/*
 * Copyright 2014, Michael Ellerman, IBM Corp.
 * Licensed under GPLv2.
 */

#define _GNU_SOURCE

#include <elf.h>
#include <limits.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <sys/prctl.h>

#include "event.h"
#include "lib.h"
#include "utils.h"

/*
 * Test that per-event excludes work.
 */

static int per_event_excludes(void)
{
	struct event *e, events[4];
	char *platform;
	int i;

	platform = (char *)get_auxv_entry(AT_BASE_PLATFORM);
	FAIL_IF(!platform);
	SKIP_IF(strcmp(platform, "power8") != 0);

	/*
	 * We need to create the events disabled, otherwise the running/enabled
	 * counts don't match up.
	 */
	e = &events[0];
	event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
			PERF_TYPE_HARDWARE, "instructions");
	e->attr.disabled = 1;

	e = &events[1];
	event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
			PERF_TYPE_HARDWARE, "instructions(k)");
	e->attr.disabled = 1;
	e->attr.exclude_user = 1;
	e->attr.exclude_hv = 1;

	e = &events[2];
	event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
			PERF_TYPE_HARDWARE, "instructions(h)");
	e->attr.disabled = 1;
	e->attr.exclude_user = 1;
	e->attr.exclude_kernel = 1;

	e = &events[3];
	event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
			PERF_TYPE_HARDWARE, "instructions(u)");
	e->attr.disabled = 1;
	e->attr.exclude_hv = 1;
	e->attr.exclude_kernel = 1;

	FAIL_IF(event_open(&events[0]));

	/*
	 * The open here will fail if we don't have per event exclude support,
	 * because the second event has an incompatible set of exclude settings
	 * and we're asking for the events to be in a group.
	 */
	for (i = 1; i < 4; i++)
		FAIL_IF(event_open_with_group(&events[i], events[0].fd));

	/*
	 * Even though the above will fail without per-event excludes we keep
	 * testing in order to be thorough.
	 */
	prctl(PR_TASK_PERF_EVENTS_ENABLE);

	/* Spin for a while */
	for (i = 0; i < INT_MAX; i++)
		asm volatile("" : : : "memory");

	prctl(PR_TASK_PERF_EVENTS_DISABLE);

	for (i = 0; i < 4; i++) {
		FAIL_IF(event_read(&events[i]));
		event_report(&events[i]);
	}

	/*
	 * We should see that all events have enabled == running. That
	 * shows that they were all on the PMU at once.
	 */
	for (i = 0; i < 4; i++)
		FAIL_IF(events[i].result.running != events[i].result.enabled);

	/*
	 * We can also check that the result for instructions is >= all the
	 * other counts. That's because it is counting all instructions while
	 * the others are counting a subset.
	 */
	for (i = 1; i < 4; i++)
		FAIL_IF(events[0].result.value < events[i].result.value);

	for (i = 0; i < 4; i++)
		event_close(&events[i]);

	return 0;
}

int main(void)
{
	return test_harness(per_event_excludes, "per_event_excludes");
}
rm>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>drivers</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>usb</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/gadget?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>gadget</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/gadget/udc?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>udc</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/gadget/udc/fusb300_udc.c?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>fusb300_udc.c</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/drivers/usb/gadget/udc/fusb300_udc.c?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>91539eb1fda2d530d3b268eef542c5414e54bf1a</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/gadget/udc/fusb300_udc.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/drivers/usb/gadget/udc/fusb300_udc.c?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>drivers/usb/gadget/udc/fusb300_udc.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/gadget/udc/fusb300_udc.c?id=6610d0edf6dc7ee97e46ab3a538a565c79d26199'>6610d0edf6dc7ee97e46ab3a538a565c79d26199</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/gadget/udc/fusb300_udc.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 'drivers/usb/gadget/udc/fusb300_udc.c')</div><table summary='diffstat' class='diffstat'>