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* pstore/pmsg: drop bounce bufferMark Salyzyn2016-09-081-0/+36
| | | | | | | | | | | | | | Removing a bounce buffer copy operation in the pmsg driver path is always better. We also gain in overall performance by not requesting a vmalloc on every write as this can cause precious RT tasks, such as user facing media operation, to stall while memory is being reclaimed. Added a write_buf_user to the pstore functions, a backup platform write_buf_user that uses the small buffer that is part of the instance, and implemented a ramoops write_buf_user that only supports PSTORE_TYPE_PMSG. Signed-off-by: Mark Salyzyn <salyzyn@android.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore: Split pstore fragile flagsNamhyung Kim2016-09-081-7/+10
| | | | | | | | | | | | | | | | | | | | | | This patch adds new PSTORE_FLAGS for each pstore type so that they can be enabled separately. This is a preparation for ongoing virtio-pstore work to support those types flexibly. The PSTORE_FLAGS_FRAGILE is changed to PSTORE_FLAGS_DMESG to preserve the original behavior. Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: linux-acpi@vger.kernel.org Cc: linux-efi@vger.kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> [kees: retained "FRAGILE" for now to make merges easier] Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore: add lzo/lz4 compression supportGeliang Tang2016-06-021-7/+211
| | | | | | | | | | | | | | | | Like zlib compression in pstore, this patch added lzo and lz4 compression support so that users can have more options and better compression ratio. The original code treats the compressed data together with the uncompressed ECC correction notice by using zlib decompress. The ECC correction notice is missing in the decompression process. The treatment also makes lzo and lz4 not working. So I treat them separately by using pstore_decompress() to treat the compressed data, and memcpy() to treat the uncompressed ECC correction notice. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore: Cleanup pstore_dump()Namhyung Kim2016-05-311-19/+13
| | | | | | | The code is duplicate between compression is enabled or not. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore: Enable compression on normal path (again)Namhyung Kim2016-05-311-6/+5
| | | | | | | | | | | | | The commit f0e2efcfd2717 ("pstore: do not use message compression without lock") added a check to 'is_locked' to avoid breakage in concurrent accesses. But it has a side-effect of disabling compression on normal path since 'is_locked' variable is not set. As normal path always takes the lock, it should be initialized to 1. This also makes the unlock code a bit simpler. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* ramoops: Only unregister when registeredKees Cook2016-05-311-3/+5
| | | | | | | | While none of the "fragile" pstore backends unregister yet, if they ever did, the unregistering code for the non-dump targets might get confused. This adds a check for fragile backends on unregister. Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore: fix code comment to match codeGeliang Tang2015-11-021-2/+3
| | | | | | | Fix code comment about kmsg_dump register so it matches the code. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: add pstore unregisterGeliang Tang2015-10-221-0/+35
| | | | | | | | | | | | | | pstore doesn't support unregistering yet. It was marked as TODO. This patch adds some code to fix it: 1) Add functions to unregister kmsg/console/ftrace/pmsg. 2) Add a function to free compression buffer. 3) Unmap the memory and free it. 4) Add a function to unregister pstore filesystem. Signed-off-by: Geliang Tang <geliangtang@163.com> Acked-by: Kees Cook <keescook@chromium.org> [Removed __exit annotation from ramoops_remove(). Reported by Arnd Bergmann] Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: add a helper function pstore_register_kmsgGeliang Tang2015-10-211-1/+6
| | | | | | | | Add a new wrapper function pstore_register_kmsg to keep the consistency with other similar pstore_register_* functions. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* fs/pstore: update the backend parameter in pstore moduleWang Long2015-05-211-0/+6
