Commit Graph

47 Commits

Author SHA1 Message Date
Ard Biesheuvel 2ce507f57b efivarfs: Drop 'duplicates' bool parameter on efivar_init()
The 'duplicates' bool argument is always true when efivar_init() is
called from its only caller so let's just drop it instead.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-02-25 09:43:39 +01:00
Ard Biesheuvel 9ca01c7adf efivarfs: Drop redundant cleanup on fill_super() failure
Al points out that kill_sb() will be called if efivarfs_fill_super()
fails and so there is no point in cleaning up the efivar entry list.

Reported-by: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-02-25 09:43:38 +01:00
Masahisa Kojima 94f7f6182c efivarfs: automatically update super block flag
efivar operation is updated when the tee_stmm_efi module is probed.
tee_stmm_efi module supports SetVariable runtime service, but user needs
to manually remount the efivarfs as RW to enable the write access if the
previous efivar operation does not support SetVariable and efivarfs is
mounted as read-only.

This commit notifies the update of efivar operation to efivarfs
subsystem, then drops SB_RDONLY flag if the efivar operation supports
SetVariable.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
[ardb: use per-superblock instance of the notifier block]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-12-11 11:19:18 +01:00
Ard Biesheuvel cdb46a8aef efivarfs: Move efivarfs list into superblock s_fs_info
syzbot reports issues with concurrent fsopen()/fsconfig() invocations on
efivarfs, which are the result of the fact that the efivarfs list (which
caches the names and GUIDs of existing EFI variables) is a global
structure. In normal use, these issues are unlikely to trigger, even in
the presence of multiple mounts of efivarfs, but the execution pattern
used by the syzkaller reproducer may result in multiple instances of the
superblock that share the global efivarfs list, and this causes list
corruption when the list is reinitialized by one user while another is
traversing it.

So let's move the list head into the superblock s_fs_info field, so that
it will never be shared between distinct instances of the superblock. In
the common case, there will still be a single instance of this list, but
in the artificial syzkaller case, no list corruption can occur any
longer.

Reported-by: syzbot+1902c359bfcaf39c46f2@syzkaller.appspotmail.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-12-11 11:19:18 +01:00
Ard Biesheuvel 547713d502 efivarfs: Free s_fs_info on unmount
Now that we allocate a s_fs_info struct on fs context creation, we
should ensure that we free it again when the superblock goes away.

Fixes: 5329aa5101 ("efivarfs: Add uid/gid mount options")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-12-11 11:19:17 +01:00
Ard Biesheuvel d28076ddda efivarfs: Move efivar availability check into FS context init
Instead of checking whether or not EFI variables are available when
creating the superblock, check it one step earlier, when initializing
the FS context for the mount. This way, no FS context will be created at
all, and we can drop the second check at .kill_sb() time entirely.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-12-11 11:19:17 +01:00
Ilias Apalodimas 0e8d244416 efivarfs: force RO when remounting if SetVariable is not supported
If SetVariable at runtime is not supported by the firmware we never assign
a callback for that function. At the same time mount the efivarfs as
RO so no one can call that.  However, we never check the permission flags
when someone remounts the filesystem as RW. As a result this leads to a
crash looking like this:

