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2021-04-28Merge tag 'printk-for-5.13' of ↵Linus Torvalds1-1/+4
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Stop synchronizing kernel log buffer readers by logbuf_lock. As a result, the access to the buffer is fully lockless now. Note that printk() itself still uses locks because it tries to flush the messages to the console immediately. Also the per-CPU temporary buffers are still there because they prevent infinite recursion and serialize backtraces from NMI. All this is going to change in the future. - kmsg_dump API rework and cleanup as a side effect of the logbuf_lock removal. - Make bstr_printf() aware that %pf and %pF formats could deference the given pointer. - Show also page flags by %pGp format. - Clarify the documentation for plain pointer printing. - Do not show no_hash_pointers warning multiple times. - Update Senozhatsky email address. - Some clean up. * tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (24 commits) lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf() printk: clarify the documentation for plain pointer printing kernel/printk.c: Fixed mundane typos printk: rename vprintk_func to vprintk vsprintf: dump full information of page flags in pGp mm, slub: don't combine pr_err with INFO mm, slub: use pGp to print page flags MAINTAINERS: update Senozhatsky email address lib/vsprintf: do not show no_hash_pointers message multiple times printk: console: remove unnecessary safe buffer usage printk: kmsg_dump: remove _nolock() variants printk: remove logbuf_lock printk: introduce a kmsg_dump iterator printk: kmsg_dumper: remove @active field printk: add syslog_lock printk: use atomic64_t for devkmsg_user.seq printk: use seqcount_latch for clear_seq printk: introduce CONSOLE_LOG_MAX printk: consolidate kmsg_dump_get_buffer/syslog_print_all code printk: refactor kmsg_dump_get_buffer() ...
2021-03-31pstore: Add mem_type property DT parsing supportMukesh Ojha2-3/+22
There could be a scenario where we define some region in normal memory and use them store to logs which is later retrieved by bootloader during warm reset. In this scenario, we wanted to treat this memory as normal cacheable memory instead of default behaviour which is an overhead. Making it cacheable could improve performance. This commit gives control to change mem_type from Device tree, and also documents the value for normal memory. Signed-off-by: Mukesh Ojha <mojha@codeaurora.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/1616438537-13719-1-git-send-email-mojha@codeaurora.org
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
2021-03-06Merge tag 'pstore-v5.12-rc2' of ↵Linus Torvalds2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull pstore fixes from Kees Cook: - Rate-limit ECC warnings (Dmitry Osipenko) - Fix error path check for NULL (Tetsuo Handa) * tag 'pstore-v5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: pstore/ram: Rate-limit "uncorrectable error in header" message pstore: Fix warning in pstore_kill_sb()
2021-03-02pstore/ram: Rate-limit "uncorrectable error in header" messageDmitry Osipenko1-1/+1
There is a quite huge "uncorrectable error in header" flood in KMSG on a clean system boot since there is no pstore buffer saved in RAM. Let's silence the redundant noisy messages by rate-limiting the printk message. Now there are maximum 10 messages printed repeatedly instead of 35+. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210302095850.30894-1-digetx@gmail.com
2021-02-23pstore: Fix warning in pstore_kill_sb()Tetsuo Handa1-1/+1
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
2021-02-22Merge tag 'docs-5.12' of git://git.lwn.net/linuxLinus Torvalds1-1/+1
Pull documentation updates from Jonathan Corbet: "It has been a relatively quiet cycle in docsland. - As promised, the minimum Sphinx version to build the docs is now 1.7, and we have dropped support for Python 2 entirely. That allowed the removal of a bunch of compatibility code. - A set of treewide warning fixups from Mauro that I applied after it became clear nobody else was going to deal with them. - The automarkup mechanism can now create cross-references from relative paths to RST files. - More translations, typo fixes, and warning fixes" * tag 'docs-5.12' of git://git.lwn.net/linux: (75 commits) docs: kernel-hacking: be more civil docs: Remove the Microsoft rhetoric Documentation/admin-guide: kernel-parameters: Update nohlt section doc/admin-guide: fix spelling mistake: "perfomance" -> "performance" docs: Document cross-referencing using relative path docs: Enable usage of relative paths to docs on automarkup docs: thermal: fix spelling mistakes Documentation: admin-guide: Update kvm/xen config option docs: Make syscalls' helpers naming consistent coding-style.rst: Avoid comma statements Documentation: /proc/loadavg: add 3 more field descriptions Documentation/submitting-patches: Add blurb about backtraces in commit messages Docs: drop Python 2 support Move our minimum Sphinx version to 1.7 Documentation: input: define ABS_PRESSURE/ABS_MT_PRESSURE resolution as grams scripts/kernel-doc: add internal hyperlink to DOC: sections Update Documentation/admin-guide/sysctl/fs.rst docs: Update DTB format references docs: zh_CN: add iio index.rst translation docs/zh_CN: add iio ep93xx_adc.rst translation ...
