/*-
 * 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/elf.h>
#include <sys/exec.h>
#include <sys/imgact.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/namei.h>
#include <sys/fcntl.h>
#include <sys/reg.h>
#include <sys/sysent.h>
#include <sys/imgact_elf.h>
#include <sys/jail.h>
#include <sys/smp.h>
#include <sys/syscall.h>
#include <sys/signalvar.h>
#include <sys/vnode.h>
#include <sys/linker.h>

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

#include <machine/altivec.h>
#include <machine/cpu.h>
#include <machine/fpu.h>
#include <machine/elf.h>
#include <machine/md_var.h>

#include <powerpc/powerpc/elf_common.c>

static void exec_setregs_funcdesc(struct thread *td, struct image_params *imgp,
    uintptr_t stack);

struct sysentvec elf64_freebsd_sysvec_v1 = {
        .sv_size        = SYS_MAXSYSCALL,
        .sv_table       = sysent,
        .sv_fixup       = __elfN(freebsd_fixup),
        .sv_sendsig     = sendsig,
        .sv_sigcode     = sigcode64,
        .sv_szsigcode   = &szsigcode64,
        .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,
        .sv_usrstack    = USRSTACK,
        .sv_psstrings   = PS_STRINGS,
        .sv_psstringssz = sizeof(struct ps_strings),
        .sv_stackprot   = VM_PROT_ALL,
        .sv_copyout_auxargs = __elfN(powerpc_copyout_auxargs),
        .sv_copyout_strings = exec_copyout_strings,
        .sv_setregs     = exec_setregs_funcdesc,
        .sv_fixlimit    = NULL,
        .sv_maxssiz     = NULL,
        .sv_flags       = SV_ABI_FREEBSD | SV_LP64 | SV_SHP | SV_ASLR |
                            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_hwcap       = &cpu_features,
        .sv_hwcap2      = &cpu_features2,
        .sv_hwcap3      = NULL,
        .sv_hwcap4      = NULL,
        .sv_onexec_old  = exec_onexec_old,
        .sv_onexit      = exit_onexit,
        .sv_regset_begin = SET_BEGIN(__elfN(regset)),
        .sv_regset_end  = SET_LIMIT(__elfN(regset)),
};

struct sysentvec elf64_freebsd_sysvec_v2 = {
        .sv_size        = SYS_MAXSYSCALL,
        .sv_table       = sysent,
        .sv_fixup       = __elfN(freebsd_fixup),
        .sv_sendsig     = sendsig,
        .sv_sigcode     = sigcode64, /* Fixed up in ppc64_init_sysvecs(). */
        .sv_szsigcode   = &szsigcode64,
        .sv_name        = "FreeBSD ELF64 V2",
        .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(powerpc_copyout_auxargs),
        .sv_copyout_strings = exec_copyout_strings,
        .sv_setregs     = exec_setregs,
        .sv_fixlimit    = NULL,
        .sv_maxssiz     = NULL,
        .sv_flags       = SV_ABI_FREEBSD | SV_LP64 | 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_hwcap       = &cpu_features,
        .sv_hwcap2      = &cpu_features2,
        .sv_hwcap3      = NULL,
        .sv_hwcap4      = NULL,
        .sv_onexec_old  = exec_onexec_old,
        .sv_onexit      = exit_onexit,
        .sv_regset_begin = SET_BEGIN(__elfN(regset)),
        .sv_regset_end  = SET_LIMIT(__elfN(regset)),
};

static bool ppc64_elfv1_header_match(const struct image_params *params,
    const int32_t *, const uint32_t *);
static bool ppc64_elfv2_header_match(const struct image_params *params,
    const int32_t *, const uint32_t *);

static const Elf64_Brandinfo freebsd_brand_info_elfv1 = {
        .brand          = ELFOSABI_FREEBSD,
        .machine        = EM_PPC64,
        .compat_3_brand = "FreeBSD",
        .interp_path    = "/libexec/ld-elf.so.1",
        .sysvec         = &elf64_freebsd_sysvec_v1,
        .interp_newpath = NULL,
        .brand_note     = &elf64_freebsd_brandnote,
        .flags          = BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
        .header_supported = &ppc64_elfv1_header_match
};

