Commit Graph

101 Commits

Author SHA1 Message Date
Oleg Nesterov
6bc080d8fd debugfs: use list_next_entry() in debugfs_remove_recursive()
Change debugfs_remove_recursive() to use list_next_entry(child), no
changes in generated code.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:24 +09:00
Oleg Nesterov
776164c1fa debugfs: debugfs_remove_recursive() must not rely on list_empty(d_subdirs)
debugfs_remove_recursive() is wrong,

1. it wrongly assumes that !list_empty(d_subdirs) means that this
   dir should be removed.

   This is not that bad by itself, but:

2. if d_subdirs does not becomes empty after __debugfs_remove()
   it gives up and silently fails, it doesn't even try to remove
   other entries.

   However ->d_subdirs can be non-empty because it still has the
   already deleted !debugfs_positive() entries.

3. simple_release_fs() is called even if __debugfs_remove() fails.

Suppose we have

	dir1/
		dir2/
			file2
		file1

and someone opens dir1/dir2/file2.

Now, debugfs_remove_recursive(dir1/dir2) succeeds, and dir1/dir2 goes
away.

But debugfs_remove_recursive(dir1) silently fails and doesn't remove
this directory. Because it tries to delete (the already deleted)
dir1/dir2/file2 again and then fails due to "Avoid infinite loop"
logic.

Test-case:

	#!/bin/sh

	cd /sys/kernel/debug/tracing
	echo 'p:probe/sigprocmask sigprocmask' >> kprobe_events
	sleep 1000 < events/probe/sigprocmask/id &
	echo -n >| kprobe_events

	[ -d events/probe ] && echo "ERR!! failed to rm probe"

And after that it is not possible to create another probe entry.

With this patch debugfs_remove_recursive() skips !debugfs_positive()
files although this is not strictly needed. The most important change
is that it does not try to make ->d_subdirs empty, it simply scans
the whole list(s) recursively and removes as much as possible.

Link: http://lkml.kernel.org/r/20130726151256.GC19472@redhat.com

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-31 12:16:31 -04:00
Mathias Krause
a3b2c8c7aa debugfs: write_file_bool() - ensure strtobool() operates on valid data
In case, userland writes an empty string to a bool debugfs file, buf[]
will still be uninitialized when being passed to strtobool() making the
outcome of that function purely random.

Fix this by always zero-terminating the buffer.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-03 13:55:02 -07:00
Seth Jennings
3a76e5e09f debugfs: add get/set for atomic types
debugfs currently lack the ability to create attributes
that set/get atomic_t values.

This patch adds support for this through a new
debugfs_create_atomic_t() function.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-03 13:55:01 -07:00
Eric W. Biederman
7f78e03513 fs: Limit sys_mount to only request filesystem modules.
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-03 19:36:31 -08:00
Greg Kroah-Hartman
ed408f7c0f Merge 3.9-rc4 into driver-core-next
This is to fix up a build problem with a wireless driver due to the
dynamic-debug patches in this branch.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17 19:48:18 -08:00
Sasha Levin
1884bd4b14 debugfs: remove redundant initialization of dentry
We already initialize it to NULL when declaring it, no need to do
that twice.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17 13:02:08 -08:00
Dave Reisner
f1688e0431 debugfs: convert gid= argument from decimal, not octal
This patch technically breaks userspace, but I suspect that anyone who
actually used this flag would have encountered this brokenness, declared
it lunacy, and already sent a patch.

Signed-off-by: Dave Reisner <dreisner@archlinux.org>
Reviewed-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-11 05:56:01 -08:00
Yan Hong
7dd2517c39 fs/debugsfs: remove unnecessary inode->i_private initialization
inode->i_private is promised to be NULL on allocation, no need to set it
explicitly.

Signed-off-by: Yan Hong <clouds.yan@gmail.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 17:46:42 -08:00
Linus Torvalds
437589a74b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace changes from Eric Biederman:
 "This is a mostly modest set of changes to enable basic user namespace
  support.  This allows the code to code to compile with user namespaces
  enabled and removes the assumption there is only the initial user
  namespace.  Everything is converted except for the most complex of the
  filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs,
  nfs, ocfs2 and xfs as those patches need a bit more review.