| | | | | | | | | | | | | | | | | This patch update the module parameter backend, so it is visible through /sys/module/pstore/parameters/backend. For example: if pstore backend is ramoops, with this patch: # cat /sys/module/pstore/parameters/backend ramoops and without this patch: # cat /sys/module/pstore/parameters/backend (null) Signed-off-by: Wang Long <long.wanglong@huawei.com> Acked-by: Mark Salyzyn <salyzyn@android.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: do not use message compression without lockKonstantin Khlebnikov2015-05-211-1/+1
| | | | | | | | pstore_compress() uses static stream buffer for zlib-deflate which easily crashes when several concurrent threads use one shared state. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Fix sprintf format specifier in pstore_dump()alex chen2015-01-161-2/+2
| | | | | | | | | | We should use sprintf format specifier "%u" instead of "%d" for argument of type 'unsigned int' in pstore_dump(). Signed-off-by: Alex Chen <alex.chen@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Add pmsg - user-space accessible pstore objectMark Salyzyn2015-01-161-0/+1
| | | | | | | | | | | | | | | | A secured user-space accessible pstore object. Writes to /dev/pmsg0 are appended to the buffer, on reboot the persistent contents are available in /sys/fs/pstore/pmsg-ramoops-[ID]. One possible use is syslogd, or other daemon, can write messages, then on reboot provides a means to triage user-space activities leading up to a panic as a companion to the pstore dmesg or console logs. Signed-off-by: Mark Salyzyn <salyzyn@android.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* fs/pstore: logging clean-upFabian Frederick2014-06-061-10/+9
| | | | | | | | | | | | | | | | | | | - Define pr_fmt in plateform.c and ram_core.c for global prefix. - Coalesce format fragments. - Separate format/arguments on lines > 80 characters. Note: Some pr_foo() were initially declared without prefix and therefore this could break existing log analyzer. [akpm@linux-foundation.org: missed a couple of prefix removals] Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Joe Perches <joe@perches.com> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pstore: Fix memory leak when decompress using big_oops_bufLiu ShuoX2014-03-171-0/+1
| | | | | | | | | After sucessful decompressing, the buffer which pointed by 'buf' will be lost as 'buf' is overwrite by 'big_oops_buf' and will never be freed. Signed-off-by: Liu ShuoX <shuox.liu@intel.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Don't allow high traffic options on fragile devicesLuck, Tony2013-12-201-2/+5
| | | | | | | | | Some pstore backing devices use on board flash as persistent storage. These have limited numbers of write cycles so it is a poor idea to use them from high frequency operations. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pstore: Remove the messages related to compression failureAruna Balakrishnaiah2013-09-161-4/+0
| | | | | | | | | | Remove the messages indicating compression failure as it will add to the space during panic path. Reported-by: Seiji Aguchi <seiji.aguchi@hds.com> Tested-by: Seiji Aguchi <seiji.aguchi@hds.com> Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Use zlib_inflateInit2 instead of zlib_inflateInitAruna Balakrishnaiah2013-09-161-1/+1
| | | | | | | | | | Since zlib_deflateInit2() is used for specifying window bit during compression, zlib_inflateInit2() is appropriate for decompression. Reported-by: Seiji Aguchi <seiji.aguchi@hds.com> Tested-by: Seiji Aguchi <seiji.aguchi@hds.com> Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Adjust buffer size for compression for smaller registered buffersAruna Balakrishnaiah2013-09-161-1/+22
| | | | | | | | | | | | | | | | | When backends (ex: efivars) have smaller registered buffers, the big_oops_buf is too big for them as number of repeated occurences in the text captured will be less. What happens is that pstore takes too big a bite from the dmesg log and then finds it cannot compress it enough to meet the backend block size. Patch takes care of adjusting the buffer size based on the registered buffer size. cmpr values have been arrived after doing experiments with plain text for buffers of size 1k - 4k (Smaller the buffer size repeated occurence will be less) and with sample crash log for buffers ranging from 4k - 10k. Reported-by: Seiji Aguchi <seiji.aguchi@hds.com> Tested-by: Seiji Aguchi <seiji.aguchi@hds.com> Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Add file extension to pstore file if compressedAruna Balakrishnaiah2013-08-191-1/+3
| | | | | | | | | | In case decompression fails, add a ".enc.z" to indicate the file has compressed data. This will help user space utilities to figure out the file contents. Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Add decompression support to pstoreAruna Balakrishnaiah2013-08-191-2/+51
