#ifndef PAGE_ACTOR_H
#define PAGE_ACTOR_H
/*
 * Copyright (c) 2013
 * Phillip Lougher <phillip@squashfs.org.uk>
 *
 * This work is licensed under the terms of the GNU GPL, version 2. See
 * the COPYING file in the top-level directory.
 */

#ifndef CONFIG_SQUASHFS_FILE_DIRECT
struct squashfs_page_actor {
	void	**page;
	int	pages;
	int	length;
	int	next_page;
};

static inline struct squashfs_page_actor *squashfs_page_actor_init(void **page,
	int pages, int length)
{
	struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL);

	if (actor == NULL)
		return NULL;

	actor->length = length ? : pages * PAGE_SIZE;
	actor->page = page;
	actor->pages = pages;
	actor->next_page = 0;
	return actor;
}

static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
{
	actor->next_page = 1;
	return actor->page[0];
}

static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
{
	return actor->next_page == actor->pages ? NULL :
		actor->page[actor->next_page++];
}

static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
{
	/* empty */
}
#else
struct squashfs_page_actor {
	union {
		void		**buffer;
		struct page	**page;
	};
	void	*pageaddr;
	void    *(*squashfs_first_page)(struct squashfs_page_actor *);
	void    *(*squashfs_next_page)(struct squashfs_page_actor *);
	void    (*squashfs_finish_page)(struct squashfs_page_actor *);
	int	pages;
	int	length;
	int	next_page;
};

extern struct squashfs_page_actor *squashfs_page_actor_init(void **, int, int);
extern struct squashfs_page_actor *squashfs_page_actor_init_special(struct page
							 **, int, int);
static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
{
	return actor->squashfs_first_page(actor);
}
static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
{
	return actor->squashfs_next_page(actor);
}
static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
{
	actor->squashfs_finish_page(actor);
}
#endif
#endif
66b6279f610a24ac1d42dcbe30e10fa61220b2'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/net/hsr/Kconfig'>
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/log/?id=c966b6279f610a24ac1d42dcbe30e10fa61220b2'>root</a>/<a href='/cgit.cgi/linux/net-next.git/log/net?id=c966b6279f610a24ac1d42dcbe30e10fa61220b2'>net</a>/<a href='/cgit.cgi/linux/net-next.git/log/net/hsr?id=c966b6279f610a24ac1d42dcbe30e10fa61220b2'>hsr</a>/<a href='/cgit.cgi/linux/net-next.git/log/net/hsr/Kconfig?id=c966b6279f610a24ac1d42dcbe30e10fa61220b2'>Kconfig</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/cgit.cgi/linux/net-next.git/log/net/hsr/Kconfig?id=c966b6279f610a24ac1d42dcbe30e10fa61220b2&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>
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<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/netrom/nr_route.c?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>91539eb1fda2d530d3b268eef542c5414e54bf1a</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/netrom/nr_route.c?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/netrom/nr_route.c?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>net/netrom/nr_route.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/netrom/nr_route.c?id=6610d0edf6dc7ee97e46ab3a538a565c79d26199'>6610d0edf6dc7ee97e46ab3a538a565c79d26199</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/netrom/nr_route.c?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/netrom/nr_route.c')</div><table summary='diffstat' class='diffstat'>