  The strategy is to push kuid_t and kgid_t values are far down into
  subsystems and filesystems as reasonable.  Leaving the make_kuid and
  from_kuid operations to happen at the edge of userspace, as the values
  come off the disk, and as the values come in from the network.
  Letting compile type incompatible compile errors (present when user
  namespaces are enabled) guide me to find the issues.

  The most tricky areas have been the places where we had an implicit
  union of uid and gid values and were storing them in an unsigned int.
  Those places were converted into explicit unions.  I made certain to
  handle those places with simple trivial patches.

  Out of that work I discovered we have generic interfaces for storing
  quota by projid.  I had never heard of the project identifiers before.
  Adding full user namespace support for project identifiers accounts
  for most of the code size growth in my git tree.

  Ultimately there will be work to relax privlige checks from
  "capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing
  root in a user names to do those things that today we only forbid to
  non-root users because it will confuse suid root applications.

  While I was pushing kuid_t and kgid_t changes deep into the audit code
  I made a few other cleanups.  I capitalized on the fact we process
  netlink messages in the context of the message sender.  I removed
  usage of NETLINK_CRED, and started directly using current->tty.

  Some of these patches have also made it into maintainer trees, with no
  problems from identical code from different trees showing up in
  linux-next.

  After reading through all of this code I feel like I might be able to
  win a game of kernel trivial pursuit."

Fix up some fairly trivial conflicts in netfilter uid/git logging code.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits)
  userns: Convert the ufs filesystem to use kuid/kgid where appropriate
  userns: Convert the udf filesystem to use kuid/kgid where appropriate
  userns: Convert ubifs to use kuid/kgid
  userns: Convert squashfs to use kuid/kgid where appropriate
  userns: Convert reiserfs to use kuid and kgid where appropriate
  userns: Convert jfs to use kuid/kgid where appropriate
  userns: Convert jffs2 to use kuid and kgid where appropriate
  userns: Convert hpfs to use kuid and kgid where appropriate
  userns: Convert btrfs to use kuid/kgid where appropriate
  userns: Convert bfs to use kuid/kgid where appropriate
  userns: Convert affs to use kuid/kgid wherwe appropriate
  userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids
  userns: On ia64 deal with current_uid and current_gid being kuid and kgid
  userns: On ppc convert current_uid from a kuid before printing.
  userns: Convert s390 getting uid and gid system calls to use kuid and kgid
  userns: Convert s390 hypfs to use kuid and kgid where appropriate
  userns: Convert binder ipc to use kuids
  userns: Teach security_path_chown to take kuids and kgids
  userns: Add user namespace support to IMA
  userns: Convert EVM to deal with kuids and kgids in it's hmac computation
  ...
2012-10-02 11:11:09 -07:00
Linus Torvalds
06d2fe153b Driver core merge for 3.7-rc1
Here is the big driver core update for 3.7-rc1.
 
 A number of firmware_class.c updates (as you saw a month or so ago), and
 some hyper-v updates and some printk fixes as well.  All patches that
 are outside of the drivers/base area have been acked by the respective
 maintainers, and have all been in the linux-next tree for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core merge from Greg Kroah-Hartman:
 "Here is the big driver core update for 3.7-rc1.

