/*
 * sysret_ss_attrs.c - test that syscalls return valid hidden SS attributes
 * Copyright (c) 2015 Andrew Lutomirski
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * On AMD CPUs, SYSRET can return with a valid SS descriptor with with
 * the hidden attributes set to an unusable state.  Make sure the kernel
 * doesn't let this happen.
 */

#define _GNU_SOURCE

#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <err.h>
#include <stddef.h>
#include <stdbool.h>
#include <pthread.h>

static void *threadproc(void *ctx)
{
	/*
	 * Do our best to cause sleeps on this CPU to exit the kernel and
	 * re-enter with SS = 0.
	 */
	while (true)
		;

	return NULL;
}

#ifdef __x86_64__
extern unsigned long call32_from_64(void *stack, void (*function)(void));

asm (".pushsection .text\n\t"
     ".code32\n\t"
     "test_ss:\n\t"
     "pushl $0\n\t"
     "popl %eax\n\t"
     "ret\n\t"
     ".code64");
extern void test_ss(void);
#endif

int main()
{
	/*
	 * Start a busy-looping thread on the same CPU we're on.
	 * For simplicity, just stick everything to CPU 0.  This will
	 * fail in some containers, but that's probably okay.
	 */
	cpu_set_t cpuset;
	CPU_ZERO(&cpuset);
	CPU_SET(0, &cpuset);
	if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0)
		printf("[WARN]\tsched_setaffinity failed\n");

	pthread_t thread;
	if (pthread_create(&thread, 0, threadproc, 0) != 0)
		err(1, "pthread_create");

#ifdef __x86_64__
	unsigned char *stack32 = mmap(NULL, 4096, PROT_READ | PROT_WRITE,
				      MAP_32BIT | MAP_ANONYMOUS | MAP_PRIVATE,
				      -1, 0);
	if (stack32 == MAP_FAILED)
		err(1, "mmap");
#endif

	printf("[RUN]\tSyscalls followed by SS validation\n");

	for (int i = 0; i < 1000; i++) {
		/*
		 * Go to sleep and return using sysret (if we're 64-bit
		 * or we're 32-bit on AMD on a 64-bit kernel).  On AMD CPUs,
		 * SYSRET doesn't fix up the cached SS descriptor, so the
		 * kernel needs some kind of workaround to make sure that we
		 * end the system call with a valid stack segment.  This
		 * can be a confusing failure because the SS *selector*
		 * is the same regardless.
		 */
		usleep(2);

#ifdef __x86_64__
		/*
		 * On 32-bit, just doing a syscall through glibc is enough
		 * to cause a crash if our cached SS descriptor is invalid.
		 * On 64-bit, it's not, so try extra hard.
		 */
		call32_from_64(stack32 + 4088, test_ss);
#endif
	}

	printf("[OK]\tWe survived\n");

#ifdef __x86_64__
	munmap(stack32, 4096);
#endif

	return 0;
}
='/cgit.cgi/linux/net-next.git/commit/drivers/usb?id=35eeacf1820a08305c2b0960febfa190f5a6dd63'>usb</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/image?id=35eeacf1820a08305c2b0960febfa190f5a6dd63'>image</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/image/microtek.h?id=35eeacf1820a08305c2b0960febfa190f5a6dd63'>microtek.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='35eeacf1820a08305c2b0960febfa190f5a6dd63'/><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>David S. Miller &lt;davem@davemloft.net&gt;</td><td class='right'>2017-02-11 02:31:11 -0500</td></tr>
<tr><th>committer</th><td>David S. Miller &lt;davem@davemloft.net&gt;</td><td class='right'>2017-02-11 02:31:11 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/image/microtek.h?id=35eeacf1820a08305c2b0960febfa190f5a6dd63'>35eeacf1820a08305c2b0960febfa190f5a6dd63</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/image/microtek.h?id=35eeacf1820a08305c2b0960febfa190f5a6dd63'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=35eeacf1820a08305c2b0960febfa190f5a6dd63'>f1227c7384ee01d3f029cc5f82223234e6456c5f</a> /<a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/image/microtek.h?id=35eeacf1820a08305c2b0960febfa190f5a6dd63'>drivers/usb/image/microtek.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/image/microtek.h?id=bed45f79a2afc9d7c279b880dfcac8f27d513b50'>bed45f79a2afc9d7c279b880dfcac8f27d513b50</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/image/microtek.h?id=35eeacf1820a08305c2b0960febfa190f5a6dd63&amp;id2=bed45f79a2afc9d7c279b880dfcac8f27d513b50'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/image/microtek.h?id=1ee18329fae936089c6c599250ae92482ff2b81f'>1ee18329fae936089c6c599250ae92482ff2b81f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/image/microtek.h?id=35eeacf1820a08305c2b0960febfa190f5a6dd63&amp;id2=1ee18329fae936089c6c599250ae92482ff2b81f'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</div><div class='commit-msg'></div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=35eeacf1820a08305c2b0960febfa190f5a6dd63'>Diffstat</a> (limited to 'drivers/usb/image/microtek.h')</div><table summary='diffstat' class='diffstat'>igning all its
MSI-X vectors to the pre and post vectors, and not having any left for the
actually spread IRQs.

Fix this issue by not asking for affinity assignment when there are no
vectors to assign left.

Fixes: 402723ad5c62 ("PCI/MSI: Provide pci_alloc_irq_vectors_affinity()")
Link: https://lkml.kernel.org/r/1485359225.3093.3.camel@sandisk.com
Reported-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Tested-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=dfef358bd1beb4e7b5c94eca944be9cd23dfc752'>Diffstat</a> (limited to 'sound/aoa/codecs/Makefile')</div><table summary='diffstat' class='diffstat'>