// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2018 Huawei.  All Rights Reserved.
 *
 * Started by nixiaoming <nixiaoming@huawei.com>
 *
 * DESCRIPTION
 *     After fanotify_init adds flags FAN_REPORT_TID,
 *     check whether the program can accurately identify which thread id
 *     in the multithreaded program triggered the event.
 *
 */
#define _GNU_SOURCE
#include "config.h"

#include <stdio.h>
#include <stdlib.h>

#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <pthread.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <linux/limits.h>
#include "tst_test.h"
#include "tst_safe_pthread.h"
#include "fanotify.h"

#if defined(HAVE_SYS_FANOTIFY_H)
#include <sys/fanotify.h>

#define gettid() syscall(SYS_gettid)
static int tid;

void *thread_create_file(void *arg LTP_ATTRIBUTE_UNUSED)
{
	char tid_file[64] = {0};

	tid = gettid();
	snprintf(tid_file, sizeof(tid_file), "test_tid_%d",  tid);
	SAFE_FILE_PRINTF(tid_file, "1");

	pthread_exit(0);
}

static unsigned int tcases[] = {
	FAN_CLASS_NOTIF,
	FAN_CLASS_NOTIF | FAN_REPORT_TID
};

void test01(unsigned int i)
{
	int ret;
	pthread_t p_id;
	struct fanotify_event_metadata event;
	int fd_notify;
	int tgid = getpid();

	tst_res(TINFO, "Test #%u: %s FAN_REPORT_TID: tgid=%d, tid=%d, event.pid=%d",
			i, (tcases[i] & FAN_REPORT_TID) ? "with" : "without",
			tgid, tid, event.pid);

	fd_notify = fanotify_init(tcases[i], 0);
	if (fd_notify < 0) {
		if (errno == EINVAL && (tcases[i] & FAN_REPORT_TID)) {
			tst_res(TCONF,
				"FAN_REPORT_TID not supported in kernel?");
			return;
		}
		tst_brk(TBROK | TERRNO, "fanotify_init(0x%x, 0) failed",
				tcases[i]);
	}

	ret = fanotify_mark(fd_notify, FAN_MARK_ADD,
			FAN_ALL_EVENTS | FAN_EVENT_ON_CHILD, AT_FDCWD, ".");
	if (ret != 0)
		tst_brk(TBROK, "fanotify_mark FAN_MARK_ADD fail ret=%d", ret);

	SAFE_PTHREAD_CREATE(&p_id, NULL, thread_create_file, NULL);

	SAFE_READ(0, fd_notify, &event, sizeof(struct fanotify_event_metadata));

	if ((tcases[i] & FAN_REPORT_TID) && event.pid == tid)
		tst_res(TPASS, "event.pid == tid");
	else if (!(tcases[i] & FAN_REPORT_TID) && event.pid == tgid)
		tst_res(TPASS, "event.pid == tgid");
	else
		tst_res(TFAIL, "unexpected event.pid value");

	if (event.fd != FAN_NOFD)
		SAFE_CLOSE(event.fd);
	SAFE_CLOSE(fd_notify);
	SAFE_PTHREAD_JOIN(p_id, NULL);
}

static void setup(void)
{
	int fd;

	fd = SAFE_FANOTIFY_INIT(FAN_CLASS_NOTIF, O_RDONLY);
	SAFE_CLOSE(fd);
}

static struct tst_test test = {
	.setup = setup,
	.test = test01,
	.tcnt =  ARRAY_SIZE(tcases),
	.needs_tmpdir = 1,
	.needs_root = 1,
};

#else
TST_TEST_TCONF("system doesn't have required fanotify support");
#endif