  A number of firmware_class.c updates (as you saw a month or so ago),
  and some hyper-v updates and some printk fixes as well.  All patches
  that are outside of the drivers/base area have been acked by the
  respective maintainers, and have all been in the linux-next tree for a
  while.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'driver-core-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits)
  memory: tegra{20,30}-mc: Fix reading incorrect register in mc_readl()
  device.h: Add missing inline to #ifndef CONFIG_PRINTK dev_vprintk_emit
  memory: emif: Add ifdef CONFIG_DEBUG_FS guard for emif_debugfs_[init|exit]
  Documentation: Fixes some translation error in Documentation/zh_CN/gpio.txt
  Documentation: Remove 3 byte redundant code at the head of the Documentation/zh_CN/arm/booting
  Documentation: Chinese translation of Documentation/video4linux/omap3isp.txt
  device and dynamic_debug: Use dev_vprintk_emit and dev_printk_emit
  dev: Add dev_vprintk_emit and dev_printk_emit
  netdev_printk/netif_printk: Remove a superfluous logging colon
  netdev_printk/dynamic_netdev_dbg: Directly call printk_emit
  dev_dbg/dynamic_debug: Update to use printk_emit, optimize stack
  driver-core: Shut up dev_dbg_reatelimited() without DEBUG
  tools/hv: Parse /etc/os-release
  tools/hv: Check for read/write errors
  tools/hv: Fix exit() error code
  tools/hv: Fix file handle leak
  Tools: hv: Implement the KVP verb - KVP_OP_GET_IP_INFO
  Tools: hv: Rename the function kvp_get_ip_address()
  Tools: hv: Implement the KVP verb - KVP_OP_SET_IP_INFO
  Tools: hv: Add an example script to configure an interface
  ...
2012-10-01 12:10:44 -07:00
Linus Torvalds
e05e279e6f debugfs: fix u32_array race in format_array_alloc
The format_array_alloc() function is fundamentally racy, in that it
prints the array twice: once to figure out how much space to allocate
for the buffer, and the second time to actually print out the data.

If any of the array contents changes in between, the allocation size may
be wrong, and the end result may be truncated in odd ways.

Just don't do it.  Allocate a maximum-sized array up-front, and just
format the array contents once.  The only user of the u32_array
interfaces is the Xen spinlock statistics code, and it has 31 entries in
the arrays, so the maximum size really isn't that big, and the end
result is much simpler code without the bug.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-21 11:48:05 -07:00
David Rientjes
36048853c5 debugfs: fix race in u32_array_read and allocate array at open
u32_array_open() is racy when multiple threads read from a file with a
seek position of zero, i.e. when two or more simultaneous reads are
occurring after the non-seekable files are created.  It is possible that
file->private_data is double-freed because the threads races between

	kfree(file->private-data);

and

	file->private_data = NULL;

The fix is to only do format_array_alloc() when the file is opened and
free it when it is closed.

Note that because the file has always been non-seekable, you can't open
it and read it multiple times anyway, so the data has always been
generated just once.  The difference is that now it is generated at open
time rather than at the time of the first read, and that avoids the
race.

Reported-by: Dave Jones <davej@redhat.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Raghavendra <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-21 10:28:17 -07:00
Eric W. Biederman
7dc05881b6 userns: Convert debugfs to use kuid/kgid where appropriate.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-06 19:02:52 -07:00
Kees Cook
82aceae4f0 debugfs: more tightly restrict default mount mode
Since the debugfs is mostly only used by root, make the default mount
mode 0700. Most system owners do not need a more permissive value,
but they can choose to weaken the restrictions via their fstab.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-27 13:42:02 -07:00
Chris Wright
3cd52ab68b debugfs: make __create_file static
It's only used locally, no need to pollute global namespace.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16 11:41:51 -07:00
Linus Torvalds
fa93669a19 Driver core merge for 3.6-rc1
Here's the big driver core pull request for 3.6-rc1.
 
 Unlike 3.5, this kernel should be a lot tamer, with the printk changes now
 settled down.  All we have here is some extcon driver updates, w1 driver
 updates, a few printk cleanups that weren't needed for 3.5, but are good to
 have now, and some other minor fixes/changes in the driver core.
 
 All of these have been in the linux-next releases for a while now.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core changes from Greg Kroah-Hartman:
 "Here's the big driver core pull request for 3.6-rc1.

  Unlike 3.5, this kernel should be a lot tamer, with the printk changes
  now settled down.  All we have here is some extcon driver updates, w1
  driver updates, a few printk cleanups that weren't needed for 3.5, but
  are good to have now, and some other minor fixes/changes in the driver
  core.