| | | | | | | | | | | Based on the flag 'compressed' set or not, pstore will decompress the data returning a plain text file. If decompression fails for a particular record it will have the compressed data in the file which can be decompressed with 'openssl' command line tool. Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Introduce new argument 'compressed' in the read callbackAruna Balakrishnaiah2013-08-191-1/+3
| | | | | | | | | | Backends will set the flag 'compressed' after reading the log from persistent store to indicate the data being returned to pstore is compressed or not. Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Add compression support to pstoreAruna Balakrishnaiah2013-08-191-9/+139
| | | | | | | | | | | | | | | | | | Add compression support to pstore which will help in capturing more data. Initially, pstore will make a call to kmsg_dump with a bigger buffer and will pass the size of bigger buffer to kmsg_dump and then compress the data to registered buffer of registered size. In case compression fails, pstore will capture the uncompressed data by making a call again to kmsg_dump with registered_buffer of registered size. Pstore will indicate the data is compressed or not with a flag in the write callback. Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Add new argument 'compressed' in pstore write callbackAruna Balakrishnaiah2013-08-191-3/+4
| | | | | | | | | | | | Addition of new argument 'compressed' in the write call back will help the backend to know if the data passed from pstore is compressed or not (In case where compression fails.). If compressed, the backend can add a tag indicating the data is compressed while writing to persistent store. Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* Merge branch 'next' of ↵Linus Torvalds2013-07-041-4/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc updates from Ben Herrenschmidt: "This is the powerpc changes for the 3.11 merge window. In addition to the usual bug fixes and small updates, the main highlights are: - Support for transparent huge pages by Aneesh Kumar for 64-bit server processors. This allows the use of 16M pages as transparent huge pages on kernels compiled with a 64K base page size. - Base VFIO support for KVM on power by Alexey Kardashevskiy - Wiring up of our nvram to the pstore infrastructure, including putting compressed oopses in there by Aruna Balakrishnaiah - Move, rework and improve our "EEH" (basically PCI error handling and recovery) infrastructure. It is no longer specific to pseries but is now usable by the new "powernv" platform as well (no hypervisor) by Gavin Shan. - I fixed some bugs in our math-emu instruction decoding and made it usable to emulate some optional FP instructions on processors with hard FP that lack them (such as fsqrt on Freescale embedded processors). - Support for Power8 "Event Based Branch" facility by Michael Ellerman. This facility allows what is basically "userspace interrupts" for performance monitor events. - A bunch of Transactional Memory vs. Signals bug fixes and HW breakpoint/watchpoint fixes by Michael Neuling. And more ... I appologize in advance if I've failed to highlight something that somebody deemed worth it." * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (156 commits) pstore: Add hsize argument in write_buf call of pstore_ftrace_call powerpc/fsl: add MPIC timer wakeup support powerpc/mpic: create mpic subsystem object powerpc/mpic: add global timer support powerpc/mpic: add irq_set_wake support powerpc/85xx: enable coreint for all the 64bit boards powerpc/8xx: Erroneous double irq_eoi() on CPM IRQ in MPC8xx powerpc/fsl: Enable CONFIG_E1000E in mpc85xx_smp_defconfig powerpc/mpic: Add get_version API both for internal and external use powerpc: Handle both new style and old style reserve maps powerpc/hw_brk: Fix off by one error when validating DAWR region end powerpc/pseries: Support compression of oops text via pstore powerpc/pseries: Re-organise the oops compression code pstore: Pass header size in the pstore write callback powerpc/powernv: Fix iommu initialization again powerpc/pseries: Inform the hypervisor we are using EBB regs powerpc/perf: Add power8 EBB support powerpc/perf: Core EBB support for 64-bit book3s powerpc/perf: Drop MMCRA from thread_struct powerpc/perf: Don't enable if we have zero events ...
