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* pstore/zone: Add a null pointer check to the psz_kmsg_readKunwu Chan2024-04-131-0/+2
| | | | | | | | | | | | | [ Upstream commit 98bc7e26e14fbb26a6abf97603d59532475e97f8 ] kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure. Ensure the allocation was successful by checking the pointer validity. Signed-off-by: Kunwu Chan <chentao@kylinos.cn> Link: https://lore.kernel.org/r/20240118100206.213928-1-chentao@kylinos.cn Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* pstore/ram: Fix crash when setting number of cpus to an odd numberWeichen Chen2024-02-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit d49270a04623ce3c0afddbf3e984cb245aa48e9c ] When the number of cpu cores is adjusted to 7 or other odd numbers, the zone size will become an odd number. The address of the zone will become: addr of zone0 = BASE addr of zone1 = BASE + zone_size addr of zone2 = BASE + zone_size*2 ... The address of zone1/3/5/7 will be mapped to non-alignment va. Eventually crashes will occur when accessing these va. So, use ALIGN_DOWN() to make sure the zone size is even to avoid this bug. Signed-off-by: Weichen Chen <weichen.chen@mediatek.com> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com> Tested-by: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Link: https://lore.kernel.org/r/20230224023632.6840-1-weichen.chen@mediatek.com Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* pstore: ram_core: fix possible overflow in persistent_ram_init_ecc()Sergey Shtylyov2024-01-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 86222a8fc16ec517de8da2604d904c9df3a08e5d ] In persistent_ram_init_ecc(), on 64-bit arches DIV_ROUND_UP() will return 64-bit value since persistent_ram_zone::buffer_size has type size_t which is derived from the 64-bit *unsigned long*, while the ecc_blocks variable this value gets assigned to has (always 32-bit) *int* type. Even if that value fits into *int* type, an overflow is still possible when calculating the size_t typed ecc_total variable further below since there's no cast to any 64-bit type before multiplication. Declaring the ecc_blocks variable as *size_t* should fix this mess... Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool. Fixes: 9cc05ad97c57 ("staging: android: persistent_ram: refactor ecc support") Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru> Link: https://lore.kernel.org/r/20231105202936.25694-1-s.shtylyov@omp.ru Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* pstore/platform: Add check for kstrdupJiasheng Jiang2023-11-201-1/+8
| | | | | | | | | | | | | [ Upstream commit a19d48f7c5d57c0f0405a7d4334d1d38fe9d3c1c ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
* pstore/ram: Check start of empty przs during initEnlin Mu2023-09-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit fe8c3623ab06603eb760444a032d426542212021 upstream. After commit 30696378f68a ("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: 30696378f68a ("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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pstore/ram: Add check for kstrdupJiasheng Jiang2023-07-271-0/+2
| | | | | | | | | | | | | [ Upstream commit d97038d5ec2062733c1e016caf9baaf68cf64ea1 ] Add check for the return value of kstrdup() and return the error if it fails in order to avoid NULL pointer dereference. Fixes: e163fdb3f7f8 ("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 Signed-off-by: Sasha Levin <sashal@kernel.org>
* pstore: Revert pmsg_lock back to a normal mutexJohn Stultz2023-05-171-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 5239a89b06d6b199f133bf0ffea421683187f257 ] This reverts commit 76d62f24db07f22ccf9bc18ca793c27d4ebef721. 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: 76d62f24db07 ("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 Signed-off-by: Sasha Levin <sashal@kernel.org>
* pstore/zone: Use GFP_ATOMIC to allocate zone bufferQiujun Huang2023-01-141-1/+1
| | | | | | | | | | | | | | | | | commit 99b3b837855b987563bcfb397cf9ddd88262814b upstream. 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: 335426c6dcdd ("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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pstore: Make sure CONFIG_PSTORE_PMSG selects CONFIG_RT_MUTEXESJohn Stultz2023-01-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 2f4fec5943407318b9523f01ce1f5d668c028332 ] 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/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: 76d62f24db07 ("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 Signed-off-by: Sasha Levin <sashal@kernel.org>
* pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversionJohn Stultz2023-01-141-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 76d62f24db07f22ccf9bc18ca793c27d4ebef721 ] 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: 9d5438f462ab ("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 Signed-off-by: Sasha Levin <sashal@kernel.org>
* pstore: Avoid kcore oops by vmap()ing with VM_IOREMAPStephen Boyd2023-01-141-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit e6b842741b4f39007215fd7e545cb55aa3d358a2 ] 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: 404a6043385d ("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 Signed-off-by: Sasha Levin <sashal@kernel.org>
* pstore/ram: Fix error return code in ramoops_probe()Wang Yufen2023-01-141-0/+2
| | | | | | | | | | | | | | [ Upstream commit e1fce564900f8734edf15b87f028c57e14f6e28d ] 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: 35da60941e44 ("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 Signed-off-by: Sasha Levin <sashal@kernel.org>
* pstore: Don't use semaphores in always-atomic-context codeJann Horn2022-04-081-20/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8126b1c73108bc691f5643df19071a59a69d0bc6 upstream. 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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mark pstore-blk as brokenChristoph Hellwig2021-07-141-0/+1
| | | | | | | | | | | | | | | | | | [ Upstream commit d07f3b081ee632268786601f55e1334d1f68b997 ] 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 <hch@lst.de> Link: https://lore.kernel.org/r/20210608161327.1537919-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* pstore: Fix warning in pstore_kill_sb()Tetsuo Handa2021-03-251-1/+1
| | | | | | | | | | | | | | | | | | | | commit 9c7d83ae6ba67d6c6199cce24573983db3b56332 upstream. syzbot is hitting WARN_ON(pstore_sb != sb) at pstore_kill_sb() [1], for the assumption that pstore_sb != NULL is wrong because pstore_fill_super() will not assign pstore_sb = sb when new_inode() for d_make_root() returned NULL (due to memory allocation fault injection). Since mount_single() calls pstore_kill_sb() when pstore_fill_super() failed, pstore_kill_sb() needs to be aware of such failure path. [1] https://syzkaller.appspot.com/bug?id=6abacb8da5137cb47a416f2bef95719ed60508a0 Reported-by: syzbot <syzbot+d0cf0ad6513e9a1da5df@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210214031307.57903-1-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pstore: Fix typo in compression option nameJiri Bohac2021-03-041-2/+2
| | | | | | | | | | | | | | | | | | | commit 19d8e9149c27b689c6224f5c84b96a159342195a upstream. 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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva2020-08-231-1/+0
| | | | | | | | | | Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
* pstore: Fix linking when crypto API disabledMatteo Croce2020-07-061-1/+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>
* Merge branch 'uaccess.__copy_from_user' of ↵Linus Torvalds2020-06-011-3/+1
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull uaccess/__copy_from_user updates from Al Viro: "Getting rid of __copy_from_user() callers - patches that don't fit into other series" * 'uaccess.__copy_from_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: pstore: switch to copy_from_user() firewire: switch ioctl_queue_iso to use of copy_from_user()
| * pstore: switch to copy_from_user()Al Viro2020-04-231-3/+1
| | | | | | | | | | | | don't bother trying to do bulk access_ok() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | pstore/blk: Introduce "best_effort" modeKees Cook2020-05-311-1/+20
| | | | | | | | | | | | | | | | | | In order to use arbitrary block devices as a pstore backend, provide a new module param named "best_effort", which will allow using any block device, even if it has not provided a panic_write callback. Link: https://lore.kernel.org/lkml/20200511233229.27745-12-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/blk: Support non-block storage devicesWeiXiong Liao2020-05-312-44/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for non-block devices (e.g. MTD). A non-block driver calls pstore_blk_register_device() to register iself. In addition, pstore/zone is updated to handle non-block devices, where an erase must be done before a write. Without this, there is no way to remove records stored to an MTD. Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com> Link: https://lore.kernel.org/lkml/20200511233229.27745-10-keescook@chromium.org/ Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/blk: Provide way to query pstore configurationWeiXiong Liao2020-05-311-7/+30