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
2021-01-22pstore/zone: fix a kernel-doc markupMauro Carvalho Chehab1-1/+1
The documented struct is psz_head and not psz_buffer. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/a67ca4d12c3ef277dadb9e0d0df8450158e637cc.1610610937.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-12-18Merge tag 'trace-v5.11' of ↵Linus Torvalds1-1/+7
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "The major update to this release is that there's a new arch config option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS. Currently, only x86_64 enables it. All the ftrace callbacks now take a struct ftrace_regs instead of a struct pt_regs. If the architecture has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will have enough information to read the arguments of the function being traced, as well as access to the stack pointer. This way, if a user (like live kernel patching) only cares about the arguments, then it can avoid using the heavier weight "regs" callback, that puts in enough information in the struct ftrace_regs to simulate a breakpoint exception (needed for kprobes). A new config option that audits the timestamps of the ftrace ring buffer at most every event recorded. Ftrace recursion protection has been cleaned up to move the protection to the callback itself (this saves on an extra function call for those callbacks). Perf now handles its own RCU protection and does not depend on ftrace to do it for it (saving on that extra function call). New debug option to add "recursed_functions" file to tracefs that lists all the places that triggered the recursion protection of the function tracer. This will show where things need to be fixed as recursion slows down the function tracer. The eval enum mapping updates done at boot up are now offloaded to a work queue, as it caused a noticeable pause on slow embedded boards. Various clean ups and last minute fixes" * tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) tracing: Offload eval map updates to a work queue Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS" ring-buffer: Add rb_check_bpage in __rb_allocate_pages ring-buffer: Fix two typos in comments tracing: Drop unneeded assignment in ring_buffer_resize() tracing: Disable ftrace selftests when any tracer is running seq_buf: Avoid type mismatch for seq_buf_init ring-buffer: Fix a typo in function description ring-buffer: Remove obsolete rb_event_is_commit() ring-buffer: Add test to validate the time stamp deltas ftrace/documentation: Fix RST C code blocks tracing: Clean up after filter logic rewriting tracing: Remove the useless value assignment in test_create_synth_event() livepatch: Use the default ftrace_ops instead of REGS when ARGS is available ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs MAINTAINERS: assign ./fs/tracefs to TRACING tracing: Fix some typos in comments ftrace: Remove unused varible 'ret' ring-buffer: Add recording of ring buffer recursion into recursed_functions ...
2020-12-16Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+1
Pull block updates from Jens Axboe: "Another series of killing more code than what is being added, again thanks to Christoph's relentless cleanups and tech debt tackling. This contains: - blk-iocost improvements (Baolin Wang) - part0 iostat fix (Jeffle Xu) - Disable iopoll for split bios (Jeffle Xu) - block tracepoint cleanups (Christoph Hellwig) - Merging of struct block_device and hd_struct (Christoph Hellwig) - Rework/cleanup of how block device sizes are updated (Christoph Hellwig) - Simplification of gendisk lookup and removal of block device aliasing (Christoph Hellwig) - Block device ioctl cleanups (Christoph Hellwig) - Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig) - Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig) - sbitmap improvements (Pavel Begunkov) - Hybrid polling fix (Pavel Begunkov) - bvec iteration improvements (Pavel Begunkov) - Zone revalidation fixes (Damien Le Moal) - blk-throttle limit fix (Yu Kuai) - Various little fixes" * tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits) blk-mq: fix msec comment from micro to milli seconds blk-mq: update arg in comment of blk_mq_map_queue blk-mq: add helper allocating tagset->tags Revert "block: Fix a lockdep complaint triggered by request queue flushing" nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class blk-mq: add new API of blk_mq_hctx_set_fq_lock_class block: disable iopoll for split bio block: Improve blk_revalidate_disk_zones() checks sbitmap: simplify wrap check sbitmap: replace CAS with atomic and sbitmap: remove swap_lock sbitmap: optimise sbitmap_deferred_clear() blk-mq: skip hybrid polling if iopoll doesn't spin blk-iocost: Factor out the base vrate change into a separate function blk-iocost: Factor out the active iocgs' state check into a separate function blk-iocost: Move the usage ratio calculation to the correct place blk-iocost: Remove unnecessary advance declaration blk-iocost: Fix some typos in comments blktrace: fix up a kerneldoc comment block: remove the request_queue to argument request based tracepoints ...
