/*
 * Copyright 2013-2015, Michael Ellerman, IBM Corp.
 * Licensed under GPLv2.
 */

#define _GNU_SOURCE	/* For CPU_ZERO etc. */

#include <elf.h>
#include <errno.h>
#include <fcntl.h>
#include <link.h>
#include <sched.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include "utils.h"

static char auxv[4096];

void *get_auxv_entry(int type)
{
	ElfW(auxv_t) *p;
	void *result;
	ssize_t num;
	int fd;

	fd = open("/proc/self/auxv", O_RDONLY);
	if (fd == -1) {
		perror("open");
		return NULL;
	}

	result = NULL;

	num = read(fd, auxv, sizeof(auxv));
	if (num < 0) {
		perror("read");
		goto out;
	}

	if (num > sizeof(auxv)) {
		printf("Overflowed auxv buffer\n");
		goto out;
	}

	p = (ElfW(auxv_t) *)auxv;

	while (p->a_type != AT_NULL) {
		if (p->a_type == type) {
			result = (void *)p->a_un.a_val;
			break;
		}

		p++;
	}
out:
	close(fd);
	return result;
}

int pick_online_cpu(void)
{
	cpu_set_t mask;
	int cpu;

	CPU_ZERO(&mask);

	if (sched_getaffinity(0, sizeof(mask), &mask)) {
		perror("sched_getaffinity");
		return -1;
	}

	/* We prefer a primary thread, but skip 0 */
	for (cpu = 8; cpu < CPU_SETSIZE; cpu += 8)
		if (CPU_ISSET(cpu, &mask))
			return cpu;

	/* Search for anything, but in reverse */
	for (cpu = CPU_SETSIZE - 1; cpu >= 0; cpu--)
		if (CPU_ISSET(cpu, &mask))
			return cpu;

	printf("No cpus in affinity mask?!\n");
	return -1;
}
</form></td></tr>
<tr><td class='sub'>net-next plumbings</td><td class='sub right'>Tobias Klauser</td></tr></table>
<table class='tabs'><tr><td>
<a href='/cgit.cgi/linux/net-next.git/'>summary</a><a href='/cgit.cgi/linux/net-next.git/refs/?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>refs</a><a href='/cgit.cgi/linux/net-next.git/log/sound/pci/emu10k1/emupcm.c'>log</a><a href='/cgit.cgi/linux/net-next.git/tree/sound/pci/emu10k1/emupcm.c?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>tree</a><a class='active' href='/cgit.cgi/linux/net-next.git/commit/sound/pci/emu10k1/emupcm.c?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>commit</a><a href='/cgit.cgi/linux/net-next.git/diff/sound/pci/emu10k1/emupcm.c?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/sound/pci/emu10k1/emupcm.c'>
<input type='hidden' name='id' value='d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>sound</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/pci?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>pci</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/emu10k1?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>emu10k1</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/emu10k1/emupcm.c?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>emupcm.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'/><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>Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;</td><td class='right'>2017-02-03 17:10:28 +1100</td></tr>
<tr><th>committer</th><td>Michael Ellerman &lt;mpe@ellerman.id.au&gt;</td><td class='right'>2017-02-08 23:36:29 +1100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/emu10k1/emupcm.c?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>d7df2443cd5f67fc6ee7c05a88e4996e8177f91b</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/pci/emu10k1/emupcm.c?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>098a7c0ca4fceb8a65cb1f693c9d71990388933d</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/pci/emu10k1/emupcm.c?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>sound/pci/emu10k1/emupcm.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/emu10k1/emupcm.c?id=a0615a16f7d0ceb5804d295203c302d496d8ee91'>a0615a16f7d0ceb5804d295203c302d496d8ee91</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/pci/emu10k1/emupcm.c?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b&amp;id2=a0615a16f7d0ceb5804d295203c302d496d8ee91'>diff</a>)</td></tr></table>
<div class='commit-subject'>powerpc/mm: Fix spurrious segfaults on radix with autonuma</div><div class='commit-msg'>When autonuma (Automatic NUMA balancing) marks a PTE inaccessible it
clears all the protection bits but leave the PTE valid.

With the Radix MMU, an attempt at executing from such a PTE will
take a fault with bit 35 of SRR1 set "SRR1_ISI_N_OR_G".

It is thus incorrect to treat all such faults as errors. We should
pass them to handle_mm_fault() for autonuma to deal with. The case
of pages that are really not executable is handled by the existing
test for VM_EXEC further down.

That leaves us with catching the kernel attempts at executing user
pages. We can catch that earlier, even before we do find_vma.

It is never valid on powerpc for the kernel to take an exec fault
to begin with. So fold that test with the existing test for the
kernel faulting on kernel addresses to bail out early.

Fixes: 1d18ad026844 ("powerpc/mm: Detect instruction fetch denied and report")
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Reviewed-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Acked-by: Balbir Singh &lt;bsingharora@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>Diffstat</a> (limited to 'sound/pci/emu10k1/emupcm.c')</div><table summary='diffstat' class='diffstat'>