| * pstore: Pass header size in the pstore write callbackAruna Balakrishnaiah2013-07-011-4/+6
| | | | | | | | | | | | | | | | | | | | Header size is needed to distinguish between header and the dump data. Incorporate the addition of new argument (hsize) in the pstore write callback. Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | pstore: Return unique error if backend registration excluded by kernel paramLenny Szubowicz2013-06-281-5/+6
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | This is patch 1/3 of a patch set that avoids what misleadingly appears to be a error during boot: ERST: Could not register with persistent store This message is displayed if the system has a valid ACPI ERST table and the pstore.backend kernel parameter has been used to disable use of ERST by pstore. But this same message is used for errors that preclude registration. As part of fixing this, return a unique error status from pstore_register if the pstore.backend kernel parameter selects a specific facility other than the requesting facility and check for this condition before any others. This allows the caller to distinquish this benign case from the other failure cases. Also, print an informational console message about which facility successfully registered as the pstore backend. Since there are various kernel parameters, config build options, and boot-time errors that can influence which facility registers with pstore, it's useful to have a positive indication. Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com> Reported-by: Naotaka Hamaguchi <n.hamaguchi@jp.fujitsu.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Avoid deadlock in panic and emergency-restart pathSeiji Aguchi2013-01-111-6/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [Issue] When pstore is in panic and emergency-restart paths, it may be blocked in those paths because it simply takes spin_lock. This is an example scenario which pstore may hang up in a panic path: - cpuA grabs psinfo->buf_lock - cpuB panics and calls smp_send_stop - smp_send_stop sends IRQ to cpuA - after 1 second, cpuB gives up on cpuA and sends an NMI instead - cpuA is now in an NMI handler while still holding buf_lock - cpuB is deadlocked This case may happen if a firmware has a bug and cpuA is stuck talking with it more than one second. Also, this is a similar scenario in an emergency-restart path: - cpuA grabs psinfo->buf_lock and stucks in a firmware - cpuB kicks emergency-restart via either sysrq-b or hangcheck timer. And then, cpuB is deadlocked by taking psinfo->buf_lock again. [Solution] This patch avoids the deadlocking issues in both panic and emergency_restart paths by introducing a function, is_non_blocking_path(), to check if a cpu can be blocked in current path. With this patch, pstore is not blocked even if another cpu has taken a spin_lock, in those paths by changing from spin_lock_irqsave to spin_trylock_irqsave. In addition, according to a comment of emergency_restart() in kernel/sys.c, spin_lock shouldn't be taken in an emergency_restart path to avoid deadlock. This patch fits the comment below. <snip> /** * emergency_restart - reboot the system * * Without shutting down any hardware or taking any locks * reboot the system. This is called when we know we are in * trouble so this is our best effort to reboot. This is * safe to call in interrupt context. */ void emergency_restart(void) <snip> Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Acked-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* efi_pstore: Add a sequence counter to a variable nameSeiji Aguchi2012-11-261-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [Issue] Currently, a variable name, which identifies each entry, consists of type, id and ctime. But if multiple events happens in a short time, a second/third event may fail to log because efi_pstore can't distinguish each event with current variable name. [Solution] A reasonable way to identify all events precisely is introducing a sequence counter to the variable name. The sequence counter has already supported in a pstore layer with "oopscount". So, this patch adds it to a variable name. Also, it is passed to read/erase callbacks of platform drivers in accordance with the modification of the variable name. <before applying this patch> a variable name of first event: dump-type0-1-12345678 a variable name of second event: dump-type0-1-12345678 type:0 id:1 ctime:12345678 If multiple events happen in a short time, efi_pstore can't distinguish them because variable names are same among them. <after applying this patch> it can be distinguishable by adding a sequence counter as follows. a variable name of first event: dump-type0-1-1-12345678 a variable name of Second event: dump-type0-1-2-12345678 type:0 id:1 sequence counter: 1(first event), 2(second event) ctime:12345678 In case of a write callback executed in pstore_console_write(), "0" is added to an argument of the write callback because it just logs all kernel messages and doesn't need to care about multiple events. