/*
 * net/ife/ife.c - Inter-FE protocol based on ForCES WG InterFE LFB
 * Copyright (c) 2015 Jamal Hadi Salim <jhs@mojatatu.com>
 * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com>
 *
 * Refer to: draft-ietf-forces-interfelfb-03 and netdev01 paper:
 * "Distributing Linux Traffic Control Classifier-Action Subsystem"
 * Authors: Jamal Hadi Salim and Damascene M. Joachimpillai
 *
 * 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.
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/module.h>
#include <linux/init.h>
#include <net/net_namespace.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/etherdevice.h>
#include <net/ife.h>

struct ifeheadr {
	__be16 metalen;
	u8 tlv_data[];
};

void *ife_encode(struct sk_buff *skb, u16 metalen)
{
	/* OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
	 * where ORIGDATA = original ethernet header ...
	 */
	int hdrm = metalen + IFE_METAHDRLEN;
	int total_push = hdrm + skb->dev->hard_header_len;
	struct ifeheadr *ifehdr;
	struct ethhdr *iethh;	/* inner ether header */
	int skboff = 0;
	int err;

	err = skb_cow_head(skb, total_push);
	if (unlikely(err))
		return NULL;

	iethh = (struct ethhdr *) skb->data;

	__skb_push(skb, total_push);
	memcpy(skb->data, iethh, skb->dev->hard_header_len);
	skb_reset_mac_header(skb);
	skboff += skb->dev->hard_header_len;

	/* total metadata length */
	ifehdr = (struct ifeheadr *) (skb->data + skboff);
	metalen += IFE_METAHDRLEN;
	ifehdr->metalen = htons(metalen);

	return ifehdr->tlv_data;
}
EXPORT_SYMBOL_GPL(ife_encode);

void *ife_decode(struct sk_buff *skb, u16 *metalen)
{
	struct ifeheadr *ifehdr;
	int total_pull;
	u16 ifehdrln;

	ifehdr = (struct ifeheadr *) (skb->data + skb->dev->hard_header_len);
	ifehdrln = ntohs(ifehdr->metalen);
	total_pull = skb->dev->hard_header_len + ifehdrln;

	if (unlikely(ifehdrln < 2))
		return NULL;

	if (unlikely(!pskb_may_pull(skb, total_pull)))
		return NULL;

	skb_set_mac_header(skb, total_pull);
	__skb_pull(skb, total_pull);
	*metalen = ifehdrln - IFE_METAHDRLEN;

	return &ifehdr->tlv_data;
}
EXPORT_SYMBOL_GPL(ife_decode);

struct meta_tlvhdr {
	__be16 type;
	__be16 len;
};

/* Caller takes care of presenting data in network order
 */
void *ife_tlv_meta_decode(void *skbdata, u16 *attrtype, u16 *dlen, u16 *totlen)
{
	struct meta_tlvhdr *tlv = (struct meta_tlvhdr *) skbdata;

	*dlen = ntohs(tlv->len) - NLA_HDRLEN;
	*attrtype = ntohs(tlv->type);

	if (totlen)
		*totlen = nla_total_size(*dlen);

	return skbdata + sizeof(struct meta_tlvhdr);
}
EXPORT_SYMBOL_GPL(ife_tlv_meta_decode);

void *ife_tlv_meta_next(void *skbdata)
{
	struct meta_tlvhdr *tlv = (struct meta_tlvhdr *) skbdata;
	u16 tlvlen = ntohs(tlv->len);

	tlvlen = NLA_ALIGN(tlvlen);

	return skbdata + tlvlen;
}
EXPORT_SYMBOL_GPL(ife_tlv_meta_next);

/* Caller takes care of presenting data in network order
 */
int ife_tlv_meta_encode(void *skbdata, u16 attrtype, u16 dlen, const void *dval)
{
	__be32 *tlv = (__be32 *) (skbdata);
	u16 totlen = nla_total_size(dlen);	/*alignment + hdr */
	char *dptr = (char *) tlv + NLA_HDRLEN;
	u32 htlv = attrtype << 16 | (dlen + NLA_HDRLEN);

	*tlv = htonl(htlv);
	memset(dptr, 0, totlen - NLA_HDRLEN);
	memcpy(dptr, dval, dlen);

	return totlen;
}
EXPORT_SYMBOL_GPL(ife_tlv_meta_encode);

MODULE_AUTHOR("Jamal Hadi Salim <jhs@mojatatu.com>");
MODULE_AUTHOR("Yotam Gigi <yotamg@mellanox.com>");
MODULE_DESCRIPTION("Inter-FE LFB action");
MODULE_LICENSE("GPL");
alue='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/drivers/usb/phy/Makefile?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>91539eb1fda2d530d3b268eef542c5414e54bf1a</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/phy/Makefile?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/drivers/usb/phy/Makefile?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>drivers/usb/phy/Makefile</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/phy/Makefile?id=6610d0edf6dc7ee97e46ab3a538a565c79d26199'>6610d0edf6dc7ee97e46ab3a538a565c79d26199</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/phy/Makefile?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 'drivers/usb/phy/Makefile')</div><table summary='diffstat' class='diffstat'>