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* net: Implement fault injection forcing skb reallocationBreno Leitao12 days1-0/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a fault injection mechanism to force skb reallocation. The primary goal is to catch bugs related to pointer invalidation after potential skb reallocation. The fault injection mechanism aims to identify scenarios where callers retain pointers to various headers in the skb but fail to reload these pointers after calling a function that may reallocate the data. This type of bug can lead to memory corruption or crashes if the old, now-invalid pointers are used. By forcing reallocation through fault injection, we can stress-test code paths and ensure proper pointer management after potential skb reallocations. Add a hook for fault injection in the following functions: * pskb_trim_rcsum() * pskb_may_pull_reason() * pskb_trim() As the other fault injection mechanism, protect it under a debug Kconfig called CONFIG_FAIL_SKB_REALLOC. This patch was *heavily* inspired by Jakub's proposal from: https://lore.kernel.org/all/20240719174140.47a868e6@kernel.org/ CC: Akinobu Mita <akinobu.mita@gmail.com> Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Guillaume Nault <gnault@redhat.com> Link: https://patch.msgid.link/20241107-fault_v6-v6-1-1b82cb6ecacd@debian.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* Fix typo "allocateed" to allocatedGianfranco Trad2024-08-261-1/+1
| | | | | | | | | Fix minor typo in the fault-injection documentation, where the word allocated was misspelled as "allocateed". Signed-off-by: Gianfranco Trad <gianf.trad@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20240819110641.1931-1-gianf.trad@gmail.com
* docs: fault-injection: document cache-filter feature for failslabBreno Leitao2024-08-071-0/+20
| | | | | | | | | | | | | | | | | | | | The failslab fault injection mechanism has an undocumented capability that provides significant utility in testing and debugging. This feature, introduced in commit 4c13dd3b48fcb ("failslab: add ability to filter slab caches"), allows for targeted error injection into specific slab caches. However, it was inadvertently left undocumented at the time of its implementation. Add documentation for the cache-filter feature in the failslab mode description. Also, providing a practical example demonstrating how to use cache-filter to inject failures specifically when allocating socket buffers (skbs). Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20240726120930.3231333-1-leitao@debian.org
* Fixed case issue with 'fault-injection' in documentationRan.Park2024-02-211-1/+1
| | | | | | | | | | In the 'fault-injection' subdirectory, the first letter F is capitalized, whereas in index.rst f is lowercase, but in index.rst all other elements in the same column are capitalized. Signed-off-by: "Ran.Park" <ranpark@foxmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/tencent_3EA07E65C43816C2A8402DC655CF98916B06@qq.com
* Documentation: Fix typosBjorn Helgaas2023-08-181-1/+1
| | | | | | | | Fix typos in Documentation. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20230814212822.193684-4-helgaas@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* lkdtm: replace ll_rw_block with submit_bhYue Zhao2023-05-311-1/+1
| | | | | | | | | | | | | | | Function ll_rw_block was removed in commit 79f597842069 ("fs/buffer: remove ll_rw_block() helper"). There is no unified function to sumbit read or write buffer in block layer for now. Consider similar sematics, we can choose submit_bh() to replace ll_rw_block() as predefined crash point. In submit_bh(), it also takes read or write flag as the first argument and invoke submit_bio() to submit I/O request to block layer. Fixes: 79f597842069 ("fs/buffer: remove ll_rw_block() helper") Signed-off-by: Yue Zhao <findns94@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230503162944.3969-1-findns94@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* block: null_blk: make fault-injection dynamically configurable per deviceAkinobu Mita2023-04-131-0/+8
| | | | | | | | | | | | | | | | | | | | | The null_blk driver has multiple driver-specific fault injection mechanisms. Each fault injection configuration can only be specified by a module parameter and cannot be reconfigured without reloading the driver. Also, each configuration is common to all devices and is initialized every time a new device is added. This change adds the following subdirectories for each null_blk device. /sys/kernel/config/nullb/<disk>/timeout_inject /sys/kernel/config/nullb/<disk>/requeue_inject /sys/kernel/config/nullb/<disk>/init_hctx_fault_inject Each fault injection attribute can be dynamically set per device by a corresponding file in these directories. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Link: https://lore.kernel.org/r/20230327143733.14599-3-akinobu.mita@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* docs: fault-injection: add requirements of error injectable functionsMasami Hiramatsu (Google)2023-02-021-0/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | Add a section about the requirements of the error injectable functions and the type of errors. Since this section must be read before using ALLOW_ERROR_INJECTION() macro, that section is referred from the comment of the macro too. Link: https://lkml.kernel.org/r/167081321427.387937.15475445689482551048.stgit@devnote3 Link: https://lore.kernel.org/all/20221211115218.2e6e289bb85f8cf53c11aa97@kernel.org/T/#u Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Chris Mason <clm@meta.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Florent Revest <revest@chromium.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: KP Singh <kpsingh@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* debugfs: fix error when writing negative value to atomic_t debugfs fileAkinobu Mita2022-11-301-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | The simple attribute files do not accept a negative value since the commit 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()"), so we have to use a 64-bit value to write a negative value for a debugfs file created by debugfs_create_atomic_t(). This restores the previous behaviour by introducing DEFINE_DEBUGFS_ATTRIBUTE_SIGNED for a signed value. Link: https://lkml.kernel.org/r/20220919172418.45257-4-akinobu.mita@gmail.com Fixes: 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()") Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reported-by: Zhao Gongyi <zhaogongyi@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Wei Yongjun <weiyongjun1@huawei.com> Cc: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* docs: notifier-error-inject: Correct test's nameZhao Gongyi2022-10-071-2/+2
| | | | | | | | Correct test's name for mem-on-off-test.sh/cpu-on-off-test.sh. Signed-off-by: Zhao Gongyi <zhaogongyi@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
* SUNRPC: Fix server-side fault injection documentationChuck Lever2022-07-291-0/+7
| | | | | Fixes: 37324e6bb120 ("SUNRPC: Cache deferral injection") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
* docs: fault-injection: fix defaultsDylan Yudaken2022-04-161-7/+7
| | | | | | | | | | | | | ignore-gfp-wait and ignore-gfp-highmem defaults are actually true (Y) in both failslab and fail_page_alloc, not false as the docs suggest. See page_alloc.c:3762 and failslab.c:13 At the same time use 'Y' instead of '1' in the example scripts just for consistency. (though 1 would work) Signed-off-by: Dylan Yudaken <dylany@fb.com> Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Merge tag 'char-misc-5.15-rc1' of ↵Linus Torvalds2021-09-011-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char / misc driver updates from Greg KH: "Here is the big set of char/misc driver changes for 5.15-rc1. Lots of different driver subsystems are being updated in here, notably: - mhi subsystem update - fpga subsystem update - coresight/hwtracing subsystem update - interconnect subsystem update - nvmem subsystem update - parport drivers update - phy subsystem update - soundwire subsystem update and there are some other char/misc drivers being updated as well: - binder driver additions - new misc drivers - lkdtm driver updates - mei driver updates - sram driver updates - other minor driver updates. Note, there are no habanalabs driver updates in this pull request, that will probably come later before -rc1 is out in a different request. All of these have been in linux-next for a while with no reported problems" * tag 'char-misc-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (169 commits) Revert "bus: mhi: Add inbound buffers allocation flag" misc/pvpanic: fix set driver data VMCI: fix NULL pointer dereference when unmapping queue pair char: mware: fix returnvar.cocci warnings parport: remove non-zero check on count soundwire: cadence: do not extend reset delay soundwire: intel: conditionally exit clock stop mode on system suspend soundwire: intel: skip suspend/resume/wake when link was not started soundwire: intel: fix potential race condition during power down phy: qcom-qmp: Add support for SM6115 UFS phy dt-bindings: phy: qcom,qmp: Add SM6115 UFS PHY bindings phy: qmp: Provide unique clock names for DP clocks lkdtm: remove IDE_CORE_CP crashpoint lkdtm: replace SCSI_DISPATCH_CMD with SCSI_QUEUE_RQ coresight: Replace deprecated CPU-hotplug functions. Documentation: coresight: Add documentation for CoreSight config coresight: syscfg: Add initial configfs support coresight: config: Add preloaded configurations coresight: etm4x: Add complex configuration handlers to etmv4 coresight: etm-perf: Update to activate selected configuration ...