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Mike Waychison <mikew@google.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Fix NULL pointer dereference in console writesColin Ian King2012-11-141-1/+2
| | | | | | | | | | | | | | | Passing a NULL id causes a NULL pointer deference in writers such as erst_writer and efi_pstore_write because they expect to update this id. Pass a dummy id instead. This avoids a cascade of oopses caused when the initial pstore_console_write passes a null which in turn causes writes to the console causing further oopses in subsequent pstore_console_write calls. Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
* pstore: Avoid recursive spinlocks in the oops_in_progress caseChuansheng Liu2012-09-201-1/+7
| | | | | | | | | | Like 8250 driver, when pstore is registered as a console, to avoid recursive spinlocks when panic happening, change the spin_lock_irqsave to spin_trylock_irqsave when oops_in_progress is true. Signed-off-by: liu chuansheng <chuansheng.liu@intel.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
* pstore/ftrace: Convert to its own enable/disable debugfs knobAnton Vorontsov2012-09-061-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | With this patch we no longer reuse function tracer infrastructure, now we register our own tracer back-end via a debugfs knob. It's a bit more code, but that is the only downside. On the bright side we have: - Ability to make persistent_ram module removable (when needed, we can move ftrace_ops struct into a module). Note that persistent_ram is still not removable for other reasons, but with this patch it's just one thing less to worry about; - Pstore part is more isolated from the generic function tracer. We tried it already by registering our own tracer in available_tracers, but that way we're loosing ability to see the traces while we record them to pstore. This solution is somewhere in the middle: we only register "internal ftracer" back-end, but not the "front-end"; - When there is only pstore tracing enabled, the kernel will only write to the pstore buffer, omitting function tracer buffer (which, of course, still can be enabled via 'echo function > current_tracer'). Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
* pstore: Add persistent function tracingAnton Vorontsov2012-07-171-1/+1
| | | | | | | | | | | | | | | | | | With this support kernel can save function call chain log into a persistent ram buffer that can be decoded and dumped after reboot through pstore filesystem. It can be used to determine what function was last called before a reset or panic. We store the log in a binary format and then decode it at read time. p.s. Mostly the code comes from trace_persistent.c driver found in the Android git tree, written by Colin Cross <ccross@android.com> (according to sign-off history). I reworked the driver a little bit, and ported it to pstore. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pstore: Introduce write_buf backend callbackAnton Vorontsov2012-07-171-0/+10
| | | | | | | | | | | | For function tracing we need to stop using pstore.buf directly, since in a tracing callback we can't use spinlocks, and thus we can't safely use the global buffer. With write_buf callback, backends no longer need to access pstore.buf directly, and thus we can pass any buffers (e.g. allocated on stack). Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge 3.5-rc4 into staging-nextGreg Kroah-Hartman2012-06-251-22/+12
