/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2004 Tim J. Robbins
 * Copyright (c) 2002 Doug Rabson
 * Copyright (c) 2000 Marcel Moolenaar
 * 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
 *    in this position and unchanged.
 * 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.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * 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/lock.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/reg.h>
#include <sys/syscallsubr.h>

#include <machine/md_var.h>
#include <machine/specialreg.h>
#include <x86/ifunc.h>

#include <compat/freebsd32/freebsd32_util.h>
#include <amd64/linux32/linux.h>
#include <amd64/linux32/linux32_proto.h>
#include <compat/linux/linux_emul.h>
#include <compat/linux/linux_fork.h>
#include <compat/linux/linux_ipc.h>
#include <compat/linux/linux_mmap.h>
#include <compat/linux/linux_signal.h>
#include <compat/linux/linux_util.h>

static void     bsd_to_linux_rusage(struct rusage *ru, struct l_rusage *lru);

struct l_old_select_argv {
        l_int           nfds;
        l_uintptr_t     readfds;
        l_uintptr_t     writefds;
        l_uintptr_t     exceptfds;
        l_uintptr_t     timeout;
} __packed;

static void
bsd_to_linux_rusage(struct rusage *ru, struct l_rusage *lru)
{

        lru->ru_utime.tv_sec = ru->ru_utime.tv_sec;
        lru->ru_utime.tv_usec = ru->ru_utime.tv_usec;
        lru->ru_stime.tv_sec = ru->ru_stime.tv_sec;
        lru->ru_stime.tv_usec = ru->ru_stime.tv_usec;
        lru->ru_maxrss = ru->ru_maxrss;
        lru->ru_ixrss = ru->ru_ixrss;
        lru->ru_idrss = ru->ru_idrss;
        lru->ru_isrss = ru->ru_isrss;
        lru->ru_minflt = ru->ru_minflt;
        lru->ru_majflt = ru->ru_majflt;
        lru->ru_nswap = ru->ru_nswap;
        lru->ru_inblock = ru->ru_inblock;
        lru->ru_oublock = ru->ru_oublock;
        lru->ru_msgsnd = ru->ru_msgsnd;
        lru->ru_msgrcv = ru->ru_msgrcv;
        lru->ru_nsignals = ru->ru_nsignals;
        lru->ru_nvcsw = ru->ru_nvcsw;
        lru->ru_nivcsw = ru->ru_nivcsw;
}

int
linux_copyout_rusage(struct rusage *ru, void *uaddr)
{
        struct l_rusage lru;

        bsd_to_linux_rusage(ru, &lru);

        return (copyout(&lru, uaddr, sizeof(struct l_rusage)));
}

int
linux_readv(struct thread *td, struct linux_readv_args *uap)
{
        struct uio *auio;
        int error;

        error = freebsd32_copyinuio(uap->iovp, uap->iovcnt, &auio);
        if (error)
                return (error);
        error = kern_readv(td, uap->fd, auio);
        freeuio(auio);
        return (error);
}

struct l_ipc_kludge {
        l_uintptr_t msgp;
        l_long msgtyp;
} __packed;

int
linux_ipc(struct thread *td, struct linux_ipc_args *args)
{

        switch (args->what & 0xFFFF) {
        case LINUX_SEMOP: {

                return (kern_semop(td, args->arg1, PTRIN(args->ptr),
                    args->arg2, NULL));
        }
        case LINUX_SEMGET: {
                struct linux_semget_args a;

                a.key = args->arg1;
                a.nsems = args->arg2;
                a.semflg = args->arg3;
                return (linux_semget(td, &a));
        }
        case LINUX_SEMCTL: {
                struct linux_semctl_args a;
                int error;

                a.semid = args->arg1;
                a.semnum = args->arg2;
                a.cmd = args->arg3;
                error = copyin(PTRIN(args->ptr), &a.arg, sizeof(a.arg));
                if (error)
                        return (error);
                return (linux_semctl(td, &a));
        }
        case LINUX_SEMTIMEDOP: {
                struct linux_semtimedop_args a;

                a.semid = args->arg1;
                a.tsops = PTRIN(args->ptr);
                a.nsops = args->arg2;
                a.timeout = PTRIN(args->arg5);
                return (linux_semtimedop(td, &a));
        }
        case LINUX_MSGSND: {
                struct linux_msgsnd_args a;

                a.msqid = args->arg1;
                a.msgp = PTRIN(args->ptr);
                a.msgsz = args->arg2;
                a.msgflg = args->arg3;
                return (linux_msgsnd(td, &a));
        }
        case LINUX_MSGRCV: {
                struct linux_msgrcv_args a;

                a.msqid = args->arg1;
                a.msgsz = args->arg2;
                a.msgflg = args->arg3;
                if ((args->what >> 16) == 0) {
                        struct l_ipc_kludge tmp;
                        int error;

