/*      $NetBSD: arm32_machdep.c,v 1.44 2004/03/24 15:34:47 atatat Exp $        */

/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 2004 Olivier Houchard
 * Copyright (c) 1994-1998 Mark Brinicombe.
 * Copyright (c) 1994 Brini.
 * All rights reserved.
 *
 * This code is derived from software written for Brini by Mark Brinicombe
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Mark Brinicombe
 *      for the NetBSD Project.
 * 4. The name of the company nor the name of the author may 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 OR CONTRIBUTORS 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/exec.h>
#include <sys/imgact.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/syscallsubr.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/vmmeter.h>

#include <machine/asm.h>
#include <machine/machdep.h>
#include <machine/pcb.h>
#include <machine/sysarch.h>
#include <machine/vfp.h>
#include <machine/vmparam.h>

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

_Static_assert(sizeof(mcontext_t) == 208, "mcontext_t size incorrect");
_Static_assert(sizeof(ucontext_t) == 260, "ucontext_t size incorrect");
_Static_assert(sizeof(siginfo_t) == 64, "siginfo_t size incorrect");

/*
 * Clear registers on exec
 */
void
exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack)
{
        struct trapframe *tf = td->td_frame;

        memset(tf, 0, sizeof(*tf));
        tf->tf_usr_sp = stack;
        tf->tf_usr_lr = imgp->entry_addr;
        tf->tf_svc_lr = 0x77777777;
        tf->tf_pc = imgp->entry_addr;
        tf->tf_spsr = PSR_USR32_MODE;
        if ((register_t)imgp->entry_addr & 1)
                tf->tf_spsr |= PSR_T;
}

#ifdef VFP
/*
 * Get machine VFP context.
 */
void
get_vfpcontext(struct thread *td, mcontext_vfp_t *vfp)
{
        struct pcb *pcb;

        MPASS(td == curthread || TD_IS_SUSPENDED(td) ||
            P_SHOULDSTOP(td->td_proc));

        pcb = td->td_pcb;
        if (td == curthread) {
                critical_enter();
                vfp_store(&pcb->pcb_vfpstate, false);
                critical_exit();
        }
        KASSERT(pcb->pcb_vfpsaved == &pcb->pcb_vfpstate,
                ("Called get_vfpcontext while the kernel is using the VFP"));

        memset(vfp, 0, sizeof(*vfp));
        memcpy(vfp->mcv_reg, pcb->pcb_vfpstate.reg,
            sizeof(vfp->mcv_reg));
        vfp->mcv_fpscr = pcb->pcb_vfpstate.fpscr;

}

/*
 * Set machine VFP context.
 */
void
set_vfpcontext(struct thread *td, mcontext_vfp_t *vfp)
{
        struct pcb *pcb;

        pcb = td->td_pcb;
        if (td == curthread) {
                critical_enter();
                vfp_discard(td);
                critical_exit();
        }
        KASSERT(pcb->pcb_vfpsaved == &pcb->pcb_vfpstate,
                ("Called set_vfpcontext while the kernel is using the VFP"));
        memcpy(pcb->pcb_vfpstate.reg, vfp->mcv_reg,
            sizeof(pcb->pcb_vfpstate.reg));
        pcb->pcb_vfpstate.fpscr = vfp->mcv_fpscr;

}
#endif

int
arm_get_vfpstate(struct thread *td, void *args)
{
        int rv;
        struct arm_get_vfpstate_args ua;
        mcontext_vfp_t  mcontext_vfp;

        rv = copyin(args, &ua, sizeof(ua));
        if (rv != 0)
                return (rv);
        if (ua.mc_vfp_size != sizeof(mcontext_vfp_t))
                return (EINVAL);
#ifdef VFP
        get_vfpcontext(td, &mcontext_vfp);
#else
        bzero(&mcontext_vfp, sizeof(mcontext_vfp));
#endif

        rv = copyout(&mcontext_vfp, ua.mc_vfp,  sizeof(mcontext_vfp));
        if (rv != 0)
                return (rv);
        return (0);
}

/*
 * Get machine context.
 */
int
get_mcontext(struct thread *td, mcontext_t *mcp, int clear_ret)
{
        struct trapframe *tf = td->td_frame;
        __greg_t *gr = mcp->__gregs;

        if (clear_ret & GET_MC_CLEAR_RET) {
                gr[_REG_R0] = 0;
                gr[_REG_CPSR] = tf->tf_spsr & ~PSR_C;
        } else {
                gr[_REG_R0]   = tf->tf_r0;
                gr[_REG_CPSR] = tf->tf_spsr;
        }
        gr[_REG_R1]   = tf->tf_r1;
        gr[_REG_R2]   = tf->tf_r2;
        gr[_REG_R3]   = tf->tf_r3;
        gr[_REG_R4]   = tf->tf_r4;
        gr[_REG_R5]   = tf->tf_r5;
        gr[_REG_R6]   = tf->tf_r6;
        gr[_REG_R7]   = tf->tf_r7;
        gr[_REG_R8]   = tf->tf_r8;
        gr[_REG_R9]   = tf->tf_r9;
        gr[_REG_R10]  = tf->tf_r10;
        gr[_REG_R11]  = tf->tf_r11;
        gr[_REG_R12]  = tf->tf_r12;
        gr[_REG_SP]   = tf->tf_usr_sp;
        gr[_REG_LR]   = tf->tf_usr_lr;
        gr[_REG_PC]   = tf->tf_pc;