|\ | | | | | | | | | | | | This picks up the staging changes made in 3.5-rc4 so that everyone can sync up properly. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * kmsg - kmsg_dump() use iterator to receive log buffer contentKay Sievers2012-06-151-22/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide an iterator to receive the log buffer content, and convert all kmsg_dump() users to it. The structured data in the kmsg buffer now contains binary data, which should no longer be copied verbatim to the kmsg_dump() users. The iterator should provide reliable access to the buffer data, and also supports proper log line-aware chunking of data while iterating. Signed-off-by: Kay Sievers <kay@vrfy.org> Tested-by: Tony Luck <tony.luck@intel.com> Reported-by: Anton Vorontsov <anton.vorontsov@linaro.org> Tested-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | pstore/platform: Disable automatic updates by defaultAnton Vorontsov2012-06-131-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Having automatic updates seems pointless for production system, and even dangerous and thus counter-productive: 1. If we can mount pstore, or read files, we can as well read /proc/kmsg. So, there's little point in duplicating the functionality and present the same information but via another userland ABI; 2. Expecting the kernel to behave sanely after oops/panic is naive. It might work, but you'd rather not try it. Screwed up kernel can do rather bad things, like recursive faults[1]; and pstore rather provoking bad things to happen. It uses: 1. Timers (assumes sane interrupts state); 2. Workqueues and mutexes (assumes scheduler in a sane state); 3. kzalloc (a working slab allocator); That's too much for a dead kernel, so the debugging facility itself might just make debugging harder, which is not what we want. Maybe for non-oops message types it would make sense to re-enable automatic updates, but so far I don't see any use case for this. Even for tracing, it has its own run-time/normal ABI, so we're only interested in pstore upon next boot, to retrieve what has gone wrong with HW or SW. So, let's disable the updates by default. [1] BUG: unable to handle kernel paging request at fffffffffffffff8 IP: [<ffffffff8104801b>] kthread_data+0xb/0x20 [...] Process kworker/0:1 (pid: 14, threadinfo ffff8800072c0000, task ffff88000725b100) [... Call Trace: [<ffffffff81043710>] wq_worker_sleeping+0x10/0xa0 [<ffffffff813687a8>] __schedule+0x568/0x7d0 [<ffffffff8106c24d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff81087e22>] ? call_rcu_sched+0x12/0x20 [<ffffffff8102b596>] ? release_task+0x156/0x2d0 [<ffffffff8102b45e>] ? release_task+0x1e/0x2d0 [<ffffffff8106c24d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff81368ac4>] schedule+0x24/0x70 [<ffffffff8102cba8>] do_exit+0x1f8/0x370 [<ffffffff810051e7>] oops_end+0x77/0xb0 [<ffffffff8135c301>] no_context+0x1a6/0x1b5 [<ffffffff8135c4de>] __bad_area_nosemaphore+0x1ce/0x1ed [<ffffffff81053156>] ? ttwu_queue+0xc6/0xe0 [<ffffffff8135c50b>] bad_area_nosemaphore+0xe/0x10 [<ffffffff8101fa47>] do_page_fault+0x2c7/0x450 [<ffffffff8106e34b>] ? __lock_release+0x6b/0xe0 [<ffffffff8106bf21>] ? mark_held_locks+0x61/0x140 [<ffffffff810502fe>] ? __wake_up+0x4e/0x70 [<ffffffff81185f7d>] ? trace_hardirqs_off_thunk+0x3a/0x3c [<ffffffff81158970>] ? pstore_register+0x120/0x120 [<ffffffff8136a37f>] page_fault+0x1f/0x30 [<ffffffff81158970>] ? pstore_register+0x120/0x120 [<ffffffff81185ab8>] ? memcpy+0x68/0x110 [<ffffffff8115875a>] ? pstore_get_records+0x3a/0x130 [<ffffffff811590f4>] ? persistent_ram_copy_old+0x64/0x90 [<ffffffff81158bf4>] ramoops_pstore_read+0x84/0x130 [<ffffffff81158799>] pstore_get_records+0x79/0x130 [<ffffffff81042536>] ? process_one_work+0x116/0x450 [<ffffffff81158970>] ? pstore_register+0x120/0x120 [<ffffffff8115897e>] pstore_dowork+0xe/0x10 [<ffffffff81042594>] process_one_work+0x174/0x450 [<ffffffff81042536>] ? process_one_work+0x116/0x450 [<ffffffff81042e13>] worker_thread+0x123/0x2d0 [<ffffffff81042cf0>] ? manage_workers.isra.28+0x120/0x120 [<ffffffff81047d8e>] kthread+0x8e/0xa0 [<ffffffff8136ba74>] kernel_thread_helper+0x4/0x10 [<ffffffff8136a199>] ? retint_restore_args+0xe/0xe [<ffffffff81047d00>] ? __init_kthread_worker+0x70/0x70 [<ffffffff8136ba70>] ? gs_change+0xb/0xb Code: be e2 00 00 00 48 c7 c7 d1 2a 4e 81 e8 bf fb fd ff 48 8b 5d f0 4c 8b 65 f8 c9 c3 0f 1f 44 00 00 48 8b 87 08 02 00 00 55 48 89 e5 <48> 8b 40 f8 5d c3 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 RIP [<ffffffff8104801b>] kthread_data+0xb/0x20 RSP <ffff8800072c1888> CR2: fffffffffffffff8 ---[ end trace 996a332dc399111d ]--- Fixing recursive fault but reboot is needed! Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | pstore/platform: Make automatic updates interval configurableAnton Vorontsov2012-06-131-4/+11