| * lkdtm: remove IDE_CORE_CP crashpointKevin Mitchell2021-08-191-2/+1
| | | | | | | | | | | | | | | | | | | | | | With the removal of the legacy IDE driver in kb7fb14d3ac63 ("ide: remove the legacy ide driver"), this crashpoint no longer points to a valid function. Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kevin Mitchell <kevmitch@arista.com> Link: https://lore.kernel.org/r/20210819022940.561875-3-kevmitch@arista.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * lkdtm: replace SCSI_DISPATCH_CMD with SCSI_QUEUE_RQKevin Mitchell2021-08-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When scsi_dispatch_cmd was moved to scsi_lib.c and made static, some compilers (i.e., at least gcc 8.4.0) decided to compile this inline. This is a problem for lkdtm.ko, which inserted a kprobe on this function for the SCSI_DISPATCH_CMD crashpoint. Move this crashpoint one function up the call chain to scsi_queue_rq. Though this is also a static function, it should never be inlined because it is assigned as a structure entry. Therefore, kprobe_register should always be able to find it. Fixes: 82042a2cdb55 ("scsi: move scsi_dispatch_cmd to scsi_lib.c") Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kevin Mitchell <kevmitch@arista.com> Link: https://lore.kernel.org/r/20210819022940.561875-2-kevmitch@arista.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | SUNRPC: Add documentation for the fail_sunrpc/ directoryChuck Lever2021-08-201-0/+18
|/ | | | Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
* docs: fault-injection: fix non-working usage of negative valuesWolfram Sang2021-06-141-10/+14
| | | | | | | | | | | | | | | Fault injection uses debugfs in a way that the provided values via sysfs are interpreted as u64. Providing negative numbers results in an error: /sys/kernel/debug/fail_function# echo -1 > times sh: write error: Invalid argument Update the docs and examples to use "printf %#x <val>" in these cases. For "retval", reword the paragraph a little and fix a typo. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20210603125841.27436-1-wsa+renesas@sang-engineering.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Merge tag 'docs-5.10-2' of git://git.lwn.net/linuxLinus Torvalds2020-10-231-23/+33
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull documentation fixes from Jonathan Corbet: "A handful of late-arriving documentation fixes" * tag 'docs-5.10-2' of git://git.lwn.net/linux: docs: Add two missing entries in vm sysctl index docs/vm: trivial fixes to several spelling mistakes docs: submitting-patches: describe preserving review/test tags Documentation: Chinese translation of Documentation/arm64/hugetlbpage.rst Documentation: x86: fix a missing word in x86_64/mm.rst. docs: driver-api: remove a duplicated index entry docs: lkdtm: Modernize and improve details docs: deprecated.rst: Expand str*cpy() replacement notes docs/cpu-load: format the example code.
