#!/bin/bash

SYSFS=

prerequisite()
{
	msg="skip all tests:"

	if [ $UID != 0 ]; then
		echo $msg must be run as root >&2
		exit 0
	fi

	taskset -p 01 $$

	SYSFS=`mount -t sysfs | head -1 | awk '{ print $3 }'`

	if [ ! -d "$SYSFS" ]; then
		echo $msg sysfs is not mounted >&2
		exit 0
	fi

	if ! ls $SYSFS/devices/system/cpu/cpu* > /dev/null 2>&1; then
		echo $msg cpu hotplug is not supported >&2
		exit 0
	fi

	echo "CPU online/offline summary:"
	online_cpus=`cat $SYSFS/devices/system/cpu/online`
	online_max=${online_cpus##*-}
	echo -e "\t Cpus in online state: $online_cpus"

	offline_cpus=`cat $SYSFS/devices/system/cpu/offline`
	if [[ "a$offline_cpus" = "a" ]]; then
		offline_cpus=0
	else
		offline_max=${offline_cpus##*-}
	fi
	echo -e "\t Cpus in offline state: $offline_cpus"
}

#
# list all hot-pluggable CPUs
#
hotpluggable_cpus()
{
	local state=${1:-.\*}

	for cpu in $SYSFS/devices/system/cpu/cpu*; do
		if [ -f $cpu/online ] && grep -q $state $cpu/online; then
			echo ${cpu##/*/cpu}
		fi
	done
}

hotplaggable_offline_cpus()
{
	hotpluggable_cpus 0
}

hotpluggable_online_cpus()
{
	hotpluggable_cpus 1
}

cpu_is_online()
{
	grep -q 1 $SYSFS/devices/system/cpu/cpu$1/online
}

cpu_is_offline()
{
	grep -q 0 $SYSFS/devices/system/cpu/cpu$1/online
}

online_cpu()
{
	echo 1 > $SYSFS/devices/system/cpu/cpu$1/online
}

offline_cpu()
{
	echo 0 > $SYSFS/devices/system/cpu/cpu$1/online
}

online_cpu_expect_success()
{
	local cpu=$1

	if ! online_cpu $cpu; then
		echo $FUNCNAME $cpu: unexpected fail >&2
	elif ! cpu_is_online $cpu; then
		echo $FUNCNAME $cpu: unexpected offline >&2
	fi
}

online_cpu_expect_fail()
{
	local cpu=$1

	if online_cpu $cpu 2> /dev/null; then
		echo $FUNCNAME $cpu: unexpected success >&2
	elif ! cpu_is_offline $cpu; then
		echo $FUNCNAME $cpu: unexpected online >&2
	fi
}

offline_cpu_expect_success()
{
	local cpu=$1

	if ! offline_cpu $cpu; then
		echo $FUNCNAME $cpu: unexpected fail >&2
	elif ! cpu_is_offline $cpu; then
		echo $FUNCNAME $cpu: unexpected offline >&2
	fi
}

offline_cpu_expect_fail()
{
	local cpu=$1

	if offline_cpu $cpu 2> /dev/null; then
		echo $FUNCNAME $cpu: unexpected success >&2
	elif ! cpu_is_online $cpu; then
		echo $FUNCNAME $cpu: unexpected offline >&2
	fi
}

error=-12
allcpus=0
priority=0
online_cpus=0
online_max=0
offline_cpus=0
offline_max=0

while getopts e:ahp: opt; do
	case $opt in
	e)
		error=$OPTARG
		;;
	a)
		allcpus=1
		;;
	h)
		echo "Usage $0 [ -a ] [ -e errno ] [ -p notifier-priority ]"
		echo -e "\t default offline one cpu"
		echo -e "\t run with -a option to offline all cpus"
		exit
		;;
	p)
		priority=$OPTARG
		;;
	esac
done

if ! [ "$error" -ge -4095 -a "$error" -lt 0 ]; then
	echo "error code must be -4095 <= errno < 0" >&2
	exit 1
fi

prerequisite

#
# Safe test (default) - offline and online one cpu
#
if [ $allcpus -eq 0 ]; then
	echo "Limited scope test: one hotplug cpu"
	echo -e "\t (leaves cpu in the original state):"
	echo -e "\t online to offline to online: cpu $online_max"
	offline_cpu_expect_success $online_max
	online_cpu_expect_success $online_max

	if [[ $offline_cpus -gt 0 ]]; then
		echo -e "\t offline to online to offline: cpu $offline_max"
		online_cpu_expect_success $offline_max
		offline_cpu_expect_success $offline_max
	fi
	exit 0
else
	echo "Full scope test: all hotplug cpus"
	echo -e "\t online all offline cpus"
	echo -e "\t offline all online cpus"
	echo -e "\t online all offline cpus"
fi