$ mount -o remount,rw /sys/firmware/efi/efivars
$ efi-updatevar -f PK.auth PK

[  303.279166] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[  303.280482] Mem abort info:
[  303.280854]   ESR = 0x0000000086000004
[  303.281338]   EC = 0x21: IABT (current EL), IL = 32 bits
[  303.282016]   SET = 0, FnV = 0
[  303.282414]   EA = 0, S1PTW = 0
[  303.282821]   FSC = 0x04: level 0 translation fault
[  303.283771] user pgtable: 4k pages, 48-bit VAs, pgdp=000000004258c000
[  303.284913] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
[  303.286076] Internal error: Oops: 0000000086000004 [#1] PREEMPT SMP
[  303.286936] Modules linked in: qrtr tpm_tis tpm_tis_core crct10dif_ce arm_smccc_trng rng_core drm fuse ip_tables x_tables ipv6
[  303.288586] CPU: 1 PID: 755 Comm: efi-updatevar Not tainted 6.3.0-rc1-00108-gc7d0c4695c68 #1
[  303.289748] Hardware name: Unknown Unknown Product/Unknown Product, BIOS 2023.04-00627-g88336918701d 04/01/2023
[  303.291150] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  303.292123] pc : 0x0
[  303.292443] lr : efivar_set_variable_locked+0x74/0xec
[  303.293156] sp : ffff800008673c10
[  303.293619] x29: ffff800008673c10 x28: ffff0000037e8000 x27: 0000000000000000
[  303.294592] x26: 0000000000000800 x25: ffff000002467400 x24: 0000000000000027
[  303.295572] x23: ffffd49ea9832000 x22: ffff0000020c9800 x21: ffff000002467000
[  303.296566] x20: 0000000000000001 x19: 00000000000007fc x18: 0000000000000000
[  303.297531] x17: 0000000000000000 x16: 0000000000000000 x15: 0000aaaac807ab54
[  303.298495] x14: ed37489f673633c0 x13: 71c45c606de13f80 x12: 47464259e219acf4
[  303.299453] x11: ffff000002af7b01 x10: 0000000000000003 x9 : 0000000000000002
[  303.300431] x8 : 0000000000000010 x7 : ffffd49ea8973230 x6 : 0000000000a85201
[  303.301412] x5 : 0000000000000000 x4 : ffff0000020c9800 x3 : 00000000000007fc
[  303.302370] x2 : 0000000000000027 x1 : ffff000002467400 x0 : ffff000002467000
[  303.303341] Call trace:
[  303.303679]  0x0
[  303.303938]  efivar_entry_set_get_size+0x98/0x16c
[  303.304585]  efivarfs_file_write+0xd0/0x1a4
[  303.305148]  vfs_write+0xc4/0x2e4
[  303.305601]  ksys_write+0x70/0x104
[  303.306073]  __arm64_sys_write+0x1c/0x28
[  303.306622]  invoke_syscall+0x48/0x114
[  303.307156]  el0_svc_common.constprop.0+0x44/0xec
[  303.307803]  do_el0_svc+0x38/0x98
[  303.308268]  el0_svc+0x2c/0x84
[  303.308702]  el0t_64_sync_handler+0xf4/0x120
[  303.309293]  el0t_64_sync+0x190/0x194
[  303.309794] Code: ???????? ???????? ???????? ???????? (????????)
[  303.310612] ---[ end trace 0000000000000000 ]---

Fix this by adding a .reconfigure() function to the fs operations which
we can use to check the requested flags and deny anything that's not RO
if the firmware doesn't implement SetVariable at runtime.

Fixes: f88814cc25 ("efi/efivars: Expose RT service availability via efivars abstraction")
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-12-11 11:19:17 +01:00
Linus Torvalds 13d88ac54d vfs-6.7.fsid
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Merge tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fanotify fsid updates from Christian Brauner:
 "This work is part of the plan to enable fanotify to serve as a drop-in
  replacement for inotify. While inotify is availabe on all filesystems,
  fanotify currently isn't.

  In order to support fanotify on all filesystems two things are needed:

   (1) all filesystems need to support AT_HANDLE_FID

   (2) all filesystems need to report a non-zero f_fsid

  This contains (1) and allows filesystems to encode non-decodable file
  handlers for fanotify without implementing any exportfs operations by
  encoding a file id of type FILEID_INO64_GEN from i_ino and
  i_generation.

  Filesystems that want to opt out of encoding non-decodable file ids
  for fanotify that don't support NFS export can do so by providing an
  empty export_operations struct.

  This also partially addresses (2) by generating f_fsid for simple
  filesystems as well as freevxfs. Remaining filesystems will be dealt
  with by separate patches.

  Finally, this contains the patch from the current exportfs maintainers
  which moves exportfs under vfs with Chuck, Jeff, and Amir as
  maintainers and vfs.git as tree"

* tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  MAINTAINERS: create an entry for exportfs
  fs: fix build error with CONFIG_EXPORTFS=m or not defined
  freevxfs: derive f_fsid from bdev->bd_dev
  fs: report f_fsid from s_dev for "simple" filesystems
  exportfs: support encoding non-decodeable file handles by default
  exportfs: define FILEID_INO64_GEN* file handle types
  exportfs: make ->encode_fh() a mandatory method for NFS export
  exportfs: add helpers to check if filesystem can encode/decode file handles
2023-11-07 12:11:26 -08:00
Linus Torvalds 4c975a43fa EFI update for v6.7
- implement uid/gid mount options for efivarfs
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Merge tag 'efi-next-for-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI update from Ard Biesheuvel:
 "This is the only remaining EFI change, as everything else was taken
  via -tip this cycle:

   - implement uid/gid mount options for efivarfs"

* tag 'efi-next-for-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efivarfs: Add uid/gid mount options
2023-11-04 08:54:20 -10:00
Amir Goldstein ae62bcb5e7
fs: report f_fsid from s_dev for "simple" filesystems
There are many "simple" filesystems (*) that report null f_fsid in
statfs(2).  Those "simple" filesystems report sb->s_dev as the st_dev
field of the stat syscalls for all inodes of the filesystem (**).

