Commit Graph

405 Commits

Author SHA1 Message Date
Linus Torvalds 82c5561b57 pstore fix for v6.6-rc1
- Adjust sizes of buffers just avoid uncompress failures (Ard Biesheuvel)
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmTyLIIWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJrdjD/9Vl4t3OmP4ahaYVaRXAC3iTCdr
 ZB2idXOdGnpDDUywthjEKHUvco9eyHr0ApjnXjRRctRByf+nBN0DnTbokF8Uv+93
 Bb4/Aqi5y8yioRMTyZ6zt4ZgYpjwiB0fknpOW2NGSVP0CpgDEE33zRU0x64drMbT
 XOcOQ41o75NN39BrZ7ccp5jKor/XIYz063/zpqYE78HwTJ9Op9+SQettIgZfdk2/
 imTNMpSiqpbMxbTnS5cldhPgpr93kRoItr6CceF/7+bd8azWJsUEe7XXcAmK9RJN
 InO6XxnySv3eML94kVMBpTdWuXwM3O4BxHRBz1lunQZfD1kES/B74UJ2iF0IfpFe
 gT6kgGy3rgIuY7rkmcFHjzIZ7zV0tynlfppTWSf/Y1lzZNBFdtX0pXBNweDEDD53
 LA7DrKbusRSMx9srIJnVFiGYSndaaTyViPYD1esVxppv2+wS6DWAHGpxLfYmBA2A
 i5geEblp3W25zAtpg6G1Uu2sTY8f1X54V3W74D9AkalnoMDSyqVz67QS/q+wsYyf
 jQZ+JgTuJBHOCYzgfRlnuQpkiGlz6EKoNlgJ59H8ls6sAygPYS0gKmdnRGDrjF9R
 cSmjVBebBcOV0FiGIoRlh03FoQyTG81DXvXpro6IeqKk4miV9PQtmCeMtIwZ9/cq
 rVxyOHK2u+Q9S0230A==
 =rf8u
 -----END PGP SIGNATURE-----

Merge tag 'pstore-v6.6-rc1-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore fix from Kees Cook:

 - Adjust sizes of buffers just avoid uncompress failures (Ard
   Biesheuvel)

* tag 'pstore-v6.6-rc1-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore: Base compression input buffer size on estimated compressed size
2023-09-02 10:45:17 -07:00
Ard Biesheuvel 9416006239 pstore: Base compression input buffer size on estimated compressed size
Commit 1756ddea69 ("pstore: Remove worst-case compression size logic")
removed some clunky per-algorithm worst case size estimation routines on
the basis that we can always store pstore records uncompressed, and
these worst case estimations are about how much the size might
inadvertently *increase* due to encapsulation overhead when the input
cannot be compressed at all. So if compression results in a size
increase, we just store the original data instead.

However, it seems that the original code was misinterpreting these
calculations as an estimation of how much uncompressed data might fit
into a compressed buffer of a given size, and it was using the results
to consume the input data in larger chunks than the pstore record size,
relying on the compression to ensure that what ultimately gets stored
fits into the available space.

One result of this, as observed and reported by Linus, is that upgrading
to a newer kernel that includes the given commit may result in pstore
decompression errors reported in the kernel log. This is due to the fact
that the existing records may unexpectedly decompress to a size that is
larger than the pstore record size.

Another potential problem caused by this change is that we may
underutilize the fixed sized records on pstore backends such as ramoops.
And on pstore backends with variable sized records such as EFI, we will
end up creating many more entries than before to store the same amount
of compressed data.

So let's fix both issues, by bringing back the typical case estimation of
how much ASCII text captured from the dmesg log might fit into a pstore
record of a given size after compression. The original implementation
used the computation given below for zlib:

  switch (size) {
  /* buffer range for efivars */
  case 1000 ... 2000:
  	cmpr = 56;
  	break;
  case 2001 ... 3000:
  	cmpr = 54;
  	break;
  case 3001 ... 3999:
  	cmpr = 52;
  	break;
  /* buffer range for nvram, erst */
  case 4000 ... 10000:
  	cmpr = 45;
  	break;
  default:
  	cmpr = 60;
  	break;
  }

  return (size * 100) / cmpr;

We will use the previous worst-case of 60% for compression. For
decompression go extra large (3x) so we make sure there's enough space
for anything.

While at it, rate limit the error message so we don't flood the log
unnecessarily on systems that have accumulated a lot of pstore history.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20230830212238.135900-1-ardb@kernel.org
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-08-31 13:58:49 -07:00
Linus Torvalds 5b07aaca18 pstore updates for v6.6-rc1
- Greatly simplify compression support (Ard Biesheuvel).
 
 - Avoid crashes for corrupted offsets when prz size is 0 (Enlin Mu).
 
 - Expand range of usable record sizes (Yuxiao Zhang).
 
 - Fix kernel-doc warning (Matthew Wilcox).
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmTs5TUWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJkn8D/9mdBm32Wfx/if84YejxHJpzHmV
 nKPRgib89vNZdL5ORP02ZTonJBZn4NC7KtJfBHSfdoW1U+5GCC/cHOpECUHQui9Q
 CN22VFm37JdmBZq2+YmPug5y7z94wbFkD79otCR9VlMt5uwbNIGxUaI10fK2M97n
 3avg/RZzz6kI9Y6BChZfBDLKXXi6ytnIRQOa9ZqZyDylN1nTLi8vqrxf0P8Am0jE
 1s2GumYj54NuuNTdqvlz0XhTyCM5pk5omTqlq1VW9Trr0fLa2CLvEBWxWo8G7odC
 Yav5p8e0jX0GjDFM3NHPgRcXTcY0vkWGnJLdZGNyEkxPq96GH09j5rhFOIo9+KPz
 Y3fhYWzZyNWjy7YujWupDyL6lozWObhOcjBRnFmW7gJHjoO2G0GT2ufW2fb9cD4q
 fTGPiX2Fum1Zl6b0CXF+j4wDaazsBxGGAGzTqj7yp2Je0rPJPotd69q8LT2bbVcP
 ZahXJsFNn/YmVKv9MhNZjOuxGZoR4Cgco114V+sU5aYZMcZ68fQNzTzMydkbbdch
 SMapAV9a99H1D8ldT9dhm+HlKZFzIrOtBDrDoIbF4qQB8OWhjEK6Ot3oBbXvLl7w
 72i1niDVRj+v/hUSc/7XYfZkUG7NYJQqXbaJp20LWvEs5OALdWRC3T6vXnvh53Qd
 9ErztYLmF6k3W/h/xA==
 =bu02
 -----END PGP SIGNATURE-----

Merge tag 'pstore-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore updates from Kees Cook:

 - Greatly simplify compression support (Ard Biesheuvel)

 - Avoid crashes for corrupted offsets when prz size is 0 (Enlin Mu)

 - Expand range of usable record sizes (Yuxiao Zhang)

 - Fix kernel-doc warning (Matthew Wilcox)

* tag 'pstore-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore: Fix kernel-doc warning
  pstore: Support record sizes larger than kmalloc() limit
  pstore/ram: Check start of empty przs during init
  pstore: Replace crypto API compression with zlib_deflate library calls
  pstore: Remove worst-case compression size logic
2023-08-28 12:36:04 -07:00
Matthew Wilcox (Oracle) af58740d8b pstore: Fix kernel-doc warning
Fix the warning for the description of struct persistent_ram_buffer and
improve the descriptions of the other struct members while I'm here.

Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Link: https://lore.kernel.org/r/20230818201253.2729485-1-willy@infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-08-18 13:27:28 -07:00
Yuxiao Zhang 104fd0b5e9 pstore: Support record sizes larger than kmalloc() limit
Currently pstore record buffers are allocated using kmalloc() which has
a maximum size based on page size. If a large "pmsg-size" module
parameter is specified, pmsg will fail to copy the contents since
memdup_user() is limited to kmalloc() allocation sizes.

Since we don't need physically contiguous memory for any of the pstore
record buffers, use kvzalloc() to avoid such limitations in the core of
pstore and in the ram backend, and explicitly read from userspace using
vmemdup_user(). This also means that any other backends that want to
(or do already) support larger record sizes will Just Work now.

Signed-off-by: Yuxiao Zhang <yuxiaozhang@google.com>
Link: https://lore.kernel.org/r/20230627202540.881909-2-yuxiaozhang@google.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-08-17 15:18:24 -07:00
Enlin Mu fe8c3623ab pstore/ram: Check start of empty przs during init
After commit 30696378f6 ("pstore/ram: Do not treat empty buffers as
valid"), initialization would assume a prz was valid after seeing that
the buffer_size is zero (regardless of the buffer start position). This
unchecked start value means it could be outside the bounds of the buffer,
leading to future access panics when written to:

 sysdump_panic_event+0x3b4/0x5b8
 atomic_notifier_call_chain+0x54/0x90
 panic+0x1c8/0x42c
 die+0x29c/0x2a8
 die_kernel_fault+0x68/0x78
 __do_kernel_fault+0x1c4/0x1e0
 do_bad_area+0x40/0x100
 do_translation_fault+0x68/0x80
 do_mem_abort+0x68/0xf8
 el1_da+0x1c/0xc0
 __raw_writeb+0x38/0x174
 __memcpy_toio+0x40/0xac
 persistent_ram_update+0x44/0x12c
 persistent_ram_write+0x1a8/0x1b8
 ramoops_pstore_write+0x198/0x1e8
 pstore_console_write+0x94/0xe0
 ...

To avoid this, also check if the prz start is 0 during the initialization
phase. If not, the next prz sanity check case will discover it (start >
size) and zap the buffer back to a sane state.

Fixes: 30696378f6 ("pstore/ram: Do not treat empty buffers as valid")
Cc: Yunlong Xing <yunlong.xing@unisoc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Enlin Mu <enlin.mu@unisoc.com>
Link: https://lore.kernel.org/r/20230801060432.1307717-1-yunlong.xing@unisoc.com
[kees: update commit log with backtrace and clarifications]
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-08-04 10:03:20 -07:00
Jeff Layton a411ea5af7 pstore: convert to ctime accessor functions
In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-66-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-24 10:30:03 +02:00
Ard Biesheuvel 438b805003 pstore: Replace crypto API compression with zlib_deflate library calls
Pstore supports compression using a variety of algorithms exposed by the
crypto API. This uses the deprecated comp (as opposed to scomp/acomp)
API, and so we should stop using that, and either move to the new API,
or switch to a different approach entirely.

Given that we only compress ASCII text in pstore, and considering that
this happens when the system is likely to be in an unstable state, the
flexibility that the complex crypto API provides does not outweigh its
impact on the risk that we might encounter additional problems when
trying to commit the kernel log contents to the pstore backend.

So let's switch [back] to the zlib deflate library API, and remove all
the complexity that really has no place in a low-level diagnostic
facility. Note that, while more modern compression algorithms have been
added to the kernel in recent years, the code size of zlib deflate is
substantially smaller than, e.g., zstd, while its performance in terms
of compression ratio is comparable for ASCII text, and speed is deemed
irrelevant in this context.

Note that this means that compressed pstore records may no longer be
accessible after a kernel upgrade, but this has never been part of the
contract. (The choice of compression algorithm is not stored in the
pstore records either)

Tested-by: "Guilherme G. Piccoli" <gpiccoli@igalia.com> # Steam Deck
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20230712162332.2670437-3-ardb@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-07-17 16:08:58 -07:00
Ard Biesheuvel 1756ddea69 pstore: Remove worst-case compression size logic
The worst case compression size used by pstore gives an upper bound for
how much the data might inadvertently *grow* due to encapsulation
overhead if the input is not compressible at all.

Given that pstore records have individual 'compressed' flags, we can
simply store the uncompressed data if compressing it would end up using
more space, making the worst case identical to the uncompressed case.

This means we can just drop all the elaborate logic that reasons about
upper bounds for each individual compression algorithm, and just store
the uncompressed data directly if compression fails for any reason.

Co-developed-by: Kees Cook <keescook@chromium.org>
Tested-by: "Guilherme G. Piccoli" <gpiccoli@igalia.com> # Steam Deck
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20230712162332.2670437-2-ardb@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-07-17 16:08:58 -07:00
Linus Torvalds 8ad78685ff pstore updates for v6.5-rc1
- Check for out-of-memory condition (Jiasheng Jiang)
 
 - Convert to platform remove callback returning void (Uwe Kleine-König)
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmSbdsYWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJrMrD/wNH1XD1sIb9p6x45hdhoXsz21u
 v5SKptYz0gLPZFbP6O67G24f1jHi2GC498sbbdaETYbJjhqEvdCJ4W1ZccjOPJbS
 pRRejpQ7FLCYUyG107q4C6QtTl0F5Ln1H0PY9e8X47zO9T2l71Qpm9GVXs1CH0JQ
 nuOP+5an6/MXNJd7Xo2p6MoRQJdWx9VSgktRahaQKjGhtTOy1JQWoxDPj0tAa/fw
 Sdcav7QWs+qYW1/X0sOEYkWtAOZLQ4XiHDNORZjcj8wtddT7N8GP2FI29NPxBXzw
 JRnmoqWeVwfRSm90Fn7vMggk+P5/fW/mlXxUp8kWWtlw5aA5oMK28M1C/bfFarxG
 73z630j0gxP+Hhv0/sV/IIcJxpQMD1yl1iE3OOhUDekrjm2OhFKBO15mBAKqWhdR
 ovq2Ho0PEBLfDb1DHC8uiaSlDlhBIDf4bL1NkOdQqVVcYvHtvrh1WYwumcRUsFcM
 6eQS92JeODXtN89aIDVpamQb6bd/0n2Tx/fxW8o81ZisquvInIj+bAJ+GkJkM8nn
 yXXVfPxw6lbHrEhRTxV+U5AYwWZHLRWz5efxp5uCBy7UNIxop14sI+Pm1+pom195
 YJKrK2Jat+9PTn7x7nFMcFescMXMKJyR4CDDox3Jmuz5YTWJ8X8vz0L2wqDFXZm1
 KlCZ4YXgaWvuKMMyFg==
 =ep0z
 -----END PGP SIGNATURE-----

Merge tag 'pstore-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore updates from Kees Cook:

 - Check for out-of-memory condition (Jiasheng Jiang)

 - Convert to platform remove callback returning void (Uwe Kleine-König)

* tag 'pstore-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/ram: Add check for kstrdup
  pstore/ram: Convert to platform remove callback returning void
2023-06-27 21:21:32 -07:00
Jiasheng Jiang d97038d5ec pstore/ram: Add check for kstrdup
Add check for the return value of kstrdup() and return the error
if it fails in order to avoid NULL pointer dereference.