| * docs: lkdtm: Modernize and improve detailsKees Cook2020-10-211-23/+33
| | | | | | | | | | | | | | | | | | | | The details on using LKDTM were overly obscure. Modernize the details and expand examples to better illustrate how to use the interfaces. Additionally add missing SPDX header. Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201015224559.2137489-1-keescook@chromium.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | lib, include/linux: add usercopy failure capabilityAlbert van der Linde2020-10-161-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "add fault injection to user memory access", v3. The goal of this series is to improve testing of fault-tolerance in usages of user memory access functions, by adding support for fault injection. syzkaller/syzbot are using the existing fault injection modes and will use this particular feature also. The first patch adds failure injection capability for usercopy functions. The second changes usercopy functions to use this new failure capability (copy_from_user, ...). The third patch adds get/put/clear_user failures to x86. This patch (of 3): Add a failure injection capability to improve testing of fault-tolerance in usages of user memory access functions. Add CONFIG_FAULT_INJECTION_USERCOPY to enable faults in usercopy functions. The should_fail_usercopy function is to be called by these functions (copy_from_user, get_user, ...) in order to fail or not. Signed-off-by: Albert van der Linde <alinde@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20200831171733.955393-1-alinde@google.com Link: http://lkml.kernel.org/r/20200831171733.955393-2-alinde@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | nvme: rename and document nvme_end_requestChristoph Hellwig2020-08-211-1/+1
|/ | | | | | | | | | | | nvme_end_request is a bit misnamed, as it wraps around the blk_mq_complete_* API. It's semantics also are non-trivial, so give it a more descriptive name and add a comment explaining the semantics. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: rename generic_make_request to submit_bio_noacctChristoph Hellwig2020-07-011-1/+1
| | | | | | | | | generic_make_request has always been very confusingly misnamed, so rename it to submit_bio_noacct to make it clear that it is submit_bio minus accounting and a few checks. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* docs: add some directories to the main documentation indexMauro Carvalho Chehab2019-07-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | The contents of those directories were orphaned at the documentation body. While those directories could likely be moved to be inside some guide, I'm opting to just adding their indexes to the main one, removing the :orphan: and adding the SPDX header. For the drivers, the rationale is that the documentation contains a mix of Kernelspace, uAPI and admin-guide. So, better to keep them on separate directories, as we've be doing with similar subsystem-specific docs that were not split yet. For the others, well... I'm too lazy to do the move. Also, it seems to make sense to keep at least some of those at the main dir (like kbuild, for example). In any case, a latter patch could do the move. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
* Merge tag 'docs-5.3' of git://git.lwn.net/linuxLinus Torvalds2019-07-097-352/+403
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull Documentation updates from Jonathan Corbet: "It's been a relatively busy cycle for docs: - A fair pile of RST conversions, many from Mauro. These create more than the usual number of simple but annoying merge conflicts with other trees, unfortunately. He has a lot more of these waiting on the wings that, I think, will go to you directly later on. - A new document on how to use merges and rebases in kernel repos, and one on Spectre vulnerabilities. - Various improvements to the build system, including automatic markup of function() references because some people, for reasons I will never understand, were of the opinion that :c:func:``function()`` is unattractive and not fun to type. - We now recommend using sphinx 1.7, but still support back to 1.4. - Lots of smaller improvements, warning fixes, typo fixes, etc" * tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits) docs: automarkup.py: ignore exceptions when seeking for xrefs docs: Move binderfs to admin-guide Disable Sphinx SmartyPants in HTML output doc: RCU callback locks need only _bh, not necessarily _irq docs: format kernel-parameters -- as code Doc : doc-guide : Fix a typo platform: x86: get rid of a non-existent document Add the RCU docs to the core-api manual Documentation: RCU: Add TOC tree hooks Documentation: RCU: Rename txt files to rst Documentation: RCU: Convert RCU UP systems to reST Documentation: RCU: Convert RCU linked list to reST Documentation: RCU: Convert RCU basic concepts to reST docs: filesystems: Remove uneeded .rst extension on toctables scripts/sphinx-pre-install: fix out-of-tree build docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/ Documentation: PGP: update for newer HW devices Documentation: Add section about CPU vulnerabilities for Spectre Documentation: platform: Delete x86-laptop-drivers.txt docs: Note that :c:func: should no longer be used ...