In order to enable fanotify reporting of events with fsid on those
"simple" filesystems, report the sb->s_dev number in f_fsid field of
statfs(2).

(*) For most of the "simple" filesystem refered to in this commit, the
->statfs() operation is simple_statfs(). Some of those fs assign the
simple_statfs() method directly in their ->s_op struct and some assign it
indirectly via a call to simple_fill_super() or to pseudo_fs_fill_super()
with either custom or "simple" s_op.
We also make the same change to efivarfs and hugetlbfs, although they do
not use simple_statfs(), because they use the simple_* inode opreations
(e.g. simple_lookup()).

(**) For most of the "simple" filesystems, the ->getattr() method is not
assigned, so stat() is implemented by generic_fillattr().  A few "simple"
filesystem use the simple_getattr() method which also calls
generic_fillattr() to fill most of the stat struct.

The two exceptions are procfs and 9p. procfs implements several different
->getattr() methods, but they all end up calling generic_fillattr() to
fill the st_dev field from sb->s_dev.

9p has more complicated ->getattr() methods, but they too, end up calling
generic_fillattr() to fill the st_dev field from sb->s_dev.

Note that 9p and kernfs also call simple_statfs() from custom ->statfs()
methods which already fill the f_fsid field, but v9fs_statfs() calls
simple_statfs() only in case f_fsid was not filled and kenrfs_statfs()
overwrites f_fsid after calling simple_statfs().

Link: https://lore.kernel.org/r/20230919094820.g5bwharbmy2dq46w@quack3/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231023143049.2944970-1-amir73il@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28 16:16:18 +02:00
Jiao Zhou 5329aa5101 efivarfs: Add uid/gid mount options
Allow UEFI variables to be modified by non-root processes in order to
run sandboxed code. This doesn't change the behavior of mounting
efivarfs unless uid/gid are specified; by default both are set to root.

Signed-off-by: Jiao Zhou <jiaozhou@google.com>
Acked-by: Matthew Garrett <mgarrett@aurora.tech>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-10-20 00:47:18 +02:00
Heinrich Schuchardt 79b83606ab efivarfs: fix statfs() on efivarfs
Some firmware (notably U-Boot) provides GetVariable() and
GetNextVariableName() but not QueryVariableInfo().

With commit d86ff3333c ("efivarfs: expose used and total size") the
statfs syscall was broken for such firmware.

If QueryVariableInfo() does not exist or returns EFI_UNSUPPORTED, just
report the file system size as 0 as statfs_simple() previously did.

Fixes: d86ff3333c ("efivarfs: expose used and total size")
Link: https://lore.kernel.org/all/20230910045445.41632-1-heinrich.schuchardt@canonical.com/
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
[ardb: log warning on QueryVariableInfo() failure]
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-09-11 09:10:02 +00:00
Anisse Astier d86ff3333c efivarfs: expose used and total size
When writing EFI variables, one might get errors with no other message
on why it fails. Being able to see how much is used by EFI variables
helps analyzing such issues.

Since this is not a conventional filesystem, block size is intentionally
set to 1 instead of PAGE_SIZE.

x86 quirks of reserved size are taken into account; so that available
and free size can be different, further helping debugging space issues.

With this patch, one can see the remaining space in EFI variable storage
via efivarfs, like this:

   $ df -h /sys/firmware/efi/efivars/
   Filesystem      Size  Used Avail Use% Mounted on
   efivarfs        176K  106K   66K  62% /sys/firmware/efi/efivars

Signed-off-by: Anisse Astier <an.astier@criteo.com>
[ardb: - rename efi_reserved_space() to efivar_reserved_space()
       - whitespace/coding style tweaks]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-05-17 18:21:34 +02:00
Johan Hovold 301de9a205 efivarfs: always register filesystem
The efivar ops are typically registered at subsys init time so that
they are available when efivarfs is registered at module init time.

