in sget
  to be safely suppressed for this kind of mount. As the permission
  check happened when the original filesystem was mounted.

  Finally a special case in the mount namespace is removed preventing
  unbounded chains in the mount hash table, and making the semantics
  simpler which benefits CRIU.

  The vfs fix along with related work in ima and evm I believe makes us
  ready to finish developing and merge fully unprivileged mounts of the
  fuse filesystem. The cleanups of the mount namespace makes discussing
  how to fix the worst case complexity of umount. The stacked filesystem
  fixes pave the way for adding multiple mappings for the filesystem
  uids so that efficient and safer containers can be implemented"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  proc/sysctl: Don't grab i_lock under sysctl_lock.
  vfs: Use upper filesystem inode in bprm_fill_uid()
  proc/sysctl: prune stale dentries during unregistering
  mnt: Tuck mounts under others instead of creating shadow/side mounts.
  prctl: propagate has_child_subreaper flag to every descendant
  introduce the walk_process_tree() helper
  nsfs: Add an ioctl() to return owner UID of a userns
  fs: Better permission checking for submounts
  exit: fix the setns() && PR_SET_CHILD_SUBREAPER interaction
  vfs: open() with O_CREAT should not create inodes with unknown ids
  nsfs: Add an ioctl() to return the namespace type
  proc: Better ownership of files for non-dumpable tasks in user namespaces
  exec: Remove LSM_UNSAFE_PTRACE_CAP
  exec: Test the ptracer's saved cred to see if the tracee can gain caps
  exec: Don't reset euid and egid when the tracee has CAP_SETUID
  inotify: Convert to using per-namespace limits
2017-02-23 20:33:51 -08:00
Omar Sandoval
a7c5437b0b debugfs: add debugfs_lookup()
We don't always have easy access to the dentry of a file or directory we
created in debugfs. Add a helper which allows us to get a dentry we
previously created.

The motivation for this change is a problem with blktrace and the blk-mq
debugfs entries introduced in 07e4fead45 ("blk-mq: create debugfs
directory tree"). Namely, in some cases, the directory that blktrace
needs to create may already exist, but in other cases, it may not. We
_could_ rely on a bunch of implied knowledge to decide whether to create
the directory or not, but it's much cleaner on our end to just look it
up.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02 10:20:16 -07:00
Eric W. Biederman
93faccbbfa fs: Better permission checking for submounts
To support unprivileged users mounting filesystems two permission
checks have to be performed: a test to see if the user allowed to
create a mount in the mount namespace, and a test to see if
the user is allowed to access the specified filesystem.

The automount case is special in that mounting the original filesystem
grants permission to mount the sub-filesystems, to any user who
happens to stumble across the their mountpoint and satisfies the
ordinary filesystem permission checks.

Attempting to handle the automount case by using override_creds
almost works.  It preserves the idea that permission to mount
the original filesystem is permission to mount the sub-filesystem.
Unfortunately using override_creds messes up the filesystems
ordinary permission checks.

Solve this by being explicit that a mount is a submount by introducing
vfs_submount, and using it where appropriate.

vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let
sget and friends know that a mount is a submount so they can take appropriate
action.

sget and sget_userns are modified to not perform any permission checks
on submounts.

follow_automount is modified to stop using override_creds as that
has proven problemantic.

do_mount is modified to always remove the new MS_SUBMOUNT flag so
that we know userspace will never by able to specify it.

autofs4 is modified to stop using current_real_cred that was put in
there to handle the previous version of submount permission checking.

cifs is modified to pass the mountpoint all of the way down to vfs_submount.

debugfs is modified to pass the mountpoint all of the way down to
trace_automount by adding a new parameter.  To make this change easier
a new typedef debugfs_automount_t is introduced to capture the type of
the debugfs automount function.

Cc: stable@vger.kernel.org
Fixes: 069d5ac9ae ("autofs:  Fix automounts by using current_real_cred()->uid")
Fixes: aeaa4a79ff ("fs: Call d_automount with the filesystems creds")
Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-02-02 04:36:12 +13:00
Linus Torvalds
101105b171 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 ">rename2() work from Miklos + current_time() from Deepa"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: Replace current_fs_time() with current_time()
  fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
  fs: Replace CURRENT_TIME with current_time() for inode timestamps
  fs: proc: Delete inode time initializations in proc_alloc_inode()
  vfs: Add current_time() api
  vfs: add note about i_op->rename changes to porting
  fs: rename "rename2" i_op to "rename"
  vfs: remove unused i_op->rename
  fs: make remaining filesystems use .rename2
  libfs: support RENAME_NOREPLACE in simple_rename()
  fs: support RENAME_NOREPLACE for local filesystems
  ncpfs: fix unused variable warning
2016-10-10 20:16:43 -07:00
Al Viro
3873691e5a Merge remote-tracking branch 'ovl/rename2' into for-linus 2016-10-10 23:02:51 -04:00
Deepa Dinamani
c2050a454c fs: Replace current_fs_time() with current_time()
current_fs_time() uses struct super_block* as an argument.
As per Linus's suggestion, this is changed to take struct
inode* as a parameter instead. This is because the function
is primarily meant for vfs inode timestamps.
Also the function was renamed as per Arnd's suggestion.

