/*-
 * 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>

#define __ELF_WORD_SIZE 32

#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/sysent.h>
#include <sys/imgact_elf.h>
#include <sys/jail.h>
#include <sys/reg.h>
#include <sys/smp.h>
#include <sys/syscall.h>
#include <sys/sysctl.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>

#ifdef __powerpc64__
#include <compat/freebsd32/freebsd32_proto.h>
#include <compat/freebsd32/freebsd32_util.h>

extern const char *freebsd32_syscallnames[];
static void ppc32_fixlimit(struct rlimit *rl, int which);

static SYSCTL_NODE(_compat, OID_AUTO, ppc32, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "32-bit mode");

#define PPC32_MAXDSIZ (1024*1024*1024)
static u_long ppc32_maxdsiz = PPC32_MAXDSIZ;
SYSCTL_ULONG(_compat_ppc32, OID_AUTO, maxdsiz, CTLFLAG_RWTUN, &ppc32_maxdsiz,
             0, "");
#define PPC32_MAXSSIZ (64*1024*1024)
u_long ppc32_maxssiz = PPC32_MAXSSIZ;
SYSCTL_ULONG(_compat_ppc32, OID_AUTO, maxssiz, CTLFLAG_RWTUN, &ppc32_maxssiz,
             0, "");
#else
static void ppc32_runtime_resolve(void);
#endif

struct sysentvec elf32_freebsd_sysvec = {
        .sv_size        = SYS_MAXSYSCALL,
#ifdef __powerpc64__
        .sv_table       = freebsd32_sysent,
#else
        .sv_table       = sysent,
#endif
        .sv_fixup       = __elfN(freebsd_fixup),
        .sv_copyout_auxargs = __elfN(powerpc_copyout_auxargs),
        .sv_sendsig     = sendsig,
        .sv_sigcode     = sigcode32,
        .sv_szsigcode   = &szsigcode32,
        .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_stackprot   = VM_PROT_ALL,
#ifdef __powerpc64__
        .sv_maxuser     = VM_MAXUSER_ADDRESS32,
        .sv_usrstack    = FREEBSD32_USRSTACK,
        .sv_psstrings   = FREEBSD32_PS_STRINGS,
        .sv_psstringssz = sizeof(struct freebsd32_ps_strings),
        .sv_copyout_strings = freebsd32_copyout_strings,
        .sv_setregs     = ppc32_setregs,
        .sv_syscallnames = freebsd32_syscallnames,
        .sv_fixlimit    = ppc32_fixlimit,
#else
        .sv_maxuser     = VM_MAXUSER_ADDRESS,
        .sv_usrstack    = USRSTACK,
        .sv_psstrings   = PS_STRINGS,
        .sv_psstringssz = sizeof(struct ps_strings),
        .sv_copyout_strings = exec_copyout_strings,
        .sv_setregs     = exec_setregs,
        .sv_syscallnames = syscallnames,
        .sv_fixlimit    = NULL,
#endif
        .sv_maxssiz     = NULL,
        .sv_flags       = SV_ABI_FREEBSD | SV_ILP32 | 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_shared_page_base = FREEBSD32_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)),
};
INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);

static const Elf32_Brandinfo freebsd_brand_info = {
        .brand          = ELFOSABI_FREEBSD,
        .machine        = EM_PPC,
        .compat_3_brand = "FreeBSD",
        .interp_path    = "/libexec/ld-elf.so.1",
        .sysvec         = &elf32_freebsd_sysvec,
#ifdef __powerpc64__
        .interp_newpath = "/libexec/ld-elf32.so.1",
#else
        .interp_newpath = NULL,
#endif
        .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_PPC,
        .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);

void elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase);

void
elf32_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 += elf32_populate_note(NT_PPC_VMX,
                            &pcb->pcb_vec, (char *)dst + len,
                            sizeof(pcb->pcb_vec), NULL);
                } else
                        len += elf32_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 += elf32_populate_note(NT_PPC_VSX,
                            vshr, (char *)dst + len,
                            sizeof(vshr), NULL);
                } else
                        len += elf32_populate_note(NT_PPC_VSX, NULL, NULL,
                            sizeof(vshr), NULL);
        }