Fixes: e163fdb3f7 ("pstore/ram: Regularize prz label allocation lifetime")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230614093733.36048-1-jiasheng@iscas.ac.cn
2023-06-14 11:52:10 -07:00
Christoph Hellwig cf056a4312 init: improve the name_to_dev_t interface
name_to_dev_t has a very misleading name, that doesn't make clear
it should only be used by the early init code, and also has a bad
calling convention that doesn't allow returning different kinds of
errors.  Rename it to early_lookup_bdev to make the use case clear,
and return an errno, where -EINVAL means the string could not be
parsed, and -ENODEV means it the string was valid, but there was
no device found for it.

Also stub out the whole call for !CONFIG_BLOCK as all the non-block
root cases are always covered in the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-05 10:56:46 -06:00
Uwe Kleine-König 48f2c681df pstore/ram: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230401120000.2487153-1-u.kleine-koenig@pengutronix.de
2023-05-10 14:06:00 -07:00
Linus Torvalds 0835b5ee87 pstore update for v6.4-rc1
- Revert pmsg_lock back to a normal mutex (John Stultz)
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmRJaPkWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJtADD/42DSLBg9dAvFHUpXSuffbbhL/w
 HhbfPlsmSujWWWRE3xmEaWJrUQ+Ag6NHyHR7Euko6tBhtj1MhtPle4Di57H5sMid
 8R+7C+3XDmy5WeUF60dribiiKjtNiRIzWefsQyHn4fguaZ5SWHN+iwtvmBofWC44
 YQXaLR5lbxukZTKwiPjdJefS139/QMsKXx3mKu7IdtjjZ5yemH8iTvsQS/2nLkIS
 LWgBN2boopSVtJJslam/29JIhtT9UGoS/ooFJGkoFKXJrVY1+aiqxrYDihgH1K6b
 FoEb/+G/z9M9KxCNGOqv/h+Nl2Oa5L8hdvBy5UsUxhGUNG8/nqsjIwWjJmba9fJu
 3bJfMpsEja955Omq73UFVsgR8OTuy5z91XbR3jJk+4YQlXWgcqvoAYiM0SHX4z7W
 tB1OPCTGDaNLInYA6YHESlbiAmtk/Peizgs9n4PkOeCN26LWGV/FfjR+zorO+6xO
 NNbM1XN/Xdzp/oNwnU3TqRdI6F7v81uQfIiS0VDJoJ7jpHAVQA042l2zwihoopC2
 ErIBKUqpgfGUDxu29QEdfhdwkSfofyjfOzZ5iHYVsvxhn7oS7Xx+zxyp/mFReoIF
 bsqUsAZdCeMgye8wZZmNDlGaLsmLJB/bnt6XqNYMtSzp6ktpIkyBn/rRqhQYRrZK
 g//x5fMMz8fNZK1z0w==
 =5Jr7
 -----END PGP SIGNATURE-----

Merge tag 'pstore-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore update from Kees Cook:

 - Revert pmsg_lock back to a normal mutex (John Stultz)

* tag 'pstore-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore: Revert pmsg_lock back to a normal mutex
2023-04-27 17:03:40 -07:00
Greg Kroah-Hartman 1aaba11da9 driver core: class: remove module * from class_create()
The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something.  So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 15:16:33 +01:00
John Stultz 5239a89b06 pstore: Revert pmsg_lock back to a normal mutex
This reverts commit 76d62f24db.

So while priority inversion on the pmsg_lock is an occasional
problem that an rt_mutex would help with, in uses where logging
is writing to pmsg heavily from multiple threads, the pmsg_lock
can be heavily contended.

After this change landed, it was reported that cases where the
mutex locking overhead was commonly adding on the order of 10s
of usecs delay had suddenly jumped to ~msec delay with rtmutex.

It seems the slight differences in the locks under this level
of contention causes the normal mutexes to utilize the spinning
optimizations, while the rtmutexes end up in the sleeping
slowpath (which allows additional threads to pile on trying
to take the lock).

In this case, it devolves to a worse case senerio where the lock
acquisition and scheduling overhead dominates, and each thread
is waiting on the order of ~ms to do ~us of work.

Obviously, having tons of threads all contending on a single
lock for logging is non-optimal, so the proper fix is probably
reworking pstore pmsg to have per-cpu buffers so we don't have
contention.

Additionally, Steven Rostedt has provided some furhter
optimizations for rtmutexes that improves the rtmutex spinning
path, but at least in my testing, I still see the test tripping
into the sleeping path on rtmutexes while utilizing the spinning
path with mutexes.

But in the short term, lets revert the change to the rt_mutex
and go back to normal mutexes to avoid a potentially major
performance regression. And we can work on optimizations to both
rtmutexes and finer-grained locking for pstore pmsg in the
future.

Cc: Wei Wang <wvw@google.com>
Cc: Midas Chien<midaschieh@google.com>
Cc: "Chunhui Li (李春辉)" <chunhui.li@mediatek.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: kernel-team@android.com
Fixes: 76d62f24db ("pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion")
Reported-by: "Chunhui Li (李春辉)" <chunhui.li@mediatek.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230308204043.2061631-1-jstultz@google.com
2023-03-08 15:00:25 -08:00
Linus Torvalds edb23125fd pstore updates for v6.2-rc1-fixes
- Switch pmsg_lock to an rt_mutex to avoid priority inversion (John Stultz)
 
 - Correctly assign mem_type property (Luca Stefani)
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmOl9XkWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJgkUD/9QoUAxaCQY6NHjbnujyF6e2gOx
 A7IHxy6h3Z7ZAYvxDrtNqB/pJEVQR81rdz+NGJ/Hsu3k3N/1NeXioD6rM5tsW3tp
 7/KdMbX3eUmGmgq2kvENS8yD6HqW4IMTdZJJeO7GaM1+LuIOvLsR6rprwoS//BfW
 5Asugk5BDsucFVmHxjC7m9eb4wuSPhRCtlFHw0HCeGIeClHY5oU6N6/LpEkjjIBo
 Hy0v8qU6xS3c7HjENw7REVdeiIb9goa4EDYt1EqjCoQ/mQXSOuuVKxT8GV0CNRWX
 pwkWF916xYOmIlWqLXjMXYSoJdt3BmpqB/KnkeKRPkUdIh8YgnSWHRMT74ib6DM1
 FEwA0j/JCOZYOmrQ0jWnLfaWKIiXKfyu56EIXKC9eRf4J2NdrfUflwhqhG56JgkW
 Yz1XoS2IviNNjEISCfwS2c22f+U2vr4PrIarHeJWJZRhO1dnP8JvHdqjl8Ps1cEn
 LePbrHIUZdLZldVE1wix5Lfv6nhR08ttgy8sp4SkTZdNUtW5DmqGV40wY9olHjqq
 JfcS0EvZXidm+aB4N2oVBTNjCcwL38EYinXF7jS+LePkJayUVSf83liS05QwNFTj
 xlQ9rr7kB49S0T5+HWV0IAOB0i5tIu1vWy5ziEyZ1pPcP1hzqqLT+gTbRvYTWxW5
 OFnZtKLTzzTteLl4Nw==
 =wpaN
 -----END PGP SIGNATURE-----

Merge tag 'pstore-v6.2-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore fixes from Kees Cook:

 - Switch pmsg_lock to an rt_mutex to avoid priority inversion (John
   Stultz)

 - Correctly assign mem_type property (Luca Stefani)

* tag 'pstore-v6.2-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore: Properly assign mem_type property
  pstore: Make sure CONFIG_PSTORE_PMSG selects CONFIG_RT_MUTEXES
  pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion
2022-12-23 11:55:54 -08:00
Luca Stefani beca3e311a pstore: Properly assign mem_type property
If mem-type is specified in the device tree
it would end up overriding the record_size
field instead of populating mem_type.