| * docs: fault-injection: convert docs to ReST and rename to *.rstMauro Carvalho Chehab2019-06-147-296/+345
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Federico Vaga <federico.vaga@vaga.pv.it> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | Documentation: nvme: add an example for nvme fault injectionAkinobu Mita2019-06-211-0/+56
|/ | | | | | | | | | | This adds an example of how to inject errors into admin commands. Suggested-by: Thomas Tai <thomas.tai@oracle.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Minwoo Im <minwoo.im@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
* doc: fault-injection: fix macro name in exampleLaurent Gauthier2019-01-071-1/+1
| | | | | Signed-off-by: Laurent Gauthier <laurent.gauthier@soccasys.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: nvme: Documentation for nvme fault injectionThomas Tai2018-03-262-0/+124
| | | | | | | | | | | Add examples to show how to use nvme fault injection. Signed-off-by: Thomas Tai <thomas.tai@oracle.com> Reviewed-by: Eric Saint-Etienne <eric.saint.etienne@oracle.com> Signed-off-by: Karl Volz <karl.volz@oracle.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge tag 'docs-4.16' of git://git.lwn.net/linuxLinus Torvalds2018-01-311-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull documentation updates from Jonathan Corbet: "Documentation updates for 4.16. New stuff includes refcount_t documentation, errseq documentation, kernel-doc support for nested structure definitions, the removal of lots of crufty kernel-doc support for unused formats, SPDX tag documentation, the beginnings of a manual for subsystem maintainers, and lots of fixes and updates. As usual, some of the changesets reach outside of Documentation/ to effect kerneldoc comment fixes. It also adds the new LICENSES directory, of which Thomas promises I do not need to be the maintainer" * tag 'docs-4.16' of git://git.lwn.net/linux: (65 commits) linux-next: docs-rst: Fix typos in kfigure.py linux-next: DOC: HWPOISON: Fix path to debugfs in hwpoison.txt Documentation: Fix misconversion of #if docs: add index entry for networking/msg_zerocopy Documentation: security/credentials.rst: explain need to sort group_list LICENSES: Add MPL-1.1 license LICENSES: Add the GPL 1.0 license LICENSES: Add Linux syscall note exception LICENSES: Add the MIT license LICENSES: Add the BSD-3-clause "Clear" license LICENSES: Add the BSD 3-clause "New" or "Revised" License LICENSES: Add the BSD 2-clause "Simplified" license LICENSES: Add the LGPL-2.1 license LICENSES: Add the LGPL 2.0 license LICENSES: Add the GPL 2.0 license Documentation: Add license-rules.rst to describe how to properly identify file licenses scripts: kernel_doc: better handle show warnings logic fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at doc: md: Fix a file name to md-fault.c in fault-injection.txt errseq: Add to documentation tree ...
| * doc: md: Fix a file name to md-fault.c in fault-injection.txtMasanari Iida2018-01-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | drivers/md/faulty.c has been renamed to md-faulty.c after following commit merged int to the main line. 935fe0983e09f4f7331ebf5ea4ae2124f6e9f9e8 . But the file name in fault-injection.txt has not been changed. Now the actual file name and document are in sync. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | error-injection: Support fault injection frameworkMasami Hiramatsu2018-01-121-0/+68
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Support in-kernel fault-injection framework via debugfs. This allows you to inject a conditional error to specified function using debugfs interfaces. Here is the result of test script described in Documentation/fault-injection/fault-injection.txt =========== # ./test_fail_function.sh 1+0 records in 1+0 records out 1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.0227404 s, 46.1 MB/s btrfs-progs v4.4 See http://btrfs.wiki.kernel.org for more information. Label: (null) UUID: bfa96010-12e9-4360-aed0-42eec7af5798 Node size: 16384 Sector size: 4096 Filesystem size: 1001.00MiB Block group profiles: Data: single 8.00MiB Metadata: DUP 58.00MiB System: DUP 12.00MiB SSD detected: no Incompat features: extref, skinny-metadata Number of devices: 1 Devices: ID SIZE PATH 1 1001.00MiB /dev/loop2 mount: mount /dev/loop2 on /opt/tmpmnt failed: Cannot allocate memory SUCCESS! =========== Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* cpu/hotplug: Get rid of CPU hotplug notifier leftoversThomas Gleixner2017-11-131-30/+0
| | | | | | | The CPU hotplug notifiers are history. Remove the last reminders. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* fault-inject: add /proc/<pid>/fail-nthAkinobu Mita2017-07-141-1/+2