Change all calls to current_fs_time() to use the new
current_time() function instead. current_fs_time() will be
deleted.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27 21:06:22 -04:00
Eric Engestrom
a1a9e5d298 debugfs: propagate release() call result
The result was being ignored and 0 was always returned.
Return the actual result instead.

Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27 12:45:57 +02:00
Miklos Szeredi
e0e0be8a83 libfs: support RENAME_NOREPLACE in simple_rename()
This is trivial to do:

 - add flags argument to simple_rename()
 - check if flags doesn't have any other than RENAME_NOREPLACE
 - assign simple_rename() to .rename2 instead of .rename

Filesystems converted:

hugetlbfs, ramfs, bpf.

Debugfs uses simple_rename() to implement debugfs_rename(), which is for
debugfs instances to rename files internally, not for userspace filesystem
access.  For this case pass zero flags to simple_rename().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
2016-09-27 11:03:57 +02:00
Christian Lamparter
86f0e06767 debugfs: introduce a public file_operations accessor
This patch introduces an accessor which can be used
by the users of debugfs (drivers, fs, ...) to get the
original file_operations struct. It also removes the
REAL_FOPS_DEREF macro in file.c and converts the code
to use the public version.

Previously, REAL_FOPS_DEREF was only available within
the file.c of debugfs. But having a public getter
available for debugfs users is important as some
drivers (carl9170 and b43) use the pointer of the
original file_operations in conjunction with container_of()
within their debugfs implementations.

Reviewed-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Cc: stable <stable@vger.kernel.org> # 4.7+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 12:13:31 +02:00
Nicolai Stange
24ef5f360f debugfs: remove extra debugfs_create_file_unsafe() declaration
debugfs_create_file_unsafe() is declared twice in exactly the same
manner each: once in fs/debugfs/internal.h and once in
include/linux/debugfs.h

All files that include the former also include the latter and thus,
the declaration in fs/debugfs/internal.h is superfluous.

Remove it.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 15:08:10 +02:00
Al Viro
b223f4e215 Merge branch 'd_real' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into work.misc 2016-06-30 23:34:49 -04:00
Nicolai Stange
75f0b68b75 debugfs: open_proxy_open(): avoid double fops release
Debugfs' open_proxy_open(), the ->open() installed at all inodes created
through debugfs_create_file_unsafe(),
- grabs a reference to the original file_operations instance passed to
  debugfs_create_file_unsafe() via fops_get(),
- installs it at the file's ->f_op by means of replace_fops()
- and calls fops_put() on it.

Since the semantics of replace_fops() are such that the reference's
ownership is transferred, the subsequent fops_put() will result in a double
release when the file is eventually closed.

Currently, this is not an issue since fops_put() basically does a
module_put() on the file_operations' ->owner only and there don't exist any
modules calling debugfs_create_file_unsafe() yet. This is expected to
change in the future though, c.f. commit c646880814 ("debugfs: add
support for self-protecting attribute file fops").

Remove the call to fops_put() from open_proxy_open().

Fixes: 9fd4dcece4 ("debugfs: prevent access to possibly dead
                      file_operations at file open")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-15 04:56:35 -07:00
Nicolai Stange
b10e3e9048 debugfs: full_proxy_open(): free proxy on ->open() failure
Debugfs' full_proxy_open(), the ->open() installed at all inodes created
through debugfs_create_file(),
- grabs a reference to the original struct file_operations instance passed
  to debugfs_create_file(),
- dynamically allocates a proxy struct file_operations instance wrapping
  the original
- and installs this at the file's ->f_op.

Afterwards, it calls the original ->open() and passes its return value back
to the VFS layer.

Now, if that return value indicates failure, the VFS layer won't ever call
->release() and thus, neither the reference to the original file_operations
nor the memory for the proxy file_operations will get released, i.e. both
are leaked.

Upon failure of the original fops' ->open(), undo the proxy installation.
That is:
- Set the struct file ->f_op to what it had been when full_proxy_open()
  was entered.
- Drop the reference to the original file_operations.
- Free the memory holding the proxy file_operations.