As record_size is currently parsed after the
improper assignment with default size 0 it
continued to work as expected regardless of the
value found in the device tree.

Simply changing the target field of the struct
is enough to get mem-type working as expected.

Fixes: 9d843e8faf ("pstore: Add mem_type property DT parsing support")
Cc: stable@vger.kernel.org
Signed-off-by: Luca Stefani <luca@osomprivacy.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221222131049.286288-1-luca@osomprivacy.com
2022-12-23 10:34:25 -08:00
John Stultz 2f4fec5943 pstore: Make sure CONFIG_PSTORE_PMSG selects CONFIG_RT_MUTEXES
In commit 76d62f24db ("pstore: Switch pmsg_lock to an rt_mutex
to avoid priority inversion") I changed a lock to an rt_mutex.

However, its possible that CONFIG_RT_MUTEXES is not enabled,
which then results in a build failure, as the 0day bot detected:
  https://lore.kernel.org/linux-mm/202212211244.TwzWZD3H-lkp@intel.com/

Thus this patch changes CONFIG_PSTORE_PMSG to select
CONFIG_RT_MUTEXES, which ensures the build will not fail.

Cc: Wei Wang <wvw@google.com>
Cc: Midas Chien<midaschieh@google.com>
Cc: Connor O'Brien <connoro@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: kernel test robot <lkp@intel.com>
Cc: kernel-team@android.com
Fixes: 76d62f24db ("pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221221051855.15761-1-jstultz@google.com
2022-12-23 10:33:27 -08:00
Linus Torvalds 71a7507afb Driver Core changes for 6.2-rc1
Here is the set of driver core and kernfs changes for 6.2-rc1.
 
 The "big" change in here is the addition of a new macro,
 container_of_const() that will preserve the "const-ness" of a pointer
 passed into it.
 
 The "problem" of the current container_of() macro is that if you pass in
 a "const *", out of it can comes a non-const pointer unless you
 specifically ask for it.  For many usages, we want to preserve the
 "const" attribute by using the same call.  For a specific example, this
 series changes the kobj_to_dev() macro to use it, allowing it to be used
 no matter what the const value is.  This prevents every subsystem from
 having to declare 2 different individual macros (i.e.
 kobj_const_to_dev() and kobj_to_dev()) and having the compiler enforce
 the const value at build time, which having 2 macros would not do
 either.
 
 The driver for all of this have been discussions with the Rust kernel
 developers as to how to properly mark driver core, and kobject, objects
 as being "non-mutable".  The changes to the kobject and driver core in
 this pull request are the result of that, as there are lots of paths
 where kobjects and device pointers are not modified at all, so marking
 them as "const" allows the compiler to enforce this.
 
 So, a nice side affect of the Rust development effort has been already
 to clean up the driver core code to be more obvious about object rules.
 
 All of this has been bike-shedded in quite a lot of detail on lkml with
 different names and implementations resulting in the tiny version we
 have in here, much better than my original proposal.  Lots of subsystem
 maintainers have acked the changes as well.
 
 Other than this change, included in here are smaller stuff like:
   - kernfs fixes and updates to handle lock contention better
   - vmlinux.lds.h fixes and updates
   - sysfs and debugfs documentation updates
   - device property updates
 
 All of these have been in the linux-next tree for quite a while with no
 problems, OTHER than some merge issues with other trees that should be
 obvious when you hit them (block tree deletes a driver that this tree
 modifies, iommufd tree modifies code that this tree also touches).  If
 there are merge problems with these trees, please let me know.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 
 iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCY5wz3A8cZ3JlZ0Brcm9h
 aC5jb20ACgkQMUfUDdst+yks0ACeKYUlVgCsER8eYW+x18szFa2QTXgAn2h/VhZe
 1Fp53boFaQkGBjl8mGF8
 =v+FB
 -----END PGP SIGNATURE-----

Merge tag 'driver-core-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the set of driver core and kernfs changes for 6.2-rc1.

  The "big" change in here is the addition of a new macro,
  container_of_const() that will preserve the "const-ness" of a pointer
  passed into it.

  The "problem" of the current container_of() macro is that if you pass
  in a "const *", out of it can comes a non-const pointer unless you
  specifically ask for it. For many usages, we want to preserve the
  "const" attribute by using the same call. For a specific example, this
  series changes the kobj_to_dev() macro to use it, allowing it to be
  used no matter what the const value is. This prevents every subsystem
  from having to declare 2 different individual macros (i.e.
  kobj_const_to_dev() and kobj_to_dev()) and having the compiler enforce
  the const value at build time, which having 2 macros would not do
  either.

  The driver for all of this have been discussions with the Rust kernel
  developers as to how to properly mark driver core, and kobject,
  objects as being "non-mutable". The changes to the kobject and driver
  core in this pull request are the result of that, as there are lots of
  paths where kobjects and device pointers are not modified at all, so
  marking them as "const" allows the compiler to enforce this.

  So, a nice side affect of the Rust development effort has been already
  to clean up the driver core code to be more obvious about object
  rules.

  All of this has been bike-shedded in quite a lot of detail on lkml
  with different names and implementations resulting in the tiny version
  we have in here, much better than my original proposal. Lots of
  subsystem maintainers have acked the changes as well.

  Other than this change, included in here are smaller stuff like:

   - kernfs fixes and updates to handle lock contention better

   - vmlinux.lds.h fixes and updates

   - sysfs and debugfs documentation updates

   - device property updates

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

* tag 'driver-core-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (58 commits)
  device property: Fix documentation for fwnode_get_next_parent()
  firmware_loader: fix up to_fw_sysfs() to preserve const
  usb.h: take advantage of container_of_const()
  device.h: move kobj_to_dev() to use container_of_const()
  container_of: add container_of_const() that preserves const-ness of the pointer
  driver core: fix up missed drivers/s390/char/hmcdrv_dev.c class.devnode() conversion.
  driver core: fix up missed scsi/cxlflash class.devnode() conversion.
  driver core: fix up some missing class.devnode() conversions.
  driver core: make struct class.devnode() take a const *
  driver core: make struct class.dev_uevent() take a const *
  cacheinfo: Remove of_node_put() for fw_token
  device property: Add a blank line in Kconfig of tests
  device property: Rename goto label to be more precise
  device property: Move PROPERTY_ENTRY_BOOL() a bit down
  device property: Get rid of __PROPERTY_ENTRY_ARRAY_EL*SIZE*()
  kernfs: fix all kernel-doc warnings and multiple typos
  driver core: pass a const * into of_device_uevent()
  kobject: kset_uevent_ops: make name() callback take a const *
  kobject: kset_uevent_ops: make filter() callback take a const *
  kobject: make kobject_namespace take a const *
  ...
2022-12-16 03:54:54 -08:00
John Stultz 76d62f24db pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion
Wei Wang reported seeing priority inversion caused latencies
caused by contention on pmsg_lock, and suggested it be switched
to a rt_mutex.

