/* 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 <uapi/linux/bpf.h>
#include "bpf_helpers.h"
#include <uapi/linux/ptrace.h>
#include <uapi/linux/perf_event.h>
#include <linux/version.h>
#include <linux/sched.h>

#define _(P) ({typeof(P) val; bpf_probe_read(&val, sizeof(val), &P); val;})

#define MINBLOCK_US	1

struct key_t {
	char waker[TASK_COMM_LEN];
	char target[TASK_COMM_LEN];
	u32 wret;
	u32 tret;
};

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") start = {
	.type = BPF_MAP_TYPE_HASH,
	.key_size = sizeof(u32),
	.value_size = sizeof(u64),
	.max_entries = 10000,
};

struct wokeby_t {
	char name[TASK_COMM_LEN];
	u32 ret;
};

struct bpf_map_def SEC("maps") wokeby = {
	.type = BPF_MAP_TYPE_HASH,
	.key_size = sizeof(u32),
	.value_size = sizeof(struct wokeby_t),
	.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 STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)

SEC("kprobe/try_to_wake_up")
int waker(struct pt_regs *ctx)
{
	struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
	struct wokeby_t woke;
	u32 pid;

	pid = _(p->pid);

	bpf_get_current_comm(&woke.name, sizeof(woke.name));
	woke.ret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);

	bpf_map_update_elem(&wokeby, &pid, &woke, BPF_ANY);
	return 0;
}

static inline int update_counts(void *ctx, u32 pid, u64 delta)
{
	struct wokeby_t *woke;
	u64 zero = 0, *val;
	struct key_t key;

	__builtin_memset(&key.waker, 0, sizeof(key.waker));
	bpf_get_current_comm(&key.target, sizeof(key.target));
	key.tret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
	key.wret = 0;

	woke = bpf_map_lookup_elem(&wokeby, &pid);
	if (woke) {
		key.wret = woke->ret;
		__builtin_memcpy(&key.waker, woke->name, sizeof(key.waker));
		bpf_map_delete_elem(&wokeby, &pid);
	}

	val = bpf_map_lookup_elem(&counts, &key);
	if (!val) {
		bpf_map_update_elem(&counts, &key, &zero, BPF_NOEXIST);
		val = bpf_map_lookup_elem(&counts, &key);
		if (!val)
			return 0;
	}
	(*val) += delta;
	return 0;
}

#if 1
/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */
struct sched_switch_args {
	unsigned long long pad;
	char prev_comm[16];
	int prev_pid;
	int prev_prio;
	long long prev_state;
	char next_comm[16];
	int next_pid;
	int next_prio;
};
SEC("tracepoint/sched/sched_switch")
int oncpu(struct sched_switch_args *ctx)
{
	/* record previous thread sleep time */
	u32 pid = ctx->prev_pid;
#else
SEC("kprobe/finish_task_switch")
int oncpu(struct pt_regs *ctx)
{
	struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
	/* record previous thread sleep time */
	u32 pid = _(p->pid);
#endif
	u64 delta, ts, *tsp;

	ts = bpf_ktime_get_ns();
	bpf_map_update_elem(&start, &pid, &ts, BPF_ANY);

	/* calculate current thread's delta time */
	pid = bpf_get_current_pid_tgid();
	tsp = bpf_map_lookup_elem(&start, &pid);
	if (!tsp)
		/* missed start or filtered */
		return 0;

	delta = bpf_ktime_get_ns() - *tsp;
	bpf_map_delete_elem(&start, &pid);
	delta = delta / 1000;
	if (delta < MINBLOCK_US)
		return 0;

	return update_counts(ctx, pid, delta);
}
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;
='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='c26665ab5c49ad3e142e0f054ca3204f259ba09c'/><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>Borislav Petkov &lt;bp@suse.de&gt;</td><td class='right'>2017-01-20 21:29:40 +0100</td></tr>
<tr><th>committer</th><td>Thomas Gleixner &lt;tglx@linutronix.de&gt;</td><td class='right'>2017-01-23 09:39:55 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/gadget/udc/bdc/bdc.h?id=c26665ab5c49ad3e142e0f054ca3204f259ba09c'>c26665ab5c49ad3e142e0f054ca3204f259ba09c</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/gadget/udc/bdc/bdc.h?id=c26665ab5c49ad3e142e0f054ca3204f259ba09c'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=c26665ab5c49ad3e142e0f054ca3204f259ba09c'>3bab11918e18e9d25ef7544dba05cdf39d1abec5</a> /<a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/gadget/udc/bdc/bdc.h?id=c26665ab5c49ad3e142e0f054ca3204f259ba09c'>drivers/usb/gadget/udc/bdc/bdc.h</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/bdc/bdc.h?id=7a308bb3016f57e5be11a677d15b821536419d36'>7a308bb3016f57e5be11a677d15b821536419d36</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/gadget/udc/bdc/bdc.h?id=c26665ab5c49ad3e142e0f054ca3204f259ba09c&amp;id2=7a308bb3016f57e5be11a677d15b821536419d36'>diff</a>)</td></tr></table>
<div class='commit-subject'>x86/microcode/intel: Drop stashed AP patch pointer optimization</div><div class='commit-msg'>This was meant to save us the scanning of the microcode containter in
the initrd since the first AP had already done that but it can also hurt
us:

Imagine a single hyperthreaded CPU (Intel(R) Atom(TM) CPU N270, for
example) which updates the microcode on the BSP but since the microcode
engine is shared between the two threads, the update on CPU1 doesn't
happen because it has already happened on CPU0 and we don't find a newer
microcode revision on CPU1.

Which doesn't set the intel_ucode_patch pointer and at initrd
jettisoning time we don't save the microcode patch for later
application.

Now, when we suspend to RAM, the loaded microcode gets cleared so we
need to reload but there's no patch saved in the cache.

Removing the optimization fixes this issue and all is fine and dandy.

Fixes: 06b8534cb728 ("x86/microcode: Rework microcode loading")
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: http://lkml.kernel.org/r/20170120202955.4091-2-bp@alien8.de
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;

</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=c26665ab5c49ad3e142e0f054ca3204f259ba09c'>Diffstat</a> (limited to 'drivers/usb/gadget/udc/bdc/bdc.h')</div><table summary='diffstat' class='diffstat'>