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2023-10-12pstore/platform: Add check for kstrdupJiasheng Jiang1-1/+8
Add check for the return value of kstrdup() and return the error if it fails in order to avoid NULL pointer dereference. Fixes: 563ca40ddf40 ("pstore/platform: Switch pstore_info::name to const") Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> Link: https://lore.kernel.org/r/20230623022706.32125-1-jiasheng@iscas.ac.cn Signed-off-by: Kees Cook <keescook@chromium.org>
2023-08-31pstore: Base compression input buffer size on estimated compressed sizeArd Biesheuvel1-7/+27
Commit 1756ddea6916 ("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>
2023-08-18pstore: Support record sizes larger than kmalloc() limitYuxiao Zhang1-13/+14
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>
2023-07-18pstore: Replace crypto API compression with zlib_deflate library callsArd Biesheuvel1-48/+88
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>
2023-07-18pstore: Remove worst-case compression size logicArd Biesheuvel1-187/+19
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>
2022-10-19pstore: Alert on backend write errorGuilherme G. Piccoli1-0/+10
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
2022-10-17pstore: Inform unregistered backend names as wellGuilherme G. Piccoli1-0/+2
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
2022-10-17pstore: Expose kmsg_bytes as a module parameterGuilherme G. Piccoli1-3/+5
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
2022-10-17pstore: Improve error reporting in case of backend overlapGuilherme G. Piccoli1-2/+3
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 0d7cd09a3dbb ("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
2022-09-30Revert "pstore: migrate to crypto acomp interface"Guilherme G. Piccoli1-51/+12
This reverts commit e4f0a7ec586b7644107839f5394fb685cf1aadcc. 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: e4f0a7ec586b ("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
2022-08-04Merge tag 'efi-next-for-v5.20' of ↵Linus Torvalds1-0/+1
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 ...
2022-06-24pstore: Add priv field to pstore_record for backend specific useArd Biesheuvel1-0/+1
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>
2022-05-12pstore: migrate to crypto acomp interfaceArd Biesheuvel1-12/+51
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>
2022-03-15pstore: Don't use semaphores in always-atomic-context codeJann Horn1-20/+18
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 ea84b580b955 ("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 959217c84c27 ("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: ea84b580b955 ("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
2021-11-09lib: zstd: Add kernel-specific APINick Terrell1-1/+1
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>
2021-03-08printk: introduce a kmsg_dump iteratorJohn Ogness1-1/+4
Rather than storing the iterator information in the registered kmsg_dumper structure, create a separate iterator structure. The kmsg_dump_iter structure can reside on the stack of the caller, thus allowing lockless use of the kmsg_dump functions. Update code that accesses the kernel logs using the kmsg_dumper structure to use the new kmsg_dump_iter structure. For kmsg_dumpers, this also means adding a call to kmsg_dump_rewind() to initialize the iterator. All this is in preparation for removal of @logbuf_lock. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> # pstore Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de
2021-02-18pstore: Fix typo in compression option nameJiri Bohac1-2/+2
Both pstore_compress() and decompress_record() use a mistyped config option name ("PSTORE_COMPRESSION" instead of "PSTORE_COMPRESS"). As a result compression and decompression of pstore records was always disabled. Use the correct config option name. Signed-off-by: Jiri Bohac <jbohac@suse.cz> Fixes: fd49e03280e5 ("pstore: Fix linking when crypto API disabled") Acked-by: Matteo Croce <mcroce@microsoft.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210218111547.johvp5klpv3xrpnn@dwarf.suse.cz
2020-12-01pstore: Move kmsg_bytes default into KconfigVasile-Laurentiu Stanimir1-1/+1
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 <vasile-laurentiu.stanimir@windriver.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-07pstore: Fix linking when crypto API disabledMatteo Croce1-1/+4
When building a kernel with CONFIG_PSTORE=y and CONFIG_CRYPTO not set, a build error happens: ld: fs/pstore/platform.o: in function `pstore_dump': platform.c:(.text+0x3f9): undefined reference to `crypto_comp_compress' ld: fs/pstore/platform.o: in function `pstore_get_backend_records': platform.c:(.text+0x784): undefined reference to `crypto_comp_decompress' This because some pstore code uses crypto_comp_(de)compress regardless of the CONFIG_CRYPTO status. Fix it by wrapping the (de)compress usage by IS_ENABLED(CONFIG_PSTORE_COMPRESS) Signed-off-by: Matteo Croce <mcroce@linux.microsoft.com> Link: https://lore.kernel.org/lkml/20200706234045.9516-1-mcroce@linux.microsoft.com Fixes: cb3bee0369bc ("pstore: Use crypto compress API") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30pstore/platform: Pass max_reason to kmesg dumpPavel Tatashin1-1/+3