Other efivars implementations, such as Google SMI, exist and can
currently be built as modules which means that efivar may not be
available when efivarfs is initialised.

Move the efivar availability check from module init to when the
filesystem is mounted to allow late registration of efivars.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-26 21:32:01 +01:00
Johan Hovold ade7fd908d efi: efivars: drop kobject from efivars_register()
Since commit 0f5b2c69a4 ("efi: vars: Remove deprecated 'efivars' sysfs
interface") and the removal of the sysfs interface there are no users of
the efivars kobject.

Drop the kobject argument from efivars_register() and add a new
efivar_is_available() helper in favour of the old efivars_kobject().

Note that the new helper uses the prefix 'efivar' (i.e. without an 's')
for consistency with efivar_supports_writes() and the rest of the
interface (except the registration functions).

For the benefit of drivers with optional EFI support, also provide a
dummy implementation of efivar_is_available().

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-17 16:14:36 +01:00
Jason A. Donenfeld 63ffb573df efi: vars: prohibit reading random seed variables
In anticipation of putting random seeds in EFI variables, it's important
that the random GUID namespace of variables remains hidden from
userspace. We accomplish this by not populating efivarfs with entries
from that GUID, as well as denying the creation of new ones in that
GUID.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-12-01 09:51:21 +01:00
Ard Biesheuvel 3a75f9f2f9 efi: vars: Use locking version to iterate over efivars linked lists
Both efivars and efivarfs uses __efivar_entry_iter() to go over the
linked list that shadows the list of EFI variables held by the firmware,
but fail to call the begin/end helpers that are documented as a
prerequisite.

So switch to the proper version, which is efivar_entry_iter(). Given
that in both cases, efivar_entry_remove() is invoked with the lock held
already, don't take the lock there anymore.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24 20:40:19 +02:00
Ard Biesheuvel ec3507b2ca efi: vars: Don't drop lock in the middle of efivar_init()
Even though the efivars_lock lock is documented as protecting the
efivars->ops pointer (among other things), efivar_init() happily
releases and reacquires the lock for every EFI variable that it
enumerates. This used to be needed because the lock was originally a
spinlock, which prevented the callback that is invoked for every
variable from being able to sleep. However, releasing the lock could
potentially invalidate the ops pointer, but more importantly, it might
allow a SetVariable() runtime service call to take place concurrently,
and the UEFI spec does not define how this affects an enumeration that
is running in parallel using the GetNextVariable() runtime service,
which is what efivar_init() uses.

In the meantime, the lock has been converted into a semaphore, and the
only reason we need to drop the lock is because the efivarfs pseudo
filesystem driver will otherwise deadlock when it invokes the efivars
API from the callback to create the efivar_entry items and insert them
into the linked list. (EFI pstore is affected in a similar way)

So let's switch to helpers that can be used while the lock is already
taken. This way, we can hold on to the lock throughout the enumeration.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24 20:40:18 +02:00
Ard Biesheuvel ff04f3b6f2 efivarfs: revert "fix memory leak in efivarfs_create()"
The memory leak addressed by commit fe5186cf12 is a false positive:
all allocations are recorded in a linked list, and freed when the
filesystem is unmounted. This leads to double frees, and as reported
by David, leads to crashes if SLUB is configured to self destruct when
double frees occur.

So drop the redundant kfree() again, and instead, mark the offending
pointer variable so the allocation is ignored by kmemleak.

Cc: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Fixes: fe5186cf12 ("efivarfs: fix memory leak in efivarfs_create()")
Reported-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-11-25 16:55:02 +01:00
Vamshi K Sthambamkadi fe5186cf12 efivarfs: fix memory leak in efivarfs_create()
kmemleak report:
  unreferenced object 0xffff9b8915fcb000 (size 4096):
  comm "efivarfs.sh", pid 2360, jiffies 4294920096 (age 48.264s)
  hex dump (first 32 bytes):
    2d 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  -...............
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000cc4d897c>] kmem_cache_alloc_trace+0x155/0x4b0
    [<000000007d1dfa72>] efivarfs_create+0x6e/0x1a0
    [<00000000e6ee18fc>] path_openat+0xe4b/0x1120
    [<000000000ad0414f>] do_filp_open+0x91/0x100
    [<00000000ce93a198>] do_sys_openat2+0x20c/0x2d0
    [<000000002a91be6d>] do_sys_open+0x46/0x80
    [<000000000a854999>] __x64_sys_openat+0x20/0x30
    [<00000000c50d89c9>] do_syscall_64+0x38/0x90
    [<00000000cecd6b5f>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

In efivarfs_create(), inode->i_private is setup with efivar_entry
object which is never freed.

