/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2006 Peter Wemm
 *
 * 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/cdefs.h>
/*
 * i386 machine dependent routines for kvm and minidumps.
 */

#include <sys/param.h>
#include <sys/endian.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <vm/vm.h>
#include <kvm.h>

#include "../../sys/i386/include/minidump.h"

#include <limits.h>

#include "kvm_private.h"
#include "kvm_i386.h"

#define i386_round_page(x)      roundup2((kvaddr_t)(x), I386_PAGE_SIZE)

struct vmstate {
        struct minidumphdr hdr;
};

static i386_pte_pae_t
_i386_pte_pae_get(kvm_t *kd, u_long pteindex)
{
        i386_pte_pae_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));

        return le64toh(*pte);
}

static i386_pte_t
_i386_pte_get(kvm_t *kd, u_long pteindex)
{
        i386_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));

        return le32toh(*pte);
}

static int
_i386_minidump_probe(kvm_t *kd)
{

        return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_386) &&
            _kvm_is_minidump(kd));
}

static void
_i386_minidump_freevtop(kvm_t *kd)
{
        struct vmstate *vm = kd->vmst;

        free(vm);
        kd->vmst = NULL;
}

static int
_i386_minidump_initvtop(kvm_t *kd)
{
        struct vmstate *vmst;
        off_t off, dump_avail_off, sparse_off;

        vmst = _kvm_malloc(kd, sizeof(*vmst));
        if (vmst == NULL) {
                _kvm_err(kd, kd->program, "cannot allocate vm");
                return (-1);
        }
        kd->vmst = vmst;
        if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
            sizeof(vmst->hdr)) {
                _kvm_err(kd, kd->program, "cannot read dump header");
                return (-1);
        }
        if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) {
                _kvm_err(kd, kd->program, "not a minidump for this platform");
                return (-1);
        }
        vmst->hdr.version = le32toh(vmst->hdr.version);
        if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
                _kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
                    MINIDUMP_VERSION, vmst->hdr.version);
                return (-1);
        }
        vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
        vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
        vmst->hdr.ptesize = le32toh(vmst->hdr.ptesize);
        vmst->hdr.kernbase = le32toh(vmst->hdr.kernbase);
        vmst->hdr.paemode = le32toh(vmst->hdr.paemode);
        vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
            le32toh(vmst->hdr.dumpavailsize) : 0;

        /* Skip header and msgbuf */
        dump_avail_off = I386_PAGE_SIZE + i386_round_page(vmst->hdr.msgbufsize);

        /* Skip dump_avail */
        off = dump_avail_off + i386_round_page(vmst->hdr.dumpavailsize);

        sparse_off = off + i386_round_page(vmst->hdr.bitmapsize) +
            i386_round_page(vmst->hdr.ptesize);
        if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
            vmst->hdr.bitmapsize, off, sparse_off, I386_PAGE_SIZE) == -1) {
                return (-1);
        }
        off += i386_round_page(vmst->hdr.bitmapsize);

        if (_kvm_pmap_init(kd, vmst->hdr.ptesize, off) == -1) {
                return (-1);
        }
        off += i386_round_page(vmst->hdr.ptesize);

        return (0);
}

static int
_i386_minidump_vatop_pae(kvm_t *kd, kvaddr_t va, off_t *pa)
{
        struct vmstate *vm;
        i386_physaddr_pae_t offset;
        i386_pte_pae_t pte;
        kvaddr_t pteindex;
        i386_physaddr_pae_t a;
        off_t ofs;

        vm = kd->vmst;
        offset = va & I386_PAGE_MASK;

        if (va >= vm->hdr.kernbase) {
                pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
                if (pteindex >= vm->hdr.ptesize / sizeof(pte))
                        goto invalid;
                pte = _i386_pte_pae_get(kd, pteindex);
                if ((pte & I386_PG_V) == 0) {
                        _kvm_err(kd, kd->program,
                            "_i386_minidump_vatop_pae: pte not valid");
                        goto invalid;
                }
                a = pte & I386_PG_FRAME_PAE;
                ofs = _kvm_pt_find(kd, a, I386_PAGE_SIZE);
                if (ofs == -1) {
                        _kvm_err(kd, kd->program,
            "_i386_minidump_vatop_pae: physical address 0x%jx not in minidump",
                            (uintmax_t)a);
                        goto invalid;
                }
                *pa = ofs + offset;
                return (I386_PAGE_SIZE - offset);
        } else {
                _kvm_err(kd, kd->program,
            "_i386_minidump_vatop_pae: virtual address 0x%jx not minidumped",
                    (uintmax_t)va);
                goto invalid;
        }

invalid:
        _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
        return (0);
}