I was initially hesitant this would help, as the tasks in that
trace all seemed to be SCHED_NORMAL, so the benefit would be
limited to only nice boosting.

However, another similar issue was raised where the priority
inversion was seen did involve a blocked RT task so it is clear
this would be helpful in that case.

Cc: Wei Wang <wvw@google.com>
Cc: Midas Chien<midaschieh@google.com>
Cc: Connor O'Brien <connoro@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: kernel-team@android.com
Fixes: 9d5438f462 ("pstore: Add pmsg - user-space accessible pstore object")
Reported-by: Wei Wang <wvw@google.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221214231834.3711880-1-jstultz@google.com
2022-12-14 19:37:42 -08:00
Stephen Boyd e6b842741b pstore: Avoid kcore oops by vmap()ing with VM_IOREMAP
An oops can be induced by running 'cat /proc/kcore > /dev/null' on
devices using pstore with the ram backend because kmap_atomic() assumes
lowmem pages are accessible with __va().

 Unable to handle kernel paging request at virtual address ffffff807ff2b000
 Mem abort info:
 ESR = 0x96000006
 EC = 0x25: DABT (current EL), IL = 32 bits
 SET = 0, FnV = 0
 EA = 0, S1PTW = 0
 FSC = 0x06: level 2 translation fault
 Data abort info:
 ISV = 0, ISS = 0x00000006
 CM = 0, WnR = 0
 swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000081d87000
 [ffffff807ff2b000] pgd=180000017fe18003, p4d=180000017fe18003, pud=180000017fe18003, pmd=0000000000000000
 Internal error: Oops: 96000006 [#1] PREEMPT SMP
 Modules linked in: dm_integrity
 CPU: 7 PID: 21179 Comm: perf Not tainted 5.15.67-10882-ge4eb2eb988cd #1 baa443fb8e8477896a370b31a821eb2009f9bfba
 Hardware name: Google Lazor (rev3 - 8) (DT)
 pstate: a0400009 (NzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : __memcpy+0x110/0x260
 lr : vread+0x194/0x294
 sp : ffffffc013ee39d0
 x29: ffffffc013ee39f0 x28: 0000000000001000 x27: ffffff807ff2b000
 x26: 0000000000001000 x25: ffffffc0085a2000 x24: ffffff802d4b3000
 x23: ffffff80f8a60000 x22: ffffff802d4b3000 x21: ffffffc0085a2000
 x20: ffffff8080b7bc68 x19: 0000000000001000 x18: 0000000000000000
 x17: 0000000000000000 x16: 0000000000000000 x15: ffffffd3073f2e60
 x14: ffffffffad588000 x13: 0000000000000000 x12: 0000000000000001
 x11: 00000000000001a2 x10: 00680000fff2bf0b x9 : 03fffffff807ff2b
 x8 : 0000000000000001 x7 : 0000000000000000 x6 : 0000000000000000
 x5 : ffffff802d4b4000 x4 : ffffff807ff2c000 x3 : ffffffc013ee3a78
 x2 : 0000000000001000 x1 : ffffff807ff2b000 x0 : ffffff802d4b3000
 Call trace:
 __memcpy+0x110/0x260
 read_kcore+0x584/0x778
 proc_reg_read+0xb4/0xe4

During early boot, memblock reserves the pages for the ramoops reserved
memory node in DT that would otherwise be part of the direct lowmem
mapping. Pstore's ram backend reuses those reserved pages to change the
memory type (writeback or non-cached) by passing the pages to vmap()
(see pfn_to_page() usage in persistent_ram_vmap() for more details) with
specific flags. When read_kcore() starts iterating over the vmalloc
region, it runs over the virtual address that vmap() returned for
ramoops. In aligned_vread() the virtual address is passed to
vmalloc_to_page() which returns the page struct for the reserved lowmem
area. That lowmem page is passed to kmap_atomic(), which effectively
calls page_to_virt() that assumes a lowmem page struct must be directly
accessible with __va() and friends. These pages are mapped via vmap()
though, and the lowmem mapping was never made, so accessing them via the
lowmem virtual address oopses like above.

Let's side-step this problem by passing VM_IOREMAP to vmap(). This will
tell vread() to not include the ramoops region in the kcore. Instead the
area will look like a bunch of zeros. The alternative is to teach kmap()
about vmalloc areas that intersect with lowmem. Presumably such a change
isn't a one-liner, and there isn't much interest in inspecting the
ramoops region in kcore files anyway, so the most expedient route is
taken for now.

Cc: Brian Geffon <bgeffon@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 404a604338 ("staging: android: persistent_ram: handle reserving and mapping memory")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221205233136.3420802-1-swboyd@chromium.org
2022-12-05 16:15:09 -08:00
Wang Yufen e1fce56490 pstore/ram: Fix error return code in ramoops_probe()
In the if (dev_of_node(dev) && !pdata) path, the "err" may be assigned a
value of 0, so the error return code -EINVAL may be incorrectly set
to 0. To fix set valid return code before calling to goto.

Fixes: 35da60941e ("pstore/ram: add Device Tree bindings")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/1669969374-46582-1-git-send-email-wangyufen@huawei.com
2022-12-02 15:16:59 -08:00
Greg Kroah-Hartman ff62b8e658 driver core: make struct class.devnode() take a const *
The devnode() in struct class should not be modifying the device that is
passed into it, so mark it as a const * and propagate the function
signature changes out into all relevant subsystems that use this
callback.

Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Justin Sanders <justin@coraid.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: John Stultz <jstultz@google.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Sean Young <sean@mess.org>
Cc: Frank Haverkamp <haver@linux.ibm.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Xie Yongji <xieyongji@bytedance.com>
Cc: Gautam Dawar <gautam.dawar@xilinx.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Eli Cohen <elic@nvidia.com>
Cc: Parav Pandit <parav@nvidia.com>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: alsa-devel@alsa-project.org
Cc: dri-devel@lists.freedesktop.org
Cc: kvm@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: linux-block@vger.kernel.org
Cc: linux-input@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: linux-rdma@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20221123122523.1332370-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-24 17:12:27 +01:00
Guilherme G. Piccoli 38b91847c3 pstore: Alert on backend write error
The pstore dump function doesn't alert at all on errors - despite
pstore is usually a last resource and if it fails users won't be
able to read the kernel log, this is not the case for server users
with serial access, for example.

