/* Copyright (c) 2016 Facebook
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 */
#include <linux/ptrace.h>
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include <uapi/linux/bpf_perf_event.h>
#include <uapi/linux/perf_event.h>
#include "bpf_helpers.h"

struct key_t {
	char comm[TASK_COMM_LEN];
	u32 kernstack;
	u32 userstack;
};

struct bpf_map_def SEC("maps") counts = {
	.type = BPF_MAP_TYPE_HASH,
	.key_size = sizeof(struct key_t),
	.value_size = sizeof(u64),
	.max_entries = 10000,
};

struct bpf_map_def SEC("maps") stackmap = {
	.type = BPF_MAP_TYPE_STACK_TRACE,
	.key_size = sizeof(u32),
	.value_size = PERF_MAX_STACK_DEPTH * sizeof(u64),
	.max_entries = 10000,
};

#define KERN_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
#define USER_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP | BPF_F_USER_STACK)

SEC("perf_event")
int bpf_prog1(struct bpf_perf_event_data *ctx)
{
	char fmt[] = "CPU-%d period %lld ip %llx";
	u32 cpu = bpf_get_smp_processor_id();
	struct key_t key;
	u64 *val, one = 1;

	if (ctx->sample_period < 10000)
		/* ignore warmup */
		return 0;
	bpf_get_current_comm(&key.comm, sizeof(key.comm));
	key.kernstack = bpf_get_stackid(ctx, &stackmap, KERN_STACKID_FLAGS);
	key.userstack = bpf_get_stackid(ctx, &stackmap, USER_STACKID_FLAGS);
	if ((int)key.kernstack < 0 && (int)key.userstack < 0) {
		bpf_trace_printk(fmt, sizeof(fmt), cpu, ctx->sample_period,
				 PT_REGS_IP(&ctx->regs));
		return 0;
	}

	val = bpf_map_lookup_elem(&counts, &key);
	if (val)
		(*val)++;
	else
		bpf_map_update_elem(&counts, &key, &one, BPF_NOEXIST);
	return 0;
}

char _license[] SEC("license") = "GPL";
.cgi/linux/net-next.git/tree/sound/pci/au88x0?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>tree</a><a class='active' href='/cgit.cgi/linux/net-next.git/commit/sound/pci/au88x0?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>commit</a><a href='/cgit.cgi/linux/net-next.git/diff/sound/pci/au88x0?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/sound/pci/au88x0'>
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<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/au88x0?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>au88x0</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/au88x0?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>d7df2443cd5f67fc6ee7c05a88e4996e8177f91b</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/pci/au88x0?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/au88x0?id=d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'>sound/pci/au88x0</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/au88x0?id=a0615a16f7d0ceb5804d295203c302d496d8ee91'>a0615a16f7d0ceb5804d295203c302d496d8ee91</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/pci/au88x0?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/au88x0')</div><table summary='diffstat' class='diffstat'>