Fixes: 49d200deaa ("debugfs: prevent access to removed files' private
                      data")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-15 04:56:35 -07:00
Al Viro
acc29fb8f7 debugfs: ->d_parent is never NULL or negative
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-29 16:22:08 -04:00
Greg Kroah-Hartman
5614e77258 Merge 4.6-rc4 into driver-core-next
We want those fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-19 04:28:28 +09:00
Seth Forshee
87243deb88 debugfs: Make automount point inodes permanently empty
Starting with 4.1 the tracing subsystem has its own filesystem
which is automounted in the tracing subdirectory of debugfs.
Prior to this debugfs could be bind mounted in a cloned mount
namespace, but if tracefs has been mounted under debugfs this
now fails because there is a locked child mount. This creates
a regression for container software which bind mounts debugfs
to satisfy the assumption of some userspace software.

In other pseudo filesystems such as proc and sysfs we're already
creating mountpoints like this in such a way that no dirents can
be created in the directories, allowing them to be exceptions to
some MNT_LOCKED tests. In fact we're already do this for the
tracefs mountpoint in sysfs.

Do the same in debugfs_create_automount(), since the intention
here is clearly to create a mountpoint. This fixes the regression,
as locked child mounts on permanently empty directories do not
cause a bind mount to fail.

Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12 15:01:53 -07:00
Nicolai Stange
c4a74f63df debugfs: unproxify files created through debugfs_create_u32_array()
The struct file_operations u32_array_fops associated with files created
through debugfs_create_u32_array() has been lifetime aware already:
everything needed for subsequent operation is copied to a ->f_private
buffer at file opening time in u32_array_open(). Now, ->open() is always
protected against file removal issues by the debugfs core.

There is no need for the debugfs core to wrap the u32_array_fops
with a file lifetime managing proxy.

Make debugfs_create_u32_array() create its files in non-proxying operation
mode by means of debugfs_create_file_unsafe().

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12 14:14:21 -07:00
Nicolai Stange
83b711cbf4 debugfs: unproxify files created through debugfs_create_blob()
Currently, the struct file_operations fops_blob associated with files
created through the debugfs_create_blob() helpers are not file
lifetime aware.

Thus, a lifetime managing proxy is created around fops_blob each time such
a file is opened which is an unnecessary waste of resources.

Implement file lifetime management for the fops_bool file_operations.
Namely, make read_file_blob() safe gainst file removals by means of
debugfs_use_file_start() and debugfs_use_file_finish().

Make debugfs_create_blob() create its files in non-proxying operation mode
by means of debugfs_create_file_unsafe().

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12 14:14:21 -07:00
Nicolai Stange
4d45f7974c debugfs: unproxify files created through debugfs_create_bool()
Currently, the struct file_operations fops_bool associated with files
created through the debugfs_create_bool() helpers are not file
lifetime aware.

Thus, a lifetime managing proxy is created around fops_bool each time such
a file is opened which is an unnecessary waste of resources.

Implement file lifetime management for the fops_bool file_operations.
Namely, make debugfs_read_file_bool() and debugfs_write_file_bool() safe
against file removals by means of debugfs_use_file_start() and
debugfs_use_file_finish().

Make debugfs_create_bool() create its files in non-proxying operation mode
through debugfs_create_mode_unsafe().

Finally, purge debugfs_create_mode() as debugfs_create_bool() had been its
last user.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12 14:14:21 -07:00
Nicolai Stange
4909f16810 debugfs: unproxify integer attribute files
Currently, the struct file_operations associated with the integer attribute
style files created through the debugfs_create_*() helpers are not file
lifetime aware as they are defined by means of DEFINE_SIMPLE_ATTRIBUTE().

Thus, a lifetime managing proxy is created around the original fops each
time such a file is opened which is an unnecessary waste of resources.

Migrate all usages of DEFINE_SIMPLE_ATTRIBUTE() within debugfs itself
to DEFINE_DEBUGFS_ATTRIBUTE() in order to implement file lifetime managing
within the struct file_operations thus defined.

Introduce the debugfs_create_mode_unsafe() helper, analogous to
debugfs_create_mode(), but distinct in that it creates the files in
non-proxying operation mode through debugfs_create_file_unsafe().

Feed all struct file_operations migrated to DEFINE_DEBUGFS_ATTRIBUTE()
into debugfs_create_mode_unsafe() instead of former debugfs_create_mode().

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12 14:14:21 -07:00
Nicolai Stange
c646880814 debugfs: add support for self-protecting attribute file fops
In order to protect them against file removal issues, debugfs_create_file()
creates a lifetime managing proxy around each struct file_operations
handed in.

In cases where this struct file_operations is able to manage file lifetime
by itself already, the proxy created by debugfs is a waste of resources.

The most common class of struct file_operations given to debugfs are those
defined by means of the DEFINE_SIMPLE_ATTRIBUTE() macro.

Introduce a DEFINE_DEBUGFS_ATTRIBUTE() macro to allow any
struct file_operations of this class to be easily made file lifetime aware
and thus, to be operated unproxied.

Specifically, introduce debugfs_attr_read() and debugfs_attr_write()
which wrap simple_attr_read() and simple_attr_write() under the protection
of a debugfs_use_file_start()/debugfs_use_file_finish() pair.

