/*
 * Copyright 2016, Cyril Bur, IBM Corp.
 *
 * 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; either version
 * 2 of the License, or (at your option) any later version.
 *
 *
 * Test the kernel's signal frame code.
 *
 * The kernel sets up two sets of ucontexts if the signal was to be
 * delivered while the thread was in a transaction.
 * Expected behaviour is that the checkpointed state is in the user
 * context passed to the signal handler. The speculated state can be
 * accessed with the uc_link pointer.
 *
 * The rationale for this is that if TM unaware code (which linked
 * against TM libs) installs a signal handler it will not know of the
 * speculative nature of the 'live' registers and may infer the wrong
 * thing.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>

#include <altivec.h>

#include "utils.h"
#include "tm.h"

#define MAX_ATTEMPT 500000

#define NV_VSX_REGS 12

long tm_signal_self_context_load(pid_t pid, long *gprs, double *fps, vector int *vms, vector int *vss);

static sig_atomic_t fail;

vector int vss[] = {
	{1, 2, 3, 4 },{5, 6, 7, 8 },{9, 10,11,12},
	{13,14,15,16},{17,18,19,20},{21,22,23,24},
	{25,26,27,28},{29,30,31,32},{33,34,35,36},
	{37,38,39,40},{41,42,43,44},{45,46,47,48},
	{-1, -2, -3, -4 },{-5, -6, -7, -8 },{-9, -10,-11,-12},
	{-13,-14,-15,-16},{-17,-18,-19,-20},{-21,-22,-23,-24},
	{-25,-26,-27,-28},{-29,-30,-31,-32},{-33,-34,-35,-36},
	{-37,-38,-39,-40},{-41,-42,-43,-44},{-45,-46,-47,-48}
};

static void signal_usr1(int signum, siginfo_t *info, void *uc)
{
	int i;
	uint8_t vsc[sizeof(vector int)];
	uint8_t vst[sizeof(vector int)];
	ucontext_t *ucp = uc;
	ucontext_t *tm_ucp = ucp->uc_link;

	/*
	 * The other half of the VSX regs will be after v_regs.
	 *
	 * In short, vmx_reserve array holds everything. v_regs is a 16
	 * byte aligned pointer at the start of vmx_reserve (vmx_reserve
	 * may or may not be 16 aligned) where the v_regs structure exists.
	 * (half of) The VSX regsters are directly after v_regs so the
	 * easiest way to find them below.
	 */
	long *vsx_ptr = (long *)(ucp->uc_mcontext.v_regs + 1);
	long *tm_vsx_ptr = (long *)(tm_ucp->uc_mcontext.v_regs + 1);
	for (i = 0; i < NV_VSX_REGS && !fail; i++) {
		memcpy(vsc, &ucp->uc_mcontext.fp_regs[i + 20], 8);
		memcpy(vsc + 8, &vsx_ptr[20 + i], 8);
		fail = memcmp(vsc, &vss[i], sizeof(vector int));
		memcpy(vst, &tm_ucp->uc_mcontext.fp_regs[i + 20], 8);
		memcpy(vst + 8, &tm_vsx_ptr[20 + i], 8);
		fail |= memcmp(vst, &vss[i + NV_VSX_REGS], sizeof(vector int));

		if (fail) {
			int j;

			fprintf(stderr, "Failed on %d vsx 0x", i);
			for (j = 0; j < 16; j++)
				fprintf(stderr, "%02x", vsc[j]);
			fprintf(stderr, " vs 0x");
			for (j = 0; j < 16; j++)
				fprintf(stderr, "%02x", vst[j]);
			fprintf(stderr, "\n");
		}
	}
}

static int tm_signal_context_chk()
{
	struct sigaction act;
	int i;
	long rc;
	pid_t pid = getpid();

	SKIP_IF(!have_htm());

	act.sa_sigaction = signal_usr1;
	sigemptyset(&act.sa_mask);
	act.sa_flags = SA_SIGINFO;
	if (sigaction(SIGUSR1, &act, NULL) < 0) {
		perror("sigaction sigusr1");
		exit(1);
	}

	i = 0;
	while (i < MAX_ATTEMPT && !fail) {
		rc = tm_signal_self_context_load(pid, NULL, NULL, NULL, vss);
		FAIL_IF(rc != pid);
		i++;
	}

	return fail;
}

int main(void)
{
	return test_harness(tm_signal_context_chk, "tm_signal_context_chk_vsx");
}
te-remove&amp;id=433e19cf33d34bb6751c874a9c00980552fe508c'>Kconfig</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='433e19cf33d34bb6751c874a9c00980552fe508c'/><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>Dexuan Cui &lt;decui@microsoft.com&gt;</td><td class='right'>2017-01-28 11:46:02 -0700</td></tr>
<tr><th>committer</th><td>Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;</td><td class='right'>2017-01-31 10:59:48 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/misc/Kconfig?h=nds-private-remove&amp;id=433e19cf33d34bb6751c874a9c00980552fe508c'>433e19cf33d34bb6751c874a9c00980552fe508c</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/misc/Kconfig?id=433e19cf33d34bb6751c874a9c00980552fe508c'>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=433e19cf33d34bb6751c874a9c00980552fe508c'>ce6547ef2987fbb289fa28f03536328a42781651</a> /<a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/misc/Kconfig?h=nds-private-remove&amp;id=433e19cf33d34bb6751c874a9c00980552fe508c'>drivers/usb/misc/Kconfig</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/misc/Kconfig?h=nds-private-remove&amp;id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>191e885a2e130e639bb0c8ee350d7047294f2ce6</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/misc/Kconfig?h=nds-private-remove&amp;id=433e19cf33d34bb6751c874a9c00980552fe508c&amp;id2=191e885a2e130e639bb0c8ee350d7047294f2ce6'>diff</a>)</td></tr></table>
<div class='commit-subject'>Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()</div><div class='commit-msg'>Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")
added the proper mb(), but removed the test "prev_write_sz &lt; pending_sz"
when making the signal decision.

As a result, the guest can signal the host unnecessarily,
and then the host can throttle the guest because the host
thinks the guest is buggy or malicious; finally the user
running stress test can perceive intermittent freeze of
the guest.

This patch brings back the test, and properly handles the
in-place consumption APIs used by NetVSC (see get_next_pkt_raw(),
put_pkt_raw() and commit_rd_index()).

Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")

Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reported-by: Rolf Neugebauer &lt;rolf.neugebauer@docker.com&gt;
Tested-by: Rolf Neugebauer &lt;rolf.neugebauer@docker.com&gt;
Cc: "K. Y. Srinivasan" &lt;kys@microsoft.com&gt;
Cc: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Cc: Stephen Hemminger &lt;sthemmin@microsoft.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: K. Y. Srinivasan &lt;kys@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=433e19cf33d34bb6751c874a9c00980552fe508c'>Diffstat</a> (limited to 'drivers/usb/misc/Kconfig')</div><table summary='diffstat' class='diffstat'>