/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright 1996-1998 John D. Polstra.
 * All rights reserved.
 *
 * 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 ``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 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>
#include "opt_cpu.h"

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/exec.h>
#include <sys/imgact.h>
#include <sys/linker.h>
#include <sys/reg.h>
#include <sys/proc.h>
#include <sys/sysent.h>
#include <sys/imgact_elf.h>
#include <sys/syscall.h>
#include <sys/signalvar.h>
#include <sys/vnode.h>

#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_param.h>

#include <machine/elf.h>
#include <machine/md_var.h>
#include <machine/npx.h>

struct sysentvec elf32_freebsd_sysvec = {
        .sv_size        = SYS_MAXSYSCALL,
        .sv_table       = sysent,
        .sv_fixup       = __elfN(freebsd_fixup),
        .sv_sendsig     = sendsig,
        .sv_sigcode     = sigcode,
        .sv_szsigcode   = &szsigcode,
        .sv_name        = "FreeBSD ELF32",
        .sv_coredump    = __elfN(coredump),
        .sv_elf_core_osabi = ELFOSABI_FREEBSD,
        .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
        .sv_elf_core_prepare_notes = __elfN(prepare_notes),
        .sv_minsigstksz = MINSIGSTKSZ,
        .sv_minuser     = VM_MIN_ADDRESS,
        .sv_maxuser     = VM_MAXUSER_ADDRESS,
        .sv_usrstack    = USRSTACK,
        .sv_psstrings   = PS_STRINGS,
        .sv_psstringssz = sizeof(struct ps_strings),
        .sv_stackprot   = VM_PROT_ALL,
        .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs),
        .sv_copyout_strings     = exec_copyout_strings,
        .sv_setregs     = exec_setregs,
        .sv_fixlimit    = NULL,
        .sv_maxssiz     = NULL,
        .sv_flags       = SV_ABI_FREEBSD | SV_ASLR | SV_ILP32 |
                            SV_SHP | SV_TIMEKEEP | SV_RNG_SEED_VER | SV_SIGSYS,
        .sv_set_syscall_retval = cpu_set_syscall_retval,
        .sv_fetch_syscall_args = cpu_fetch_syscall_args,
        .sv_syscallnames = syscallnames,
        .sv_shared_page_base = SHAREDPAGE,
        .sv_shared_page_len = PAGE_SIZE,
        .sv_schedtail   = NULL,
        .sv_thread_detach = NULL,
        .sv_trap        = NULL,
        .sv_onexec_old  = exec_onexec_old,
        .sv_onexit      = exit_onexit,
        .sv_set_fork_retval = x86_set_fork_retval,
        .sv_regset_begin = SET_BEGIN(__elfN(regset)),
        .sv_regset_end  = SET_LIMIT(__elfN(regset)),
};
INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);

static const Elf32_Brandinfo freebsd_brand_info = {
        .brand          = ELFOSABI_FREEBSD,
        .machine        = EM_386,
        .compat_3_brand = "FreeBSD",
        .interp_path    = "/libexec/ld-elf.so.1",
        .sysvec         = &elf32_freebsd_sysvec,
        .interp_newpath = NULL,
        .brand_note     = &elf32_freebsd_brandnote,
        .flags          = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
};

C_SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
        (sysinit_cfunc_t) elf32_insert_brand_entry,
        &freebsd_brand_info);

static const Elf32_Brandinfo freebsd_brand_oinfo = {
        .brand          = ELFOSABI_FREEBSD,
        .machine        = EM_386,
        .compat_3_brand = "FreeBSD",
        .interp_path    = "/usr/libexec/ld-elf.so.1",
        .sysvec         = &elf32_freebsd_sysvec,
        .interp_newpath = NULL,
        .brand_note     = &elf32_freebsd_brandnote,
        .flags          = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
};

C_SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY,
        (sysinit_cfunc_t) elf32_insert_brand_entry,
        &freebsd_brand_oinfo);

static const Elf32_Brandinfo kfreebsd_brand_info = {
        .brand          = ELFOSABI_FREEBSD,
        .machine        = EM_386,
        .compat_3_brand = "FreeBSD",
        .interp_path    = "/lib/ld.so.1",
        .sysvec         = &elf32_freebsd_sysvec,
        .interp_newpath = NULL,
        .brand_note     = &elf32_kfreebsd_brandnote,
        .flags          = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY
};

