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2017-08-10fault-inject: fix wrong should_fail() decision in task contextAkinobu Mita
Commit 1203c8e6fb0a ("fault-inject: simplify access check for fail-nth") unintentionally broke a conditional statement in should_fail(). Any faults are not injected in the task context by the change when the systematic fault injection is not used. This change restores to the previous correct behaviour. Link: http://lkml.kernel.org/r/1501633700-3488-1-git-send-email-akinobu.mita@gmail.com Fixes: 1203c8e6fb0a ("fault-inject: simplify access check for fail-nth") Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reported-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Tested-by: Lu Fengqi <lufq.fnst@cn.fujitsu.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>
2017-07-14fault-inject: simplify access check for fail-nthAkinobu Mita
The fail-nth file is created with 0666 and the access is permitted if and only if the task is current. This file is owned by the currnet user. So we can create it with 0644 and allow the owner to write it. This enables to watch the status of task->fail_nth from another processes. [akinobu.mita@gmail.com: don't convert unsigned type value as signed int] Link: http://lkml.kernel.org/r/1492444483-9239-1-git-send-email-akinobu.mita@gmail.com [akinobu.mita@gmail.com: avoid unwanted data race to task->fail_nth] Link: http://lkml.kernel.org/r/1499962492-8931-1-git-send-email-akinobu.mita@gmail.com Link: http://lkml.kernel.org/r/1491490561-10485-5-git-send-email-akinobu.mita@gmail.com Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12fault-inject: support systematic fault injectionDmitry Vyukov
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>
2017-05-08lib/fault-inject.c: use correct check for interruptsDmitry Vyukov
in_interrupt() also returns true when bh is disabled in task context. That's not what fail_task() wants to check. Use the new in_task() predicate that does the right thing. Link: http://lkml.kernel.org/r/20170321091805.140676-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-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>
2015-10-23fault-inject: fix inverted interval/probability values in printkFlorian Westphal
interval displays the probability and vice versa. Fixes: 6adc4a22f20bb ("fault-inject: add ratelimit option") Acked-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13fault-inject: add ratelimit optionDmitry Monakhov
Current debug levels are not optimal. Especially if one want to provoke big numbers of faults(broken device simulator) then any verbose level will produce giant numbers of identical logging messages. Let's add ratelimit parameter for that purpose. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.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>
2013-06-03debugfs: add get/set for atomic typesSeth Jennings
debugfs currently lack the ability to create attributes that set/get atomic_t values. This patch adds support for this through a new debugfs_create_atomic_t() function. Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-29lib/: rename random32() to prandom_u32()Akinobu Mita
Use preferable function name which implies using a pseudo-random number generator. 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>
2012-06-20fault-inject: avoid call to random32() if fault injection is disabledAnton Blanchard
After enabling CONFIG_FAILSLAB I noticed random32 in profiles even if slub fault injection wasn't enabled at runtime. should_fail forces a comparison against random32() even if probability is 0: if (attr->probability <= random32() % 100) return false; Add a check up front for probability == 0 and avoid all of the more complicated checks. 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>
2012-03-07lib: reduce the use of module.h wherever possiblePaul Gortmaker
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-01-03switch debugfs to umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-10-26fault-inject: export setup_fault_attr()Per Forlin
mmc_core module needs to use setup_fault_attr() in order to set fault injection attributes during module load time. 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>
2011-10-26fault-inject: export fault injection functionsPer Forlin
Export symbols should_fail() and fault_create_debugfs_attr() in order to let modules utilize the fault injection framework. Signed-off-by: Per Forlin <per.forlin@linaro.org> Acked-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Chris Ball <cjb@laptop.org>
2011-08-03fault-injection: add ability to export fault_attr in arbitrary directoryAkinobu Mita
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>
2011-07-26fault-injection: use debugfs_remove_recursiveAkinobu Mita
Use debugfs_remove_recursive() to simplify initialization and deinitialization of fault injection debugfs files. 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>
2011-07-26fault-injection: cleanup simple attribute of stacktrace_depthAkinobu Mita
Minor cosmetic changes for simple attribute of stacktrace_depth: - use min_t() - reduce #ifdef by moving a function - do not use partly capitalized function name 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>
2011-07-26fault-injection: do not include unneeded headerAkinobu Mita
No need to include linux/kallsyms.h. 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>
2009-10-11headers: remove sched.h from interrupt.hAlexey Dobriyan