Make DEFINE_DEBUGFS_ATTRIBUTE() set the defined struct file_operations'
->read() and ->write() members to these wrappers.

Export debugfs_create_file_unsafe() in order to allow debugfs users to
create their files in non-proxying operation mode.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12 14:14:21 -07:00
Nicolai Stange
49d200deaa debugfs: prevent access to removed files' private data
Upon return of debugfs_remove()/debugfs_remove_recursive(), it might
still be attempted to access associated private file data through
previously opened struct file objects. If that data has been freed by
the caller of debugfs_remove*() in the meanwhile, the reading/writing
process would either encounter a fault or, if the memory address in
question has been reassigned again, unrelated data structures could get
overwritten.

However, since debugfs files are seldomly removed, usually from module
exit handlers only, the impact is very low.

Currently, there are ~1000 call sites of debugfs_create_file() spread
throughout the whole tree and touching all of those struct file_operations
in order to make them file removal aware by means of checking the result of
debugfs_use_file_start() from within their methods is unfeasible.

Instead, wrap the struct file_operations by a lifetime managing proxy at
file open:
- In debugfs_create_file(), the original fops handed in has got stashed
  away in ->d_fsdata already.
- In debugfs_create_file(), install a proxy file_operations factory,
  debugfs_full_proxy_file_operations, at ->i_fop.

This proxy factory has got an ->open() method only. It carries out some
lifetime checks and if successful, dynamically allocates and sets up a new
struct file_operations proxy at ->f_op. Afterwards, it forwards to the
->open() of the original struct file_operations in ->d_fsdata, if any.

The dynamically set up proxy at ->f_op has got a lifetime managing wrapper
set for each of the methods defined in the original struct file_operations
in ->d_fsdata.

Its ->release()er frees the proxy again and forwards to the original
->release(), if any.

In order not to mislead the VFS layer, it is strictly necessary to leave
those fields blank in the proxy that have been NULL in the original
struct file_operations also, i.e. aren't supported. This is why there is a
need for dynamically allocated proxies. The choice made not to allocate a
proxy instance for every dentry at file creation, but for every
struct file object instantiated thereof is justified by the expected usage
pattern of debugfs, namely that in general very few files get opened more
than once at a time.

The wrapper methods set in the struct file_operations implement lifetime
managing by means of the SRCU protection facilities already in place for
debugfs:
They set up a SRCU read side critical section and check whether the dentry
is still alive by means of debugfs_use_file_start(). If so, they forward
the call to the original struct file_operation stored in ->d_fsdata, still
under the protection of the SRCU read side critical section.
This SRCU read side critical section prevents any pending debugfs_remove()
and friends to return to their callers. Since a file's private data must
only be freed after the return of debugfs_remove(), the ongoing proxied
call is guarded against any file removal race.

If, on the other hand, the initial call to debugfs_use_file_start() detects
that the dentry is dead, the wrapper simply returns -EIO and does not
forward the call. Note that the ->poll() wrapper is special in that its
signature does not allow for the return of arbitrary -EXXX values and thus,
POLLHUP is returned here.

In order not to pollute debugfs with wrapper definitions that aren't ever
needed, I chose not to define a wrapper for every struct file_operations
method possible. Instead, a wrapper is defined only for the subset of
methods which are actually set by any debugfs users.
Currently, these are:

  ->llseek()
  ->read()
  ->write()
  ->unlocked_ioctl()
  ->poll()

The ->release() wrapper is special in that it does not protect the original
->release() in any way from dead files in order not to leak resources.
Thus, any ->release() handed to debugfs must implement file lifetime
management manually, if needed.
For only 33 out of a total of 434 releasers handed in to debugfs, it could
not be verified immediately whether they access data structures that might
have been freed upon a debugfs_remove() return in the meanwhile.

Export debugfs_use_file_start() and debugfs_use_file_finish() in order to
allow any ->release() to manually implement file lifetime management.

For a set of common cases of struct file_operations implemented by the
debugfs_core itself, future patches will incorporate file lifetime
management directly within those in order to allow for their unproxied
operation. Rename the original, non-proxying "debugfs_create_file()" to
"debugfs_create_file_unsafe()" and keep it for future internal use by
debugfs itself. Factor out code common to both into the new
__debugfs_create_file().

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12 14:14:21 -07:00
Nicolai Stange
9fd4dcece4 debugfs: prevent access to possibly dead file_operations at file open
Nothing prevents a dentry found by path lookup before a return of
__debugfs_remove() to actually get opened after that return. Now, after
the return of __debugfs_remove(), there are no guarantees whatsoever
regarding the memory the corresponding inode's file_operations object
had been kept in.

Since __debugfs_remove() is seldomly invoked, usually from module exit
handlers only, the race is hard to trigger and the impact is very low.