| | | | | | | | | | | | | | | | There is no behavioural change, the default value is still 60 seconds. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | pstore: Add console log messages supportAnton Vorontsov2012-06-131-0/+37
|/ | | | | | | | | | | | | | | Pstore doesn't support logging kernel messages in run-time, it only dumps dmesg when kernel oopses/panics. This makes pstore useless for debugging hangs caused by HW issues or improper use of HW (e.g. weird device inserted -> driver tried to write a reserved bits -> SoC hanged. In that case we don't get any messages in the pstore. Therefore, let's add a runtime logging support: PSTORE_TYPE_CONSOLE. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Colin Cross <ccross@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pstore: Introduce get_reason_str() to pstoreSeiji Aguchi2012-03-161-8/+22
| | | | | | | | | | | | | | | | | | Recently, there has been some changes in kmsg_dump() below and they have been applied to linus-tree. (1) kmsg_dump(KMSG_DUMP_KEXEC) was removed. http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=a3dd3323058d281abd584b15ad4c5b65064d7a61 (2) The order of "enum kmsg_dump_reason" was modified. http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=c22ab332902333f83766017478c1ef6607ace681 Replace the fragile reason_str array with a more robust solution that will not be broken by future re-arrangements of the enum values. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Don Zickus <dzickus@redhat.com> Link: https://lkml.org/lkml/2012/3/16/417 Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: gracefully handle NULL pstore_info functionsKees Cook2011-11-181-3/+3
| | | | | | | | | If a pstore backend doesn't want to support various portions of the pstore interface, it can just leave those functions NULL instead of creating no-op stubs. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: pass reason to backend write callbackKees Cook2011-11-171-29/+1
| | | | | | | | | | | | This allows a backend to filter on the dmesg reason as well as the pstore reason. When ramoops is switched to pstore, this is needed since it has no interest in storing non-crash dmesg details. Drop pstore_write() as it has no users, and handling the "reason" here has no obviously correct value. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: pass allocated memory region back to callerKees Cook2011-11-171-5/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The buf_lock cannot be held while populating the inodes, so make the backend pass forward an allocated and filled buffer instead. This solves the following backtrace. The effect is that "buf" is only ever used to notify the backends that something was written to it, and shouldn't be used in the read path. To replace the buf_lock during the read path, isolate the open/read/close loop with a separate mutex to maintain serialized access to the backend. Note that is is up to the pstore backend to cope if the (*write)() path is called in the middle of the read path. [ 59.691019] BUG: sleeping function called from invalid context at .../mm/slub.c:847 [ 59.691019] in_atomic(): 0, irqs_disabled(): 1, pid: 1819, name: mount [ 59.691019] Pid: 1819, comm: mount Not tainted 3.0.8 #1 [ 59.691019] Call Trace: [ 59.691019] [<810252d5>] __might_sleep+0xc3/0xca [ 59.691019] [<810a26e6>] kmem_cache_alloc+0x32/0xf3 [ 59.691019] [<810b53ac>] ? __d_lookup_rcu+0x6f/0xf4 [ 59.691019] [<810b68b1>] alloc_inode+0x2a/0x64 [ 59.691019] [<810b6903>] new_inode+0x18/0x43 [ 59.691019] [<81142447>] pstore_get_inode.isra.1+0x11/0x98 [ 59.691019] [<81142623>] pstore_mkfile+0xae/0x26f [ 59.691019] [<810a2a66>] ? kmem_cache_free+0x19/0xb1 [ 59.691019] [<8116c821>] ? ida_get_new_above+0x140/0x158 [ 59.691019] [<811708ea>] ? __init_rwsem+0x1e/0x2c [ 59.691019] [<810b67e8>] ? inode_init_always+0x111/0x1b0 [ 59.691019] [<8102127e>] ? should_resched+0xd/0x27 [ 59.691019] [<8137977f>] ? _cond_resched+0xd/0x21 [ 59.691019] [<81142abf>] pstore_get_records+0x52/0xa7 [ 59.691019] [<8114254b>] pstore_fill_super+0x7d/0x91 [ 59.691019] [<810a7ff5>] mount_single+0x46/0x82 [ 59.691019] [<8114231a>] pstore_mount+0x15/0x17 [ 59.691019] [<811424ce>] ? pstore_get_inode.isra.1+0x98/0x98 [ 59.691019] [<810a8199>] mount_fs+0x5a/0x12d [ 59.691019] [<810b9174>] ? alloc_vfsmnt+0xa4/0x14a [ 59.691019] [<810b9474>] vfs_kern_mount+0x4f/0x7d [ 59.691019] [<810b9d7e>] do_kern_mount+0x34/0xb2 [ 59.691019] [<810bb15f>] do_mount+0x5fc/0x64a [ 59.691019] [<810912fb>] ? strndup_user+0x2e/0x3f [ 59.691019] [<810bb3cb>] sys_mount+0x66/0x99 [ 59.691019] [<8137b537>] sysenter_do_call+0x12/0x26 Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: make pstore write function return normal success/fail valueChen Gong2011-10-121-5/+6
