#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>

#include "notifier-error-inject.h"

static int priority;
module_param(priority, int, 0);
MODULE_PARM_DESC(priority, "specify netdevice notifier priority");

static struct notifier_err_inject netdev_notifier_err_inject = {
	.actions = {
		{ NOTIFIER_ERR_INJECT_ACTION(NETDEV_REGISTER) },
		{ NOTIFIER_ERR_INJECT_ACTION(NETDEV_CHANGEMTU) },
		{ NOTIFIER_ERR_INJECT_ACTION(NETDEV_CHANGENAME) },
		{ NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRE_UP) },
		{ NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRE_TYPE_CHANGE) },
		{ NOTIFIER_ERR_INJECT_ACTION(NETDEV_POST_INIT) },
		{ NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRECHANGEMTU) },
		{ NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRECHANGEUPPER) },
		{ NOTIFIER_ERR_INJECT_ACTION(NETDEV_CHANGEUPPER) },
		{}
	}
};

static struct dentry *dir;

static int netdev_err_inject_init(void)
{
	int err;

	dir = notifier_err_inject_init("netdev", notifier_err_inject_dir,
				       &netdev_notifier_err_inject, priority);
	if (IS_ERR(dir))
		return PTR_ERR(dir);

	err = register_netdevice_notifier(&netdev_notifier_err_inject.nb);
	if (err)
		debugfs_remove_recursive(dir);

	return err;
}

static void netdev_err_inject_exit(void)
{
	unregister_netdevice_notifier(&netdev_notifier_err_inject.nb);
	debugfs_remove_recursive(dir);
}

module_init(netdev_err_inject_init);
module_exit(netdev_err_inject_exit);

MODULE_DESCRIPTION("Netdevice notifier error injection module");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Nikolay Aleksandrov <razor@blackwall.org>");
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/tree/?id=c3396656666c2c98db306dc91c480d9fbde35cc9'>root</a>/<a href='/cgit.cgi/linux/net-next.git/tree/include?id=c3396656666c2c98db306dc91c480d9fbde35cc9'>include</a></div><div class='content'><table summary='tree listing' class='list'>
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'/cgit.cgi/linux/net-next.git/commit/include/drm?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>drm</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/drm/drm_displayid.h?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>drm_displayid.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='91539eb1fda2d530d3b268eef542c5414e54bf1a'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</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>Iago Abal &lt;mail@iagoabal.eu&gt;</td><td class='right'>2017-01-11 14:00:21 +0100</td></tr>
<tr><th>committer</th><td>Vinod Koul &lt;vinod.koul@intel.com&gt;</td><td class='right'>2017-01-25 15:35:11 +0530</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/drm/drm_displayid.h?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>91539eb1fda2d530d3b268eef542c5414e54bf1a</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/drm/drm_displayid.h?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>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/include/drm/drm_displayid.h?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>include/drm/drm_displayid.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/drm/drm_displayid.h?id=6610d0edf6dc7ee97e46ab3a538a565c79d26199'>6610d0edf6dc7ee97e46ab3a538a565c79d26199</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/drm/drm_displayid.h?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 'include/drm/drm_displayid.h')</div><table summary='diffstat' class='diffstat'>