Cc: <stable@vger.kernel.org>
Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Link: https://lore.kernel.org/r/20201023115429.GA2479@cosmos
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-10-26 08:15:24 +01:00
Michael Schaller 336af6a468 efivarfs: Replace invalid slashes with exclamation marks in dentries.
Without this patch efivarfs_alloc_dentry creates dentries with slashes in
their name if the respective EFI variable has slashes in its name. This in
turn causes EIO on getdents64, which prevents a complete directory listing
of /sys/firmware/efi/efivars/.

This patch replaces the invalid shlashes with exclamation marks like
kobject_set_name_vargs does for /sys/firmware/efi/vars/ to have consistently
named dentries under /sys/firmware/efi/vars/ and /sys/firmware/efi/efivars/.

Signed-off-by: Michael Schaller <misch@google.com>
Link: https://lore.kernel.org/r/20200925074502.150448-1-misch@google.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-25 23:29:04 +02:00
Ard Biesheuvel f88814cc25 efi/efivars: Expose RT service availability via efivars abstraction
Commit

  bf67fad19e ("efi: Use more granular check for availability for variable services")

introduced a check into the efivarfs, efi-pstore and other drivers that
aborts loading of the module if not all three variable runtime services
(GetVariable, SetVariable and GetNextVariable) are supported. However, this
results in efivarfs being unavailable entirely if only SetVariable support
is missing, which is only needed if you want to make any modifications.
Also, efi-pstore and the sysfs EFI variable interface could be backed by
another implementation of the 'efivars' abstraction, in which case it is
completely irrelevant which services are supported by the EFI firmware.

So make the generic 'efivars' abstraction dependent on the availibility of
the GetVariable and GetNextVariable EFI runtime services, and add a helper
'efivar_supports_writes()' to find out whether the currently active efivars
abstraction supports writes (and wire it up to the availability of
SetVariable for the generic one).

Then, use the efivar_supports_writes() helper to decide whether to permit
efivarfs to be mounted read-write, and whether to enable efi-pstore or the
sysfs EFI variable interface altogether.

Fixes: bf67fad19e ("efi: Use more granular check for availability for variable services")
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-07-09 10:14:29 +03:00
Ard Biesheuvel bf67fad19e efi: Use more granular check for availability for variable services
The UEFI spec rev 2.8 permits firmware implementations to support only
a subset of EFI runtime services at OS runtime (i.e., after the call to
ExitBootServices()), so let's take this into account in the drivers that
rely specifically on the availability of the EFI variable services.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23 21:59:42 +01:00
Linus Torvalds 933a90bf4f Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount updates from Al Viro:
 "The first part of mount updates.

  Convert filesystems to use the new mount API"

* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  mnt_init(): call shmem_init() unconditionally
  constify ksys_mount() string arguments
  don't bother with registering rootfs
  init_rootfs(): don't bother with init_ramfs_fs()
  vfs: Convert smackfs to use the new mount API
  vfs: Convert selinuxfs to use the new mount API
  vfs: Convert securityfs to use the new mount API
  vfs: Convert apparmorfs to use the new mount API
  vfs: Convert openpromfs to use the new mount API
  vfs: Convert xenfs to use the new mount API
  vfs: Convert gadgetfs to use the new mount API
  vfs: Convert oprofilefs to use the new mount API
  vfs: Convert ibmasmfs to use the new mount API
  vfs: Convert qib_fs/ipathfs to use the new mount API
  vfs: Convert efivarfs to use the new mount API
  vfs: Convert configfs to use the new mount API
  vfs: Convert binfmt_misc to use the new mount API
  convenience helper: get_tree_single()
  convenience helper get_tree_nodev()
  vfs: Kill sget_userns()
  ...
2019-07-19 10:42:02 -07:00
David Howells 4799974555 vfs: Convert efivarfs to use the new mount API
Convert the efivarfs filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

[AV: get rid of efivarfs_sb nonsense - it has never been used]

