#include <net/ip.h>
#include <net/udp.h>
#include <net/udplite.h>
#include <asm/checksum.h>

#ifndef _HAVE_ARCH_IPV6_CSUM
__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
			const struct in6_addr *daddr,
			__u32 len, __u8 proto, __wsum csum)
{

	int carry;
	__u32 ulen;
	__u32 uproto;
	__u32 sum = (__force u32)csum;

	sum += (__force u32)saddr->s6_addr32[0];
	carry = (sum < (__force u32)saddr->s6_addr32[0]);
	sum += carry;

	sum += (__force u32)saddr->s6_addr32[1];
	carry = (sum < (__force u32)saddr->s6_addr32[1]);
	sum += carry;

	sum += (__force u32)saddr->s6_addr32[2];
	carry = (sum < (__force u32)saddr->s6_addr32[2]);
	sum += carry;

	sum += (__force u32)saddr->s6_addr32[3];
	carry = (sum < (__force u32)saddr->s6_addr32[3]);
	sum += carry;

	sum += (__force u32)daddr->s6_addr32[0];
	carry = (sum < (__force u32)daddr->s6_addr32[0]);
	sum += carry;

	sum += (__force u32)daddr->s6_addr32[1];
	carry = (sum < (__force u32)daddr->s6_addr32[1]);
	sum += carry;

	sum += (__force u32)daddr->s6_addr32[2];
	carry = (sum < (__force u32)daddr->s6_addr32[2]);
	sum += carry;

	sum += (__force u32)daddr->s6_addr32[3];
	carry = (sum < (__force u32)daddr->s6_addr32[3]);
	sum += carry;

	ulen = (__force u32)htonl((__u32) len);
	sum += ulen;
	carry = (sum < ulen);
	sum += carry;

	uproto = (__force u32)htonl(proto);
	sum += uproto;
	carry = (sum < uproto);
	sum += carry;

	return csum_fold((__force __wsum)sum);
}
EXPORT_SYMBOL(csum_ipv6_magic);
#endif

int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
{
	int err;

	UDP_SKB_CB(skb)->partial_cov = 0;
	UDP_SKB_CB(skb)->cscov = skb->len;

	if (proto == IPPROTO_UDPLITE) {
		err = udplite_checksum_init(skb, uh);
		if (err)
			return err;
	}

	/* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)
	 * we accept a checksum of zero here. When we find the socket
	 * for the UDP packet we'll check if that socket allows zero checksum
	 * for IPv6 (set by socket option).
	 *
	 * Note, we are only interested in != 0 or == 0, thus the
	 * force to int.
	 */
	return (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
							 ip6_compute_pseudo);
}
EXPORT_SYMBOL(udp6_csum_init);

/* Function to set UDP checksum for an IPv6 UDP packet. This is intended
 * for the simple case like when setting the checksum for a UDP tunnel.
 */
void udp6_set_csum(bool nocheck, struct sk_buff *skb,
		   const struct in6_addr *saddr,
		   const struct in6_addr *daddr, int len)
{
	struct udphdr *uh = udp_hdr(skb);

	if (nocheck)
		uh->check = 0;
	else if (skb_is_gso(skb))
		uh->check = ~udp_v6_check(len, saddr, daddr, 0);
	else if (skb->ip_summed == CHECKSUM_PARTIAL) {
		uh->check = 0;
		uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb));
		if (uh->check == 0)
			uh->check = CSUM_MANGLED_0;
	} else {
		skb->ip_summed = CHECKSUM_PARTIAL;
		skb->csum_start = skb_transport_header(skb) - skb->head;
		skb->csum_offset = offsetof(struct udphdr, check);
		uh->check = ~udp_v6_check(len, saddr, daddr, 0);
	}
}
EXPORT_SYMBOL(udp6_set_csum);
268eef542c5414e54bf1a'>ircomm</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/irda/ircomm/Kconfig?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>Kconfig</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/net/irda/ircomm/Kconfig?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>91539eb1fda2d530d3b268eef542c5414e54bf1a</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/irda/ircomm/Kconfig?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/net/irda/ircomm/Kconfig?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>net/irda/ircomm/Kconfig</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/irda/ircomm/Kconfig?id=6610d0edf6dc7ee97e46ab3a538a565c79d26199'>6610d0edf6dc7ee97e46ab3a538a565c79d26199</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/irda/ircomm/Kconfig?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 'net/irda/ircomm/Kconfig')</div><table summary='diffstat' class='diffstat'>