/*-
 * 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/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/exec.h>
#include <sys/imgact.h>
#include <sys/linker.h>
#include <sys/proc.h>
#include <sys/reg.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/fpu.h>
#include <machine/md_var.h>

#include "vdso_offsets.h"

extern const char _binary_elf_vdso_so_1_start[];
extern const char _binary_elf_vdso_so_1_end[];
extern char _binary_elf_vdso_so_1_size;

struct sysentvec elf64_freebsd_sysvec_la48 = {
        .sv_size        = SYS_MAXSYSCALL,
        .sv_table       = sysent,
        .sv_fixup       = __elfN(freebsd_fixup),
        .sv_sendsig     = sendsig,
        .sv_sigcode     = _binary_elf_vdso_so_1_start,
        .sv_szsigcode   = (int *)&_binary_elf_vdso_so_1_size,
        .sv_sigcodeoff  = VDSO_SIGCODE_OFFSET,
        .sv_name        = "FreeBSD ELF64",
        .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_LA48,
        .sv_usrstack    = USRSTACK_LA48,
        .sv_psstrings   = PS_STRINGS_LA48,
        .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_LP64 | SV_SHP |
                            SV_TIMEKEEP | SV_RNG_SEED_VER | SV_DSO_SIG |
                            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_LA48,
        .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)),
};

struct sysentvec elf64_freebsd_sysvec_la57 = {
        .sv_size        = SYS_MAXSYSCALL,
        .sv_table       = sysent,
        .sv_fixup       = __elfN(freebsd_fixup),
        .sv_sendsig     = sendsig,
        .sv_sigcode     = _binary_elf_vdso_so_1_start,
        .sv_szsigcode   = (int *)&_binary_elf_vdso_so_1_size,
        .sv_sigcodeoff  = VDSO_SIGCODE_OFFSET,
        .sv_name        = "FreeBSD ELF64",
        .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_LA57,
        .sv_usrstack    = USRSTACK_LA57,
        .sv_psstrings   = PS_STRINGS_LA57,
        .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_LP64 | SV_SHP |
                            SV_TIMEKEEP | SV_RNG_SEED_VER | SV_DSO_SIG |
                            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_LA57,
        .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)),
};

static void
amd64_init_sysvecs(void *arg)
{
        amd64_lower_shared_page(&elf64_freebsd_sysvec_la48);
        if (la57) {
                exec_sysvec_init(&elf64_freebsd_sysvec_la57);
                exec_sysvec_init_secondary(&elf64_freebsd_sysvec_la57,
                    &elf64_freebsd_sysvec_la48);
        } else {
                exec_sysvec_init(&elf64_freebsd_sysvec_la48);
        }
}
SYSINIT(elf64_sysvec, SI_SUB_EXEC, SI_ORDER_ANY, amd64_init_sysvecs, NULL);

void
amd64_lower_shared_page(struct sysentvec *sv)
{
        if (hw_lower_amd64_sharedpage != 0) {
                sv->sv_maxuser -= PAGE_SIZE;
                sv->sv_shared_page_base -= PAGE_SIZE;
                sv->sv_usrstack -= PAGE_SIZE;
                sv->sv_psstrings -= PAGE_SIZE;
        }
}

static bool
freebsd_brand_info_la57_img_compat(const struct image_params *imgp,
    const int32_t *osrel __unused, const uint32_t *fctl0)
{
        if ((imgp->proc->p_md.md_flags & P_MD_LA57) != 0)
                return (true);
        if (fctl0 != NULL && (*fctl0 & NT_FREEBSD_FCTL_LA57) != 0)
                return (true);
        if (fctl0 == NULL || (*fctl0 & NT_FREEBSD_FCTL_LA48) != 0)
                return (false);
        if ((imgp->proc->p_md.md_flags & P_MD_LA48) != 0)
                return (false);
        return (!prefer_uva_la48);
}

static const Elf64_Brandinfo freebsd_brand_info_la48 = {
        .brand          = ELFOSABI_FREEBSD,
        .machine        = EM_X86_64,
        .compat_3_brand = "FreeBSD",
        .interp_path    = "/libexec/ld-elf.so.1",
        .sysvec         = &elf64_freebsd_sysvec_la48,
        .interp_newpath = NULL,
        .brand_note     = &elf64_freebsd_brandnote,
        .flags          = BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
};

static const Elf64_Brandinfo freebsd_brand_info_la57 = {
        .brand          = ELFOSABI_FREEBSD,
        .machine        = EM_X86_64,
        .compat_3_brand = "FreeBSD",
        .interp_path    = "/libexec/ld-elf.so.1",
        .sysvec         = &elf64_freebsd_sysvec_la57,
        .interp_newpath = NULL,
        .brand_note     = &elf64_freebsd_brandnote,
        .flags          = BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
        .header_supported = freebsd_brand_info_la57_img_compat,
};

static void
sysinit_register_elf64_brand_entries(void *arg __unused)
{
        /*
         * _57 must go first so it can either claim the image or hand
         * it to _48.
         */
        if (la57)
                elf64_insert_brand_entry(&freebsd_brand_info_la57);
        elf64_insert_brand_entry(&freebsd_brand_info_la48);
}
SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST,
    sysinit_register_elf64_brand_entries, NULL);

static const Elf64_Brandinfo freebsd_brand_oinfo = {
        .brand          = ELFOSABI_FREEBSD,
        .machine        = EM_X86_64,
        .compat_3_brand = "FreeBSD",
        .interp_path    = "/usr/libexec/ld-elf.so.1",
        .sysvec         = &elf64_freebsd_sysvec_la48,
        .interp_newpath = NULL,
        .brand_note     = &elf64_freebsd_brandnote,
        .flags          = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
};
C_SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY,
    (sysinit_cfunc_t)elf64_insert_brand_entry, &freebsd_brand_oinfo);

static const Elf64_Brandinfo kfreebsd_brand_info = {
        .brand          = ELFOSABI_FREEBSD,
        .machine        = EM_X86_64,
        .compat_3_brand = "FreeBSD",
        .interp_path    = "/lib/ld-kfreebsd-x86-64.so.1",
        .sysvec         = &elf64_freebsd_sysvec_la48,
        .interp_newpath = NULL,
        .brand_note     = &elf64_kfreebsd_brandnote,
        .flags          = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY
};
C_SYSINIT(kelf64, SI_SUB_EXEC, SI_ORDER_ANY,
    (sysinit_cfunc_t)elf64_insert_brand_entry, &kfreebsd_brand_info);

void
elf64_dump_thread(struct thread *td, void *dst, size_t *off)
{
        void *buf;
        size_t len;

        len = 0;
        if (use_xsave) {
                if (dst != NULL) {
                        fpugetregs(td);
                        len += elf64_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 += elf64_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_X86_64_IRELATIVE);
}

/* Process one elf relocation with addend. */
static int
elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
    int type, bool late_ifunc, elf_lookup_fn lookup)
{
        Elf64_Addr *where, val;
        Elf32_Addr *where32, val32;
        Elf_Addr addr;
        Elf_Addr addend;
        Elf_Size 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);
                rtype = ELF_R_TYPE(rel->r_info);
                symidx = ELF_R_SYM(rel->r_info);
                /* Addend is 32 bit on 32 bit relocs */
                switch (rtype) {
                case R_X86_64_PC32:
                case R_X86_64_32S:
                case R_X86_64_PLT32:
                        addend = *(Elf32_Addr *)where;
                        break;
                default:
                        addend = *where;
                        break;
                }
                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 (late_ifunc) {
                KASSERT(type == ELF_RELOC_RELA,
                    ("Only RELA ifunc relocations are supported"));
                if (rtype != R_X86_64_IRELATIVE)
                        return (0);
        }

        switch (rtype) {
                case R_X86_64_NONE:     /* none */
                        break;

                case R_X86_64_64:       /* S + A */
                        error = lookup(lf, symidx, 1, &addr);
                        val = addr + addend;
                        if (error != 0)
                                return (-1);
                        if (*where != val)
                                *where = val;
                        break;

                case R_X86_64_PC32:     /* S + A - P */
                case R_X86_64_PLT32:    /* L + A - P, L is PLT location for
                                           the symbol, which we treat as S */
                        error = lookup(lf, symidx, 1, &addr);
                        where32 = (Elf32_Addr *)where;
                        val32 = (Elf32_Addr)(addr + addend - (Elf_Addr)where);
                        if (error != 0)
                                return (-1);
                        if (*where32 != val32)
                                *where32 = val32;
                        break;

                case R_X86_64_32S:      /* S + A sign extend */
                        error = lookup(lf, symidx, 1, &addr);
                        val32 = (Elf32_Addr)(addr + addend);
                        where32 = (Elf32_Addr *)where;
                        if (error != 0)
                                return (-1);
                        if (*where32 != val32)
                                *where32 = val32;
                        break;

                case R_X86_64_COPY:     /* none */
                        /*
                         * There shouldn't be copy relocations in kernel
                         * objects.
                         */
                        printf("kldload: unexpected R_COPY relocation, "
                            "symbol index %ld\n", symidx);
                        return (-1);

                case R_X86_64_GLOB_DAT: /* S */
                case R_X86_64_JMP_SLOT: /* XXX need addend + offset */
                        error = lookup(lf, symidx, 1, &addr);
                        if (error != 0)
                                return (-1);
                        if (*where != addr)
                                *where = addr;
                        break;

                case R_X86_64_RELATIVE: /* B + A */
                        addr = elf_relocaddr(lf, relocbase + addend);
                        val = addr;
                        if (*where != val)
                                *where = val;
                        break;

                case R_X86_64_IRELATIVE:
                        addr = relocbase + addend;
                        val = ((Elf64_Addr (*)(void))addr)();
                        if (*where != val)
                                *where = val;
                        break;

                default:
                        printf("kldload: unexpected relocation type %ld, "
                            "symbol index %ld\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, false, lookup));
}

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, false, lookup));
}

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

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

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);
}