A discussion of the problem outlined above as well as a suggested
solution can be found in the (sub-)thread rooted at

  http://lkml.kernel.org/g/20130401203445.GA20862@ZenIV.linux.org.uk
  ("Yet another pipe related oops.")

Basically, Greg KH suggests to introduce an intermediate fops and
Al Viro points out that a pointer to the original ones may be stored in
->d_fsdata.

Follow this line of reasoning:
- Add SRCU as a reverse dependency of DEBUG_FS.
- Introduce a srcu_struct object for the debugfs subsystem.
- In debugfs_create_file(), store a pointer to the original
  file_operations object in ->d_fsdata.
- Make debugfs_remove() and debugfs_remove_recursive() wait for a
  SRCU grace period after the dentry has been delete()'d and before they
  return to their callers.
- Introduce an intermediate file_operations object named
  "debugfs_open_proxy_file_operations". It's ->open() functions checks,
  under the protection of a SRCU read lock, whether the dentry is still
  alive, i.e. has not been d_delete()'d and if so, tries to acquire a
  reference on the owning module.
  On success, it sets the file object's ->f_op to the original
  file_operations and forwards the ongoing open() call to the original
  ->open().
- For clarity, rename the former debugfs_file_operations to
  debugfs_noop_file_operations -- they are in no way canonical.

The choice of SRCU over "normal" RCU is justified by the fact, that the
former may also be used to protect ->i_private data from going away
during the execution of a file's readers and writers which may (and do)
sleep.

Finally, introduce the fs/debugfs/internal.h header containing some
declarations internal to the debugfs implementation.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12 14:14:21 -07:00
Deepa Dinamani
1b48b530da fs: debugfs: Replace CURRENT_TIME by current_fs_time()
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_fs_time() instead.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-29 10:11:44 -07:00
Roman Pen
a8f324a46f debugfs: fix inode i_nlink references for automount dentry
Directory inodes should start off with i_nlink == 2 (one extra ref
for "." entry).  debugfs_create_automount() increases neither the
i_nlink reference for current inode nor for parent inode.

On attempt to remove the automount dentry, kernel complains:

  [   86.288070] WARNING: CPU: 1 PID: 3616 at fs/inode.c:273 drop_nlink+0x3e/0x50()
  [   86.288461] Modules linked in: debugfs_example2(O-)
  [   86.288745] CPU: 1 PID: 3616 Comm: rmmod Tainted: G           O    4.4.0-rc3-next-20151207+ #135
  [   86.289197] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.2-20150617_082717-anatol 04/01/2014
  [   86.289696]  ffffffff81be05c9 ffff8800b9e6fda0 ffffffff81352e2c 0000000000000000
  [   86.290110]  ffff8800b9e6fdd8 ffffffff81065142 ffff8801399175e8 ffff8800bb78b240
  [   86.290507]  ffff8801399175e8 ffff8800b73d7898 ffff8800b73d7840 ffff8800b9e6fde8
  [   86.290933] Call Trace:
  [   86.291080]  [<ffffffff81352e2c>] dump_stack+0x4e/0x82
  [   86.291340]  [<ffffffff81065142>] warn_slowpath_common+0x82/0xc0
  [   86.291640]  [<ffffffff8106523a>] warn_slowpath_null+0x1a/0x20
  [   86.291932]  [<ffffffff811ae62e>] drop_nlink+0x3e/0x50
  [   86.292208]  [<ffffffff811ba35b>] simple_unlink+0x4b/0x60
  [   86.292481]  [<ffffffff811ba3a7>] simple_rmdir+0x37/0x50
  [   86.292748]  [<ffffffff812d9808>] __debugfs_remove.part.16+0xa8/0xd0
  [   86.293082]  [<ffffffff812d9a0b>] debugfs_remove_recursive+0xdb/0x1c0
  [   86.293406]  [<ffffffffa00004dd>] cleanup_module+0x2d/0x3b [debugfs_example2]
  [   86.293762]  [<ffffffff810d959b>] SyS_delete_module+0x16b/0x220
  [   86.294077]  [<ffffffff818ef857>] entry_SYSCALL_64_fastpath+0x12/0x6a
  [   86.294405] ---[ end trace c9fc53353fe14a36 ]---
  [   86.294639] ------------[ cut here ]------------

To reproduce the issue it is enough to invoke these lines:

     autom = debugfs_create_automount("automount", NULL, vfsmount_cb, data);
     BUG_ON(IS_ERR_OR_NULL(autom));
     debugfs_remove(autom);

The issue is fixed by increasing inode i_nlink references for current
and parent inodes.

Signed-off-by: Roman Pen <r.peniaev@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-29 10:11:44 -07:00
Al Viro
5955102c99 wrappers for ->i_mutex access
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22 18:04:28 -05:00
Daniel Borkmann
0ee9608c89 debugfs: fix refcount imbalance in start_creating
In debugfs' start_creating(), we pin the file system to safely access
its root. When we failed to create a file, we unpin the file system via
failed_creating() to release the mount count and eventually the reference
of the vfsmount.

