/*
 * net/sched/sch_blackhole.c	Black hole queue
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 * Authors:	Thomas Graf <tgraf@suug.ch>
 *
 * Note: Quantum tunneling is not supported.
 */

#include <linux/init.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <net/pkt_sched.h>

static int blackhole_enqueue(struct sk_buff *skb, struct Qdisc *sch,
			     struct sk_buff **to_free)
{
	qdisc_drop(skb, sch, to_free);
	return NET_XMIT_SUCCESS;
}

static struct sk_buff *blackhole_dequeue(struct Qdisc *sch)
{
	return NULL;
}

static struct Qdisc_ops blackhole_qdisc_ops __read_mostly = {
	.id		= "blackhole",
	.priv_size	= 0,
	.enqueue	= blackhole_enqueue,
	.dequeue	= blackhole_dequeue,
	.peek		= blackhole_dequeue,
	.owner		= THIS_MODULE,
};

static int __init blackhole_init(void)
{
	return register_qdisc(&blackhole_qdisc_ops);
}
device_initcall(blackhole_init)
tion value='master' selected='selected'>master</option>
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<tr><td class='sub'>net-next plumbings</td><td class='sub right'>Tobias Klauser</td></tr></table>
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>sound</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/soc?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>soc</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/pxa?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>pxa</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/pxa/e800_wm9712.c?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>e800_wm9712.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='c8f325a59cfc718d13a50fbc746ed9b415c25e92'/><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>Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;</td><td class='right'>2017-02-01 17:45:02 +0000</td></tr>
<tr><th>committer</th><td>Ingo Molnar &lt;mingo@kernel.org&gt;</td><td class='right'>2017-02-01 21:17:49 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/pxa/e800_wm9712.c?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>c8f325a59cfc718d13a50fbc746ed9b415c25e92</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/soc/pxa/e800_wm9712.c?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>d53fbdac9d0781e39a13b2ac6b2bd258cf3b4140</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/soc/pxa/e800_wm9712.c?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>sound/soc/pxa/e800_wm9712.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/pxa/e800_wm9712.c?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>bf29bddf0417a4783da3b24e8c9e017ac649326f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/soc/pxa/e800_wm9712.c?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92&amp;id2=bf29bddf0417a4783da3b24e8c9e017ac649326f'>diff</a>)</td></tr></table>
<div class='commit-subject'>efi/fdt: Avoid FDT manipulation after ExitBootServices()</div><div class='commit-msg'>Some AArch64 UEFI implementations disable the MMU in ExitBootServices(),
after which unaligned accesses to RAM are no longer supported.

Commit:

  abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")

fixed an issue in the memory map handling of the stub FDT code, but
inadvertently created an issue with such firmware, by moving some
of the FDT manipulation to after the invocation of ExitBootServices().

Given that the stub's libfdt implementation uses the ordinary, accelerated
string functions, which rely on hardware handling of unaligned accesses,
manipulating the FDT with the MMU off may result in alignment faults.

So fix the situation by moving the update_fdt_memmap() call into the
callback function invoked by efi_exit_boot_services() right before it
calls the ExitBootServices() UEFI service (which is arguably a better
place for it anyway)

Note that disabling the MMU in ExitBootServices() is not compliant with
the UEFI spec, and carries great risk due to the fact that switching from
cached to uncached memory accesses halfway through compiler generated code
(i.e., involving a stack) can never be done in a way that is architecturally
safe.

Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Tested-by: Riku Voipio &lt;riku.voipio@linaro.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Cc: mark.rutland@arm.com
Cc: linux-efi@vger.kernel.org
Cc: matt@codeblueprint.co.uk
Cc: leif.lindholm@linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>Diffstat</a> (limited to 'sound/soc/pxa/e800_wm9712.c')</div><table summary='diffstat' class='diffstat'>