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

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" <[email protected]> # Steam Deck
Signed-off-by: Ard Biesheuvel <[email protected]>
Reviewed-by: Eric Biggers <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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pstore: Make sure CONFIG_PSTORE_PMSG selects CONFIG_RT_MUTEXES

In commit 76d62f24db07 ("pstore: Switch pmsg_lock to an rt_mutex
to avoid priority inversion") I changed a lock to an rt_mutex.

Howeve

pstore: Make sure CONFIG_PSTORE_PMSG selects CONFIG_RT_MUTEXES

In commit 76d62f24db07 ("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/[email protected]/

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

Cc: Wei Wang <[email protected]>
Cc: Midas Chien<[email protected]>
Cc: Connor O'Brien <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Anton Vorontsov <[email protected]>
Cc: Colin Cross <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: kernel test robot <[email protected]>
Cc: [email protected]
Fixes: 76d62f24db07 ("pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion")
Reported-by: kernel test robot <[email protected]>
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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Revert "mark pstore-blk as broken"

This reverts commit d07f3b081ee632268786601f55e1334d1f68b997.

pstore-blk was fixed to avoid the unwanted APIs in commit 7bb9557b48fc
("pstore/blk: Use the normal

Revert "mark pstore-blk as broken"

This reverts commit d07f3b081ee632268786601f55e1334d1f68b997.

pstore-blk was fixed to avoid the unwanted APIs in commit 7bb9557b48fc
("pstore/blk: Use the normal block device I/O path"), which landed in
the same release as the commit adding BROKEN.

Cc: Jens Axboe <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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mark pstore-blk as broken

pstore-blk just pokes directly into the pagecache for the block
device without going through the file operations for that by faking
up it's own file operations that do not

mark pstore-blk as broken

pstore-blk just pokes directly into the pagecache for the block
device without going through the file operations for that by faking
up it's own file operations that do not match the block device ones.

As this breaks the control of the block layer of it's page cache,
and even now just works by accident only the best thing is to just
disable this driver.

Fixes: 17639f67c1d6 ("pstore/blk: Introduce backend for block devices")
Signed-off-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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pstore: Move kmsg_bytes default into Kconfig

While kmsg_bytes can be set for pstore via mount, if a crash occurs
before the mount only partial console log will be stored as kmsg_bytes
defaults to a

pstore: Move kmsg_bytes default into Kconfig

While kmsg_bytes can be set for pstore via mount, if a crash occurs
before the mount only partial console log will be stored as kmsg_bytes
defaults to a potentially different hardcoded value in the kernel
(PSTORE_DEFAULT_KMSG_BYTES). This makes it impossible to analyze valuable
post-mortem data especially on the embedded development or in the process
of bringing up new boards. Change this value to be a Kconfig option
with the default of old PSTORE_DEFAULT_KMSG_BYTES

Signed-off-by: Vasile-Laurentiu Stanimir <[email protected]>
Signed-off-by: Kees Cook <[email protected]>

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Documentation: Add details for pstore/blk

Add details on using pstore/blk, the new backend of pstore to record
dumps to block devices, in Documentation/admin-guide/pstore-blk.rst

Signed-off-by: Wei

Documentation: Add details for pstore/blk

Add details on using pstore/blk, the new backend of pstore to record
dumps to block devices, in Documentation/admin-guide/pstore-blk.rst

Signed-off-by: WeiXiong Liao <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Signed-off-by: Kees Cook <[email protected]>

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pstore/zone,blk: Add ftrace frontend support

Support backend for ftrace. To enable ftrace backend, just make
ftrace_size be greater than 0 and a multiple of 4096.

Signed-off-by: WeiXiong Liao <liao

pstore/zone,blk: Add ftrace frontend support

Support backend for ftrace. To enable ftrace backend, just make
ftrace_size be greater than 0 and a multiple of 4096.

Signed-off-by: WeiXiong Liao <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Co-developed-by: Colin Ian King <[email protected]>
Signed-off-by: Colin Ian King <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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pstore/zone,blk: Add console frontend support

Support backend for console. To enable console backend, just make
console_size be greater than 0 and a multiple of 4096.

Signed-off-by: WeiXiong Liao <

pstore/zone,blk: Add console frontend support

Support backend for console. To enable console backend, just make
console_size be greater than 0 and a multiple of 4096.

