// SPDX-License-Identifier: GPL-2.0
/*
 * User Events Perf Events Test Program
 *
 * Copyright (c) 2021 Beau Belgrave <beaub@linux.microsoft.com>
 */

#include <errno.h>
#include <linux/user_events.h>
#include <linux/perf_event.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <unistd.h>
#include <asm/unistd.h>

#include "kselftest_harness.h"
#include "user_events_selftests.h"

const char *data_file = "/sys/kernel/tracing/user_events_data";
const char *id_file = "/sys/kernel/tracing/events/user_events/__test_event/id";
const char *fmt_file = "/sys/kernel/tracing/events/user_events/__test_event/format";

struct event {
        __u32 index;
        __u32 field1;
        __u32 field2;
};

static long perf_event_open(struct perf_event_attr *pe, pid_t pid,
                            int cpu, int group_fd, unsigned long flags)
{
        return syscall(__NR_perf_event_open, pe, pid, cpu, group_fd, flags);
}

static int get_id(void)
{
        FILE *fp = fopen(id_file, "r");
        int ret, id = 0;

        if (!fp)
                return -1;

        ret = fscanf(fp, "%d", &id);
        fclose(fp);

        if (ret != 1)
                return -1;

        return id;
}

static int get_offset(void)
{
        FILE *fp = fopen(fmt_file, "r");
        int ret, c, last = 0, offset = 0;

        if (!fp)
                return -1;

        /* Read until empty line */
        while (true) {
                c = getc(fp);

                if (c == EOF)
                        break;

                if (last == '\n' && c == '\n')
                        break;

                last = c;
        }

        ret = fscanf(fp, "\tfield:u32 field1;\toffset:%d;", &offset);
        fclose(fp);

        if (ret != 1)
                return -1;

        return offset;
}

static int clear(int *check)
{
        struct user_unreg unreg = {0};

        unreg.size = sizeof(unreg);
        unreg.disable_bit = 31;
        unreg.disable_addr = (__u64)check;

        int fd = open(data_file, O_RDWR);

        if (fd == -1)
                return -1;

        if (ioctl(fd, DIAG_IOCSUNREG, &unreg) == -1)
                if (errno != ENOENT)
                        return -1;

        if (ioctl(fd, DIAG_IOCSDEL, "__test_event") == -1)
                if (errno != ENOENT)
                        return -1;

        close(fd);

        return 0;
}

FIXTURE(user) {
        int data_fd;
        int check;
        bool umount;
};

FIXTURE_SETUP(user) {
        USER_EVENT_FIXTURE_SETUP(return, self->umount);

        self->data_fd = open(data_file, O_RDWR);
        ASSERT_NE(-1, self->data_fd);
}

FIXTURE_TEARDOWN(user) {
        USER_EVENT_FIXTURE_TEARDOWN(self->umount);

        close(self->data_fd);

        if (clear(&self->check) != 0)
                printf("WARNING: Clear didn't work!\n");
}

TEST_F(user, perf_write) {
        struct perf_event_attr pe = {0};
        struct user_reg reg = {0};
        struct event event;
        struct perf_event_mmap_page *perf_page;
        int page_size = sysconf(_SC_PAGESIZE);
        int id, fd, offset;
        __u32 *val;

        reg.size = sizeof(reg);
        reg.name_args = (__u64)"__test_event u32 field1; u32 field2";
        reg.enable_bit = 31;
        reg.enable_addr = (__u64)&self->check;
        reg.enable_size = sizeof(self->check);

        /* Register should work */
        ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
        ASSERT_EQ(0, reg.write_index);
        ASSERT_EQ(0, self->check);

        /* Id should be there */
        id = get_id();
        ASSERT_NE(-1, id);
        offset = get_offset();
        ASSERT_NE(-1, offset);

        pe.type = PERF_TYPE_TRACEPOINT;
        pe.size = sizeof(pe);
        pe.config = id;
        pe.sample_type = PERF_SAMPLE_RAW;
        pe.sample_period = 1;
        pe.wakeup_events = 1;

        /* Tracepoint attach should work */
        fd = perf_event_open(&pe, 0, -1, -1, 0);
        ASSERT_NE(-1, fd);

        perf_page = mmap(NULL, page_size * 2, PROT_READ, MAP_SHARED, fd, 0);
        ASSERT_NE(MAP_FAILED, perf_page);

        /* Status should be updated */
        ASSERT_EQ(1 << reg.enable_bit, self->check);

        event.index = reg.write_index;
        event.field1 = 0xc001;
        event.field2 = 0xc01a;

        /* Ensure write shows up at correct offset */
        ASSERT_NE(-1, write(self->data_fd, &event, sizeof(event)));
        val = (void *)(((char *)perf_page) + perf_page->data_offset);
        ASSERT_EQ(PERF_RECORD_SAMPLE, *val);
        /* Skip over header and size, move to offset */
        val += 3;
        val = (void *)((char *)val) + offset;
        /* Ensure correct */
        ASSERT_EQ(event.field1, *val++);
        ASSERT_EQ(event.field2, *val++);

        munmap(perf_page, page_size * 2);
        close(fd);

        /* Status should be updated */
        ASSERT_EQ(0, self->check);
}

TEST_F(user, perf_empty_events) {
        struct perf_event_attr pe = {0};
        struct user_reg reg = {0};
        struct perf_event_mmap_page *perf_page;
        int page_size = sysconf(_SC_PAGESIZE);
        int id, fd;
        __u32 *val;

        reg.size = sizeof(reg);
        reg.name_args = (__u64)"__test_event";
        reg.enable_bit = 31;
        reg.enable_addr = (__u64)&self->check;
        reg.enable_size = sizeof(self->check);

        /* Register should work */
        ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
        ASSERT_EQ(0, reg.write_index);
        ASSERT_EQ(0, self->check);

        /* Id should be there */
        id = get_id();
        ASSERT_NE(-1, id);

        pe.type = PERF_TYPE_TRACEPOINT;
        pe.size = sizeof(pe);
        pe.config = id;
        pe.sample_type = PERF_SAMPLE_RAW;
        pe.sample_period = 1;
        pe.wakeup_events = 1;

        /* Tracepoint attach should work */
        fd = perf_event_open(&pe, 0, -1, -1, 0);
        ASSERT_NE(-1, fd);

        perf_page = mmap(NULL, page_size * 2, PROT_READ, MAP_SHARED, fd, 0);
        ASSERT_NE(MAP_FAILED, perf_page);

        /* Status should be updated */
        ASSERT_EQ(1 << reg.enable_bit, self->check);

        /* Ensure write shows up at correct offset */
        ASSERT_NE(-1, write(self->data_fd, (void *)&reg.write_index,
                                        sizeof(reg.write_index)));
        val = (void *)(((char *)perf_page) + perf_page->data_offset);
        ASSERT_EQ(PERF_RECORD_SAMPLE, *val);

        munmap(perf_page, page_size * 2);
        close(fd);

        /* Status should be updated */
        ASSERT_EQ(0, self->check);
}

int main(int argc, char **argv)
{
        return test_harness_run(argc, argv);
}