fault-injection: add tool to run command with failslab or fail_page_alloc

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>

2 files changed, 246 insertions, 0 deletions

diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt
index ba4be8b77093..4cf1a2a6bd72 100644
--- a/Documentation/fault-injection/fault-injection.txt
+++ b/Documentation/fault-injection/fault-injection.txt
@@ -240,3 +240,30 @@ trap "echo 0 > /sys/kernel/debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT
 echo "Injecting errors into the module $module... (interrupt to stop)"
 sleep 1000000
 
+Tool to run command with failslab or fail_page_alloc
+----------------------------------------------------
+In order to make it easier to accomplish the tasks mentioned above, we can use
+tools/testing/fault-injection/failcmd.sh.  Please run a command
+"./tools/testing/fault-injection/failcmd.sh --help" for more information and
+see the following examples.
+
+Examples:
+
+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
diff --git a/tools/testing/fault-injection/failcmd.sh b/tools/testing/fault-injection/failcmd.sh
new file mode 100644
index 000000000000..1776e924b202
--- /dev/null
+++ b/tools/testing/fault-injection/failcmd.sh
@@ -0,0 +1,219 @@
+#!/bin/bash
+#
+# NAME
+#       failcmd.sh - run a command with injecting slab/page allocation failures
+#
+# SYNOPSIS
+#       failcmd.sh --help
+#       failcmd.sh [<options>] command [arguments]
+#
+# DESCRIPTION
+#       Run command with injecting slab/page allocation failures by fault
+#       injection.
+#
+#       NOTE: you need to run this script as root.
+#
+
+usage()
+{
+        cat >&2 <<EOF
+Usage: $0 [options] command [arguments]
+
+OPTIONS
+        -p percent
+        --probability=percent
+                likelihood of failure injection, in percent.
+                Default value is 1
+
+        -t value
+        --times=value
+                specifies how many times failures may happen at most.
+                Default value is 1
+
+        --oom-kill-allocating-task=value
+                set /proc/sys/vm/oom_kill_allocating_task to specified value
+                before running the command.
+                Default value is 1
+
+        -h, --help
+                Display a usage message and exit
+
+        --interval=value, --space=value, --verbose=value, --task-filter=value,
+        --stacktrace-depth=value, --require-start=value, --require-end=value,
+        --reject-start=value, --reject-end=value, --ignore-gfp-wait=value
+                See Documentation/fault-injection/fault-injection.txt for more
+                information
+
+        failslab options:
+        --cache-filter=value
+
+        fail_page_alloc options:
+        --ignore-gfp-highmem=value, --min-order=value
+
+ENVIRONMENT
+        FAILCMD_TYPE
+                The following values for FAILCMD_TYPE are recognized:
+
+                failslab
+                        inject slab allocation failures
+                fail_page_alloc
+                        inject page allocation failures
+
+                If FAILCMD_TYPE is not defined, then failslab is used.
+EOF
+}
+
+if [ $UID != 0 ]; then
+        echo must be run as root >&2
+        exit 1
+fi
+
+DEBUGFS=`mount -t debugfs | head -1 | awk '{ print $3}'`
+
+if [ ! -d "$DEBUGFS" ]; then
+        echo debugfs is not mounted >&2
+        exit 1
+fi
+
+FAILCMD_TYPE=${FAILCMD_TYPE:-failslab}
+FAULTATTR=$DEBUGFS/$FAILCMD_TYPE
+
+if [ ! -d $FAULTATTR ]; then
+        echo $FAILCMD_TYPE is not available >&2
+        exit 1
+fi
+
+LONGOPTS=probability:,interval:,times:,space:,verbose:,task-filter:
+LONGOPTS=$LONGOPTS,stacktrace-depth:,require-start:,require-end:
+LONGOPTS=$LONGOPTS,reject-start:,reject-end:,oom-kill-allocating-task:,help
+
+if [ $FAILCMD_TYPE = failslab ]; then
+        LONGOPTS=$LONGOPTS,ignore-gfp-wait:,cache-filter:
+elif [ $FAILCMD_TYPE = fail_page_alloc ]; then
+        LONGOPTS=$LONGOPTS,ignore-gfp-wait:,ignore-gfp-highmem:,min-order:
+fi
+
+TEMP=`getopt -o p:i:t:s:v:h --long $LONGOPTS -n 'failcmd.sh' -- "$@"`
+
+if [ $? != 0 ]; then
+        usage
+        exit 1
+fi
+
+eval set -- "$TEMP"
+
+fault_attr_default()
+{
+        echo N > $FAULTATTR/task-filter
+        echo 0 > $FAULTATTR/probability
+        echo 1 > $FAULTATTR/times
+}
+
+fault_attr_default
+
+oom_kill_allocating_task_saved=`cat /proc/sys/vm/oom_kill_allocating_task`
+
+restore_values()
+{
+        fault_attr_default
+        echo $oom_kill_allocating_task_saved \
+                > /proc/sys/vm/oom_kill_allocating_task
+}
+
+#
+# Default options
+#
+declare -i oom_kill_allocating_task=1
+declare task_filter=Y
+declare -i probability=1
+declare -i times=1
+
+while true; do
+        case "$1" in
+        -p|--probability)
+                probability=$2
+                shift 2
+                ;;
+        -i|--interval)
+                echo $2 > $FAULTATTR/interval
+                shift 2
+                ;;
+        -t|--times)
+                times=$2
+                shift 2
+                ;;
+        -s|--space)
+                echo $2 > $FAULTATTR/space
+                shift 2
+                ;;
+        -v|--verbose)
+                echo $2 > $FAULTATTR/verbose
+                shift 2
+                ;;
+        --task-filter)
+                task_filter=$2
+                shift 2
+                ;;
+        --stacktrace-depth)
+                echo $2 > $FAULTATTR/stacktrace-depth
+                shift 2
+                ;;
+        --require-start)
+                echo $2 > $FAULTATTR/require-start
+                shift 2
+                ;;
+        --require-end)
+                echo $2 > $FAULTATTR/require-end
+                shift 2
+                ;;
+        --reject-start)
+                echo $2 > $FAULTATTR/reject-start
+                shift 2
+                ;;
+        --reject-end)
+                echo $2 > $FAULTATTR/reject-end
+                shift 2
+                ;;
+        --oom-kill-allocating-task)
+                oom_kill_allocating_task=$2
+                shift 2
+                ;;
+        --ignore-gfp-wait)
+                echo $2 > $FAULTATTR/ignore-gfp-wait
+                shift 2
+                ;;
+        --cache-filter)
+                echo $2 > $FAULTATTR/cache_filter
+                shift 2
+                ;;
+        --ignore-gfp-highmem)
+                echo $2 > $FAULTATTR/ignore-gfp-highmem
+                shift 2
+                ;;
+        --min-order)
+                echo $2 > $FAULTATTR/min-order
+                shift 2
+                ;;
+        -h|--help)
+                usage
+                exit 0
+                shift
+                ;;
+        --)
+                shift
+                break
+                ;;
+        esac
+done
+
+[ -z "$@" ] && exit 0
+
+echo $oom_kill_allocating_task > /proc/sys/vm/oom_kill_allocating_task
+echo $task_filter > $FAULTATTR/task-filter
+echo $probability > $FAULTATTR/probability
+echo $times > $FAULTATTR/times
+
+trap "restore_values" SIGINT SIGTERM EXIT
+
+cmd="echo 1 > /proc/self/make-it-fail && exec $@"
+bash -c "$cmd"