Signed-off-by: WeiXiong Liao <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Signed-off-by: Kees Cook <[email protected]>

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pstore/zone,blk: Add support for pmsg frontend

Add pmsg support to pstore/blk (through pstore/zone). To enable, pmsg_size
must be greater than 0 and a multiple of 4096.

Signed-off-by: WeiXiong Liao

pstore/zone,blk: Add support for pmsg frontend

Add pmsg support to pstore/blk (through pstore/zone). To enable, pmsg_size
must be greater than 0 and a multiple of 4096.

Signed-off-by: WeiXiong Liao <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Co-developed-by: Colin Ian King <[email protected]>
Signed-off-by: Colin Ian King <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]
Co-developed-by: Kees Cook <[email protected]>
Signed-off-by: Kees Cook <[email protected]>

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pstore/blk: Introduce backend for block devices

pstore/blk is similar to pstore/ram, but uses a block device as the
storage rather than persistent ram.

The pstore/blk backend solves two common use-

pstore/blk: Introduce backend for block devices

pstore/blk is similar to pstore/ram, but uses a block device as the
storage rather than persistent ram.

The pstore/blk backend solves two common use-cases that used to preclude
using pstore/ram:
- not all devices have a battery that could be used to persist
regular RAM across power failures.
- most embedded intelligent equipment have no persistent ram, which
increases costs, instead preferring cheaper solutions, like block
devices.

pstore/blk provides separate configurations for the end user and for the
block drivers. User configuration determines how pstore/blk operates, such
as record sizes, max kmsg dump reasons, etc. These can be set by Kconfig
and/or module parameters, but module parameter have priority over Kconfig.
Driver configuration covers all the details about the target block device,
such as total size of the device and how to perform read/write operations.
These are provided by block drivers, calling pstore_register_blkdev(),
including an optional panic_write callback used to bypass regular IO
APIs in an effort to avoid potentially destabilized kernel code during
a panic.

Signed-off-by: WeiXiong Liao <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Co-developed-by: Kees Cook <[email protected]>
Signed-off-by: Kees Cook <[email protected]>

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pstore/zone: Introduce common layer to manage storage zones

Implement a common set of APIs needed to support pstore storage zones,
based on how ramoops is designed. This will be used by pstore/blk w

pstore/zone: Introduce common layer to manage storage zones

Implement a common set of APIs needed to support pstore storage zones,
based on how ramoops is designed. This will be used by pstore/blk with
the intention of migrating pstore/ram in the future.

Signed-off-by: WeiXiong Liao <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Co-developed-by: Kees Cook <[email protected]>
Signed-off-by: Kees Cook <[email protected]>

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treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

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

GPL-2.0-only

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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mm: remove CONFIG_HAVE_MEMBLOCK

All architecures use memblock for early memory management. There is no need
for the CONFIG_HAVE_MEMBLOCK configuration option.

[[email protected]: of/fdt: fixu

mm: remove CONFIG_HAVE_MEMBLOCK

All architecures use memblock for early memory management. There is no need
for the CONFIG_HAVE_MEMBLOCK configuration option.

[[email protected]: of/fdt: fixup #ifdefs]
Link: http://lkml.kernel.org/r/20180919103457.GA20545@rapoport-lnx
[[email protected]: csky: fixups after bootmem removal]
Link: http://lkml.kernel.org/r/20180926112744.GC4628@rapoport-lnx
[[email protected]: remove stale #else and the code it protects]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Tested-by: Jonathan Cameron <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Greentime Hu <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Guan Xuetao <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Jonas Bonn <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Ley Foon Tan <[email protected]>
Cc: Mark Salter <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Burton <[email protected]>
Cc: Richard Kuo <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Russell King <[email protected]>
Cc: Serge Semin <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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pstore: add zstd compression support

This patch added the 6th compression algorithm support for pstore: zstd.

Signed-off-by: Geliang Tang <[email protected]>
Signed-off-by: Kees Cook <keescook@

pstore: add zstd compression support

This patch added the 6th compression algorithm support for pstore: zstd.