        *off = len;
}

#ifndef __powerpc64__
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_Half *hwhere;
        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 *) ((uintptr_t)relocbase + rela->r_offset);
                hwhere = (Elf_Half *) ((uintptr_t)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_PPC_ADDR32: /* word32 S + A */
                error = lookup(lf, symidx, 1, &addr);
                if (error != 0)
                        return (-1);
                *where = elf_relocaddr(lf, addr + addend);
                        break;

        case R_PPC_ADDR16_LO: /* #lo(S) */
                error = lookup(lf, symidx, 1, &addr);
                if (error != 0)
                        return (-1);
                /*
                 * addend values are sometimes relative to sections
                 * (i.e. .rodata) in rela, where in reality they
                 * are relative to relocbase. Detect this condition.
                 */
                if (addr > relocbase && addr <= (relocbase + addend))
                        addr = relocbase;
                addr = elf_relocaddr(lf, addr + addend);
                *hwhere = addr & 0xffff;
                break;

        case R_PPC_ADDR16_HA: /* #ha(S) */
                error = lookup(lf, symidx, 1, &addr);
                if (error != 0)
                        return (-1);
                /*
                 * addend values are sometimes relative to sections
                 * (i.e. .rodata) in rela, where in reality they
                 * are relative to relocbase. Detect this condition.
                 */
                if (addr > relocbase && addr <= (relocbase + addend))
                        addr = relocbase;
                addr = elf_relocaddr(lf, addr + addend);
                *hwhere = ((addr >> 16) + ((addr & 0x8000) ? 1 : 0))
                    & 0xffff;
                break;

        case R_PPC_RELATIVE: /* word32 B + A */
                *where = elf_relocaddr(lf, relocbase + addend);
                break;

        case R_PPC_JMP_SLOT: /* PLT jump slot entry */
                /*
                 * We currently only support Secure-PLT jump slots.
                 * Given that we reject BSS-PLT modules during load, we
                 * don't need to check again.
                 * The method we are using here is equivilent to
                 * LD_BIND_NOW.
                 */
                error = lookup(lf, symidx, 1, &addr);
                if (error != 0)
                        return (-1);
                *where = elf_relocaddr(lf, addr + addend);
                break;

        case R_PPC_IRELATIVE:
                addr = relocbase + addend;
                val = ((Elf32_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);
}

static void
ppc32_runtime_resolve(void)
{

        /*
         * Since we don't support lazy binding, panic immediately if anyone
         * manages to call the runtime resolver.
         */
        panic("kldload: Runtime resolver was called unexpectedly!");
}

int
elf_cpu_parse_dynamic(caddr_t loadbase, Elf_Dyn *dynamic)
{
        Elf_Dyn *dp;
        bool has_plt = false;
        bool secure_plt = false;
        Elf_Addr *got;

        for (dp = dynamic; dp->d_tag != DT_NULL; dp++) {
                switch (dp->d_tag) {
                case DT_PPC_GOT:
                        secure_plt = true;
                        got = (Elf_Addr *)(loadbase + dp->d_un.d_ptr);
                        /* Install runtime resolver canary. */
                        got[1] = (Elf_Addr)ppc32_runtime_resolve;
                        got[2] = (Elf_Addr)0;
                        break;
                case DT_PLTGOT:
                        has_plt = true;
                        break;
                }
        }

        if (has_plt && !secure_plt) {
                printf("kldload: BSS-PLT modules are not supported.\n");
                return (-1);
        }
        return (0);
}
#endif

#ifdef __powerpc64__
static void
ppc32_fixlimit(struct rlimit *rl, int which)
{
        switch (which) {
        case RLIMIT_DATA:
                if (ppc32_maxdsiz != 0) {
                        if (rl->rlim_cur > ppc32_maxdsiz)
                                rl->rlim_cur = ppc32_maxdsiz;
                        if (rl->rlim_max > ppc32_maxdsiz)
                                rl->rlim_max = ppc32_maxdsiz;
                }
                break;
        case RLIMIT_STACK:
                if (ppc32_maxssiz != 0) {
                        if (rl->rlim_cur > ppc32_maxssiz)
                                rl->rlim_cur = ppc32_maxssiz;
                        if (rl->rlim_max > ppc32_maxssiz)
                                rl->rlim_max = ppc32_maxssiz;
                }
                break;
        }
}
#endif