| | | | | | | | | | | | | | | fail-nth interface is only created in /proc/self/task/<current-tid>/. This change also adds it in /proc/<pid>/. This makes shell based tool a bit simpler. $ bash -c "builtin echo 100 > /proc/self/fail-nth && exec ls /" Link: http://lkml.kernel.org/r/1491490561-10485-6-git-send-email-akinobu.mita@gmail.com Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-inject: make fail-nth read/write interface symmetricAkinobu Mita2017-07-141-6/+7
| | | | | | | | | | | | | | | | The read interface for fail-nth looks a bit odd. Read from this file returns "NYYYY..." or "YYYYY..." (this makes me surprise when cat this file). Because there is no EOF condition. The first character indicates current->fail_nth is zero or not, and then current->fail_nth is reset to zero. Just returning task->fail_nth value is more natural to understand. Link: http://lkml.kernel.org/r/1491490561-10485-4-git-send-email-akinobu.mita@gmail.com Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-inject: parse as natural 1-based value for fail-nth write interfaceAkinobu Mita2017-07-141-4/+3
| | | | | | | | | | | | | | The value written to fail-nth file is parsed as 0-based. Parsing as one-based is more natural to understand and it enables to cancel the previous setup by simply writing '0'. This change also converts task->fail_nth from signed to unsigned int. Link: http://lkml.kernel.org/r/1491490561-10485-3-git-send-email-akinobu.mita@gmail.com Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-inject: support systematic fault injectionDmitry Vyukov2017-07-121-0/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add /proc/self/task/<current-tid>/fail-nth file that allows failing 0-th, 1-st, 2-nd and so on calls systematically. Excerpt from the added documentation: "Write to this file of integer N makes N-th call in the current task fail (N is 0-based). Read from this file returns a single char 'Y' or 'N' that says if the fault setup with a previous write to this file was injected or not, and disables the fault if it wasn't yet injected. Note that this file enables all types of faults (slab, futex, etc). This setting takes precedence over all other generic settings like probability, interval, times, etc. But per-capability settings (e.g. fail_futex/ignore-private) take precedence over it. This feature is intended for systematic testing of faults in a single system call. See an example below" Why add a new setting: 1. Existing settings are global rather than per-task. So parallel testing is not possible. 2. attr->interval is close but it depends on attr->count which is non reset to 0, so interval does not work as expected. 3. Trying to model this with existing settings requires manipulations of all of probability, interval, times, space, task-filter and unexposed count and per-task make-it-fail files. 4. Existing settings are per-failure-type, and the set of failure types is potentially expanding. 5. make-it-fail can't be changed by unprivileged user and aggressive stress testing better be done from an unprivileged user. Similarly, this would require opening the debugfs files to the unprivileged user, as he would need to reopen at least times file (not possible to pre-open before dropping privs). The proposed interface solves all of the above (see the example). We want to integrate this into syzkaller fuzzer. A prototype has found 10 bugs in kernel in first day of usage: https://groups.google.com/forum/#!searchin/syzkaller/%22FAULT_INJECTION%22%7Csort:relevance I've made the current interface work with all types of our sandboxes. For setuid the secret sauce was prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) to make /proc entries non-root owned. So I am fine with the current version of the code. [akpm@linux-foundation.org: fix build] Link: http://lkml.kernel.org/r/20170328130128.101773-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* net: Add support for CHANGEUPPER notifier error injectionIdo Schimmel2015-12-031-0/+1
| | | | | | | | | | Since CHANGEUPPER can now fail, add support for it in the newly introduced netdev notifier error injection infrastructure. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: add support for netdev notifier error injectionNikolay Aleksandrov2015-12-011-0/+24