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

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Matthew Garrett <matthew.garrett@nebula.com>
cc: Jeremy Kerr <jk@ozlabs.org>
cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
cc: linux-efi@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-04 22:01:59 -04:00
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
David Howells 1d278a8790 VFS: Kill off s_options and helpers
Kill off s_options, save/replace_mount_options() and generic_show_options()
as all filesystems now implement ->show_options() for themselves.  This
should make it easier to implement a context-based mount where the mount
options can be passed individually over a file descriptor.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-11 06:09:21 -04:00
Matt Fleming 22c2b77f41 fs/efivarfs: Fix double kfree() in error path
Julia reported that we may double free 'name' in efivarfs_callback(),
and that this bug was introduced by commit 0d22f33bc37c ("efi: Don't
use spinlocks for efi vars").

Move one of the kfree()s until after the point at which we know we are
definitely on the success path.

Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09 16:08:48 +01:00
Sylvain Chouleur 21b3ddd39f efi: Don't use spinlocks for efi vars
All efivars operations are protected by a spinlock which prevents
interruptions and preemption. This is too restricted, we just need a
lock preventing concurrency.
The idea is to use a semaphore of count 1 and to have two ways of
locking, depending on the context:
- In interrupt context, we call down_trylock(), if it fails we return
  an error
- In normal context, we call down_interruptible()

We don't use a mutex here because the mutex_trylock() function must not
be called from interrupt context, whereas the down_trylock() can.

Signed-off-by: Sylvain Chouleur <sylvain.chouleur@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09 16:08:42 +01:00
Al Viro 6fa67e7075 get rid of 'parent' argument of ->d_compare()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-31 16:37:25 -04:00
Linus Torvalds 8387ff2577 vfs: make the string hashes salt the hash
We always mixed in the parent pointer into the dentry name hash, but we
did it late at lookup time.  It turns out that we can simplify that
lookup-time action by salting the hash with the parent pointer early
instead of late.

A few other users of our string hashes also wanted to mix in their own
pointers into the hash, and those are updated to use the same mechanism.

Hash users that don't have any particular initial salt can just use the
NULL pointer as a no-salt.

Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-10 20:21:46 -07:00
Julia Lawall 1cfd63166c efi: Merge boolean flag arguments
The parameters atomic and duplicates of efivar_init always have opposite
values.  Drop the parameter atomic, replace the uses of !atomic with
duplicates, and update the call sites accordingly.

The code using duplicates is slightly reorganized with an 'else', to avoid
duplicating the lock code.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Saurabh Sengar <saurabh.truth@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1462570771-13324-5-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-07 07:06:13 +02:00
Kirill A. Shutemov 09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00
Peter Jones ed8b0de5a3 efi: Make efivarfs entries immutable by default
"rm -rf" is bricking some peoples' laptops because of variables being
used to store non-reinitializable firmware driver data that's required
to POST the hardware.

These are 100% bugs, and they need to be fixed, but in the mean time it
shouldn't be easy to *accidentally* brick machines.

We have to have delete working, and picking which variables do and don't
work for deletion is quite intractable, so instead make everything
immutable by default (except for a whitelist), and make tools that
aren't quite so broad-spectrum unset the immutable flag.

Signed-off-by: Peter Jones <pjones@redhat.com>
Tested-by: Lee, Chun-Yi <jlee@suse.com>
Acked-by: Matthew Garrett <mjg59@coreos.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-02-10 16:25:52 +00:00
Peter Jones e0d64e6a88 efi: Use ucs2_as_utf8 in efivarfs instead of open coding a bad version
Translate EFI's UCS-2 variable names to UTF-8 instead of just assuming
all variable names fit in ASCII.

Signed-off-by: Peter Jones <pjones@redhat.com>
Acked-by: Matthew Garrett <mjg59@coreos.com>
Tested-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-02-10 13:19:14 +00:00
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
Linus Torvalds 3d54ac9e35 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "EFI fixes, and FPU fix, a ticket spinlock boundary condition fix and
  two build fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Always restore_xinit_state() when use_eager_cpu()
  x86: Make cpu_tss available to external modules
  efi: Fix error handling in add_sysfs_runtime_map_entry()
  x86/spinlocks: Fix regression in spinlock contention detection
  x86/mm: Clean up types in xlate_dev_mem_ptr()
  x86/efi: Store upper bits of command line buffer address in ext_cmd_line_ptr
  efivarfs: Ensure VariableName is NUL-terminated
2015-05-06 10:57:37 -07:00
Ross Lagerwall c57dcb566d efivarfs: Ensure VariableName is NUL-terminated
Some buggy firmware implementations update VariableNameSize on success
such that it does not include the final NUL character which results in
garbage in the efivarfs name entries.  Use kzalloc on the efivar_entry
(as is done in efivars.c) to ensure that the name is always
NUL-terminated.