  All of these have been in the linux-next releases for a while now.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'driver-core-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (38 commits)
  printk: Export struct log size and member offsets through vmcoreinfo
  Drivers: hv: Change the hex constant to a decimal constant
  driver core: don't trigger uevent after failure
  extcon: MAX77693: Add extcon-max77693 driver to support Maxim MAX77693 MUIC device
  sysfs: fail dentry revalidation after namespace change fix
  sysfs: fail dentry revalidation after namespace change
  extcon: spelling of detach in function doc
  extcon: arizona: Stop microphone detection if we give up on it
  extcon: arizona: Update cable reporting calls and split headset
  PM / Runtime: Do not increment device usage counts before probing
  kmsg - do not flush partial lines when the console is busy
  kmsg - export "continuation record" flag to /dev/kmsg
  kmsg - avoid warning for CONFIG_PRINTK=n compilations
  kmsg - properly print over-long continuation lines
  driver-core: Use kobj_to_dev instead of re-implementing it
  driver-core: Move kobj_to_dev from genhd.h to device.h
  driver core: Move deferred devices to the end of dpm_list before probing
  driver core: move uevent call to driver_register
  driver core: fix shutdown races with probe/remove(v3)
  Extcon: Arizona: Add driver for Wolfson Arizona class devices
  ...
2012-07-26 11:25:33 -07:00
Al Viro
ac481d6ca4 debugfs: get rid of useless arguments to debugfs_{mkdir,symlink}
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:35:30 +04:00
Al Viro
cfa57c11b0 debugfs: fold debugfs_create_by_name() into the only caller
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:35:25 +04:00
Al Viro
c3b1a35084 debugfs: make sure that debugfs_create_file() gets used only for regulars
It, debugfs_create_dir() and debugfs_create_link() use the common helper
now.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:35:19 +04:00
Arend van Spriel
a59d6293e5 debugfs: change parameter check in debugfs_remove() functions
The dentry parameter in debugfs_remove() and debugfs_remove_recursive()
is checked being a NULL pointer. To make cleanup by callers easier this
check is extended using the IS_ERR_OR_NULL macro instead because the
debugfs_create_... functions can return a ERR_PTR() value.

Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:40:41 -07:00
Srivatsa Vaddagiri
9fe2a70153 debugfs: Add support to print u32 array in debugfs
Move the code from Xen to debugfs to make the code common
for other users as well.

Accked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Suzuki Poulose <suzuki@in.ibm.com>
[v1: Fixed rebase issues]
[v2: Fixed PPC compile issues]
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-04-17 00:18:36 -04:00
Stephen Boyd
234e340582 simple_open: automatically convert to simple_open()
Many users of debugfs copy the implementation of default_open() when
they want to support a custom read/write function op.  This leads to a
proliferation of the default_open() implementation across the entire
tree.

Now that the common implementation has been consolidated into libfs we
can replace all the users of this function with simple_open().

This replacement was done with the following semantic patch:

<smpl>
@ open @
identifier open_f != simple_open;
identifier i, f;
@@
-int open_f(struct inode *i, struct file *f)
-{
(
-if (i->i_private)
-f->private_data = i->i_private;
|
-f->private_data = i->i_private;
)
-return 0;
-}

@ has_open depends on open @
identifier fops;
identifier open.open_f;
@@
struct file_operations fops = {
...
-.open = open_f,
+.open = simple_open,
...
};
</smpl>

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-05 15:25:50 -07:00
Linus Torvalds
e2a0883e40 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile 1 from Al Viro:
 "This is _not_ all; in particular, Miklos' and Jan's stuff is not there
  yet."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits)
  ext4: initialization of ext4_li_mtx needs to be done earlier
  debugfs-related mode_t whack-a-mole
  hfsplus: add an ioctl to bless files
  hfsplus: change finder_info to u32
  hfsplus: initialise userflags
  qnx4: new helper - try_extent()
  qnx4: get rid of qnx4_bread/qnx4_getblk
  take removal of PF_FORKNOEXEC to flush_old_exec()
  trim includes in inode.c
  um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it
  um: embed ->stub_pages[] into mmu_context
  gadgetfs: list_for_each_safe() misuse
  ocfs2: fix leaks on failure exits in module_init
  ecryptfs: make register_filesystem() the last potential failure exit
  ntfs: forgets to unregister sysctls on register_filesystem() failure
  logfs: missing cleanup on register_filesystem() failure
  jfs: mising cleanup on register_filesystem() failure
  make configfs_pin_fs() return root dentry on success
  configfs: configfs_create_dir() has parent dentry in dentry->d_parent
  configfs: sanitize configfs_create()
  ...
2012-03-21 13:36:41 -07:00
Al Viro
88187398cc debugfs-related mode_t whack-a-mole
all of those should be umode_t...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:53 -04:00
Greg Kroah-Hartman
bd1d462e13 Merge 3.3-rc2 into the driver-core-next branch.
This was done to resolve a merge and build problem with the
drivers/acpi/processor_driver.c file.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-02 11:24:44 -08:00
Ludwig Nussel
d6e486868c debugfs: add mode, uid and gid options
Cautious admins may want to restrict access to debugfs. Currently a
manual chown/chmod e.g. in an init script is needed to achieve that.
Distributions that want to make the mount options configurable need
to add extra config files. By allowing to set the root inode's uid,
gid and mode via mount options no such hacks are needed anymore.
Instead configuration becomes straight forward via fstab.