| | | | | | | | | | | | | | | | | | | | | This module allows to insert errors in some of netdevice's notifier events. All network drivers use these notifiers to signal various events and to check if they are allowed, e.g. PRECHANGEMTU and CHANGEMTU afterwards. Until recently I had to run failure tests by injecting a custom module, but now this infrastructure makes it trivial to test these failure paths. Some of the recent bugs I fixed were found using this module. Here's an example: $ cd /sys/kernel/debug/notifier-error-inject/netdev $ echo -22 > actions/NETDEV_CHANGEMTU/error $ ip link set eth0 mtu 1024 RTNETLINK answers: Invalid argument CC: Akinobu Mita <akinobu.mita@gmail.com> CC: "David S. Miller" <davem@davemloft.net> CC: netdev <netdev@vger.kernel.org> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* futex: Fault/error injection capabilitiesDavidlohr Bueso2015-07-201-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | Although futexes are well known for being a royal pita, we really have very little debugging capabilities - except for relying on tglx's eye half the time. By simply making use of the existing fault-injection machinery, we can improve this situation, allowing generating artificial uaddress faults and deadlock scenarios. Of course, when this is disabled in production systems, the overhead for failure checks is practically zero -- so this is very cheap at the same time. Future work would be nice to now enhance trinity to make use of this. There is a special tunable 'ignore-private', which can filter out private futexes. Given the tsk->make_it_fail filter and this option, pi futexes can be narrowed down pretty closely. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <darren@dvhart.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Link: http://lkml.kernel.org/r/1435645562-975-3-git-send-email-dave@stgolabs.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* doc: fix quite a few typos within DocumentationMasanari Iida2012-11-191-2/+2
| | | | | | Correct spelling typo in Documentations Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* fault-injection: add tool to run command with failslab or fail_page_allocAkinobu Mita2012-07-301-0/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds tools/testing/fault-injection/failcmd.sh to run a command while injecting slab/page allocation failures via fault injection. Example: Run a command "make -C tools/testing/selftests/ run_tests" with injecting slab allocation failure. # ./tools/testing/fault-injection/failcmd.sh \ -- make -C tools/testing/selftests/ run_tests Same as above except to specify 100 times failures at most instead of one time at most by default. # ./tools/testing/fault-injection/failcmd.sh --times=100 \ -- make -C tools/testing/selftests/ run_tests Same as above except to inject page allocation failure instead of slab allocation failure. # env FAILCMD_TYPE=fail_page_alloc \ ./tools/testing/fault-injection/failcmd.sh --times=100 \ -- make -C tools/testing/selftests/ run_tests Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-injection: notifier error injectionAkinobu Mita2012-07-301-0/+99
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patchset provides kernel modules that can be used to test the error handling of notifier call chain failures by injecting artifical errors to the following notifier chain callbacks. * CPU notifier * PM notifier * memory hotplug notifier * powerpc pSeries reconfig notifier Example: Inject CPU offline error (-1 == -EPERM) # cd /sys/kernel/debug/notifier-error-inject/cpu # echo -1 > actions/CPU_DOWN_PREPARE/error # echo 0 > /sys/devices/system/cpu/cpu1/online bash: echo: write error: Operation not permitted The patchset also adds cpu and memory hotplug tests to tools/testing/selftests These tests first do simple online and offline test and then do fault injection tests if notifier error injection module is available. This patch: The notifier error injection provides the ability to inject artifical errors to specified notifier chain callbacks. It is useful to test the error handling of notifier call chain failures. This adds common basic functions to define which type of events can be fail and to initialize the debugfs interface to control what error code should be returned and which event should be failed. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-injection: update documentation with the mmc module paramPer Forlin2011-10-261-1/+1
| | | | | | Signed-off-by: Per Forlin <per.forlin@linaro.org> Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Chris Ball <cjb@laptop.org>
* fault-inject: add documentation on MMC IO fault injectionPer Forlin2011-10-261-1/+7
| | | | | | | | | | Add description on how to enable random fault injection for MMC IO. Signed-off-by: Per Forlin <per.forlin@linaro.org> Acked-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Chris Ball <cjb@laptop.org>