After m68k's task_thread_info() doesn't refer to current, it's possible to remove sched.h from interrupt.h and not break m68k! Many thanks to Heiko Carstens for allowing this. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-01-06Remove remaining unwinder codeAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Gabor Gombas <gombasg@sztaki.hu> Cc: Jan Beulich <jbeulich@novell.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu>, Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08libfs: allow error return from simple attributesChristoph Hellwig
Sometimes simple attributes might need to return an error, e.g. for acquiring a mutex interruptibly. In fact we have that situation in spufs already which is the original user of the simple attributes. This patch merged the temporarily forked attributes in spufs back into the main ones and allows to return errors. [akpm@linux-foundation.org: build fix] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: <stefano.brivio@polimi.it> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg KH <greg@kroah.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-24fault_inject: silence a warningStephen Rothwell
lib/fault-inject.c:168: warning: 'debugfs_create_ul_MAX_STACK_TRACE_DEPTH' defined but not used Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08simplify the stacktrace codeChristoph Hellwig
Simplify the stacktrace code: - remove the unused task argument to save_stack_trace, it's always current - remove the all_contexts flag, it's alwasy 0 Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andi Kleen <ak@suse.de> Cc: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20[PATCH] fault injection: split up stacktrace filter Kconfig optionAkinobu Mita
There is no prompt for CONFIG_STACKTRACE, so FAULT_INJECTION cannot be selected without LOCKDEP enabled. (found by Paolo 'Blaisorblade' Giarrusso) In order to fix such broken Kconfig dependency, this patch splits up the stacktrace filter support for fault injection by new Kconfig option, which enables to use fault injection on the architecture which doesn't have general stacktrace support. Cc: "Paolo 'Blaisorblade' Giarrusso" <blaisorblade@yahoo.it> 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>
2006-12-15Remove stack unwinder for nowLinus Torvalds
It has caused more problems than it ever really solved, and is apparently not getting cleaned up and fixed. We can put it back when it's stable and isn't likely to make warning or bug events worse. In the meantime, enable frame pointers for more readable stack traces. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] fault-injection: optimize and simplify should_fail()Don Mullis
Trivial optimization and simplification of should_fail(). Do cheaper disqualification tests first (performance gain not quantified). Simplify logic; eliminate goto. Signed-off-by: Don Mullis <dwm@meer.net> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] fault-injection: Clamp debugfs stacktrace-depth to MAX_STACK_TRACE_DEPTHDon Mullis
Clamp /debug/fail*/stacktrace-depth to MAX_STACK_TRACE_DEPTH. Ensures that a read of /debug/fail*/stacktrace-depth always returns a truthful answer. Signed-off-by: Don Mullis <dwm@meer.net> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] fault-injection: Use bool-true-false throughoutDon Mullis
Use bool-true-false throughout. Signed-off-by: Don Mullis <dwm@meer.net> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] fault injection: stacktrace filteringAkinobu Mita
This patch provides stacktrace filtering feature. The stacktrace filter allows failing only for the caller you are interested in. For example someone may want to inject kmalloc() failures into only e100 module. they want to inject not only direct kmalloc() call, but also indirect allocation, too. - e100_poll --> netif_receive_skb --> packet_rcv_spkt --> skb_clone --> kmem_cache_alloc This patch enables to detect function calls like this by stacktrace and inject failures. The script Documentaion/fault-injection/failmodule.sh helps it. The range of text section of loaded e100 is expected to be [/sys/module/e100/sections/.text, /sys/module/e100/sections/.exit.text) So failmodule.sh stores these values into /debug/failslab/address-start and /debug/failslab/address-end. The maximum stacktrace depth is specified by /debug/failslab/stacktrace-depth. Please see the example that demonstrates how to inject slab allocation failures only for a specific module in Documentation/fault-injection/fault-injection.txt [dwm@meer.net: reject failure if any caller lies within specified range] Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Don Mullis <dwm@meer.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] fault injection: process filtering for fault-injection capabilitiesAkinobu Mita
This patch provides process filtering feature. The process filter allows failing only permitted processes by /proc/<pid>/make-it-fail Please see the example that demostrates how to inject slab allocation failures into module init/cleanup code in Documentation/fault-injection/fault-injection.txt Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] fault-injection capabilities infrastructureAkinobu Mita
This patch provides base functions implement to fault-injection capabilities. - The function should_fail() is taken from failmalloc-1.0 (http://www.nongnu.org/failmalloc/) [akpm@osdl.org: cleanups, comments, add __init] Cc: <okuji@enbug.org> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Don Mullis <dwm@meer.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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