/*
 * MM Events - eBPF programs
 *
 * Copyright 2024 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License
 * You may obtain a copy of the License at
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <string.h>

#include <linux/bpf_perf_event.h>

#include <memevents/bpf_helpers.h>
#include <memevents/bpf_types.h>
#include <memevents/memevents_test.h>

DEFINE_BPF_RINGBUF(rb, struct mem_event_t, MEM_EVENTS_RINGBUF_SIZE, DEFAULT_BPF_MAP_UID, AID_SYSTEM,
                   0660)

DEFINE_BPF_PROG_KVER("tracepoint/oom/mark_victim", AID_ROOT, AID_SYSTEM, tp_ams, KVER_5_8)
(struct mark_victim_args* args) {
    unsigned long long timestamp_ns = bpf_ktime_get_ns();
    struct mem_event_t* data = bpf_rb_reserve();
    if (data == NULL) return 1;

    data->type = MEM_EVENT_OOM_KILL;
    data->event_data.oom_kill.pid = args->pid;
    data->event_data.oom_kill.oom_score_adj = args->oom_score_adj;
    data->event_data.oom_kill.uid = args->uid;
    data->event_data.oom_kill.timestamp_ms = timestamp_ns / 1000000;  // Convert to milliseconds
    data->event_data.oom_kill.total_vm_kb = args->total_vm;
    data->event_data.oom_kill.anon_rss_kb = args->anon_rss;
    data->event_data.oom_kill.file_rss_kb = args->file_rss;
    data->event_data.oom_kill.shmem_rss_kb = args->shmem_rss;
    data->event_data.oom_kill.pgtables_kb = args->pgtables;

    read_str((char*)args, args->__data_loc_comm, data->event_data.oom_kill.process_name,
             MEM_EVENT_PROC_NAME_LEN);

    bpf_rb_submit(data);

    return 0;
}

/*
 * Following progs (`skfilter`) are for testing purposes in `memevents_test`.
 * Note that these programs should never be attached to a socket, only
 * executed manually with BPF_PROG_RUN, and the tracepoint bpf-progs do not
 * currently implement this BPF_PROG_RUN operation.
 */
DEFINE_BPF_PROG_KVER("skfilter/oom_kill", AID_ROOT, AID_ROOT, tp_memevents_test_oom, KVER_5_8)
(void* __unused ctx) {
    struct mem_event_t* data = bpf_rb_reserve();
    if (data == NULL) return 1;

    data->type = mocked_oom_event.type;
    data->event_data.oom_kill.pid = mocked_oom_event.event_data.oom_kill.pid;
    data->event_data.oom_kill.uid = mocked_oom_event.event_data.oom_kill.uid;
    data->event_data.oom_kill.oom_score_adj = mocked_oom_event.event_data.oom_kill.oom_score_adj;
    data->event_data.oom_kill.timestamp_ms = mocked_oom_event.event_data.oom_kill.timestamp_ms;
    data->event_data.oom_kill.total_vm_kb = mocked_oom_event.event_data.oom_kill.total_vm_kb;
    data->event_data.oom_kill.anon_rss_kb = mocked_oom_event.event_data.oom_kill.anon_rss_kb;
    data->event_data.oom_kill.file_rss_kb = mocked_oom_event.event_data.oom_kill.file_rss_kb;
    data->event_data.oom_kill.shmem_rss_kb = mocked_oom_event.event_data.oom_kill.shmem_rss_kb;
    data->event_data.oom_kill.pgtables_kb = mocked_oom_event.event_data.oom_kill.pgtables_kb;

    strncpy(data->event_data.oom_kill.process_name,
            mocked_oom_event.event_data.oom_kill.process_name, 13);

    bpf_rb_submit(data);

    return 0;
}

DEFINE_BPF_PROG_KVER("skfilter/direct_reclaim_begin", AID_ROOT, AID_ROOT,
                     tp_memevents_test_dr_begin, KVER_5_8)
(void* __unused ctx) {
    struct mem_event_t* data = bpf_rb_reserve();
    if (data == NULL) return 1;

    data->type = MEM_EVENT_DIRECT_RECLAIM_BEGIN;

    bpf_rb_submit(data);

    return 0;
}

DEFINE_BPF_PROG_KVER("skfilter/direct_reclaim_end", AID_ROOT, AID_ROOT, tp_memevents_test_dr_end,
                     KVER_5_8)
(void* __unused ctx) {
    struct mem_event_t* data = bpf_rb_reserve();
    if (data == NULL) return 1;

    data->type = MEM_EVENT_DIRECT_RECLAIM_END;

    bpf_rb_submit(data);

    return 0;
}

DEFINE_BPF_PROG_KVER("skfilter/kswapd_wake", AID_ROOT, AID_ROOT, tp_memevents_test_kswapd_wake,
                     KVER_5_8)
(void* __unused ctx) {
    struct mem_event_t* data = bpf_rb_reserve();
    if (data == NULL) return 1;

    data->type = MEM_EVENT_KSWAPD_WAKE;
    data->event_data.kswapd_wake.node_id = mocked_kswapd_wake_event.event_data.kswapd_wake.node_id;
    data->event_data.kswapd_wake.zone_id = mocked_kswapd_wake_event.event_data.kswapd_wake.zone_id;
    data->event_data.kswapd_wake.alloc_order =
            mocked_kswapd_wake_event.event_data.kswapd_wake.alloc_order;

    bpf_rb_submit(data);

    return 0;
}

DEFINE_BPF_PROG_KVER("skfilter/kswapd_sleep", AID_ROOT, AID_ROOT, tp_memevents_test_kswapd_sleep,
                     KVER_5_8)
(void* __unused ctx) {
    struct mem_event_t* data = bpf_rb_reserve();
    if (data == NULL) return 1;

    data->type = MEM_EVENT_KSWAPD_SLEEP;
    data->event_data.kswapd_sleep.node_id =
            mocked_kswapd_sleep_event.event_data.kswapd_sleep.node_id;

    bpf_rb_submit(data);

    return 0;
}

// bpf_probe_read_str is GPL only symbol
LICENSE("GPL");