Add a new member to struct pstore_info for passing information about kmesg dump maximum reason. This allows a finer control of what kmesg dumps are sent to pstore storage backends. Those backends that do not explicitly set this field (keeping it equal to 0), get the default behavior: store only Oopses and Panics, or everything if the printk.always_kmsg_dump boot param is set. Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/lkml/20200515184434.8470-5-keescook@chromium.org/ Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30printk: Introduce kmsg_dump_reason_str()Kees Cook1-17/+1
The pstore subsystem already had a private version of this function. With the coming addition of the pstore/zone driver, this needs to be shared. As it really should live with printk, move it there instead. Link: https://lore.kernel.org/lkml/20200515184434.8470-4-keescook@chromium.org/ Acked-by: Petr Mladek <pmladek@suse.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30printk: Collapse shutdown types into a single dump reasonKees Cook1-6/+2
To turn the KMSG_DUMP_* reasons into a more ordered list, collapse the redundant KMSG_DUMP_(RESTART|HALT|POWEROFF) reasons into KMSG_DUMP_SHUTDOWN. The current users already don't meaningfully distinguish between them, so there's no need to, as discussed here: https://lore.kernel.org/lkml/CA+CK2bAPv5u1ih5y9t5FUnTyximtFCtDYXJCpuyjOyHNOkRdqw@mail.gmail.com/ Link: https://lore.kernel.org/lkml/20200515184434.8470-2-keescook@chromium.org/ Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30pstore/platform: Move module params after declarationsKees Cook1-6/+5
It is easier to see how module params are used if they're near the variables they use. Link: https://lore.kernel.org/lkml/20200510202436.63222-4-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30pstore/platform: Use backend name for console registrationKees Cook1-1/+3
If the pstore backend changes, there's no indication in the logs what the console is (it always says "pstore"). Instead, pass through the active backend's name. (Also adjust the selftest to match.) Link: https://lore.kernel.org/lkml/20200510202436.63222-5-keescook@chromium.org/ Link: https://lore.kernel.org/lkml/20200526135429.GQ12456@shao2-debian Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30pstore/platform: Switch pstore_info::name to constKees Cook1-1/+2
In order to more cleanly pass around backend names, make the "name" member const. This means the module param needs to be dynamic (technically, it was before, so this actually cleans up a minor memory leak if a backend was specified and then gets unloaded.) Link: https://lore.kernel.org/lkml/20200510202436.63222-3-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30pstore: Make sure console capturing will restartKees Cook1-1/+5
The CON_ENABLED flag gets cleared during unregister_console(), so make sure we already reset the console flags before calling register_console(), otherwise unloading and reloading a pstore backend will not restart console logging. Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30pstore: Remove filesystem records when backend is unregisteredKees Cook1-0/+3
If a backend was unloaded without having first removed all its associated records in pstorefs, subsequent removals would crash while attempting to call into the now missing backend. Add automatic removal from the tree in pstore_unregister(), so that no references to the backend remain. Reported-by: Luis Henriques <lhenriques@suse.com> Link: https://lore.kernel.org/lkml/87o8yrmv69.fsf@suse.com Link: https://lore.kernel.org/lkml/20200506152114.50375-11-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30pstore: Do not leave timer disabled for next backendKees Cook1-15/+19
The pstore.update_ms value was being disabled during pstore_unregister(), which would cause any prior value to go unnoticed on the next pstore_register(). Instead, just let del_timer() stop the timer, which was always sufficient. This additionally refactors the timer reset code and allows the timer to be enabled if the module parameter is changed away from the default. Link: https://lore.kernel.org/lkml/20200506152114.50375-10-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30pstore: Add locking around superblock changesKees Cook1-3/+2
Nothing was protecting changes to the pstorefs superblock. Add locking and refactor away is_pstore_mounted(), instead using a helper to add a way to safely lock the pstorefs root inode during filesystem changes. Link: https://lore.kernel.org/lkml/20200506152114.50375-9-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-12pstore: Add proper unregister lock checkingKees Cook1-4/+17
The pstore backend lock wasn't being used during pstore_unregister(). Add sanity check and locking. Link: https://lore.kernel.org/lkml/20200506152114.50375-7-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-12pstore: Convert "psinfo" locking to mutexKees Cook1-4/+4
Currently pstore can only have a single backend attached at a time, and it tracks the active backend via "psinfo", under a lock. The locking for this does not need to be a spinlock, and in order to avoid may_sleep() issues during future changes to pstore_unregister(), switch to a mutex instead. Link: https://lore.kernel.org/lkml/20200506152114.50375-4-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-12pstore: Rename "pstore_lock" to "psinfo_lock"Kees Cook1-5/+5
