/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2023-2025 Ruslan Bukin <br@bsdpad.com>
 *
 * This work was supported by Innovate UK project 105694, "Digital Security
 * by Design (DSbD) Technology Platform Prototype".
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/hwt.h>
#include <sys/linker.h>
#include <sys/pmckern.h> /* linker_hwpmc_list_objects */

#include <vm/vm.h>
#include <vm/uma.h>

#include <dev/hwt/hwt_hook.h>
#include <dev/hwt/hwt_context.h>
#include <dev/hwt/hwt_contexthash.h>
#include <dev/hwt/hwt_config.h>
#include <dev/hwt/hwt_thread.h>
#include <dev/hwt/hwt_record.h>

#define HWT_RECORD_DEBUG
#undef  HWT_RECORD_DEBUG

#ifdef  HWT_RECORD_DEBUG
#define dprintf(fmt, ...)       printf(fmt, ##__VA_ARGS__)
#else
#define dprintf(fmt, ...)
#endif

static MALLOC_DEFINE(M_HWT_RECORD, "hwt_record", "Hardware Trace");
static uma_zone_t record_zone = NULL;

static struct hwt_record_entry *
hwt_record_clone(struct hwt_record_entry *ent, int flags)
{
        struct hwt_record_entry *entry;

        entry = uma_zalloc(record_zone, flags);
        if (entry == NULL)
                return (NULL);
        memcpy(entry, ent, sizeof(struct hwt_record_entry));
        switch (ent->record_type) {
        case HWT_RECORD_MMAP:
        case HWT_RECORD_EXECUTABLE:
        case HWT_RECORD_KERNEL:
                entry->fullpath = strdup(ent->fullpath, M_HWT_RECORD);
                break;
        default:
                break;
        }

        return (entry);
}

static void
hwt_record_to_user(struct hwt_record_entry *ent,
    struct hwt_record_user_entry *usr)
{
        usr->record_type = ent->record_type;
        switch (ent->record_type) {
        case HWT_RECORD_MMAP:
        case HWT_RECORD_EXECUTABLE:
        case HWT_RECORD_KERNEL:
                usr->addr = ent->addr;
                usr->baseaddr = ent->baseaddr;
                strncpy(usr->fullpath, ent->fullpath, MAXPATHLEN);
                break;
        case HWT_RECORD_BUFFER:
                usr->buf_id = ent->buf_id;
                usr->curpage = ent->curpage;
                usr->offset = ent->offset;
                break;
        case HWT_RECORD_THREAD_CREATE:
        case HWT_RECORD_THREAD_SET_NAME:
                usr->thread_id = ent->thread_id;
                break;
        default:
                break;
        }
}

void
hwt_record_load(void)
{
        record_zone = uma_zcreate("HWT records",
            sizeof(struct hwt_record_entry), NULL, NULL, NULL, NULL, 0, 0);
}

void
hwt_record_unload(void)
{
        uma_zdestroy(record_zone);
}

void
hwt_record_ctx(struct hwt_context *ctx, struct hwt_record_entry *ent, int flags)
{
        struct hwt_record_entry *entry;

        KASSERT(ent != NULL, ("ent is NULL"));
        entry = hwt_record_clone(ent, flags);
        if (entry == NULL) {
                /* XXX: Not sure what to do here other than logging an error. */
                return;
        }

        HWT_CTX_LOCK(ctx);
        TAILQ_INSERT_TAIL(&ctx->records, entry, next);
        HWT_CTX_UNLOCK(ctx);
        hwt_record_wakeup(ctx);
}

void
hwt_record_td(struct thread *td, struct hwt_record_entry *ent, int flags)
{
        struct hwt_record_entry *entry;
        struct hwt_context *ctx;
        struct proc *p;

        p = td->td_proc;