                        if (args->ptr == 0)
                                return (EINVAL);
                        error = copyin(PTRIN(args->ptr), &tmp, sizeof(tmp));
                        if (error)
                                return (error);
                        a.msgp = PTRIN(tmp.msgp);
                        a.msgtyp = tmp.msgtyp;
                } else {
                        a.msgp = PTRIN(args->ptr);
                        a.msgtyp = args->arg5;
                }
                return (linux_msgrcv(td, &a));
        }
        case LINUX_MSGGET: {
                struct linux_msgget_args a;

                a.key = args->arg1;
                a.msgflg = args->arg2;
                return (linux_msgget(td, &a));
        }
        case LINUX_MSGCTL: {
                struct linux_msgctl_args a;

                a.msqid = args->arg1;
                a.cmd = args->arg2;
                a.buf = PTRIN(args->ptr);
                return (linux_msgctl(td, &a));
        }
        case LINUX_SHMAT: {
                struct linux_shmat_args a;
                l_uintptr_t addr;
                int error;

                a.shmid = args->arg1;
                a.shmaddr = PTRIN(args->ptr);
                a.shmflg = args->arg2;
                error = linux_shmat(td, &a);
                if (error != 0)
                        return (error);
                addr = td->td_retval[0];
                error = copyout(&addr, PTRIN(args->arg3), sizeof(addr));
                td->td_retval[0] = 0;
                return (error);
        }
        case LINUX_SHMDT: {
                struct linux_shmdt_args a;

                a.shmaddr = PTRIN(args->ptr);
                return (linux_shmdt(td, &a));
        }
        case LINUX_SHMGET: {
                struct linux_shmget_args a;

                a.key = args->arg1;
                a.size = args->arg2;
                a.shmflg = args->arg3;
                return (linux_shmget(td, &a));
        }
        case LINUX_SHMCTL: {
                struct linux_shmctl_args a;

                a.shmid = args->arg1;
                a.cmd = args->arg2;
                a.buf = PTRIN(args->ptr);
                return (linux_shmctl(td, &a));
        }
        default:
                break;
        }

        return (EINVAL);
}

int
linux_old_select(struct thread *td, struct linux_old_select_args *args)
{
        struct l_old_select_argv linux_args;
        struct linux_select_args newsel;
        int error;

        error = copyin(args->ptr, &linux_args, sizeof(linux_args));
        if (error)
                return (error);

        newsel.nfds = linux_args.nfds;
        newsel.readfds = PTRIN(linux_args.readfds);
        newsel.writefds = PTRIN(linux_args.writefds);
        newsel.exceptfds = PTRIN(linux_args.exceptfds);
        newsel.timeout = PTRIN(linux_args.timeout);
        return (linux_select(td, &newsel));
}

int
linux_set_cloned_tls(struct thread *td, void *desc)
{
        struct l_user_desc info;
        struct pcb *pcb;
        int error;

        error = copyin(desc, &info, sizeof(struct l_user_desc));
        if (error) {
                linux_msg(td, "set_cloned_tls copyin info failed!");
        } else {
                /* We might copy out the entry_number as GUGS32_SEL. */
                info.entry_number = GUGS32_SEL;
                error = copyout(&info, desc, sizeof(struct l_user_desc));
                if (error)
                        linux_msg(td, "set_cloned_tls copyout info failed!");

                pcb = td->td_pcb;
                update_pcb_bases(pcb);
                pcb->pcb_gsbase = (register_t)info.base_addr;
                td->td_frame->tf_gs = GSEL(GUGS32_SEL, SEL_UPL);
        }

        return (error);
}

int
linux_set_upcall(struct thread *td, register_t stack)
{

        if (stack)
                td->td_frame->tf_rsp = stack;