The name "pstore_lock" sounds very global, but it is only supposed to be used for managing changes to "psinfo", so rename it accordingly. Link: https://lore.kernel.org/lkml/20200506152114.50375-3-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-12pstore: Drop useless try_module_get() for backendKees Cook1-8/+0
There is no reason to be doing a module get/put in pstore_register(), since the module calling pstore_register() cannot be unloaded since it hasn't finished its initialization. Remove it so there is no confusion about how registration ordering works. Link: https://lore.kernel.org/lkml/20200506152114.50375-2-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
2020-02-25pstore/platform: fix potential mem leak if pstore_init_fs failedchenqiwu1-2/+2
There is a potential mem leak when pstore_init_fs failed, since the pstore compression maybe unlikey to initialized successfully. We must clean up the allocation once this unlikey issue happens. Signed-off-by: chenqiwu <chenqiwu@xiaomi.com> Link: https://lore.kernel.org/r/1581068800-13817-1-git-send-email-qiwuchen55@gmail.com Signed-off-by: Kees Cook <keescook@chromium.org>
2019-10-29pstore: Make pstore_choose_compression() staticBen Dooks (Codethink)1-1/+1
The pstore_choose_compression() function is not exported so make it static to avoid the following sparse warning: fs/pstore/platform.c:796:13: warning: symbol 'pstore_choose_compression' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Link: https://lore.kernel.org/r/20191016123317.3154-1-ben.dooks@codethink.co.uk Fixes: cb095afd4476 ("pstore: Centralize init/exit routines") Signed-off-by: Kees Cook <keescook@chromium.org>
2019-06-08Merge tag 'spdx-5.2-rc4' of ↵Linus Torvalds1-13/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull yet more SPDX updates from Greg KH: "Another round of SPDX header file fixes for 5.2-rc4 These are all more "GPL-2.0-or-later" or "GPL-2.0-only" tags being added, based on the text in the files. We are slowly chipping away at the 700+ different ways people tried to write the license text. All of these were reviewed on the spdx mailing list by a number of different people. We now have over 60% of the kernel files covered with SPDX tags: $ ./scripts/spdxcheck.py -v 2>&1 | grep Files Files checked: 64533 Files with SPDX: 40392 Files with errors: 0 I think the majority of the "easy" fixups are now done, it's now the start of the longer-tail of crazy variants to wade through" * tag 'spdx-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (159 commits) treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 450 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 449 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 448 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 446 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 445 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 444 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 443 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 442 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 440 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 438 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 437 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 436 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 435 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 434 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 433 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 432 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 431 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 430 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 429 ...
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333Thomas Gleixner1-13/+1
Based on 1 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 distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 136 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000436.384967451@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-31pstore/ram: Run without kernel crash dump regionKees Cook1-1/+2
The ram pstore backend has always had the crash dumper frontend enabled unconditionally. However, it was possible to effectively disable it by setting a record_size=0. All the machinery would run (storing dumps to the temporary crash buffer), but 0 bytes would ultimately get stored due to there being no przs allocated for dumps. Commit 89d328f637b9 ("pstore/ram: Correctly calculate usable PRZ bytes"), however, assumed that there would always be at least one allocated dprz for calculating the size of the temporary crash buffer. This was, of course, not the case when record_size=0, and would lead to a NULL deref trying to find the dprz buffer size: BUG: unable to handle kernel NULL pointer dereference at (null) ... IP: ramoops_probe+0x285/0x37e (fs/pstore/ram.c:808) cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size; Instead, we need to only enable the frontends based on the success of the prz initialization and only take the needed actions when those zones are available. (This also fixes a possible error in detecting if the ftrace frontend should be enabled.) Reported-and-tested-by: Yaro Slav <yaro330@gmail.com> Fixes: 89d328f637b9 ("pstore/ram: Correctly calculate usable PRZ bytes") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
2019-05-31pstore: Set tfm to NULL on free_buf_for_compressionPi-Hsun Shih1-1/+3