| | | | | | | | | | | | | | | | | | | | | | In order to configure itself, the MTD backend needs to be able to query the current pstore configuration. Introduce pstore_blk_get_config() for this purpose. Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com> Link: https://lore.kernel.org/lkml/20200511233229.27745-9-keescook@chromium.org/ Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/zone: Provide way to skip "broken" zone for MTD devicesWeiXiong Liao2020-05-312-14/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One requirement to support MTD devices in pstore/zone is having a way to declare certain regions as broken. Add this support to pstore/zone. The MTD driver should return -ENOMSG when encountering a bad region, which tells pstore/zone to skip and try the next one. Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com> Link: https://lore.kernel.org/lkml/20200511233229.27745-8-keescook@chromium.org/ Co-developed-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> Link: //lore.kernel.org/lkml/20200512173801.222666-1-colin.king@canonical.com Signed-off-by: Kees Cook <keescook@chromium.org>
* | Documentation: Add details for pstore/blkWeiXiong Liao2020-05-301-0/+2
| | | | | | | | | | | | | | | | | | 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 <liaoweixiong@allwinnertech.com> Link: https://lore.kernel.org/lkml/20200511233229.27745-7-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/zone,blk: Add ftrace frontend supportWeiXiong Liao2020-05-303-1/+134
| | | | | | | | | | | | | | | | | | | | | | | | 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 <liaoweixiong@allwinnertech.com> Link: https://lore.kernel.org/lkml/20200511233229.27745-6-keescook@chromium.org/ Co-developed-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/lkml/20200512170719.221514-1-colin.king@canonical.com Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/zone,blk: Add console frontend supportWeiXiong Liao2020-05-303-9/+102
| | | | | | | | | | | | | | | | | | 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 <liaoweixiong@allwinnertech.com> Link: https://lore.kernel.org/lkml/20200511233229.27745-5-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/zone,blk: Add support for pmsg frontendWeiXiong Liao2020-05-303-9/+280
| | | | | | | | | | | | | | | | | | | | | | | | | | 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 <liaoweixiong@allwinnertech.com> Link: https://lore.kernel.org/lkml/20200511233229.27745-4-keescook@chromium.org/ Co-developed-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/lkml/20200512171932.222102-1-colin.king@canonical.com Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/blk: Introduce backend for block devicesWeiXiong Liao2020-05-303-0/+501
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <liaoweixiong@allwinnertech.com> Link: https://lore.kernel.org/lkml/20200511233229.27745-3-keescook@chromium.org/ Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/zone: Introduce common layer to manage storage zonesWeiXiong Liao2020-05-303-0/+995
| | | | | | | | | | | | | | | | | | | | | | 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 <liaoweixiong@allwinnertech.com> Link: https://lore.kernel.org/lkml/20200511233229.27745-2-keescook@chromium.org/ Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/ram: Introduce max_reason and convert dump_oopsKees Cook2020-05-301-19/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that pstore_register() can correctly pass max_reason to the kmesg dump facility, introduce a new "max_reason" module parameter and "max-reason" Device Tree field. The "dump_oops" module parameter and "dump-oops" Device Tree field are now considered deprecated, but are now automatically converted to their corresponding max_reason values when present, though the new max_reason setting has precedence. For struct ramoops_platform_data, the "dump_oops" member is entirely replaced by a new "max_reason" member, with the only existing user updated in place. Additionally remove the "reason" filter logic from ramoops_pstore_write(), as that is not specifically needed anymore, though technically this is a change in behavior for any ramoops users also setting the printk.always_kmsg_dump boot param, which will cause ramoops to behave as if max_reason was set to KMSG_DUMP_MAX. Co-developed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/lkml/20200515184434.8470-6-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/platform: Pass max_reason to kmesg dumpPavel Tatashin2020-05-301-1/+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>