However, when we run into an error during lookup_one_len() when still
in start_creating(), we only release the parent's mutex but not so the
reference on the mount. Looks like it was done in the past, but after
splitting portions of __create_file() into start_creating() and
end_creating() via 190afd81e4 ("debugfs: split the beginning and the
end of __create_file() off"), this seemed missed. Noticed during code
review.

Fixes: 190afd81e4 ("debugfs: split the beginning and the end of __create_file() off")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-11 02:04:44 -05:00
Viresh Kumar
c23fe83138 debugfs: Add debugfs_create_ulong()
Add debugfs_create_ulong() for the users of type 'unsigned long'. These
will be 32 bits long on a 32 bit machine and 64 bits long on a 64 bit
machine.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-18 10:14:39 -07:00
Stephen Boyd
6713e8fb54 debugfs: Add read-only/write-only bool file ops
There aren't any read-only or write-only bool file ops, but there
is a caller of debugfs_create_bool() that calls it with mode
equal to 0400. This leads to the possibility of userspace
modifying the file, so let's use the newly created
debugfs_create_mode() helper here to fix this.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 22:09:03 -07:00
Stephen Boyd
6db6652abc debugfs: Add read-only/write-only size_t file ops
There aren't any read-only or write-only size_t file ops, but there
is a caller of debugfs_create_size_t() that calls it with mode
equal to 0400. This leads to the possibility of userspace
modifying the file, so let's use the newly created
debugfs_create_mode() helper here to fix this.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 22:09:03 -07:00
Stephen Boyd
82b7d4fb4e debugfs: Add read-only/write-only x64 file ops
There aren't any read-only or write-only x64 file ops, but there
is a caller of debugfs_create_x64() that calls it with mode equal
to S_IRUGO. This leads to the possibility of userspace modifying
the file, so let's use the newly created debugfs_create_mode()
helper here to fix this.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 22:09:03 -07:00
Stephen Boyd
b97f679954 debugfs: Consolidate file mode checks in debugfs_create_*()
The code that creates debugfs file with different file ops based
on the file mode is duplicated in each debugfs_create_*() API.
Consolidate that code into debugfs_create_mode(), that takes
three file ops structures so that we don't have to keep
copy/pasting that logic.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 22:09:03 -07:00
Ulf Magnusson
398dc4ad52 debugfs: document that debugfs_remove*() accepts NULL and error values
According to commit a59d6293e5 ("debugfs: change parameter check in
debugfs_remove() functions"), this is meant to make cleanup easier for
callers. In that case it ought to be documented.

Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 11:36:07 +01:00
Viresh Kumar
621a5f7ad9 debugfs: Pass bool pointer to debugfs_create_bool()
Its a bit odd that debugfs_create_bool() takes 'u32 *' as an argument,
when all it needs is a boolean pointer.

It would be better to update this API to make it accept 'bool *'
instead, as that will make it more consistent and often more convenient.
Over that bool takes just a byte.

That required updates to all user sites as well, in the same commit
updating the API. regmap core was also using
debugfs_{read|write}_file_bool(), directly and variable types were
updated for that to be bool as well.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 11:36:07 +01:00
Richard Fitzgerald
0642ef6f29 debugfs: Export bool read/write functions
The file read/write functions for bools have no special dependencies
on debugfs internals and are sufficiently non-trivial to be worth
exporting so clients can re-use the implementation.

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-20 18:44:50 +01:00
Linus Torvalds
1dc51b8288 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...
2015-07-04 19:36:06 -07:00
Linus Torvalds
0cbee99269 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace updates from Eric Biederman:
 "Long ago and far away when user namespaces where young it was realized
  that allowing fresh mounts of proc and sysfs with only user namespace
  permissions could violate the basic rule that only root gets to decide
  if proc or sysfs should be mounted at all.

  Some hacks were put in place to reduce the worst of the damage could
  be done, and the common sense rule was adopted that fresh mounts of
  proc and sysfs should allow no more than bind mounts of proc and
  sysfs.  Unfortunately that rule has not been fully enforced.

  There are two kinds of gaps in that enforcement.  Only filesystems
  mounted on empty directories of proc and sysfs should be ignored but
  the test for empty directories was insufficient.  So in my tree
  directories on proc, sysctl and sysfs that will always be empty are
  created specially.  Every other technique is imperfect as an ordinary
  directory can have entries added even after a readdir returns and
  shows that the directory is empty.  Special creation of directories
  for mount points makes the code in the kernel a smidge clearer about
  it's purpose.  I asked container developers from the various container
  projects to help test this and no holes were found in the set of mount
  points on proc and sysfs that are created specially.