Set tfm to NULL on free_buf_for_compression() after crypto_free_comp(). This avoid a use-after-free when allocate_buf_for_compression() and free_buf_for_compression() are called twice. Although free_buf_for_compression() freed the tfm, allocate_buf_for_compression() won't reinitialize the tfm since the tfm pointer is not NULL. Fixes: 95047b0519c1 ("pstore: Refactor compression initialization") Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
2019-02-12pstore: Avoid writing records with zero sizeYue Hu1-0/+3
Sometimes pstore_console_write() will write records with zero size to persistent ram zone, which is unnecessary. It will only increase resource consumption. Also adjust ramoops_write_kmsg_hdr() to have same logic if memory allocation fails. Signed-off-by: Yue Hu <huyue2@yulong.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-04pstore: Convert buf_lock to semaphoreKees Cook1-21/+23
Instead of running with interrupts disabled, use a semaphore. This should make it easier for backends that may need to sleep (e.g. EFI) when performing a write: |BUG: sleeping function called from invalid context at kernel/sched/completion.c:99 |in_atomic(): 1, irqs_disabled(): 1, pid: 2236, name: sig-xstate-bum |Preemption disabled at: |[<ffffffff99d60512>] pstore_dump+0x72/0x330 |CPU: 26 PID: 2236 Comm: sig-xstate-bum Tainted: G D 4.20.0-rc3 #45 |Call Trace: | dump_stack+0x4f/0x6a | ___might_sleep.cold.91+0xd3/0xe4 | __might_sleep+0x50/0x90 | wait_for_completion+0x32/0x130 | virt_efi_query_variable_info+0x14e/0x160 | efi_query_variable_store+0x51/0x1a0 | efivar_entry_set_safe+0xa3/0x1b0 | efi_pstore_write+0x109/0x140 | pstore_dump+0x11c/0x330 | kmsg_dump+0xa4/0xd0 | oops_exit+0x22/0x30 ... Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Fixes: 21b3ddd39fee ("efi: Don't use spinlocks for efi vars") Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-04pstore: Map PSTORE_TYPE_* to stringsJoel Fernandes (Google)1-0/+37
In later patches we will need to map types to names, so create a constant table for that which can also be used in different parts of old and new code. This saves the type in the PRZ which will be useful in later patches. Instead of having an explicit PSTORE_TYPE_UNKNOWN, just use ..._MAX. This includes removing the now redundant filename templates which can use a single format string. Also, there's no reason to limit the "is it still compressed?" test to only PSTORE_TYPE_DMESG when building the pstorefs filename. Records are zero-initialized, so a backend would need to have explicitly set compressed=1. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-04pstore: Improve and update some comments and status outputKees Cook1-4/+3
This improves and updates some comments: - dump handler comment out of sync from calling convention - fix kern-doc typo and improves status output: - reminder that only kernel crash dumps are compressed - do not be silent about ECC infrastructure failures Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-04pstore: Remove needless lock during console writesKees Cook1-23/+6
Since the console writer does not use the preallocated crash dump buffer any more, there is no reason to perform locking around it. Fixes: 70ad35db3321 ("pstore: Convert console write to use ->write_buf") Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
2018-12-04pstore: Do not use crash buffer for decompressionKees Cook1-31/+25
The pre-allocated compression buffer used for crash dumping was also being used for decompression. This isn't technically safe, since it's possible the kernel may attempt a crashdump while pstore is populating the pstore filesystem (and performing decompression). Instead, just allocate a separate buffer for decompression. Correctness is preferred over performance here. Signed-off-by: Kees Cook <keescook@chromium.org>
2018-10-22pstore: Refactor compression initializationKees Cook1-15/+33
This refactors compression initialization slightly to better handle getting potentially called twice (via early pstore_register() calls and later pstore_init()) and improves the comments and reporting to be more verbose. Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Guenter Roeck <groeck@chromium.org>
2018-10-22pstore: Allocate compression during late_initcall()Joel Fernandes (Google)1-1/+9
ramoops's call of pstore_register() was recently moved to run during late_initcall() because the crypto backend may not have been ready during postcore_initcall(). This meant early-boot crash dumps were not getting caught by pstore any more. Instead, lets allow calls to pstore_register() earlier, and once crypto is ready we can initialize the compression. Reported-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Fixes: cb3bee0369bc ("pstore: Use crypto compress API") [kees: trivial rebase] Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Guenter Roeck <groeck@chromium.org>
2018-10-22pstore: Centralize init/exit routinesKees Cook1-0/+23
In preparation for having additional actions during init/exit, this moves the init/exit into platform.c, centralizing the logic to make call outs to the fs init/exit. Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Guenter Roeck <groeck@chromium.org>
2018-08-04pstore: add zstd compression supportGeliang Tang1-0/+16
This patch added the 6th compression algorithm support for pstore: zstd. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-06pstore: Convert internal records to timespec64Kees Cook1-1/+1
This prepares pstore for converting the VFS layer to timespec64. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>