        /*
         * The newly created Linux thread returns
         * to the user space by the same path that a parent do.
         */
        td->td_frame->tf_rax = 0;
        return (0);
}

int
linux_mmap(struct thread *td, struct linux_mmap_args *args)
{
        int error;
        struct l_mmap_argv linux_args;

        error = copyin(args->ptr, &linux_args, sizeof(linux_args));
        if (error)
                return (error);

        return (linux_mmap_common(td, linux_args.addr, linux_args.len,
            linux_args.prot, linux_args.flags, linux_args.fd,
            (uint32_t)linux_args.pgoff));
}

int
linux_iopl(struct thread *td, struct linux_iopl_args *args)
{
        int error;

        if (args->level < 0 || args->level > 3)
                return (EINVAL);
        if ((error = priv_check(td, PRIV_IO)) != 0)
                return (error);
        if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
                return (error);
        td->td_frame->tf_rflags = (td->td_frame->tf_rflags & ~PSL_IOPL) |
            (args->level * (PSL_IOPL / 3));

        return (0);
}

int
linux_sigaction(struct thread *td, struct linux_sigaction_args *args)
{
        l_osigaction_t osa;
        l_sigaction_t act, oact;
        int error;

        if (args->nsa != NULL) {
                error = copyin(args->nsa, &osa, sizeof(l_osigaction_t));
                if (error)
                        return (error);
                act.lsa_handler = osa.lsa_handler;
                act.lsa_flags = osa.lsa_flags;
                act.lsa_restorer = osa.lsa_restorer;
                LINUX_SIGEMPTYSET(act.lsa_mask);
                act.lsa_mask.__mask = osa.lsa_mask;
        }

        error = linux_do_sigaction(td, args->sig, args->nsa ? &act : NULL,
            args->osa ? &oact : NULL);

        if (args->osa != NULL && !error) {
                osa.lsa_handler = oact.lsa_handler;
                osa.lsa_flags = oact.lsa_flags;
                osa.lsa_restorer = oact.lsa_restorer;
                osa.lsa_mask = oact.lsa_mask.__mask;
                error = copyout(&osa, args->osa, sizeof(l_osigaction_t));
        }

        return (error);
}

/*
 * Linux has two extra args, restart and oldmask.  We don't use these,
 * but it seems that "restart" is actually a context pointer that
 * enables the signal to happen with a different register set.
 */
int
linux_sigsuspend(struct thread *td, struct linux_sigsuspend_args *args)
{
        sigset_t sigmask;
        l_sigset_t mask;

        LINUX_SIGEMPTYSET(mask);
        mask.__mask = args->mask;
        linux_to_bsd_sigset(&mask, &sigmask);
        return (kern_sigsuspend(td, sigmask));
}

int
linux_pause(struct thread *td, struct linux_pause_args *args)
{
        struct proc *p = td->td_proc;
        sigset_t sigmask;

        PROC_LOCK(p);
        sigmask = td->td_sigmask;
        PROC_UNLOCK(p);
        return (kern_sigsuspend(td, sigmask));
}

int
linux_gettimeofday(struct thread *td, struct linux_gettimeofday_args *uap)
{
        struct timeval atv;
        l_timeval atv32;
        struct timezone rtz;
        int error = 0;

        if (uap->tp) {
                microtime(&atv);
                atv32.tv_sec = atv.tv_sec;
                atv32.tv_usec = atv.tv_usec;
                error = copyout(&atv32, uap->tp, sizeof(atv32));
        }
        if (error == 0 && uap->tzp != NULL) {
                rtz.tz_minuteswest = 0;
                rtz.tz_dsttime = 0;
                error = copyout(&rtz, uap->tzp, sizeof(rtz));
        }
        return (error);
}

int
linux_settimeofday(struct thread *td, struct linux_settimeofday_args *uap)
{
        l_timeval atv32;
        struct timeval atv, *tvp;
        struct timezone atz, *tzp;
        int error;

        if (uap->tp) {
                error = copyin(uap->tp, &atv32, sizeof(atv32));
                if (error)
                        return (error);
                atv.tv_sec = atv32.tv_sec;
                atv.tv_usec = atv32.tv_usec;
                tvp = &atv;
        } else
                tvp = NULL;
        if (uap->tzp) {
                error = copyin(uap->tzp, &atz, sizeof(atz));
                if (error)
                        return (error);
                tzp = &atz;
        } else
                tzp = NULL;
        return (kern_settimeofday(td, tvp, tzp));
}

int
linux_getrusage(struct thread *td, struct linux_getrusage_args *uap)
{
        struct rusage s;
        int error;

        error = kern_getrusage(td, uap->who, &s);
        if (error != 0)
                return (error);
        if (uap->rusage != NULL)
                error = linux_copyout_rusage(&s, uap->rusage);
        return (error);
}

int
linux_set_thread_area(struct thread *td,
    struct linux_set_thread_area_args *args)
{
        struct l_user_desc info;
        struct pcb *pcb;
        int error;

        error = copyin(args->desc, &info, sizeof(struct l_user_desc));
        if (error)
                return (error);