* | printk: Introduce kmsg_dump_reason_str()Kees Cook2020-05-301-17/+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>
* | printk: Collapse shutdown types into a single dump reasonKees Cook2020-05-301-6/+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>
* | pstore/ftrace: Provide ftrace log merging routineKees Cook2020-05-303-54/+66
| | | | | | | | | | | | | | | | Move the ftrace log merging logic out of pstore/ram into pstore/ftrace so other backends can use it, like pstore/zone. Link: https://lore.kernel.org/lkml/20200510202436.63222-7-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/ram: Refactor ftrace buffer mergingKees Cook2020-05-301-12/+17
| | | | | | | | | | | | | | | | | | This changes the ftrace record merging code to be agnostic of pstore/ram, as the first step to making it available as a generic routine for other backends to use, such as pstore/zone. Link: https://lore.kernel.org/lkml/20200510202436.63222-6-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/ram: Refactor DT size parsingKees Cook2020-05-301-12/+19
| | | | | | | | | | | | | | | | | | | | | | | | Refactor device tree size parsing routines to be able to pass a non-zero default value for providing a configurable default for the coming "max_reason" field. Also rename the helpers, since we're not always parsing a size -- we're parsing a u32 and making sure it's not greater than INT_MAX. Link: https://lore.kernel.org/lkml/20200506211523.15077-4-keescook@chromium.org/ Link: https://lore.kernel.org/lkml/20200521205223.175957-1-tyhicks@linux.microsoft.com Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/ram: Adjust module param permissions to reflect realityKees Cook2020-05-301-3/+3
| | | | | | | | | | | | | | | | A couple module parameters had 0600 permissions, but changing them would have no impact on ramoops, so switch these to 0400 to reflect reality. Link: https://lore.kernel.org/lkml/20200506211523.15077-7-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore/platform: Move module params after declarationsKees Cook2020-05-301-6/+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>
* | pstore/platform: Use backend name for console registrationKees Cook2020-05-301-1/+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>
* | pstore/platform: Switch pstore_info::name to constKees Cook2020-05-301-1/+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>
* | pstore: Make sure console capturing will restartKees Cook2020-05-301-1/+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>
* | pstore: Remove filesystem records when backend is unregisteredKees Cook2020-05-303-0/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | pstore: Do not leave timer disabled for next backendKees Cook2020-05-301-15/+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>
* | pstore: Add locking around superblock changesKees Cook2020-05-303-26/+45
| | | | | | | | | | | | | | | | | | 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>
* | pstore: Refactor pstorefs record list removalKees Cook2020-05-121-6/+13
| | | | | | | | | | | | | | | | | | The "unlink" handling should perform list removal (which can also make sure records don't get double-erased), and the "evict" handling should be responsible only for memory freeing. Link: https://lore.kernel.org/lkml/20200506152114.50375-8-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore: Add proper unregister lock checkingKees Cook2020-05-121-4/+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>
* | pstore: Convert "records_list" locking to mutexKees Cook2020-05-121-10/+7
| | | | | | | | | | | | | | | | | | | | The pstorefs internal list lock doesn't need to be a spinlock and will create problems when trying to access the list in the subsequent patch that will walk the pstorefs records during pstore_unregister(). Change this to a mutex to avoid may_sleep() warnings when unregistering devices. Link: https://lore.kernel.org/lkml/20200506152114.50375-6-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore: Rename "allpstore" to "records_list"Kees Cook2020-05-121-10/+10
| | | | | | | | | | | | | | | | | | The name "allpstore" doesn't carry much meaning, so rename it to what it actually is: the list of all records present in the filesystem. The lock is also renamed accordingly. Link: https://lore.kernel.org/lkml/20200506152114.50375-5-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org>
* | pstore: Convert "psinfo" locking to mutexKees Cook2020-05-121-4/+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>