| | | | | | | | | | | Currently pstore write interface employs record id as return value, but it is not enough because it can't tell caller if the write operation is successful. Pass the record id back via an argument pointer and return zero for success, non-zero for failure. Signed-off-by: Chen Gong <gong.chen@linux.intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: change mutex locking to spin_locksDon Zickus2011-08-161-7/+21
| | | | | | | | | | | | | | | | | | | | pstore was using mutex locking to protect read/write access to the backend plug-ins. This causes problems when pstore is executed in an NMI context through panic() -> kmsg_dump(). This patch changes the mutex to a spin_lock_irqsave then also checks to see if we are in an NMI context. If we are in an NMI and can't get the lock, just print a message stating that and blow by the locking. All this is probably a hack around the bigger locking problem but it solves my current situation of trying to sleep in an NMI context. Tested by loading the lkdtm module and executing a HARDLOCKUP which will cause the machine to panic inside the nmi handler. Signed-off-by: Don Zickus <dzickus@redhat.com> Acked-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: defer inserting OOPS entries into pstoreLuck, Tony2011-08-161-9/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | Life is simple for all the kernel terminating types of kmsg_dump call backs - pstore just saves the tail end of the console log. But for "oops" the situation is more complex - the kernel may carry on running (possibly for ever). So we'd like to make the logged copy of the oops appear in the pstore filesystem - so that the user has a handle to clear the entry from the persistent backing store (if we don't, the store may fill with "oops" entries (that are also safely stashed in /var/log/messages) leaving no space for real errors. Current code calls pstore_mkfile() immediately. But this may not be safe. The oops could have happened with arbitrary locks held, or in interrupt or NMI context. So allocating memory and calling into generic filesystem code seems unwise. This patch defers making the entry appear. At the time of the oops, we merely set a flag "pstore_new_entry" noting that a new entry has been added. A periodic timer checks once a minute to see if the flag is set - if so, it schedules a work queue to rescan the backing store and make all new entries appear in the pstore filesystem. Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Allow the user to explicitly choose a backendMatthew Garrett2011-07-221-0/+11
| | | | | | | | | pstore only allows one backend to be registered at present, but the system may provide several. Add a parameter to allow the user to choose which backend will be used rather than just relying on load order. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Make "part" unsignedMatthew Garrett2011-07-221-1/+2
| | | | | | | We'll never have a negative part, so just make this an unsigned int. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Add extra context for writes and erasesMatthew Garrett2011-07-221-4/+5
| | | | | | | | | | | EFI only provides small amounts of individual storage, and conventionally puts metadata in the storage variable name. Rather than add a metadata header to the (already limited) variable storage, it's easier for us to modify pstore to pass all the information we need to construct a unique variable name to the appropriate functions. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Extend API for more flexibility in new backendsMatthew Garrett2011-07-221-6/+7
| | | | | | | | | Some pstore implementations may not have a static context, so extend the API to pass the pstore_info struct to all calls and allow for a context pointer. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-18 00:20:00 +0000