The buggy firmware is:
BIOS Information
        Vendor: Intel Corp.
        Version: S1200RP.86B.02.02.0005.102320140911
        Release Date: 10/23/2014
        BIOS Revision: 4.6
System Information
        Manufacturer: Intel Corporation
        Product Name: S1200RP_SE

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Matthew Garrett <mjg59@coreos.com>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-04-17 15:41:13 +01:00
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
Borislav Petkov 26e022727f efi: Rename efi_guid_unparse to efi_guid_to_str
Call it what it does - "unparse" is plain-misleading.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
2015-01-07 19:07:44 -08:00
Mathias Krause af5a29aee4 efivarfs: Allow unloading when build as module
There is no need to keep the module loaded when it serves no function in
case the EFI runtime services are disabled. Return an error in this case
so loading the module will fail.

Also supply a module_exit function to allow unloading the module.

Last, but not least, set the owner of the file_system_type struct.

Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-11-11 22:22:27 +00:00
Fabian Frederick e37dcbfbb2 fs/efivarfs/super.c: use static const for dentry_operations
...like other filesystems.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:14 -07:00
Al Viro b26d4cd385 consolidate simple ->d_delete() instances
Rename simple_delete_dentry() to always_delete_dentry() and export it.
Export simple_dentry_operations, while we are at it, and get rid of
their duplicates

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-15 22:04:17 -05:00
Linus Torvalds da53be12bb Don't pass inode to ->d_hash() and ->d_compare()
Instances either don't look at it at all (the majority of cases) or
only want it to find the superblock (which can be had as dentry->d_sb).
A few cases that want more are actually safe with dentry->d_inode -
the only precaution needed is the check that it hadn't been replaced with
NULL by rmdir() or by overwriting rename(), which case should be simply
treated as cache miss.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:36 +04:00
Linus Torvalds 20b4fb4852 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS updates from Al Viro,

Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).

7kloc removed.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
  don't bother with deferred freeing of fdtables
  proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
  proc: Make the PROC_I() and PDE() macros internal to procfs
  proc: Supply a function to remove a proc entry by PDE
  take cgroup_open() and cpuset_open() to fs/proc/base.c
  ppc: Clean up scanlog
  ppc: Clean up rtas_flash driver somewhat
  hostap: proc: Use remove_proc_subtree()
  drm: proc: Use remove_proc_subtree()
  drm: proc: Use minor->index to label things, not PDE->name
  drm: Constify drm_proc_list[]
  zoran: Don't print proc_dir_entry data in debug
  reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
  proc: Supply an accessor for getting the data from a PDE's parent
  airo: Use remove_proc_subtree()
  rtl8192u: Don't need to save device proc dir PDE
  rtl8187se: Use a dir under /proc/net/r8180/
  proc: Add proc_mkdir_data()
  proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
  proc: Move PDE_NET() to fs/proc/proc_net.c
  ...
2013-05-01 17:51:54 -07:00
Matt Fleming a614e1923d Linux 3.9
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Merge tag 'v3.9' into efi-for-tip2

Resolve conflicts for Ingo.

Conflicts:
	drivers/firmware/Kconfig
	drivers/firmware/efivars.c

Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-30 11:42:13 +01:00
Matt Fleming d68772b7c8 efivarfs: Move to fs/efivarfs
Now that efivarfs uses the efivar API, move it out of efivars.c and
into fs/efivarfs where it belongs. This move will eventually allow us
to enable the efivarfs code without having to also enable
CONFIG_EFI_VARS built, and vice versa.

Furthermore, things like,

    mount -t efivarfs none /sys/firmware/efi/efivars

will now work if efivarfs is built as a module without requiring the
use of MODULE_ALIAS(), which would have been necessary when the
efivarfs code was part of efivars.c.

Cc: Matthew Garrett <matthew.garrett@nebula.com>
Cc: Jeremy Kerr <jk@ozlabs.org>
Reviewed-by: Tom Gundersen <teg@jklm.no>
Tested-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-17 13:25:09 +01:00