  This set of changes also starts enforcing the mount flags of fresh
  mounts of proc and sysfs are consistent with the existing mount of
  proc and sysfs.  I expected this to be the boring part of the work but
  unfortunately unprivileged userspace winds up mounting fresh copies of
  proc and sysfs with noexec and nosuid clear when root set those flags
  on the previous mount of proc and sysfs.  So for now only the atime,
  read-only and nodev attributes which userspace happens to keep
  consistent are enforced.  Dealing with the noexec and nosuid
  attributes remains for another time.

  This set of changes also addresses an issue with how open file
  descriptors from /proc/<pid>/ns/* are displayed.  Recently readlink of
  /proc/<pid>/fd has been triggering a WARN_ON that has not been
  meaningful since it was added (as all of the code in the kernel was
  converted) and is not now actively wrong.

  There is also a short list of issues that have not been fixed yet that
  I will mention briefly.

  It is possible to rename a directory from below to above a bind mount.
  At which point any directory pointers below the renamed directory can
  be walked up to the root directory of the filesystem.  With user
  namespaces enabled a bind mount of the bind mount can be created
  allowing the user to pick a directory whose children they can rename
  to outside of the bind mount.  This is challenging to fix and doubly
  so because all obvious solutions must touch code that is in the
  performance part of pathname resolution.

  As mentioned above there is also a question of how to ensure that
  developers by accident or with purpose do not introduce exectuable
  files on sysfs and proc and in doing so introduce security regressions
  in the current userspace that will not be immediately obvious and as
  such are likely to require breaking userspace in painful ways once
  they are recognized"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  vfs: Remove incorrect debugging WARN in prepend_path
  mnt: Update fs_fully_visible to test for permanently empty directories
  sysfs: Create mountpoints with sysfs_create_mount_point
  sysfs: Add support for permanently empty directories to serve as mount points.
  kernfs: Add support for always empty directories.
  proc: Allow creating permanently empty directories that serve as mount points
  sysctl: Allow creating permanently empty directories that serve as mountpoints.
  fs: Add helper functions for permanently empty directories.
  vfs: Ignore unlocked mounts in fs_fully_visible
  mnt: Modify fs_fully_visible to deal with locked ro nodev and atime
  mnt: Refactor the logic for mounting sysfs and proc in a user namespace
2015-07-03 15:20:57 -07:00
Eric W. Biederman
f9bb48825a sysfs: Create mountpoints with sysfs_create_mount_point
This allows for better documentation in the code and
it allows for a simpler and fully correct version of
fs_fully_visible to be written.

The mount points converted and their filesystems are:
/sys/hypervisor/s390/       s390_hypfs
/sys/kernel/config/         configfs
/sys/kernel/debug/          debugfs
/sys/firmware/efi/efivars/  efivarfs
/sys/fs/fuse/connections/   fusectl
/sys/fs/pstore/             pstore
/sys/kernel/tracing/        tracefs
/sys/fs/cgroup/             cgroup
/sys/kernel/security/       securityfs
/sys/fs/selinux/            selinuxfs
/sys/fs/smackfs/            smackfs

Cc: stable@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-07-01 10:36:47 -05:00
Al Viro
dc3f4198ea make simple_positive() public
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:02:01 -04:00
Al Viro
5723cb01f0 debugfs: switch to simple_follow_link()
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:18:24 -04:00
Linus Torvalds
9ec3a646fe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-26 17:22:07 -07:00
Linus Torvalds
4fc8adcfec Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull third hunk of vfs changes from Al Viro:
 "This contains the ->direct_IO() changes from Omar + saner
  generic_write_checks() + dealing with fcntl()/{read,write}() races
  (mirroring O_APPEND/O_DIRECT into iocb->ki_flags and instead of
  repeatedly looking at ->f_flags, which can be changed by fcntl(2),
  check ->ki_flags - which cannot) + infrastructure bits for dhowells'
  d_inode annotations + Christophs switch of /dev/loop to
  vfs_iter_write()"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (30 commits)
  block: loop: switch to VFS ITER_BVEC
  configfs: Fix inconsistent use of file_inode() vs file->f_path.dentry->d_inode
  VFS: Make pathwalk use d_is_reg() rather than S_ISREG()
  VFS: Fix up debugfs to use d_is_dir() in place of S_ISDIR()
  VFS: Combine inode checks with d_is_negative() and d_is_positive() in pathwalk
  NFS: Don't use d_inode as a variable name
  VFS: Impose ordering on accesses of d_inode and d_flags
  VFS: Add owner-filesystem positive/negative dentry checks
  nfs: generic_write_checks() shouldn't be done on swapout...
  ocfs2: use __generic_file_write_iter()
  mirror O_APPEND and O_DIRECT into iocb->ki_flags
  switch generic_write_checks() to iocb and iter
  ocfs2: move generic_write_checks() before the alignment checks
  ocfs2_file_write_iter: stop messing with ppos
  udf_file_write_iter: reorder and simplify
  fuse: ->direct_IO() doesn't need generic_write_checks()
  ext4_file_write_iter: move generic_write_checks() up
  xfs_file_aio_write_checks: switch to iocb/iov_iter
  generic_write_checks(): drop isblk argument
  blkdev_write_iter: expand generic_file_checks() call in there
  ...
2015-04-16 23:27:56 -04:00
David Howells
2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
David Howells
7ceab50c0b VFS: Fix up debugfs to use d_is_dir() in place of S_ISDIR()
Fix up debugfs to use d_is_dir(dentry) in place of
S_ISDIR(dentry->d_inode->i_mode).