So, let's at least attempt to inform such advanced users on the first
backend writing error detected during the kmsg dump - this is also
very useful for pstore debugging purposes.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221013210648.137452-2-gpiccoli@igalia.com
2022-10-19 09:25:39 -07:00
Kees Cook 06b4e09aab pstore/ram: Set freed addresses to NULL
For good measure, set all the freed addresses to NULL when managing
przs.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-and-tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20221011200112.731334-5-keescook@chromium.org
2022-10-19 09:25:39 -07:00
Kees Cook 8bd4da0f06 pstore/ram: Move internal definitions out of kernel-wide include
Most of the details of the ram backend are entirely internal to the
backend itself. Leave only what is needed to instantiate a ram backend
in the kernel-wide header.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-and-tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20221011200112.731334-4-keescook@chromium.org
2022-10-17 13:14:32 -07:00
Kees Cook 6daf4e82bd pstore/ram: Move pmsg init earlier
Since the ftrace area can vary in size based on CPU count, move pmsg
initialization earlier so it will have a stable location.

Suggested-by: Paramjit Oberoi <pso@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20221011200112.731334-3-keescook@chromium.org
2022-10-17 13:14:32 -07:00
Kees Cook 3219122b8c pstore/ram: Consolidate kfree() paths
There's no reason to keep separate kfree() paths: either all allocations
succeeded, or not. Everything is torn down in the case of failure, so
adjust the callers to reflect this.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-and-tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20221011200112.731334-2-keescook@chromium.org
2022-10-17 13:14:32 -07:00
Guilherme G. Piccoli 6a14f1982e pstore: Inform unregistered backend names as well
Currently we only show the registered ones in the kernel
log; users that change backend for some reason require
first to unregister the current one, so let's confirm this
operation with a message in the log.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221006224212.569555-4-gpiccoli@igalia.com
2022-10-17 13:14:10 -07:00
Guilherme G. Piccoli 8f5de3fd38 pstore: Expose kmsg_bytes as a module parameter
Currently this tuning is only exposed as a filesystem option,
but most Linux distros automatically mount pstore, hence changing
this setting requires remounting it. Also, if that mount option
wasn't explicitly set it doesn't show up in mount information,
so users cannot check what is the current value of kmsg_bytes.

Let's then expose it as a module parameter, allowing both user
visibility at all times (even if not manually set) and also the
possibility of setting that as a boot/module parameter.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221006224212.569555-3-gpiccoli@igalia.com
2022-10-17 13:14:10 -07:00
Guilherme G. Piccoli d85644dc5c pstore: Improve error reporting in case of backend overlap
The pstore infrastructure supports one single backend at a time;
trying to load a another backend causes an error and displays a
message, introduced on commit 0d7cd09a3d ("pstore: Improve
register_pstore() error reporting").

Happens that this message is not really clear about the situation,
also the current error returned (-EPERM) isn't accurate, whereas
-EBUSY makes more sense. We have another place in the code that
relies in the -EBUSY return for a similar check.

So, make it consistent here by returning -EBUSY and using a
similar message in both scenarios.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221006224212.569555-2-gpiccoli@igalia.com
2022-10-17 13:14:10 -07:00
Qiujun Huang 99b3b83785 pstore/zone: Use GFP_ATOMIC to allocate zone buffer
There is a case found when triggering a panic_on_oom, pstore fails to dump
kmsg. Because psz_kmsg_write_record can't get the new buffer.

Handle this by using GFP_ATOMIC to allocate a buffer at lower watermark.

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Fixes: 335426c6dc ("pstore/zone: Provide way to skip "broken" zone for MTD devices")
Cc: WeiXiong Liao <gmpy.liaowx@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/CAJRQjofRCF7wjrYmw3D7zd5QZnwHQq+F8U-mJDJ6NZ4bddYdLA@mail.gmail.com
2022-10-17 13:14:10 -07:00
Guilherme G. Piccoli 40158dbf7e Revert "pstore: migrate to crypto acomp interface"
This reverts commit e4f0a7ec58.

When using this new interface, both efi_pstore and ramoops
backends are unable to properly decompress dmesg if using
zstd, lz4 and lzo algorithms (and maybe more). It does succeed
with deflate though.

The message observed in the kernel log is:

[2.328828] pstore: crypto_acomp_decompress failed, ret = -22!

The pstore infrastructure is able to collect the dmesg with
both backends tested, but since decompression fails it's
unreadable. With this revert everything is back to normal.

Fixes: e4f0a7ec58 ("pstore: migrate to crypto acomp interface")
Cc: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220929215515.276486-1-gpiccoli@igalia.com
2022-09-30 08:16:06 -07:00
Linus Torvalds 97a77ab14f EFI updates for v5.20
- Enable mirrored memory for arm64
 - Fix up several abuses of the efivar API
 - Refactor the efivar API in preparation for moving the 'business logic'
   part of it into efivarfs
 - Enable ACPI PRM on arm64
 -----BEGIN PGP SIGNATURE-----
 
 iQGzBAABCgAdFiEE+9lifEBpyUIVN1cpw08iOZLZjyQFAmLhuDIACgkQw08iOZLZ
 jyS9IQv/Wc2nhjN50S3gfrL+68/el/hGdP/J0FK5BOOjNosG2t1ZNYZtSthXqpPH
 hRrTU2m6PpQUalRpFDyLiHkJvdBFQe4VmvrzBa3TIBIzyflLQPJzkWrqThPchV+B
 qi4lmCtTDNIEJmayewqx1wWA+QmUiyI5zJ8wrZp84LTctBPL75seVv0SB20nqai0
 3/I73omB2RLVGpCpeWvb++vePXL8euFW3FEwCTM8hRboICjORTyIZPy8Y5os+3xT
 UgrIgVDOtn1Xwd4tK0qVwjOVA51east4Fcn3yGOrL40t+3SFm2jdpAJOO3UvyNPl
 vkbtjvXsIjt3/oxreKxXHLbamKyueWIfZRyCLsrg6wrr96oypPk6ID4iDCQoen/X
 Zf0VjM2vmvSd4YgnEIblOfSBxVg48cHJA4iVHVxFodNTrVnzGGFYPTmNKmJqo+Xn
 JeUILM7jlR4h/t0+cTTK3Busu24annTuuz5L5rjf4bUm6pPf4crb1yJaFWtGhlpa
 er233D6O
 =zI0R
 -----END PGP SIGNATURE-----

Merge tag 'efi-next-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:

 - Enable mirrored memory for arm64

 - Fix up several abuses of the efivar API

 - Refactor the efivar API in preparation for moving the 'business
   logic' part of it into efivarfs

 - Enable ACPI PRM on arm64

* tag 'efi-next-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits)
  ACPI: Move PRM config option under the main ACPI config
  ACPI: Enable Platform Runtime Mechanism(PRM) support on ARM64
  ACPI: PRM: Change handler_addr type to void pointer
  efi: Simplify arch_efi_call_virt() macro
  drivers: fix typo in firmware/efi/memmap.c
  efi: vars: Drop __efivar_entry_iter() helper which is no longer used
  efi: vars: Use locking version to iterate over efivars linked lists
  efi: pstore: Omit efivars caching EFI varstore access layer
  efi: vars: Add thin wrapper around EFI get/set variable interface
  efi: vars: Don't drop lock in the middle of efivar_init()
  pstore: Add priv field to pstore_record for backend specific use
  Input: applespi - avoid efivars API and invoke EFI services directly
  selftests/kexec: remove broken EFI_VARS secure boot fallback check
  brcmfmac: Switch to appropriate helper to load EFI variable contents
  iwlwifi: Switch to proper EFI variable store interface
  media: atomisp_gmin_platform: stop abusing efivar API
  efi: efibc: avoid efivar API for setting variables
  efi: avoid efivars layer when loading SSDTs from variables
  efi: Correct comment on efi_memmap_alloc
  memblock: Disable mirror feature if kernelcore is not specified
  ...
2022-08-03 14:38:02 -07:00
Ard Biesheuvel 8ca869b245 pstore: Add priv field to pstore_record for backend specific use
The EFI pstore backend will need to store per-record variable name data
when we switch away from the efivars layer. Add a priv field to struct
pstore_record, and document it as holding a backend specific pointer
that is assumed to be a kmalloc()d buffer, and will be kfree()d when the
entire record is freed.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24 20:40:04 +02:00
Dan Carpenter 2c09d1443b pstore/zone: cleanup "rcnt" type
The info->read() function returns ssize_t.  That means that info->read()
either returns either negative error codes or a positive number
representing the bytes read.

