kernel/Documentation/fault-injection, branch linux-5.1.y

doc: fault-injection: fix macro name in example

2019-01-07T22:36:11Z

Signed-off-by: Laurent Gauthier Signed-off-by: Jonathan Corbet

Documentation: nvme: Documentation for nvme fault injection

2018-03-26T14:53:43Z

Add examples to show how to use nvme fault injection. Signed-off-by: Thomas Tai Reviewed-by: Eric Saint-Etienne Signed-off-by: Karl Volz Reviewed-by: Keith Busch Signed-off-by: Sagi Grimberg Signed-off-by: Jens Axboe

Merge tag 'docs-4.16' of git://git.lwn.net/linux

2018-02-01T03:25:25Z

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 ...

error-injection: Support fault injection framework

2018-01-13T01:33:38Z

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 Reviewed-by: Josef Bacik Signed-off-by: Alexei Starovoitov

doc: md: Fix a file name to md-fault.c in fault-injection.txt

2018-01-01T19:43:09Z

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 Signed-off-by: Jonathan Corbet

cpu/hotplug: Get rid of CPU hotplug notifier leftovers

2017-11-13T09:03:53Z

The CPU hotplug notifiers are history. Remove the last reminders. Reported-by: Ingo Molnar Signed-off-by: Thomas Gleixner

fault-inject: add /proc//fail-nth

2017-07-14T22:05:13Z

fail-nth interface is only created in /proc/self/task//. This change also adds it in /proc//. 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 Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fault-inject: make fail-nth read/write interface symmetric

2017-07-14T22:05:13Z

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 Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fault-inject: parse as natural 1-based value for fail-nth write interface

2017-07-14T22:05:13Z

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 Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fault-inject: support systematic fault injection

2017-07-12T23:26:01Z

Add /proc/self/task//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 Cc: Akinobu Mita Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds