/*
 * Guest agent for virtio-trace
 *
 * Copyright (C) 2012 Hitachi, Ltd.
 * Created by Yoshihiro Yunomae <yoshihiro.yunomae.ez@hitachi.com>
 *            Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
 *
 * Licensed under GPL version 2 only.
 *
 */

#define _GNU_SOURCE
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "trace-agent.h"

#define PAGE_SIZE		(sysconf(_SC_PAGE_SIZE))
#define PIPE_DEF_BUFS		16
#define PIPE_MIN_SIZE		(PAGE_SIZE*PIPE_DEF_BUFS)
#define PIPE_MAX_SIZE		(1024*1024)
#define READ_PATH_FMT	\
		"/sys/kernel/debug/tracing/per_cpu/cpu%d/trace_pipe_raw"
#define WRITE_PATH_FMT		"/dev/virtio-ports/trace-path-cpu%d"
#define CTL_PATH		"/dev/virtio-ports/agent-ctl-path"

pthread_mutex_t mutex_notify = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cond_wakeup = PTHREAD_COND_INITIALIZER;

static int get_total_cpus(void)
{
	int nr_cpus = (int)sysconf(_SC_NPROCESSORS_CONF);

	if (nr_cpus <= 0) {
		pr_err("Could not read cpus\n");
		goto error;
	} else if (nr_cpus > MAX_CPUS) {
		pr_err("Exceed max cpus(%d)\n", (int)MAX_CPUS);
		goto error;
	}

	return nr_cpus;

error:
	exit(EXIT_FAILURE);
}

static void *agent_info_new(void)
{
	struct agent_info *s;
	int i;

	s = zalloc(sizeof(struct agent_info));
	if (s == NULL) {
		pr_err("agent_info zalloc error\n");
		exit(EXIT_FAILURE);
	}

	s->pipe_size = PIPE_INIT;
	s->use_stdout = false;
	s->cpus = get_total_cpus();
	s->ctl_fd = -1;

	/* read/write threads init */
	for (i = 0; i < s->cpus; i++)
		s->rw_ti[i] = rw_thread_info_new();

	return s;
}

static unsigned long parse_size(const char *arg)
{
	unsigned long value, round;
	char *ptr;

	value = strtoul(arg, &ptr, 10);
	switch (*ptr) {
	case 'K': case 'k':
		value <<= 10;
		break;
	case 'M': case 'm':
		value <<= 20;
		break;
	default:
		break;
	}

	if (value > PIPE_MAX_SIZE) {
		pr_err("Pipe size must be less than 1MB\n");
		goto error;
	} else if (value < PIPE_MIN_SIZE) {
		pr_err("Pipe size must be over 64KB\n");
		goto error;
	}

	/* Align buffer size with page unit */
	round = value & (PAGE_SIZE - 1);
	value = value - round;

	return value;
error:
	return 0;
}

static void usage(char const *prg)
{
	pr_err("usage: %s [-h] [-o] [-s <size of pipe>]\n", prg);
}

static const char *make_path(int cpu_num, bool this_is_write_path)
{
	int ret;
	char *buf;

	buf = zalloc(PATH_MAX);
	if (buf == NULL) {
		pr_err("Could not allocate buffer\n");
		goto error;
	}

	if (this_is_write_path)
		/* write(output) path */
		ret = snprintf(buf, PATH_MAX, WRITE_PATH_FMT, cpu_num);
	else
		/* read(input) path */
		ret = snprintf(buf, PATH_MAX, READ_PATH_FMT, cpu_num);

	if (ret <= 0) {
		pr_err("Failed to generate %s path(CPU#%d):%d\n",
			this_is_write_path ? "read" : "write", cpu_num, ret);
		goto error;
	}

	return buf;

error:
	free(buf);
	return NULL;
}

static const char *make_input_path(int cpu_num)
{
	return make_path(cpu_num, false);
}

static const char *make_output_path(int cpu_num)
{
	return make_path(cpu_num, true);
}

static void *agent_info_init(struct agent_info *s)
{
	int cpu;
	const char *in_path = NULL;
	const char *out_path = NULL;

	/* init read/write threads */
	for (cpu = 0; cpu < s->cpus; cpu++) {
		/* set read(input) path per read/write thread */
		in_path = make_input_path(cpu);
		if (in_path == NULL)
			goto error;

		/* set write(output) path per read/write thread*/
		if (!s->use_stdout) {
			out_path = make_output_path(cpu);
			if (out_path == NULL)
				goto error;
		} else
			/* stdout mode */
			pr_debug("stdout mode\n");

		rw_thread_init(cpu, in_path, out_path, s->use_stdout,
						s->pipe_size, s->rw_ti[cpu]);
	}