Signed-off-by: Geliang Tang <[email protected]>
Signed-off-by: Kees Cook <[email protected]>

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pstore: fix crypto dependencies

The new crypto API use causes some problems with Kconfig dependencies,
including this link error:

fs/pstore/platform.o: In function `pstore_register':
platform.c:(.t

pstore: fix crypto dependencies

The new crypto API use causes some problems with Kconfig dependencies,
including this link error:

fs/pstore/platform.o: In function `pstore_register':
platform.c:(.text+0x248): undefined reference to `crypto_has_alg'
platform.c:(.text+0x2a0): undefined reference to `crypto_alloc_base'
fs/pstore/platform.o: In function `pstore_unregister':
platform.c:(.text+0x498): undefined reference to `crypto_destroy_tfm'
crypto/lz4hc.o: In function `lz4hc_sdecompress':
lz4hc.c:(.text+0x1a): undefined reference to `LZ4_decompress_safe'
crypto/lz4hc.o: In function `lz4hc_decompress_crypto':
lz4hc.c:(.text+0x5a): undefined reference to `LZ4_decompress_safe'
crypto/lz4hc.o: In function `lz4hc_scompress':
lz4hc.c:(.text+0xaa): undefined reference to `LZ4_compress_HC'
crypto/lz4hc.o: In function `lz4hc_mod_init':
lz4hc.c:(.init.text+0xf): undefined reference to `crypto_register_alg'
lz4hc.c:(.init.text+0x1f): undefined reference to `crypto_register_scomp'
lz4hc.c:(.init.text+0x2f): undefined reference to `crypto_unregister_alg'

The problem is that with CONFIG_CRYPTO=m, we must not 'select CRYPTO_LZ4'
from a bool symbol, or call crypto API functions from a built-in
module.

This turns the sub-options into 'tristate' ones so the dependencies
are honored, and makes the pstore itself select the crypto core
if necessary.

Fixes: cb3bee0369bc ("pstore: Use crypto compress API")
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Kees Cook <[email protected]>

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pstore: Use crypto compress API

In the pstore compression part, we use zlib/lzo/lz4/lz4hc/842
compression algorithm API to implement pstore compression backends. But
there are many repeat codes in t

pstore: Use crypto compress API

In the pstore compression part, we use zlib/lzo/lz4/lz4hc/842
compression algorithm API to implement pstore compression backends. But
there are many repeat codes in these implementations. This patch uses
crypto compress API to simplify these codes.

1) rewrite allocate_buf_for_compression, free_buf_for_compression,
pstore_compress, pstore_decompress functions using crypto compress API.
2) drop compress, decompress, allocate, free functions in pstore_zbackend,
and add zbufsize function to get each different compress buffer size.
3) use late_initcall to call ramoops_init later, to make sure the crypto
subsystem has already initialized.
4) use 'unsigned int' type instead of 'size_t' in pstore_compress,
pstore_decompress functions' length arguments.
5) rename 'zlib' to 'deflate' to follow the crypto API's name convention.

Signed-off-by: Geliang Tang <[email protected]>
[kees: tweaked error messages on allocation failures and Kconfig help]
Signed-off-by: Kees Cook <[email protected]>

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pstore: Select compression at runtime

To allow for easier build test coverage and run-time testing, this allows
multiple compression algorithms to be built into pstore. Still only one
is supported t

pstore: Select compression at runtime

To allow for easier build test coverage and run-time testing, this allows
multiple compression algorithms to be built into pstore. Still only one
is supported to operate at a time (which can be selected at build time
or at boot time, similar to how LSMs are selected).

Signed-off-by: Kees Cook <[email protected]>

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pstore: Add lz4hc and 842 compression support

Currently, pstore has supported three compression algorithms: zlib,
lzo and lz4. This patch added two more compression algorithms: lz4hc
and 842.

Signe

pstore: Add lz4hc and 842 compression support

Currently, pstore has supported three compression algorithms: zlib,
lzo and lz4. This patch added two more compression algorithms: lz4hc
and 842.

Signed-off-by: Geliang Tang <[email protected]>
[kees: tweaked Kconfig help text slightly]
Signed-off-by: Kees Cook <[email protected]>

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docs: fix locations of several documents that got moved

The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right plac

docs: fix locations of several documents that got moved

The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.

Signed-off-by: Mauro Carvalho Chehab <[email protected]>

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pstore: add lzo/lz4 compression support

Like zlib compression in pstore, this patch added lzo and lz4
compression support so that users can have more options and better
compression ratio.

The origi

pstore: add lzo/lz4 compression support

Like zlib compression in pstore, this patch added lzo and lz4
compression support so that users can have more options and better
compression ratio.