The "rcnt" variable should be declared as ssize_t as well.  Most places
do this correctly but psz_kmsg_recover_meta() needed to be fixed.

This code casts the "rcnt" to int.  That is unnecessary when "rcnt"
is already signed.  It's also slightly wrong because if info->read()
returned a very high (more than INT_MAX) number of bytes then this might
treat that as an error.  This bug cannot happen in real life, so it
doesn't affect run time, but static checkers correctly complain that it
is wrong.

fs/pstore/zone.c:366 psz_kmsg_recover_data() warn: casting 'rcnt' truncates high bits

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/YrRtPSFHDVJzV6d+@kili
2022-06-23 08:27:52 -07:00
Ard Biesheuvel e4f0a7ec58 pstore: migrate to crypto acomp interface
The crypto 'compress' interface is deprecated, so before adding new
features, migrate to the acomp interface. Note that we are only using
synchronous implementations of acomp, so we don't have to deal with
asynchronous completion.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-05-12 09:31:00 -07:00
Jann Horn 8126b1c731 pstore: Don't use semaphores in always-atomic-context code
pstore_dump() is *always* invoked in atomic context (nowadays in an RCU
read-side critical section, before that under a spinlock).
It doesn't make sense to try to use semaphores here.

This is mostly a revert of commit ea84b580b9 ("pstore: Convert buf_lock
to semaphore"), except that two parts aren't restored back exactly as they
were:

 - keep the lock initialization in pstore_register
 - in efi_pstore_write(), always set the "block" flag to false
 - omit "is_locked", that was unnecessary since
   commit 959217c84c ("pstore: Actually give up during locking failure")
 - fix the bailout message

The actual problem that the buggy commit was trying to address may have
been that the use of preemptible() in efi_pstore_write() was wrong - it
only looks at preempt_count() and the state of IRQs, but __rcu_read_lock()
doesn't touch either of those under CONFIG_PREEMPT_RCU.
(Sidenote: CONFIG_PREEMPT_RCU means that the scheduler can preempt tasks in
RCU read-side critical sections, but you're not allowed to actively
block/reschedule.)

Lockdep probably never caught the problem because it's very rare that you
actually hit the contended case, so lockdep always just sees the
down_trylock(), not the down_interruptible(), and so it can't tell that
there's a problem.

Fixes: ea84b580b9 ("pstore: Convert buf_lock to semaphore")
Cc: stable@vger.kernel.org
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220314185953.2068993-1-jannh@google.com
2022-03-15 11:08:23 -07:00
Vincent Whitchurch 023bbde3db pstore: Add prefix to ECC messages
The "No errors detected" message from the ECC code is shown at the end
of the pstore log and can be confusing or misleading, especially since
it usually appears just after a kernel crash log which normally means
quite the opposite of "no errors".  Prefix the message to clarify that
this message is only about ECC-detected errors.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220301144932.89549-1-vincent.whitchurch@axis.com
2022-03-01 10:36:59 -08:00
Linus Torvalds 404dbad382 pstore update for v5.17-rc1
- Add boot param for early ftrace recording in pstore (Uwe Kleine-König)
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmHV0TIWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJveID/0a/qRLfwNyjjLZ2MNtZLfL8ejs
 Qc/3wXJy7IoMe6OagbwS+boJ7PTOa3EMYh0h7GUGc8EjxFai+N2mGqEDMX/JZFRy
 zk1eWfNDpmCBrzo3VlOXrMM0Zb5cj3y9bfsLK31FcLN7gu+ivSXrA6BlPA513E+s
 SISPfK04tXJsLMBg12kKDkp8OcQ9ybKYDxUnScCFg+ef50pFdgzU6K79fUMGac8P
 M0n/ZDZRadUK8fCI2CChlOghWe09gWjWZIxstfn4qY+3C6R97ueB7IVCVgn/fbzX
 JIhsVmxjubQhd6AP/t5Ib5yzRFQ1O+p60LBGuwG8uA25DvnH3MfYhNRqpOB9R0a8
 3IygXuMcCGDl5LCBDteKrktdIKKCA8gLt0IydWD1xcVt8z7ux52/KTPyQZYYCPn4
 LvzACEL6O1qoPEod5k//BbF8p4A8JRBUPUCy55xtdQbOw/kg5H1fWg6xjGYW20Vs
 GpmuKKtDrAKX4OxIdLnaA5p3eBaF98OEo/d/H9PEUkYVc6xoPIGqwvepbt+N5Zpc
 vQ8FRqLTG+KvS3uUyXFlIdR5Rt/qwF0OoFxrMEEp0X/5aKwJHjW9v5qSkKehfQDI
 Ly4QsAaIZJx7w8FckGCBQzvTxfteMp5yivHW0ccOmnqxDLK04keoCxNSFBfP4FLQ
 4puMlfhXcL2ZO640bA==
 =Ux14
 -----END PGP SIGNATURE-----

Merge tag 'pstore-v5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore update from Kees Cook:

 - Add boot param for early ftrace recording in pstore (Uwe
   Kleine-König)

* tag 'pstore-v5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/ftrace: Allow immediate recording
2022-01-10 11:48:37 -08:00
Geert Uytterhoeven 61eb495c83 pstore/blk: Use "%lu" to format unsigned long
On 32-bit:

    fs/pstore/blk.c: In function ‘__best_effort_init’:
    include/linux/kern_levels.h:5:18: warning: format ‘%zu’ expects argument of type ‘size_t’, but argument 3 has type ‘long unsigned int’ [-Wformat=]
	5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
	  |                  ^~~~~~
    include/linux/kern_levels.h:14:19: note: in expansion of macro ‘KERN_SOH’
       14 | #define KERN_INFO KERN_SOH "6" /* informational */
	  |                   ^~~~~~~~
    include/linux/printk.h:373:9: note: in expansion of macro ‘KERN_INFO’
      373 |  printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
	  |         ^~~~~~~~~
    fs/pstore/blk.c:314:3: note: in expansion of macro ‘pr_info’
      314 |   pr_info("attached %s (%zu) (no dedicated panic_write!)\n",
	  |   ^~~~~~~

Cc: stable@vger.kernel.org
Fixes: 7bb9557b48 ("pstore/blk: Use the normal block device I/O path")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210629103700.1935012-1-geert@linux-m68k.org
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-21 09:44:19 -08:00
Uwe Kleine-König a5d05b0796 pstore/ftrace: Allow immediate recording
Without a module param knob there was no way to enable pstore ftrace
recording early enough to debug hangs happening during the boot process
before userspace is up enough to enable it via the regular debugfs
knobs.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210610082134.20636-1-u.kleine-koenig@pengutronix.de
2021-11-18 10:29:52 -08:00
Kees Cook d1faacbf67 Revert "mark pstore-blk as broken"
This reverts commit d07f3b081e.

