1#!/bin/bash
  2# SPDX-License-Identifier: GPL-2.0
  3#
  4# NAME
  5#	failcmd.sh - run a command with injecting slab/page allocation failures
  6#
  7# SYNOPSIS
  8#	failcmd.sh --help
  9#	failcmd.sh [<options>] command [arguments]
 10#
 11# DESCRIPTION
 12#	Run command with injecting slab/page allocation failures by fault
 13#	injection.
 14#
 15#	NOTE: you need to run this script as root.
 16#
 17
 18usage()
 19{
 20	cat >&2 <<EOF
 21Usage: $0 [options] command [arguments]
 22
 23OPTIONS
 24	-p percent
 25	--probability=percent
 26		likelihood of failure injection, in percent.
 27		Default value is 1
 28
 29	-t value
 30	--times=value
 31		specifies how many times failures may happen at most.
 32		Default value is 1
 33
 34	--oom-kill-allocating-task=value
 35		set /proc/sys/vm/oom_kill_allocating_task to specified value
 36		before running the command.
 37		Default value is 1
 38
 39	-h, --help
 40		Display a usage message and exit
 41
 42	--interval=value, --space=value, --verbose=value, --task-filter=value,
 43	--stacktrace-depth=value, --require-start=value, --require-end=value,
 44	--reject-start=value, --reject-end=value, --ignore-gfp-wait=value
 45		See Documentation/fault-injection/fault-injection.rst for more
 46		information
 47
 48	failslab options:
 49	--cache-filter=value
 50
 51	fail_page_alloc options:
 52	--ignore-gfp-highmem=value, --min-order=value
 53
 54ENVIRONMENT
 55	FAILCMD_TYPE
 56		The following values for FAILCMD_TYPE are recognized:
 57
 58		failslab
 59			inject slab allocation failures
 60		fail_page_alloc
 61			inject page allocation failures
 62
 63		If FAILCMD_TYPE is not defined, then failslab is used.
 64EOF
 65}
 66
 67exit_if_not_hex() {
 68    local value="$1"
 69    if ! [[ $value =~ ^0x[0-9a-fA-F]+$ ]]; then
 70        echo "Error: The provided value '$value' is not a valid hexadecimal number." >&2
 71        exit 1
 72    fi
 73}
 74
 75if [ $UID != 0 ]; then
 76	echo must be run as root >&2
 77	exit 1
 78fi
 79
 80DEBUGFS=`mount -t debugfs | head -1 | awk '{ print $3}'`
 81
 82if [ ! -d "$DEBUGFS" ]; then
 83	echo debugfs is not mounted >&2
 84	exit 1
 85fi
 86
 87FAILCMD_TYPE=${FAILCMD_TYPE:-failslab}
 88FAULTATTR=$DEBUGFS/$FAILCMD_TYPE
 89
 90if [ ! -d $FAULTATTR ]; then
 91	echo $FAILCMD_TYPE is not available >&2
 92	exit 1
 93fi
 94
 95LONGOPTS=probability:,interval:,times:,space:,verbose:,task-filter:
 96LONGOPTS=$LONGOPTS,stacktrace-depth:,require-start:,require-end:
 97LONGOPTS=$LONGOPTS,reject-start:,reject-end:,oom-kill-allocating-task:,help
 98
 99if [ $FAILCMD_TYPE = failslab ]; then
100	LONGOPTS=$LONGOPTS,ignore-gfp-wait:,cache-filter:
101elif [ $FAILCMD_TYPE = fail_page_alloc ]; then
102	LONGOPTS=$LONGOPTS,ignore-gfp-wait:,ignore-gfp-highmem:,min-order:
103fi
104
105TEMP=`getopt -o p:i:t:s:v:h --long $LONGOPTS -n 'failcmd.sh' -- "$@"`
106
107if [ $? != 0 ]; then
108	usage
109	exit 1
110fi
111
112eval set -- "$TEMP"
113
114fault_attr_default()
115{
116	echo N > $FAULTATTR/task-filter
117	echo 0 > $FAULTATTR/probability
118	echo 1 > $FAULTATTR/times
119}
120
121fault_attr_default
122
123oom_kill_allocating_task_saved=`cat /proc/sys/vm/oom_kill_allocating_task`
124
125restore_values()
126{
127	fault_attr_default
128	echo $oom_kill_allocating_task_saved \
129		> /proc/sys/vm/oom_kill_allocating_task
130}
131
132#
133# Default options
134#
135declare -i oom_kill_allocating_task=1
136declare task_filter=Y
137declare -i probability=1
138declare -i times=1
139
140while true; do
141	case "$1" in
142	-p|--probability)
143		probability=$2
144		shift 2
145		;;
146	-i|--interval)
147		echo $2 > $FAULTATTR/interval
148		shift 2
149		;;
150	-t|--times)
151		times=$2
152		shift 2
153		;;
154	-s|--space)
155		echo $2 > $FAULTATTR/space
156		shift 2
157		;;
158	-v|--verbose)
159		echo $2 > $FAULTATTR/verbose
160		shift 2
161		;;
162	--task-filter)
163		task_filter=$2
164		shift 2
165		;;
166	--stacktrace-depth)
167		echo $2 > $FAULTATTR/stacktrace-depth
168		shift 2
169		;;
170	--require-start)
171		exit_if_not_hex "$2"
172		echo $2 > $FAULTATTR/require-start
173		shift 2
174		;;
175	--require-end)
176		exit_if_not_hex "$2"
177		echo $2 > $FAULTATTR/require-end
178		shift 2
179		;;
180	--reject-start)
181		exit_if_not_hex "$2"
182		echo $2 > $FAULTATTR/reject-start
183		shift 2
184		;;
185	--reject-end)
186		exit_if_not_hex "$2"
187		echo $2 > $FAULTATTR/reject-end
188		shift 2
189		;;
190	--oom-kill-allocating-task)
191		oom_kill_allocating_task=$2
192		shift 2
193		;;
194	--ignore-gfp-wait)
195		echo $2 > $FAULTATTR/ignore-gfp-wait
196		shift 2
197		;;
198	--cache-filter)
199		echo $2 > $FAULTATTR/cache_filter
200		shift 2
201		;;
202	--ignore-gfp-highmem)
203		echo $2 > $FAULTATTR/ignore-gfp-highmem
204		shift 2
205		;;
206	--min-order)
207		echo $2 > $FAULTATTR/min-order
208		shift 2
209		;;
210	-h|--help)
211		usage
212		exit 0
213		shift
214		;;
215	--)
216		shift
217		break
218		;;
219	esac
220done
221
222[ -z "$1" ] && exit 0
223
224echo $oom_kill_allocating_task > /proc/sys/vm/oom_kill_allocating_task
225echo $task_filter > $FAULTATTR/task-filter
226echo $probability > $FAULTATTR/probability
227echo $times > $FAULTATTR/times
228
229trap "restore_values" SIGINT SIGTERM EXIT
230
231cmd="echo 1 > /proc/self/make-it-fail && exec $@"
232bash -c "$cmd"