The original code treats the compressed data together with the
uncompressed ECC correction notice by using zlib decompress. The
ECC correction notice is missing in the decompression process. The
treatment also makes lzo and lz4 not working. So I treat them
separately by using pstore_decompress() to treat the compressed
data, and memcpy() to treat the uncompressed ECC correction notice.

Signed-off-by: Geliang Tang <[email protected]>
Signed-off-by: Kees Cook <[email protected]>

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pstore: add pstore unregister

pstore doesn't support unregistering yet. It was marked as TODO.
This patch adds some code to fix it:
1) Add functions to unregister kmsg/console/ftrace/pmsg.
2) Add

pstore: add pstore unregister

pstore doesn't support unregistering yet. It was marked as TODO.
This patch adds some code to fix it:
1) Add functions to unregister kmsg/console/ftrace/pmsg.
2) Add a function to free compression buffer.
3) Unmap the memory and free it.
4) Add a function to unregister pstore filesystem.

Signed-off-by: Geliang Tang <[email protected]>
Acked-by: Kees Cook <[email protected]>
[Removed __exit annotation from ramoops_remove(). Reported by Arnd Bergmann]
Signed-off-by: Tony Luck <[email protected]>

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pstore: Add pmsg - user-space accessible pstore object

A secured user-space accessible pstore object. Writes
to /dev/pmsg0 are appended to the buffer, on reboot
the persistent contents are available

pstore: Add pmsg - user-space accessible pstore object

A secured user-space accessible pstore object. Writes
to /dev/pmsg0 are appended to the buffer, on reboot
the persistent contents are available in
/sys/fs/pstore/pmsg-ramoops-[ID].

One possible use is syslogd, or other daemon, can
write messages, then on reboot provides a means to
triage user-space activities leading up to a panic
as a companion to the pstore dmesg or console logs.

Signed-off-by: Mark Salyzyn <[email protected]>
Acked-by: Kees Cook <[email protected]>
Signed-off-by: Tony Luck <[email protected]>

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pstore/Kconfig: Select ZLIB_DEFLATE and ZLIB_INFLATE when PSTORE is selected

Pstore will make use of deflate and inflate algorithm to compress and decompress
the data. So when Pstore is enabled sele

pstore/Kconfig: Select ZLIB_DEFLATE and ZLIB_INFLATE when PSTORE is selected

Pstore will make use of deflate and inflate algorithm to compress and decompress
the data. So when Pstore is enabled select zlib_deflate and zlib_inflate.

Signed-off-by: Aruna Balakrishnaiah <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Tony Luck <[email protected]>

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pstore/ftrace: Convert to its own enable/disable debugfs knob

With this patch we no longer reuse function tracer infrastructure, now
we register our own tracer back-end via a debugfs knob.

It's a b

pstore/ftrace: Convert to its own enable/disable debugfs knob

With this patch we no longer reuse function tracer infrastructure, now
we register our own tracer back-end via a debugfs knob.

It's a bit more code, but that is the only downside. On the bright side we
have:

- Ability to make persistent_ram module removable (when needed, we can
move ftrace_ops struct into a module). Note that persistent_ram is still
not removable for other reasons, but with this patch it's just one
thing less to worry about;

- Pstore part is more isolated from the generic function tracer. We tried
it already by registering our own tracer in available_tracers, but that
way we're loosing ability to see the traces while we record them to
pstore. This solution is somewhere in the middle: we only register
"internal ftracer" back-end, but not the "front-end";

- When there is only pstore tracing enabled, the kernel will only write
to the pstore buffer, omitting function tracer buffer (which, of course,
still can be enabled via 'echo function > current_tracer').

Suggested-by: Steven Rostedt <[email protected]>
Signed-off-by: Anton Vorontsov <[email protected]>

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pstore: Add persistent function tracing

With this support kernel can save function call chain log into a
persistent ram buffer that can be decoded and dumped after reboot
through pstore filesystem.

pstore: Add persistent function tracing

With this support kernel can save function call chain log into a
persistent ram buffer that can be decoded and dumped after reboot
through pstore filesystem. It can be used to determine what function
was last called before a reset or panic.

We store the log in a binary format and then decode it at read time.

p.s.
Mostly the code comes from trace_persistent.c driver found in the
Android git tree, written by Colin Cross <[email protected]>
(according to sign-off history). I reworked the driver a little bit,
and ported it to pstore.

Signed-off-by: Anton Vorontsov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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