pstore-blk was fixed to avoid the unwanted APIs in commit 7bb9557b48
("pstore/blk: Use the normal block device I/O path"), which landed in
the same release as the commit adding BROKEN.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211116181559.3975566-1-keescook@chromium.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-16 17:23:42 -07:00
Nick Terrell cf30f6a5f0 lib: zstd: Add kernel-specific API
This patch:
- Moves `include/linux/zstd.h` -> `include/linux/zstd_lib.h`
- Updates modified zstd headers to yearless copyright
- Adds a new API in `include/linux/zstd.h` that is functionally
  equivalent to the in-use subset of the current API. Functions are
  renamed to avoid symbol collisions with zstd, to make it clear it is
  not the upstream zstd API, and to follow the kernel style guide.
- Updates all callers to use the new API.

There are no functional changes in this patch. Since there are no
functional change, I felt it was okay to update all the callers in a
single patch. Once the API is approved, the callers are mechanically
changed.

This patch is preparing for the 3rd patch in this series, which updates
zstd to version 1.4.10. Since the upstream zstd API is no longer exposed
to callers, the update can happen transparently.

Signed-off-by: Nick Terrell <terrelln@fb.com>
Tested By: Paul Jones <paul@pauljones.id.au>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13.0.0 on x86-64
Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>
2021-11-08 16:55:21 -08:00
Christoph Hellwig 4646198519 pstore/blk: use bdev_nr_bytes instead of open coding it
Use the proper helper to read the block device size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211018101130.1838532-22-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18 14:43:23 -06:00
Linus Torvalds 440462198d for-5.14/drivers-2021-06-29
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmDbd5UQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpvsNEADCJKP81boFzRcdJo7EqaNDAzZyKOIg9Oq7
 4GZE0Wm0SgA6+04bKrNVd9KLcKvQ+NC1pK7UJemSSH2y9ir+zHfyYgAV0/+wFmYm
 NgHlDjBvf80XSI5wezcb6MxZT+R7IaIpDsW1ZvV9hFtPSncn5o2OIWiSdJtHT/Rv
 enlgZPc7OwNWoVMX8eR58IoO0k3S6GLpctUZHt/AUukaKgoOks0X523qhEPf3Upr
 RkbIZuqLWVgpdT6457iSE/OijUczD4thTI8bdprxzhgimOm2vV52sO6F5HtHc7GX
 qW+PWYUaiUk7UpObuOuyv0yyUG45ii73iY1W0w66RiyCjVTgtpdwwMQ38VlBcoOg
 zcE1jneAEJt6TiS6zfRaER/10JoCIG4gp1+apPuaXud/o3BqWI0cagVHAgaLziBI
 F7bDJkbJZIR6GrWMgemBI+mc5/LACBePxzPGLScKFptejtQ/ysfZQ6aCLROJWB2U
 4EnysAaUBf6tywj30JqfQvqFNGkHIgY95FKiXJW6GzqqwgBouNf48vS15BgkwI+2
 EijcqUhlOVNfc3RIc0ZL5c9KcPIN9t5sqBrWZe3wgCErhxAx6w6Za9nDdP+US9bl
 /apCpvDFlu59g8n1wtkNE/uC+XqdKDwsplYhnfpX0FGni5wIknhQq3bSe4dPFgSn
 pG5VMrw3pA==
 =D6dS
 -----END PGP SIGNATURE-----

Merge tag 'for-5.14/drivers-2021-06-29' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "Pretty calm round, mostly just NVMe and a bit of MD:

   - NVMe updates (via Christoph)
        - improve the APST configuration algorithm (Alexey Bogoslavsky)
        - look for StorageD3Enable on companion ACPI device
          (Mario Limonciello)
        - allow selecting the network interface for TCP connections
          (Martin Belanger)
        - misc cleanups (Amit Engel, Chaitanya Kulkarni, Colin Ian King,
          Christoph)
        - move the ACPI StorageD3 code to drivers/acpi/ and add quirks
          for certain AMD CPUs (Mario Limonciello)
        - zoned device support for nvmet (Chaitanya Kulkarni)
        - fix the rules for changing the serial number in nvmet
          (Noam Gottlieb)
        - various small fixes and cleanups (Dan Carpenter, JK Kim,
          Chaitanya Kulkarni, Hannes Reinecke, Wesley Sheng, Geert
          Uytterhoeven, Daniel Wagner)

   - MD updates (Via Song)
        - iostats rewrite (Guoqing Jiang)
        - raid5 lock contention optimization (Gal Ofri)

   - Fall through warning fix (Gustavo)

   - Misc fixes (Gustavo, Jiapeng)"

* tag 'for-5.14/drivers-2021-06-29' of git://git.kernel.dk/linux-block: (78 commits)
  nvmet: use NVMET_MAX_NAMESPACES to set nn value
  loop: Fix missing discard support when using LOOP_CONFIGURE
  nvme.h: add missing nvme_lba_range_type endianness annotations
  nvme: remove zeroout memset call for struct
  nvme-pci: remove zeroout memset call for struct
  nvmet: remove zeroout memset call for struct
  nvmet: add ZBD over ZNS backend support
  nvmet: add Command Set Identifier support
  nvmet: add nvmet_req_bio put helper for backends
  nvmet: add req cns error complete helper
  block: export blk_next_bio()
  nvmet: remove local variable
  nvmet: use nvme status value directly
  nvmet: use u32 type for the local variable nsid
  nvmet: use u32 for nvmet_subsys max_nsid
  nvmet: use req->cmd directly in file-ns fast path
  nvmet: use req->cmd directly in bdev-ns fast path
  nvmet: make ver stable once connection established
  nvmet: allow mn change if subsys not discovered
  nvmet: make sn stable once connection was established
  ...
2021-06-30 12:21:16 -07:00
Kees Cook 1d1f6cc581 pstore/blk: Include zone in pstore_device_info
Information was redundant between struct pstore_zone_info and struct
pstore_device_info. Use struct pstore_zone_info, with member name "zone".

Additionally untangle the logic for the "best effort" block device
instance.

Signed-off-by: Kees Cook <keescook@chromium.org>
Fixed-by: Pu Lehui <pulehui@huawei.com>
Link: https://lore.kernel.org/lkml/20210617005424.182305-1-pulehui@huawei.com
2021-06-16 21:09:31 -07:00
Kees Cook c811659bb9 pstore/blk: Fix kerndoc and redundancy on blkdev param
Remove redundant details of blkdev and fix up resulting kerndoc.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
2021-06-16 09:27:32 -07:00
Kees Cook 7bb9557b48 pstore/blk: Use the normal block device I/O path
Stop poking into block layer internals and just open the block device
file an use kernel_read and kernel_write on it. Note that this means
the transformation from name_to_dev_t can't be used anymore when
pstore_blk is loaded as a module: a full filesystem device path name
must be used instead. Additionally removes ":internal:" kerndoc link,
since no such documentation remains.

Co-developed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
2021-06-16 09:26:56 -07:00