#!/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 "$1" ] && 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"
/option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;</td><td class='right'>2017-02-03 17:10:28 +1100</td></tr>
<tr><th>committer</th><td>Michael Ellerman &lt;mpe@ellerman.id.au&gt;</td><td class='right'>2017-02-08 23:36:29 +1100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/bluetooth/l2cap_sock.c?h=nds-private-remove&amp;id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>d7df2443cd5f67fc6ee7c05a88e4996e8177f91b</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/bluetooth/l2cap_sock.c?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>098a7c0ca4fceb8a65cb1f693c9d71990388933d</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/bluetooth/l2cap_sock.c?h=nds-private-remove&amp;id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>net/bluetooth/l2cap_sock.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/bluetooth/l2cap_sock.c?h=nds-private-remove&amp;id=a0615a16f7d0ceb5804d295203c302d496d8ee91'>a0615a16f7d0ceb5804d295203c302d496d8ee91</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/bluetooth/l2cap_sock.c?h=nds-private-remove&amp;id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b&amp;id2=a0615a16f7d0ceb5804d295203c302d496d8ee91'>diff</a>)</td></tr></table>
<div class='commit-subject'>powerpc/mm: Fix spurrious segfaults on radix with autonuma</div><div class='commit-msg'>When autonuma (Automatic NUMA balancing) marks a PTE inaccessible it
clears all the protection bits but leave the PTE valid.

With the Radix MMU, an attempt at executing from such a PTE will
take a fault with bit 35 of SRR1 set "SRR1_ISI_N_OR_G".

It is thus incorrect to treat all such faults as errors. We should
pass them to handle_mm_fault() for autonuma to deal with. The case
of pages that are really not executable is handled by the existing
test for VM_EXEC further down.

That leaves us with catching the kernel attempts at executing user
pages. We can catch that earlier, even before we do find_vma.

It is never valid on powerpc for the kernel to take an exec fault
to begin with. So fold that test with the existing test for the
kernel faulting on kernel addresses to bail out early.

Fixes: 1d18ad026844 ("powerpc/mm: Detect instruction fetch denied and report")
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Reviewed-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Acked-by: Balbir Singh &lt;bsingharora@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>Diffstat</a> (limited to 'net/bluetooth/l2cap_sock.c')</div><table summary='diffstat' class='diffstat'>