	/* init controller of read/write threads */
	s->ctl_fd = rw_ctl_init((const char *)CTL_PATH);

	return NULL;

error:
	exit(EXIT_FAILURE);
}

static void *parse_args(int argc, char *argv[], struct agent_info *s)
{
	int cmd;
	unsigned long size;

	while ((cmd = getopt(argc, argv, "hos:")) != -1) {
		switch (cmd) {
		/* stdout mode */
		case 'o':
			s->use_stdout = true;
			break;
		/* size of pipe */
		case 's':
			size = parse_size(optarg);
			if (size == 0)
				goto error;
			s->pipe_size = size;
			break;
		case 'h':
		default:
			usage(argv[0]);
			goto error;
		}
	}

	agent_info_init(s);

	return NULL;

error:
	exit(EXIT_FAILURE);
}

static void agent_main_loop(struct agent_info *s)
{
	int cpu;
	pthread_t rw_thread_per_cpu[MAX_CPUS];

	/* Start all read/write threads */
	for (cpu = 0; cpu < s->cpus; cpu++)
		rw_thread_per_cpu[cpu] = rw_thread_run(s->rw_ti[cpu]);

	rw_ctl_loop(s->ctl_fd);

	/* Finish all read/write threads */
	for (cpu = 0; cpu < s->cpus; cpu++) {
		int ret;

		ret = pthread_join(rw_thread_per_cpu[cpu], NULL);
		if (ret != 0) {
			pr_err("pthread_join() error:%d (cpu %d)\n", ret, cpu);
			exit(EXIT_FAILURE);
		}
	}
}

static void agent_info_free(struct agent_info *s)
{
	int i;

	close(s->ctl_fd);
	for (i = 0; i < s->cpus; i++) {
		close(s->rw_ti[i]->in_fd);
		close(s->rw_ti[i]->out_fd);
		close(s->rw_ti[i]->read_pipe);
		close(s->rw_ti[i]->write_pipe);
		free(s->rw_ti[i]);
	}
	free(s);
}

int main(int argc, char *argv[])
{
	struct agent_info *s = NULL;

	s = agent_info_new();
	parse_args(argc, argv, s);

	agent_main_loop(s);

	agent_info_free(s);

	return 0;
}
it/commit/tools/lguest/.gitignore?h=nds-private-remove&amp;id=0becc0ae5b42828785b589f686725ff5bc3b9b25'>0becc0ae5b42828785b589f686725ff5bc3b9b25</a> (<a href='/cgit.cgi/linux/net-next.git/patch/tools/lguest/.gitignore?id=0becc0ae5b42828785b589f686725ff5bc3b9b25'>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=0becc0ae5b42828785b589f686725ff5bc3b9b25'>be6d0e1f37c38ed0a7dd5da2d4b1e93f0fb43101</a> /<a href='/cgit.cgi/linux/net-next.git/tree/tools/lguest/.gitignore?h=nds-private-remove&amp;id=0becc0ae5b42828785b589f686725ff5bc3b9b25'>tools/lguest/.gitignore</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/lguest/.gitignore?h=nds-private-remove&amp;id=24c2503255d35c269b67162c397a1a1c1e02f6ce'>24c2503255d35c269b67162c397a1a1c1e02f6ce</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/lguest/.gitignore?h=nds-private-remove&amp;id=0becc0ae5b42828785b589f686725ff5bc3b9b25&amp;id2=24c2503255d35c269b67162c397a1a1c1e02f6ce'>diff</a>)</td></tr></table>
<div class='commit-subject'>x86/mce: Make timer handling more robust</div><div class='commit-msg'>Erik reported that on a preproduction hardware a CMCI storm triggers the
BUG_ON in add_timer_on(). The reason is that the per CPU MCE timer is
started by the CMCI logic before the MCE CPU hotplug callback starts the
timer with add_timer_on(). So the timer is already queued which triggers
the BUG.

Using add_timer_on() is pretty pointless in this code because the timer is
strictlty per CPU, initialized as pinned and all operations which arm the
timer happen on the CPU to which the timer belongs.

Simplify the whole machinery by using mod_timer() instead of add_timer_on()
which avoids the problem because mod_timer() can handle already queued
timers. Use __start_timer() everywhere so the earliest armed expiry time is
preserved.

Reported-by: Erik Veijola &lt;erik.veijola@intel.com&gt;
Tested-by: Borislav Petkov &lt;bp@alien8.de&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701310936080.3457@nanos
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;

</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=0becc0ae5b42828785b589f686725ff5bc3b9b25'>Diffstat</a> (limited to 'tools/lguest/.gitignore')</div><table summary='diffstat' class='diffstat'>