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path: root/Documentation/fault-injection/fault-injection.txt
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2012-07-31fault-injection: add tool to run command with failslab or fail_page_allocAkinobu Mita1-0/+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>
2011-10-27fault-injection: update documentation with the mmc module paramPer Forlin1-1/+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>
2011-10-26fault-inject: add documentation on MMC IO fault injectionPer Forlin1-1/+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>
2011-08-04fault-injection: add ability to export fault_attr in arbitrary directoryAkinobu Mita1-2/+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>
2010-02-03fault injection: correct function names in documentationAnton Blanchard1-2/+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>
2009-06-16debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem.GeunSik Lim1-35/+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>
2007-07-16fault-injection: fix example scripts in documentationAkinobu Mita1-49/+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>
2007-07-16fault-injection: add min-order parameter to fail_page_allocAkinobu Mita1-0/+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>
2006-12-08[PATCH] fault-injection: Correct, disambiguate, and reformat documentationDon Mullis1-35/+35
Correct, disambiguate, and reformat documentation. 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 Mita1-4/+8
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 capability for kmallocAkinobu Mita1-2/+0
This patch provides fault-injection capability for kmalloc. Boot option: failslab=<interval>,<probability>,<space>,<times> <interval> -- specifies the interval of failures. <probability> -- specifies how often it should fail in percent. <space> -- specifies the size of free space where memory can be allocated safely in bytes. <times> -- specifies how many times failures may happen at most. Debugfs: /debug/failslab/interval /debug/failslab/probability /debug/failslab/specifies /debug/failslab/times /debug/failslab/ignore-gfp-highmem /debug/failslab/ignore-gfp-wait Example: failslab=10,100,0,-1 slab allocation (kmalloc(), kmem_cache_alloc(),..) fails once per 10 times. Cc: Pekka Enberg <penberg@cs.helsinki.fi> 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: documentation and scriptsAkinobu Mita1-0/+223
This patch set provides some fault-injection capabilities. - kmalloc() failures - alloc_pages() failures - disk IO errors We can see what really happens if those failures happen. In order to enable these fault-injection capabilities: 1. Enable relevant config options (CONFIG_FAILSLAB, CONFIG_PAGE_ALLOC, CONFIG_MAKE_REQUEST) and if you want to configure them via debugfs, enable CONFIG_FAULT_INJECTION_DEBUG_FS. 2. Build and boot with this kernel 3. Configure fault-injection capabilities behavior by boot option or debugfs - Boot option failslab= fail_page_alloc= fail_make_request= - Debugfs /debug/failslab/* /debug/fail_page_alloc/* /debug/fail_make_request/* Please refer to the Documentation/fault-injection/fault-injection.txt for details. 4. See what really happens. 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>