C_SYSINIT(elf64v1, SI_SUB_EXEC, SI_ORDER_ANY,
    (sysinit_cfunc_t) elf64_insert_brand_entry,
    &freebsd_brand_info_elfv1);

static const Elf64_Brandinfo freebsd_brand_info_elfv2 = {
        .brand          = ELFOSABI_FREEBSD,
        .machine        = EM_PPC64,
        .compat_3_brand = "FreeBSD",
        .interp_path    = "/libexec/ld-elf.so.1",
        .sysvec         = &elf64_freebsd_sysvec_v2,
        .interp_newpath = NULL,
        .brand_note     = &elf64_freebsd_brandnote,
        .flags          = BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
        .header_supported = &ppc64_elfv2_header_match
};

C_SYSINIT(elf64v2, SI_SUB_EXEC, SI_ORDER_ANY,
    (sysinit_cfunc_t) elf64_insert_brand_entry,
    &freebsd_brand_info_elfv2);

static const Elf64_Brandinfo freebsd_brand_oinfo = {
        .brand          = ELFOSABI_FREEBSD,
        .machine        = EM_PPC64,
        .compat_3_brand = "FreeBSD",
        .interp_path    = "/usr/libexec/ld-elf.so.1",
        .sysvec         = &elf64_freebsd_sysvec_v1,
        .interp_newpath = NULL,
        .brand_note     = &elf64_freebsd_brandnote,
        .flags          = BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
        .header_supported = &ppc64_elfv1_header_match
};

C_SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY,
        (sysinit_cfunc_t) elf64_insert_brand_entry,
        &freebsd_brand_oinfo);

void elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase);

static void
ppc64_init_sysvecs(void *arg)
{
        exec_sysvec_init(&elf64_freebsd_sysvec_v2);
        exec_sysvec_init_secondary(&elf64_freebsd_sysvec_v2,
            &elf64_freebsd_sysvec_v1);
        /*
         * Adjust elfv2 sigcode after elfv1 sysvec is initialized.
         * exec_sysvec_init_secondary() assumes secondary sysvecs use
         * identical signal code, and skips allocating a second copy.
         * Since the ELFv2 trampoline is a strict subset of the ELFv1 code,
         * we can work around this by adjusting the offset. This also
         * avoids two copies of the trampoline code being allocated!
         */
        elf64_freebsd_sysvec_v2.sv_sigcode_offset +=
            (uintptr_t)sigcode64_elfv2 - (uintptr_t)&sigcode64;
        elf64_freebsd_sysvec_v2.sv_szsigcode = &szsigcode64_elfv2;
}
SYSINIT(elf64_sysvec, SI_SUB_EXEC, SI_ORDER_ANY, ppc64_init_sysvecs, NULL);

static bool
ppc64_elfv1_header_match(const struct image_params *params,
    const int32_t *osrel __unused, const uint32_t *fctl0 __unused)
{
        const Elf64_Ehdr *hdr = (const Elf64_Ehdr *)params->image_header;
        int abi = (hdr->e_flags & 3);

        return (abi == 0 || abi == 1);
}

static bool
ppc64_elfv2_header_match(const struct image_params *params,
    const int32_t *osrel __unused, const uint32_t *fctl0 __unused)
{
        const Elf64_Ehdr *hdr = (const Elf64_Ehdr *)params->image_header;
        int abi = (hdr->e_flags & 3);

        return (abi == 2);
}

static void  
exec_setregs_funcdesc(struct thread *td, struct image_params *imgp,
    uintptr_t stack)
{
        struct trapframe *tf;
        register_t entry_desc[3];

        tf = trapframe(td);
        exec_setregs(td, imgp, stack);

        /*
         * For 64-bit ELFv1, we need to disentangle the function
         * descriptor
         *
         * 0. entry point
         * 1. TOC value (r2)
         * 2. Environment pointer (r11)
         */