        KASSERT(ent != NULL, ("ent is NULL"));
        entry = hwt_record_clone(ent, flags);
        if (entry == NULL) {
                /* XXX: Not sure what to do here other than logging an error. */
                return;
        }
        ctx = hwt_contexthash_lookup(p);
        if (ctx == NULL) {
                hwt_record_entry_free(entry);
                return;
        }
        HWT_CTX_LOCK(ctx);
        TAILQ_INSERT_TAIL(&ctx->records, entry, next);
        HWT_CTX_UNLOCK(ctx);
        hwt_record_wakeup(ctx);

        hwt_ctx_put(ctx);
}

struct hwt_record_entry *
hwt_record_entry_alloc(void)
{
        return (uma_zalloc(record_zone, M_WAITOK | M_ZERO));
}

void
hwt_record_entry_free(struct hwt_record_entry *entry)
{

        switch (entry->record_type) {
        case HWT_RECORD_MMAP:
        case HWT_RECORD_EXECUTABLE:
        case HWT_RECORD_KERNEL:
                free(entry->fullpath, M_HWT_RECORD);
                break;
        default:
                break;
        }

        uma_zfree(record_zone, entry);
}

static int
hwt_record_grab(struct hwt_context *ctx,
    struct hwt_record_user_entry *user_entry, int nitems_req, int wait)
{
        struct hwt_record_entry *entry;
        int i;

        if (wait) {
                mtx_lock(&ctx->rec_mtx);
                if (TAILQ_FIRST(&ctx->records) == NULL) {
                        /* Wait until we have new records. */
                        msleep(ctx, &ctx->rec_mtx, PCATCH, "recsnd", 0);
                }
                mtx_unlock(&ctx->rec_mtx);
        }

        for (i = 0; i < nitems_req; i++) {
                HWT_CTX_LOCK(ctx);
                entry = TAILQ_FIRST(&ctx->records);
                if (entry)
                        TAILQ_REMOVE_HEAD(&ctx->records, next);
                HWT_CTX_UNLOCK(ctx);

                if (entry == NULL)
                        break;
                hwt_record_to_user(entry, &user_entry[i]);
                hwt_record_entry_free(entry);
        }

        return (i);
}

void
hwt_record_free_all(struct hwt_context *ctx)
{
        struct hwt_record_entry *entry;

        while (1) {
                HWT_CTX_LOCK(ctx);
                entry = TAILQ_FIRST(&ctx->records);
                if (entry)
                        TAILQ_REMOVE_HEAD(&ctx->records, next);
                HWT_CTX_UNLOCK(ctx);

                if (entry == NULL)
                        break;

                hwt_record_entry_free(entry);
        }
}

int
hwt_record_send(struct hwt_context *ctx, struct hwt_record_get *record_get)
{
        struct hwt_record_user_entry *user_entry;
        int nitems_req;
        int error;
        int i;

        nitems_req = 0;

        error = copyin(record_get->nentries, &nitems_req, sizeof(int));
        if (error)
                return (error);

        if (nitems_req < 1 || nitems_req > 1024)
                return (ENXIO);

        user_entry = malloc(sizeof(struct hwt_record_user_entry) * nitems_req,
            M_HWT_RECORD, M_WAITOK | M_ZERO);

        i = hwt_record_grab(ctx, user_entry, nitems_req, record_get->wait);
        if (i > 0)
                error = copyout(user_entry, record_get->records,
                    sizeof(struct hwt_record_user_entry) * i);

        if (error == 0)
                error = copyout(&i, record_get->nentries, sizeof(int));

        free(user_entry, M_HWT_RECORD);

        return (error);
}

void
hwt_record_kernel_objects(struct hwt_context *ctx)
{
        struct hwt_record_entry *entry;
        struct pmckern_map_in *kobase;
        int i;

        kobase = linker_hwpmc_list_objects();
        for (i = 0; kobase[i].pm_file != NULL; i++) {
                entry = hwt_record_entry_alloc();
                entry->record_type = HWT_RECORD_KERNEL;
                entry->fullpath = strdup(kobase[i].pm_file, M_HWT_RECORD);
                entry->addr = kobase[i].pm_address;

                HWT_CTX_LOCK(ctx);
                TAILQ_INSERT_HEAD(&ctx->records, entry, next);
                HWT_CTX_UNLOCK(ctx);
        }
        free(kobase, M_LINKER);
}

void
hwt_record_wakeup(struct hwt_context *ctx)
{
        wakeup(ctx);
}