#
# Online all hot-pluggable CPUs
#
for cpu in `hotplaggable_offline_cpus`; do
	online_cpu_expect_success $cpu
done

#
# Offline all hot-pluggable CPUs
#
for cpu in `hotpluggable_online_cpus`; do
	offline_cpu_expect_success $cpu
done

#
# Online all hot-pluggable CPUs again
#
for cpu in `hotplaggable_offline_cpus`; do
	online_cpu_expect_success $cpu
done

#
# Test with cpu notifier error injection
#

DEBUGFS=`mount -t debugfs | head -1 | awk '{ print $3 }'`
NOTIFIER_ERR_INJECT_DIR=$DEBUGFS/notifier-error-inject/cpu

prerequisite_extra()
{
	msg="skip extra tests:"

	/sbin/modprobe -q -r cpu-notifier-error-inject
	/sbin/modprobe -q cpu-notifier-error-inject priority=$priority

	if [ ! -d "$DEBUGFS" ]; then
		echo $msg debugfs is not mounted >&2
		exit 0
	fi

	if [ ! -d $NOTIFIER_ERR_INJECT_DIR ]; then
		echo $msg cpu-notifier-error-inject module is not available >&2
		exit 0
	fi
}

prerequisite_extra

#
# Offline all hot-pluggable CPUs
#
echo 0 > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_DOWN_PREPARE/error
for cpu in `hotpluggable_online_cpus`; do
	offline_cpu_expect_success $cpu
done

#
# Test CPU hot-add error handling (offline => online)
#
echo $error > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_UP_PREPARE/error
for cpu in `hotplaggable_offline_cpus`; do
	online_cpu_expect_fail $cpu
done

#
# Online all hot-pluggable CPUs
#
echo 0 > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_UP_PREPARE/error
for cpu in `hotplaggable_offline_cpus`; do
	online_cpu_expect_success $cpu
done

#
# Test CPU hot-remove error handling (online => offline)
#
echo $error > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_DOWN_PREPARE/error
for cpu in `hotpluggable_online_cpus`; do
	offline_cpu_expect_fail $cpu
done

echo 0 > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_DOWN_PREPARE/error
/sbin/modprobe -q -r cpu-notifier-error-inject
1539eb1fda2d530d3b268eef542c5414e54bf1a'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>960f5ca6342ad20837aff18aad6e8ecd7da32fd6</a> /<a href='/cgit.cgi/linux/net-next.git/tree/fs/xfs/libxfs/xfs_ialloc_btree.c?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>fs/xfs/libxfs/xfs_ialloc_btree.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/fs/xfs/libxfs/xfs_ialloc_btree.c?id=6610d0edf6dc7ee97e46ab3a538a565c79d26199'>6610d0edf6dc7ee97e46ab3a538a565c79d26199</a> (<a href='/cgit.cgi/linux/net-next.git/diff/fs/xfs/libxfs/xfs_ialloc_btree.c?id=91539eb1fda2d530d3b268eef542c5414e54bf1a&amp;id2=6610d0edf6dc7ee97e46ab3a538a565c79d26199'>diff</a>)</td></tr></table>
<div class='commit-subject'>dmaengine: pl330: fix double lock</div><div class='commit-msg'>The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the
following double-lock bug:

    Double lock:
    1. spin_lock_irqsave(pch-&gt;lock, flags) at pl330_free_chan_resources:2236;
    2. call to function `pl330_release_channel' immediately after;
    3. call to function `dma_pl330_rqcb' in line 1753;
    4. spin_lock_irqsave(pch-&gt;lock, flags) at dma_pl330_rqcb:1505.

I have fixed it as suggested by Marek Szyprowski.

First, I have replaced `pch-&gt;lock' with `pl330-&gt;lock' in functions
`pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids
the double-lock by acquiring a different lock than `dma_pl330_rqcb'.

NOTE that, as a result, `pl330_free_chan_resources' executes
`list_splice_tail_init' on `pch-&gt;work_list' under lock `pl330-&gt;lock',
whereas in the rest of the code `pch-&gt;work_list' is protected by
`pch-&gt;lock'. I don't know if this may cause race conditions. Similarly
`pch-&gt;cyclic' is written by `pl330_alloc_chan_resources' under
`pl330-&gt;lock' but read by `pl330_tx_submit' under `pch-&gt;lock'.

Second, I have removed locking from `pl330_request_channel' and
`pl330_release_channel' functions. Function `pl330_request_channel' is
only called from `pl330_alloc_chan_resources', so the lock is already
held. Function `pl330_release_channel' is called from
`pl330_free_chan_resources', which already holds the lock, and from
`pl330_del'. Function `pl330_del' is called in an error path of
`pl330_probe' and at the end of `pl330_remove', but I assume that there
cannot be concurrent accesses to the protected data at those points.

Signed-off-by: Iago Abal &lt;mail@iagoabal.eu&gt;
Reviewed-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Signed-off-by: Vinod Koul &lt;vinod.koul@intel.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>Diffstat</a> (limited to 'fs/xfs/libxfs/xfs_ialloc_btree.c')</div><table summary='diffstat' class='diffstat'>