Signed-off-by: Ludwig Nussel <ludwig.nussel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-26 11:28:49 -08:00
Randy Dunlap
b5763accd3 kernel-doc: fix new warnings in debugfs
Fix new kernel-doc warnings:

Warning(fs/debugfs/file.c:556): No description found for parameter 'nregs'
Warning(fs/debugfs/file.c:556): Excess function parameter 'mregs' description in 'debugfs_print_regs32'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-23 08:44:53 -08:00
Linus Torvalds
972b2c7199 Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (165 commits)
  reiserfs: Properly display mount options in /proc/mounts
  vfs: prevent remount read-only if pending removes
  vfs: count unlinked inodes
  vfs: protect remounting superblock read-only
  vfs: keep list of mounts for each superblock
  vfs: switch ->show_options() to struct dentry *
  vfs: switch ->show_path() to struct dentry *
  vfs: switch ->show_devname() to struct dentry *
  vfs: switch ->show_stats to struct dentry *
  switch security_path_chmod() to struct path *
  vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb
  vfs: trim includes a bit
  switch mnt_namespace ->root to struct mount
  vfs: take /proc/*/mounts and friends to fs/proc_namespace.c
  vfs: opencode mntget() mnt_set_mountpoint()
  vfs: spread struct mount - remaining argument of next_mnt()
  vfs: move fsnotify junk to struct mount
  vfs: move mnt_devname
  vfs: move mnt_list to struct mount
  vfs: switch pnode.h macros to struct mount *
  ...
2012-01-08 12:19:57 -08:00
Al Viro
f4ae40a6a5 switch debugfs to umode_t
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:56 -05:00
Al Viro
4c1d5a64f1 vfs: for usbfs, etc. internal vfsmounts ->mnt_sb->s_root == ->mnt_root
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:52:41 -05:00
Heiko Carstens
3b85e4ab2e debugfs: add missing #ifdef HAS_IOMEM
"debugfs: add tools to printk 32-bit registers" adds new functions which rely
on IOMEM functionality which is not present on all architectures and therefore
result in compile errors:

fs/debugfs/file.c: In function 'debugfs_print_regs32':
fs/debugfs/file.c:561:7: error: implicit declaration of function 'readl' [-Werror=implicit-function-declaration]

Add an #ifdef CONFIG_HAS_IOMEM to fix this

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-03 16:45:16 -08:00
Dan Carpenter
5858441c95 debugfs: remove unneeded cast in debugfs_print_regs32()
The cast here causes a Sparse warning:
fs/debugfs/file.c:561:42: warning: cast removes address space of expression
fs/debugfs/file.c:561:42: warning: incorrect type in argument 1 (different address spaces)
fs/debugfs/file.c:561:42:    expected void const volatile [noderef] <asn:2>*addr
fs/debugfs/file.c:561:42:    got void *<noident>

It's redundant to cast it to a (void *) anyway when it is already a
(void __iomem *).