        (void)copyin((void *)imgp->entry_addr, entry_desc,
            sizeof(entry_desc));
        tf->srr0 = entry_desc[0] + imgp->reloc_base;
        tf->fixreg[2] = entry_desc[1] + imgp->reloc_base;
        tf->fixreg[11] = entry_desc[2] + imgp->reloc_base;
}

void
elf64_dump_thread(struct thread *td, void *dst, size_t *off)
{
        size_t len;
        struct pcb *pcb;
        uint64_t vshr[32];
        uint64_t *vsr_dw1;
        int vsr_idx;

        len = 0;
        pcb = td->td_pcb;

        if (pcb->pcb_flags & PCB_VEC) {
                if (dst != NULL) {
                        len += elf64_populate_note(NT_PPC_VMX,
                            &pcb->pcb_vec, (char *)dst + len,
                            sizeof(pcb->pcb_vec), NULL);
                } else
                        len += elf64_populate_note(NT_PPC_VMX, NULL, NULL,
                            sizeof(pcb->pcb_vec), NULL);
        }

        if (pcb->pcb_flags & PCB_VSX) {
                if (dst != NULL) {
                        /*
                         * Doubleword 0 of VSR0-VSR31 overlap with FPR0-FPR31 and
                         * VSR32-VSR63 overlap with VR0-VR31, so we only copy
                         * the non-overlapping data, which is doubleword 1 of VSR0-VSR31.
                         */
                        for (vsr_idx = 0; vsr_idx < nitems(vshr); vsr_idx++) {
                                vsr_dw1 = (uint64_t *)&pcb->pcb_fpu.fpr[vsr_idx].vsr[2];
                                vshr[vsr_idx] = *vsr_dw1;
                        }
                        len += elf64_populate_note(NT_PPC_VSX,
                            vshr, (char *)dst + len,
                            sizeof(vshr), NULL);
                } else
                        len += elf64_populate_note(NT_PPC_VSX, NULL, NULL,
                            sizeof(vshr), NULL);
        }

        *off = len;
}

bool
elf_is_ifunc_reloc(Elf_Size r_info)
{

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

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

        switch (type) {
        case ELF_RELOC_REL:
                panic("PPC only supports RELA relocations");
                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("elf_reloc: unknown relocation mode %d\n", type);
        }

        switch (rtype) {
        case R_PPC_NONE:
                break;

        case R_PPC64_ADDR64:    /* doubleword64 S + A */
                error = lookup(lf, symidx, 1, &addr);
                if (error != 0)
                        return (-1);
                addr += addend;
                *where = addr;
                break;

        case R_PPC_RELATIVE:    /* doubleword64 B + A */
                *where = elf_relocaddr(lf, relocbase + addend);
                break;

        case R_PPC_JMP_SLOT:    /* function descriptor copy */
                lookup(lf, symidx, 1, &addr);
#if !defined(_CALL_ELF) || _CALL_ELF == 1
                memcpy(where, (Elf_Addr *)addr, 3*sizeof(Elf_Addr));
#else
                *where = addr;
#endif
                __asm __volatile("dcbst 0,%0; sync" :: "r"(where) : "memory");
                break;

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

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

void
elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase)
{
        Elf_Rela *rela = NULL, *relalim;
        Elf_Addr relasz = 0;
        Elf_Addr *where;

        /*
         * Extract the rela/relasz values from the dynamic section
         */
        for (; dynp->d_tag != DT_NULL; dynp++) {
                switch (dynp->d_tag) {
                case DT_RELA:
                        rela = (Elf_Rela *)(relocbase+dynp->d_un.d_ptr);
                        break;
                case DT_RELASZ:
                        relasz = dynp->d_un.d_val;
                        break;
                }
        }

        /*
         * Relocate these values
         */
        relalim = (Elf_Rela *)((caddr_t)rela + relasz);
        for (; rela < relalim; rela++) {
                if (ELF_R_TYPE(rela->r_info) != R_PPC_RELATIVE)
                        continue;
                where = (Elf_Addr *)(relocbase + rela->r_offset);
                *where = (Elf_Addr)(relocbase + rela->r_addend);
        }
}

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, 0, 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, 1, lookup));
}

int
elf_cpu_load_file(linker_file_t lf)
{
        /* Only sync the cache for non-kernel modules */
        if (lf->id != 1)
                __syncicache(lf->address, lf->size);
        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);
}