* fault-injection: add ability to export fault_attr in arbitrary directoryAkinobu Mita2011-08-031-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | init_fault_attr_dentries() is used to export fault_attr via debugfs. But it can only export it in debugfs root directory. Per Forlin is working on mmc_fail_request which adds support to inject data errors after a completed host transfer in MMC subsystem. The fault_attr for mmc_fail_request should be defined per mmc host and export it in debugfs directory per mmc host like /sys/kernel/debug/mmc0/mmc_fail_request. init_fault_attr_dentries() doesn't help for mmc_fail_request. So this introduces fault_create_debugfs_attr() which is able to create a directory in the arbitrary directory and replace init_fault_attr_dentries(). [akpm@linux-foundation.org: extraneous semicolon, per Randy] Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Tested-by: Per Forlin <per.forlin@linaro.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lkdtm: add debugfs access and loosen KPROBE tiesSimon Kagstrom2010-03-061-0/+38
| | | | | | | | | | | | | | | | | | | | | | | Add adds a debugfs interface and additional failure modes to LKDTM to provide similar functionality to the provoke-crash driver submitted here: http://lwn.net/Articles/371208/ Crashes can now be induced either through module parameters (as before) or through the debugfs interface as in provoke-crash. The patch also provides a new "direct" interface, where KPROBES are not used, i.e., the crash is invoked directly upon write to the debugfs file. When built without KPROBES configured, only this mode is available. Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net> Cc: M. Mohan Kumar <mohan@in.ibm.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: "Eric W. Biederman" <ebiederm@xmission.com>, Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault injection: correct function names in documentationAnton Blanchard2010-02-021-2/+2
| | | | | | | | | | | init_fault_attr_entries() should be init_fault_attr_dentries(). cleanup_fault_attr_entries() should be cleanup_fault_attr_dentries(). Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem.GeunSik Lim2009-06-151-35/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many developers use "/debug/" or "/debugfs/" or "/sys/kernel/debug/" directory name to mount debugfs filesystem for ftrace according to ./Documentation/tracers/ftrace.txt file. And, three directory names(ex:/debug/, /debugfs/, /sys/kernel/debug/) is existed in kernel source like ftrace, DRM, Wireless, Documentation, Network[sky2]files to mount debugfs filesystem. debugfs means debug filesystem for debugging easy to use by greg kroah hartman. "/sys/kernel/debug/" name is suitable as directory name of debugfs filesystem. - debugfs related reference: http://lwn.net/Articles/334546/ Fix inconsistency of directory name to mount debugfs filesystem. * From Steven Rostedt - find_debugfs() and tracing_files() in this patch. Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com> Acked-by : Inaky Perez-Gonzalez <inaky@linux.intel.com> Reviewed-by : Steven Rostedt <rostedt@goodmis.org> Reviewed-by : James Smart <james.smart@emulex.com> CC: Jiri Kosina <trivial@kernel.org> CC: David Airlie <airlied@linux.ie> CC: Peter Osterlund <petero2@telia.com> CC: Ananth N Mavinakayanahalli <ananth@in.ibm.com> CC: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> CC: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* fault-injection: fix example scripts in documentationAkinobu Mita2007-07-163-84/+56
| | | | | | | | | | | | | | | | | | Fix and cleanup example scripts in fault injection documentation. 1. Eliminate broken oops() shell function. 2. Fold failcmd.sh and failmodule.sh into example scripts. It makes the example scripts work independent of current working directory. 3. Set "space" parameter to 0 to start injecting errors immediately. 4. Use /sys/module/<modulename>/sections/.data as upper bound of .text section. Because some module doesn't have .exit.text section. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-injection: add min-order parameter to fail_page_allocAkinobu Mita2007-07-161-0/+5
| | | | | | | | | | | | | Limiting smaller allocation failures by fault injection helps to find real possible bugs. Because higher order allocations are likely to fail and zero-order allocations are not likely to fail. This patch adds min-order parameter to fail_page_alloc. It specifies the minimum page allocation order to be injected failures. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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