static int
_i386_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
{
        struct vmstate *vm;
        i386_physaddr_t offset;
        i386_pte_t pte;
        kvaddr_t pteindex;
        i386_physaddr_t a;
        off_t ofs;

        vm = kd->vmst;
        offset = va & I386_PAGE_MASK;

        if (va >= vm->hdr.kernbase) {
                pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
                if (pteindex >= vm->hdr.ptesize / sizeof(pte))
                        goto invalid;
                pte = _i386_pte_get(kd, pteindex);
                if ((pte & I386_PG_V) == 0) {
                        _kvm_err(kd, kd->program,
                            "_i386_minidump_vatop: pte not valid");
                        goto invalid;
                }
                a = pte & I386_PG_FRAME;
                ofs = _kvm_pt_find(kd, a, I386_PAGE_SIZE);
                if (ofs == -1) {
                        _kvm_err(kd, kd->program,
            "_i386_minidump_vatop: physical address 0x%jx not in minidump",
                            (uintmax_t)a);
                        goto invalid;
                }
                *pa = ofs + offset;
                return (I386_PAGE_SIZE - offset);
        } else {
                _kvm_err(kd, kd->program,
            "_i386_minidump_vatop: virtual address 0x%jx not minidumped",
                    (uintmax_t)va);
                goto invalid;
        }

invalid:
        _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
        return (0);
}

static int
_i386_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
{

        if (ISALIVE(kd)) {
                _kvm_err(kd, 0, "_i386_minidump_kvatop called in live kernel!");
                return (0);
        }
        if (kd->vmst->hdr.paemode)
                return (_i386_minidump_vatop_pae(kd, va, pa));
        else
                return (_i386_minidump_vatop(kd, va, pa));
}

static vm_prot_t
_i386_entry_to_prot(uint64_t pte)
{
        vm_prot_t prot = VM_PROT_READ;

        /* Source: i386/pmap.c:pmap_protect() */
        if (pte & I386_PG_RW)
                prot |= VM_PROT_WRITE;
        if ((pte & I386_PG_NX) == 0)
                prot |= VM_PROT_EXECUTE;

        return prot;
}

struct i386_iter {
        kvm_t *kd;
        u_long nptes;
        u_long pteindex;
};

static void
_i386_iterator_init(struct i386_iter *it, kvm_t *kd)
{
        struct vmstate *vm = kd->vmst;

        it->kd = kd;
        it->pteindex = 0;
        if (vm->hdr.paemode) {
                it->nptes = vm->hdr.ptesize / sizeof(i386_pte_pae_t);
        } else {
                it->nptes = vm->hdr.ptesize / sizeof(i386_pte_t);
        }
        return;
}

static int
_i386_iterator_next(struct i386_iter *it, u_long *pa, u_long *va, u_long *dva,
    vm_prot_t *prot)
{
        struct vmstate *vm = it->kd->vmst;
        i386_pte_t pte32;
        i386_pte_pae_t pte64;
        int found = 0;

        *dva = 0;
        *pa = 0;
        *va = 0;
        *dva = 0;
        *prot = 0;
        for (; it->pteindex < it->nptes && found == 0; it->pteindex++) {
                if (vm->hdr.paemode) {
                        pte64 = _i386_pte_pae_get(it->kd, it->pteindex);
                        if ((pte64 & I386_PG_V) == 0)
                                continue;
                        *prot = _i386_entry_to_prot(pte64);
                        *pa = pte64 & I386_PG_FRAME_PAE;
                } else {
                        pte32 = _i386_pte_get(it->kd, it->pteindex);
                        if ((pte32 & I386_PG_V) == 0)
                                continue;
                        *prot = _i386_entry_to_prot(pte32);
                        *pa = pte32 & I386_PG_FRAME;
                }
                *va = vm->hdr.kernbase + (it->pteindex << I386_PAGE_SHIFT);
                found = 1;
        }
        return found;
}

static int
_i386_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
{
        struct i386_iter it;
        u_long dva, pa, va;
        vm_prot_t prot;

        _i386_iterator_init(&it, kd);
        while (_i386_iterator_next(&it, &pa, &va, &dva, &prot)) {
                if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
                    prot, I386_PAGE_SIZE, 0)) {
                        return (0);
                }
        }
        return (1);
}

static struct kvm_arch kvm_i386_minidump = {
        .ka_probe = _i386_minidump_probe,
        .ka_initvtop = _i386_minidump_initvtop,
        .ka_freevtop = _i386_minidump_freevtop,
        .ka_kvatop = _i386_minidump_kvatop,
        .ka_native = _i386_native,
        .ka_walk_pages = _i386_minidump_walk_pages,
};

KVM_ARCH(kvm_i386_minidump);