/*
 * netsniff-ng - the packet sniffing beast
 * Copyright 2009, 2010, 2011, 2012 Daniel Borkmann.
 * Subject to the GPL, version 2.
 */

#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>

#include "built_in.h"
#include "tprintf.h"
#include "pkt_buff.h"
#include "proto.h"
#include "dissector.h"
#include "dissector_eth.h"
#include "dissector_sll.h"
#include "dissector_80211.h"
#include "dissector_netlink.h"
#include "linktype.h"

int dissector_set_print_type(void *ptr, int type)
{
	struct protocol *proto;

	for (proto = ptr; proto; proto = proto->next) {
		switch (type) {
		case PRINT_NORM:
			proto->process = proto->print_full;
			break;
		case PRINT_LESS:
			proto->process = proto->print_less;
			break;
		default:
			proto->process = NULL;
			break;
		}
	}

	return 0;
}

static void dissector_main(struct pkt_buff *pkt, struct protocol *start,
			   struct protocol *end)
{
	struct protocol *dissector;

	if (!start)
		return;

	for (pkt->dissector = start; pkt->dissector; ) {
		if (unlikely(!pkt->dissector->process))
			break;

		dissector = pkt->dissector;
		pkt->dissector = NULL;
		dissector->process(pkt);
	}

	if (end && likely(end->process))
		end->process(pkt);
}

void dissector_entry_point(uint8_t *packet, size_t len, int linktype, int mode,
			   struct sockaddr_ll *sll)
{
	struct protocol *proto_start, *proto_end;
	struct pkt_buff *pkt;

	if (mode == PRINT_NONE)
		return;

	pkt = pkt_alloc(packet, len);
	pkt->link_type = linktype;
	pkt->sll = sll;

	switch (linktype) {
	case LINKTYPE_EN10MB:
	case ___constant_swab32(LINKTYPE_EN10MB):
		proto_start = dissector_get_ethernet_entry_point();
		proto_end = dissector_get_ethernet_exit_point();
		break;
	case LINKTYPE_IEEE802_11_RADIOTAP:
	case ___constant_swab32(LINKTYPE_IEEE802_11_RADIOTAP):
	case LINKTYPE_IEEE802_11:
	case ___constant_swab32(LINKTYPE_IEEE802_11):
		proto_start = dissector_get_ieee80211_entry_point();
		proto_end = dissector_get_ieee80211_exit_point();
		break;
	case LINKTYPE_NETLINK:
	case ___constant_swab32(LINKTYPE_NETLINK):
		proto_start = dissector_get_netlink_entry_point();
		proto_end = dissector_get_netlink_exit_point();
		break;
	case LINKTYPE_LINUX_SLL:
	case ___constant_swab32(LINKTYPE_LINUX_SLL):
		proto_start = dissector_get_sll_entry_point();
		proto_end = dissector_get_sll_exit_point();
		break;
	default:
		proto_start = &none_ops;
		proto_end = NULL;
		break;
	};

	dissector_main(pkt, proto_start, proto_end);

	switch (mode) {
	case PRINT_HEX:
		hex(pkt);
		break;
	case PRINT_ASCII:
		ascii(pkt);
		break;
	case PRINT_HEX_ASCII:
		hex_ascii(pkt);
		break;
	}

	tprintf_flush();
	pkt_free(pkt);
}

void dissector_init_all(int fnttype)
{
	dissector_init_ethernet(fnttype);
	dissector_init_ieee80211(fnttype);
	dissector_init_netlink(fnttype);
	dissector_init_sll(fnttype);
}

void dissector_cleanup_all(void)
{
	dissector_cleanup_ethernet();
	dissector_cleanup_ieee80211();
	dissector_cleanup_netlink();
	dissector_cleanup_sll();
}
mit/?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>sound</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/pci?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>pci</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/cs5535audio?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>cs5535audio</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='966d2b04e070bc040319aaebfec09e0144dc3341'/><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>Douglas Miller &lt;dougmill@linux.vnet.ibm.com&gt;</td><td class='right'>2017-01-28 06:42:20 -0600</td></tr>
<tr><th>committer</th><td>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-28 07:49:42 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/cs5535audio?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>966d2b04e070bc040319aaebfec09e0144dc3341</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/pci/cs5535audio?id=966d2b04e070bc040319aaebfec09e0144dc3341'>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=966d2b04e070bc040319aaebfec09e0144dc3341'>4b96156e3d1dd4dfd6039b7c219c9dc4616da52d</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/pci/cs5535audio?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>sound/pci/cs5535audio</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/cs5535audio?h=nds-private-remove&amp;id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>1b1bc42c1692e9b62756323c675a44cb1a1f9dbd</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/pci/cs5535audio?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341&amp;id2=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>diff</a>)</td></tr></table>
<div class='commit-subject'>percpu-refcount: fix reference leak during percpu-atomic transition</div><div class='commit-msg'>percpu_ref_tryget() and percpu_ref_tryget_live() should return
"true" IFF they acquire a reference. But the return value from
atomic_long_inc_not_zero() is a long and may have high bits set,
e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines
is bool so the reference may actually be acquired but the routines
return "false" which results in a reference leak since the caller
assumes it does not need to do a corresponding percpu_ref_put().

This was seen when performing CPU hotplug during I/O, as hangs in
blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start)
raced with percpu_ref_tryget (blk_mq_timeout_work).
Sample stack trace:

__switch_to+0x2c0/0x450
__schedule+0x2f8/0x970
schedule+0x48/0xc0
blk_mq_freeze_queue_wait+0x94/0x120
blk_mq_queue_reinit_work+0xb8/0x180
blk_mq_queue_reinit_prepare+0x84/0xa0
cpuhp_invoke_callback+0x17c/0x600
cpuhp_up_callbacks+0x58/0x150
_cpu_up+0xf0/0x1c0
do_cpu_up+0x120/0x150
cpu_subsys_online+0x64/0xe0
device_online+0xb4/0x120
online_store+0xb4/0xc0
dev_attr_store+0x68/0xa0
sysfs_kf_write+0x80/0xb0
kernfs_fop_write+0x17c/0x250
__vfs_write+0x6c/0x1e0
vfs_write+0xd0/0x270
SyS_write+0x6c/0x110
system_call+0x38/0xe0

Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS,
and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests.
However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0
and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set.

The fix is to make the tryget routines use an actual boolean internally instead
of the atomic long result truncated to a int.

Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints
Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751
Signed-off-by: Douglas Miller &lt;dougmill@linux.vnet.ibm.com&gt;
Reviewed-by: Jens Axboe &lt;axboe@fb.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints")
Cc: stable@vger.kernel.org # v3.18+
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>Diffstat</a> (limited to 'sound/pci/cs5535audio')</div><table summary='diffstat' class='diffstat'>