2020-12-02block: remove the nr_sects field in struct hd_structChristoph Hellwig1-1/+1
Now that the hd_struct always has a block device attached to it, there is no need for having two size field that just get out of sync. Additionally the field in hd_struct did not use proper serialization, possibly allowing for torn writes. By only using the block_device field this problem also gets fixed. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: Chao Yu <yuchao0@huawei.com> [f2fs] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01pstore: Move kmsg_bytes default into KconfigVasile-Laurentiu Stanimir4-3/+10
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>
2020-12-01pstore/blk: remove {un,}register_pstore_blkChristoph Hellwig1-73/+10
This interface is entirely unused, so remove them and various bits of unreachable code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201016132047.3068029-4-hch@lst.de
2020-12-01pstore/zone: cap the maximum device sizeChristoph Hellwig1-0/+4
Introduce an abritrary 128MiB cap to avoid malloc failures when using a larger block device. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: WeiXiong Liao <gmpy.liaowx@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201016132047.3068029-2-hch@lst.de
2020-11-13ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regsSteven Rostedt (VMware)1-1/+1
In preparation to have arguments of a function passed to callbacks attached to functions as default, change the default callback prototype to receive a struct ftrace_regs as the forth parameter instead of a pt_regs. For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they will now need to get the pt_regs via a ftrace_get_regs() helper call. If this is called by a callback that their ftrace_ops did not have a FL_SAVE_REGS flag set, it that helper function will return NULL. This will allow the ftrace_regs to hold enough just to get the parameters and stack pointer, but without the worry that callbacks may have a pt_regs that is not completely filled. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06ftrace: Add recording of functions that caused recursionSteven Rostedt (VMware)1-1/+1
This adds CONFIG_FTRACE_RECORD_RECURSION that will record to a file "recursed_functions" all the functions that caused recursion while a callback to the function tracer was running. Link: https://lkml.kernel.org/r/20201106023548.102375687@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Guo Ren <guoren@kernel.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: x86@kernel.org Cc: "H. Peter Anvin" <hpa@zytor.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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-csky@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: live-patching@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06pstore/ftrace: Add recursion protection to the ftrace callbackSteven Rostedt (VMware)1-0/+6
If a ftrace callback does not supply its own recursion protection and does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will make a helper trampoline to do so before calling the callback instead of just calling the callback directly. The default for ftrace_ops is going to change. It will expect that handlers provide their own recursion protection, unless its ftrace_ops states otherwise. Link: https://lkml.kernel.org/r/20201028115612.990886844@goodmis.org Link: https://lkml.kernel.org/r/20201106023546.720372267@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Meyer <thomas@m3y3r.de> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-08-24treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+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>
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>
2020-06-02Merge branch 'uaccess.__copy_from_user' of ↵Linus Torvalds1-3/+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()
2020-06-01pstore/blk: Introduce "best_effort" modeKees Cook1-1/+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>
2020-06-01pstore/blk: Support non-block storage devicesWeiXiong Liao2-44/+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>
2020-06-01pstore/blk: Provide way to query pstore configurationWeiXiong Liao1-7/+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>
2020-06-01pstore/zone: Provide way to skip "broken" zone for MTD devicesWeiXiong Liao2-14/+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>
2020-05-30Documentation: Add details for pstore/blkWeiXiong Liao1-0/+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>
2020-05-30pstore/zone,blk: Add ftrace frontend supportWeiXiong Liao3-1/+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>
2020-05-30pstore/zone,blk: Add console frontend supportWeiXiong Liao3-9/+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>
2020-05-30pstore/zone,blk: Add support for pmsg frontendWeiXiong Liao3-9/+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>
2020-05-30pstore/blk: Introduce backend for block devicesWeiXiong Liao3-0/+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>
2020-05-30pstore/zone: Introduce common layer to manage storage zonesWeiXiong Liao3-0/+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>
2020-05-30pstore/ram: Introduce max_reason and convert dump_oopsKees Cook1-19/+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>
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/ftrace: Provide ftrace log merging routineKees Cook3-54/+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>
2020-05-30pstore/ram: Refactor ftrace buffer mergingKees Cook1-12/+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>
2020-05-30pstore/ram: Refactor DT size parsingKees Cook1-12/+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>
2020-05-30pstore/ram: Adjust module param permissions to reflect realityKees Cook1-3/+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>
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 Cook3-0/+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>
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 Cook3-26/+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>
2020-05-12pstore: Refactor pstorefs record list removalKees Cook1-6/+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>
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 "records_list" locking to mutexKees Cook1-10/+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>
2020-05-12pstore: Rename "allpstore" to "records_list"Kees Cook1-10/+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>