C_SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY,
        (sysinit_cfunc_t) elf32_insert_brand_entry,
        &kfreebsd_brand_info);

void
elf32_dump_thread(struct thread *td, void *dst, size_t *off)
{
        void *buf;
        size_t len;

        len = 0;
        if (use_xsave) {
                if (dst != NULL) {
                        npxgetregs(td);
                        len += elf32_populate_note(NT_X86_XSTATE,
                            get_pcb_user_save_td(td), dst,
                            cpu_max_ext_state_size, &buf);
                        *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) =
                            xsave_mask;
                } else
                        len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL,
                            cpu_max_ext_state_size, NULL);
        }
        *off = len;
}

bool
elf_is_ifunc_reloc(Elf_Size r_info)
{

        return (ELF_R_TYPE(r_info) == R_386_IRELATIVE);
}

#define ERI_LOCAL       0x0001

/* Process one elf relocation with addend. */
static int
elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
    int type, elf_lookup_fn lookup, int flags)
{
        Elf_Addr *where;
        Elf_Addr addr;
        Elf_Addr addend;
        Elf_Word rtype, symidx;
        const Elf_Rel *rel;
        const Elf_Rela *rela;
        int error;

        switch (type) {
        case ELF_RELOC_REL:
                rel = (const Elf_Rel *)data;
                where = (Elf_Addr *) (relocbase + rel->r_offset);
                addend = *where;
                rtype = ELF_R_TYPE(rel->r_info);
                symidx = ELF_R_SYM(rel->r_info);
                break;
        case ELF_RELOC_RELA:
                rela = (const Elf_Rela *)data;
                where = (Elf_Addr *) (relocbase + rela->r_offset);
                addend = rela->r_addend;
                rtype = ELF_R_TYPE(rela->r_info);
                symidx = ELF_R_SYM(rela->r_info);
                break;
        default:
                panic("unknown reloc type %d\n", type);
        }

        if ((flags & ERI_LOCAL) != 0) {
                if (rtype == R_386_RELATIVE) {  /* A + B */
                        addr = elf_relocaddr(lf, relocbase + addend);
                        if (*where != addr)
                                *where = addr;
                }
                return (0);
        }

        switch (rtype) {
                case R_386_NONE:        /* none */
                        break;

                case R_386_32:          /* S + A */
                        error = lookup(lf, symidx, 1, &addr);
                        if (error != 0)
                                return (-1);
                        addr += addend;
                        if (*where != addr)
                                *where = addr;
                        break;

                case R_386_PC32:        /* S + A - P */
                        error = lookup(lf, symidx, 1, &addr);
                        if (error != 0)
                                return (-1);
                        addr += addend - (Elf_Addr)where;
                        if (*where != addr)
                                *where = addr;
                        break;

                case R_386_COPY:        /* none */
                        /*
                         * There shouldn't be copy relocations in kernel
                         * objects.
                         */
                        printf("kldload: unexpected R_COPY relocation, "
                            "symbol index %d\n", symidx);
                        return (-1);
                        break;

                case R_386_GLOB_DAT:    /* S */
                case R_386_JMP_SLOT:    /* S */
                        error = lookup(lf, symidx, 1, &addr);
                        if (error != 0)
                                return (-1);
                        if (*where != addr)
                                *where = addr;
                        break;

                case R_386_RELATIVE:
                        break;

                case R_386_IRELATIVE:
                        addr = relocbase + addend;
                        addr = ((Elf_Addr (*)(void))addr)();
                        if (*where != addr)
                                *where = addr;
                        break;

                default:
                        printf("kldload: unexpected relocation type %d, "
                            "symbol index %d\n", rtype, symidx);
                        return (-1);
        }
        return(0);
}

int
elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
    elf_lookup_fn lookup)
{

        return (elf_reloc_internal(lf, relocbase, data, type, lookup, 0));
}

int
elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
    int type, elf_lookup_fn lookup)
{

        return (elf_reloc_internal(lf, relocbase, data, type, lookup,
            ERI_LOCAL));
}

int
elf_cpu_load_file(linker_file_t lf __unused)
{

        return (0);
}

int
elf_cpu_unload_file(linker_file_t lf __unused)
{

        return (0);
}

int
elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused)
{

        return (0);
}