kernel/linux.git/fs/pstore/platform.c, branch linux-6.0.y

Revert "pstore: migrate to crypto acomp interface"

2022-09-30T15:16:06+00:00

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 Signed-off-by: Guilherme G. Piccoli Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220929215515.276486-1-gpiccoli@igalia.com

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

2022-08-03T21:38:02+00:00

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 ...

pstore: Add priv field to pstore_record for backend specific use

2022-06-24T18:40:04+00:00

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 Signed-off-by: Ard Biesheuvel

pstore: migrate to crypto acomp interface

2022-05-12T16:31:00+00:00

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 Signed-off-by: Kees Cook

pstore: Don't use semaphores in always-atomic-context code

2022-03-15T18:08:23+00:00

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 Signed-off-by: Jann Horn Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220314185953.2068993-1-jannh@google.com

lib: zstd: Add kernel-specific API

2021-11-09T00:55:21+00:00

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 Tested By: Paul Jones Tested-by: Oleksandr Natalenko Tested-by: Sedat Dilek # LLVM/Clang v13.0.0 on x86-64 Tested-by: Jean-Denis Girard

printk: introduce a kmsg_dump iterator

2021-03-08T10:43:27+00:00

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 Reviewed-by: Kees Cook # pstore Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de

pstore: Fix typo in compression option name

2021-02-18T20:27:49+00:00

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 Fixes: fd49e03280e5 ("pstore: Fix linking when crypto API disabled") Acked-by: Matteo Croce Signed-off-by: Kees Cook Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210218111547.johvp5klpv3xrpnn@dwarf.suse.cz

pstore: Move kmsg_bytes default into Kconfig

2020-12-01T20:09:17+00:00

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 Signed-off-by: Kees Cook

pstore: Fix linking when crypto API disabled

2020-07-07T02:42:31+00:00

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 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