        /*
         * Semantics of Linux version: every thread in the system has array
         * of three TLS descriptors. 1st is GLIBC TLS, 2nd is WINE, 3rd unknown.
         * This syscall loads one of the selected TLS descriptors with a value
         * and also loads GDT descriptors 6, 7 and 8 with the content of
         * the per-thread descriptors.
         *
         * Semantics of FreeBSD version: I think we can ignore that Linux has
         * three per-thread descriptors and use just the first one.
         * The tls_array[] is used only in [gs]et_thread_area() syscalls and
         * for loading the GDT descriptors. We use just one GDT descriptor
         * for TLS, so we will load just one.
         *
         * XXX: This doesn't work when a user space process tries to use more
         * than one TLS segment. Comment in the Linux source says wine might
         * do this.
         */

        /*
         * GLIBC reads current %gs and call set_thread_area() with it.
         * We should let GUDATA_SEL and GUGS32_SEL proceed as well because
         * we use these segments.
         */
        switch (info.entry_number) {
        case GUGS32_SEL:
        case GUDATA_SEL:
        case 6:
        case -1:
                info.entry_number = GUGS32_SEL;
                break;
        default:
                return (EINVAL);
        }

        /*
         * We have to copy out the GDT entry we use.
         *
         * XXX: What if a user space program does not check the return value
         * and tries to use 6, 7 or 8?
         */
        error = copyout(&info, args->desc, sizeof(struct l_user_desc));
        if (error)
                return (error);

        pcb = td->td_pcb;
        update_pcb_bases(pcb);
        pcb->pcb_gsbase = (register_t)info.base_addr;
        update_gdt_gsbase(td, info.base_addr);

        return (0);
}

void
bsd_to_linux_regset32(const struct reg32 *b_reg,
    struct linux_pt_regset32 *l_regset)
{

        l_regset->ebx = b_reg->r_ebx;
        l_regset->ecx = b_reg->r_ecx;
        l_regset->edx = b_reg->r_edx;
        l_regset->esi = b_reg->r_esi;
        l_regset->edi = b_reg->r_edi;
        l_regset->ebp = b_reg->r_ebp;
        l_regset->eax = b_reg->r_eax;
        l_regset->ds = b_reg->r_ds;
        l_regset->es = b_reg->r_es;
        l_regset->fs = b_reg->r_fs;
        l_regset->gs = b_reg->r_gs;
        l_regset->orig_eax = b_reg->r_eax;
        l_regset->eip = b_reg->r_eip;
        l_regset->cs = b_reg->r_cs;
        l_regset->eflags = b_reg->r_eflags;
        l_regset->esp = b_reg->r_esp;
        l_regset->ss = b_reg->r_ss;
}

int futex_xchgl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
int futex_xchgl_smap(int oparg, uint32_t *uaddr, int *oldval);
DEFINE_IFUNC(, int, futex_xchgl, (int, uint32_t *, int *))
{

        return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
            futex_xchgl_smap : futex_xchgl_nosmap);
}

int futex_addl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
int futex_addl_smap(int oparg, uint32_t *uaddr, int *oldval);
DEFINE_IFUNC(, int, futex_addl, (int, uint32_t *, int *))
{

        return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
            futex_addl_smap : futex_addl_nosmap);
}

int futex_orl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
int futex_orl_smap(int oparg, uint32_t *uaddr, int *oldval);
DEFINE_IFUNC(, int, futex_orl, (int, uint32_t *, int *))
{

        return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
            futex_orl_smap : futex_orl_nosmap);
}

int futex_andl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
int futex_andl_smap(int oparg, uint32_t *uaddr, int *oldval);
DEFINE_IFUNC(, int, futex_andl, (int, uint32_t *, int *))
{

        return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
            futex_andl_smap : futex_andl_nosmap);
}

int futex_xorl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
int futex_xorl_smap(int oparg, uint32_t *uaddr, int *oldval);
DEFINE_IFUNC(, int, futex_xorl, (int, uint32_t *, int *))
{

        return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
            futex_xorl_smap : futex_xorl_nosmap);
}

int
linux_ptrace_peekuser(struct thread *td, pid_t pid, void *addr, void *data)
{

        LINUX_RATELIMIT_MSG_OPT1("PTRACE_PEEKUSER offset %ld not implemented; "
            "returning EINVAL", (uintptr_t)addr);
        return (EINVAL);
}

int
linux_ptrace_pokeuser(struct thread *td, pid_t pid, void *addr, void *data)
{

        LINUX_RATELIMIT_MSG_OPT1("PTRACE_POKEUSER offset %ld "
            "not implemented; returning EINVAL", (uintptr_t)addr);
        return (EINVAL);
}