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:05:30 -04:00
Greg KH
c9e15f25f5 debugfs: allow bad parent pointers to be passed in
If something went wrong with creating a debugfs file/symlink/directory,
that value could be passed down into debugfs again as a parent dentry.
To make caller code simpler, just error out if this happens, and don't
crash the kernel.

Reported-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alex Elder <elder@linaro.org>
2015-04-03 16:30:12 +02:00
Al Viro
0db59e5929 debugfs: leave freeing a symlink body until inode eviction
As it is, we have debugfs_remove() racing with symlink traversals.
Supply ->evict_inode() and do freeing there - inode will remain
pinned until we are done with the symlink body.

And rip the idiocy with checking if dentry is positive right after
we'd verified debugfs_positive(), which is a stronger check...

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-22 11:38:43 -05:00
David Howells
e36cb0b89c VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)
Convert the following where appropriate:

 (1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry).

 (2) S_ISREG(dentry->d_inode) to d_is_reg(dentry).

 (3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry).  This is actually more
     complicated than it appears as some calls should be converted to
     d_can_lookup() instead.  The difference is whether the directory in
     question is a real dir with a ->lookup op or whether it's a fake dir with
     a ->d_automount op.

In some circumstances, we can subsume checks for dentry->d_inode not being
NULL into this, provided we the code isn't in a filesystem that expects
d_inode to be NULL if the dirent really *is* negative (ie. if we're going to
use d_inode() rather than d_backing_inode() to get the inode pointer).

Note that the dentry type field may be set to something other than
DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS
manages the fall-through from a negative dentry to a lower layer.  In such a
case, the dentry type of the negative union dentry is set to the same as the
type of the lower dentry.

However, if you know d_inode is not NULL at the call site, then you can use
the d_is_xxx() functions even in a filesystem.

There is one further complication: a 0,0 chardev dentry may be labelled
DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE.  Strictly, this was
intended for special directory entry types that don't have attached inodes.

The following perl+coccinelle script was used:

use strict;

my @callers;
open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') ||
    die "Can't grep for S_ISDIR and co. callers";
@callers = <$fd>;
close($fd);
unless (@callers) {
    print "No matches\n";
    exit(0);
}

my @cocci = (
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISLNK(E->d_inode->i_mode)',
    '+ d_is_symlink(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISDIR(E->d_inode->i_mode)',
    '+ d_is_dir(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISREG(E->d_inode->i_mode)',
    '+ d_is_reg(E)' );

my $coccifile = "tmp.sp.cocci";
open($fd, ">$coccifile") || die $coccifile;
print($fd "$_\n") || die $coccifile foreach (@cocci);
close($fd);

foreach my $file (@callers) {
    chomp $file;
    print "Processing ", $file, "\n";
    system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 ||
	die "spatch failed";
}

[AV: overlayfs parts skipped]

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-22 11:38:41 -05:00
David Howells
e59b4e9187 debugfs: Provide a file creation function that also takes an initial size
Provide a file creation function that also takes an initial size so that the
caller doesn't have to set i_size, thus meaning that we don't have to call
deal with ->d_inode in the callers.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-17 12:21:51 -05:00
Al Viro
77b3da6e32 new primitive: debugfs_create_automount()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 16:52:53 -05:00
Al Viro
5233e31191 debugfs: split end_creating() into success and failure cases
... and don't bother with dput(dentry) in the former and with
dget(dentry) preceding all its calls.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 16:52:53 -05:00
Al Viro
edac65eaf8 debugfs: take mode-dependent parts of debugfs_get_inode() into callers
... and trim the arguments list

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 16:52:53 -05:00
Al Viro
680b302409 fold debugfs_mknod() into callers
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 16:52:52 -05:00
Al Viro
3473cde565 fold debugfs_create() into caller
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 16:52:52 -05:00
Al Viro
02538a75ba fold debugfs_mkdir() into caller
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 16:52:51 -05:00
Al Viro
160f7592f2 debugfs_mknod(): get rid useless arguments
dev is always zero, dir was only used to get its ->i_sb, which is
equal to ->d_sb of dentry...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 16:52:51 -05:00
Al Viro
9b73fab01b fold debugfs_link() into caller
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 16:52:50 -05:00