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-26 20:12:47 -08:00
Alessandro Rubini
03e099fbb0 debugfs: bugfix: include <linux/io.h> in file.c
The regs32 machinery uses readl. I forgot the mandatory include
and the code was not compiling on all archs.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-22 10:20:05 -08:00
Alessandro Rubini
8ee4dd9f06 debugfs: print_regs32: make regs array a const pointer
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-18 15:19:21 -08:00
Alessandro Rubini
1a087c6ad9 debugfs: add tools to printk 32-bit registers
Some debugfs file I deal with are mostly blocks of registers,
i.e. lines of the form "<name> = 0x<value>". Some files are only
registers, some include registers blocks among other material.  This
patch introduces data structures and functions to deal with both
cases.  I expect more users of this over time.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-18 10:31:22 -08:00
Harry Wei
bd33d12fba debugfs: Fix a comment mistake
The file is fs/debugfs/inode.c but the comment says it is file.c.
This patch can fix this little mistake.

Signed-off-by: Harry Wei <harryxiyou@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-22 17:41:48 -07:00
Stephen Boyd
c42d223714 debugfs: Silence DEBUG_STRICT_USER_COPY_CHECKS=y warning
Enabling DEBUG_STRICT_USER_COPY_CHECKS causes the following
warning:

In file included from arch/x86/include/asm/uaccess.h:573,
                 from include/linux/uaccess.h:5,
                 from include/linux/highmem.h:7,
                 from include/linux/pagemap.h:10,
                 from fs/debugfs/file.c:18:
In function 'copy_from_user',
    inlined from 'write_file_bool' at fs/debugfs/file.c:435:
arch/x86/include/asm/uaccess_64.h:65: warning: call to
'copy_from_user_overflow' declared with attribute warning:
copy_from_user() buffer size is not provably correct

presumably due to buf_size being signed causing GCC to fail to
see that buf_size can't become negative.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-13 16:15:35 -07:00
Jonathan Cameron
8705b48e71 debugfs: move to new strtobool
No functional changes requires that we eat errors from strtobool.
If people want to not do this, then it should be fixed at a later date.

V2: Simplification suggested by Rusty Russell removes the need for
additional variable ret.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-25 16:04:52 -07:00
Jan Kara
25d41d8455 debugfs: Fix filesystem reference counting on debugfs_remove() failure
When __debugfs_remove() fails (because simple_rmdir() fails e.g. when a
directory is not empty), we must not decrement use count of the filesystem
as nothing was in fact deleted.

This fixes use after free caused by debugfs in some cases.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-18 08:07:18 -08:00
Amerigo Wang
1f7da214e2 debugfs: remove module_exit()
debugfs can't be a module, so module_exit() is meaningless for it.

Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 15:39:17 -08:00
Al Viro
fc14f2fef6 convert get_sb_single() users
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:28 -04:00
Christoph Hellwig
85fe4025c6 fs: do not assign default i_ino in new_inode
Instead of always assigning an increasing inode number in new_inode
move the call to assign it into those callers that actually need it.
For now callers that need it is estimated conservatively, that is
the call is added to all filesystems that do not assign an i_ino
by themselves.  For a few more filesystems we can avoid assigning
any inode number given that they aren't user visible, and for others
it could be done lazily when an inode number is actually needed,
but that's left for later patches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:11 -04:00
Arnd Bergmann
6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00
Huang Ying
15b0beaa33 Add x64 support to debugfs
Add debugfs_create_x64. This is needed by ACPI APEI EINJ parameters support.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-05-19 22:41:57 -04:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Al Viro
123df2944c Lose the new_name argument of fsnotify_move()
it's always new_dentry->d_name.name

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-02-08 14:38:36 -05:00
Al Viro
ef52c75e4b get rid of pointless checks after simple_pin_fs()
if we'd just got success from it, vfsmount won't be NULL

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-01-26 22:22:26 -05:00
Mathieu Desnoyers
d3a3b0adad debugfs: fix create mutex racy fops and private data
Setting fops and private data outside of the mutex at debugfs file
creation introduces a race where the files can be opened with the wrong
file operations and private data.  It is easy to trigger with a process
waiting on file creation notification.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 11:24:53 -08:00
Alberto Bertogli
be030e653f fs/debugfs/inode.c: fix comment typos
Signed-off-by: Alberto Bertogli <albertito@blitiri.com.ar>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-04 15:39:52 +01:00