        mcp->mc_vfp_size = 0;
        mcp->mc_vfp_ptr = NULL;
        memset(&mcp->mc_spare, 0, sizeof(mcp->mc_spare));

        return (0);
}

/*
 * Set machine context.
 *
 * However, we don't set any but the user modifiable flags, and we won't
 * touch the cs selector.
 */
int
set_mcontext(struct thread *td, mcontext_t *mcp)
{
        mcontext_vfp_t mc_vfp, *vfp;
        struct trapframe *tf = td->td_frame;
        const __greg_t *gr = mcp->__gregs;
        int spsr;

        /*
         * Make sure the processor mode has not been tampered with and
         * interrupts have not been disabled.
         */
        spsr = gr[_REG_CPSR];
        if ((spsr & PSR_MODE) != PSR_USR32_MODE ||
            (spsr & (PSR_I | PSR_F)) != 0)
                return (EINVAL);

#ifdef WITNESS
        if (mcp->mc_vfp_size != 0 && mcp->mc_vfp_size != sizeof(mc_vfp)) {
                printf("%s: %s: Malformed mc_vfp_size: %d (0x%08X)\n",
                    td->td_proc->p_comm, __func__,
                    mcp->mc_vfp_size, mcp->mc_vfp_size);
        } else if (mcp->mc_vfp_size != 0 && mcp->mc_vfp_ptr == NULL) {
                printf("%s: %s: c_vfp_size != 0 but mc_vfp_ptr == NULL\n",
                    td->td_proc->p_comm, __func__);
        }
#endif

        if (mcp->mc_vfp_size == sizeof(mc_vfp) && mcp->mc_vfp_ptr != NULL) {
                if (copyin(mcp->mc_vfp_ptr, &mc_vfp, sizeof(mc_vfp)) != 0)
                        return (EFAULT);
                vfp = &mc_vfp;
        } else {
                vfp = NULL;
        }

        tf->tf_r0 = gr[_REG_R0];
        tf->tf_r1 = gr[_REG_R1];
        tf->tf_r2 = gr[_REG_R2];
        tf->tf_r3 = gr[_REG_R3];
        tf->tf_r4 = gr[_REG_R4];
        tf->tf_r5 = gr[_REG_R5];
        tf->tf_r6 = gr[_REG_R6];
        tf->tf_r7 = gr[_REG_R7];
        tf->tf_r8 = gr[_REG_R8];
        tf->tf_r9 = gr[_REG_R9];
        tf->tf_r10 = gr[_REG_R10];
        tf->tf_r11 = gr[_REG_R11];
        tf->tf_r12 = gr[_REG_R12];
        tf->tf_usr_sp = gr[_REG_SP];
        tf->tf_usr_lr = gr[_REG_LR];
        tf->tf_pc = gr[_REG_PC];
        tf->tf_spsr = gr[_REG_CPSR];
#ifdef VFP
        if (vfp != NULL)
                set_vfpcontext(td, vfp);
#endif
        return (0);
}

void
sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
        struct thread *td;
        struct proc *p;
        struct trapframe *tf;
        struct sigframe *fp, frame;
        struct sigacts *psp;
        struct sysentvec *sysent;
        int onstack;
        int sig;

        td = curthread;
        p = td->td_proc;
        PROC_LOCK_ASSERT(p, MA_OWNED);
        sig = ksi->ksi_signo;
        psp = p->p_sigacts;
        mtx_assert(&psp->ps_mtx, MA_OWNED);
        tf = td->td_frame;
        onstack = sigonstack(tf->tf_usr_sp);

        CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm,
            catcher, sig);

        /* Allocate and validate space for the signal handler context. */
        if ((td->td_pflags & TDP_ALTSTACK) != 0 && !(onstack) &&
            SIGISMEMBER(psp->ps_sigonstack, sig)) {
                fp = (struct sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
                    td->td_sigstk.ss_size);
#if defined(COMPAT_43)
                td->td_sigstk.ss_flags |= SS_ONSTACK;
#endif
        } else
                fp = (struct sigframe *)td->td_frame->tf_usr_sp;

        /* make room on the stack */
        fp--;

        /* make the stack aligned */
        fp = STACKALIGN(fp);
        /* Populate the siginfo frame. */
        bzero(&frame, sizeof(frame));
        get_mcontext(td, &frame.sf_uc.uc_mcontext, 0);

#ifdef VFP
        get_vfpcontext(td, &frame.sf_vfp);
        frame.sf_uc.uc_mcontext.mc_vfp_size = sizeof(fp->sf_vfp);
        frame.sf_uc.uc_mcontext.mc_vfp_ptr = &fp->sf_vfp;
#else
        frame.sf_uc.uc_mcontext.mc_vfp_size = 0;
        frame.sf_uc.uc_mcontext.mc_vfp_ptr = NULL;
#endif

        frame.sf_si = ksi->ksi_info;
        frame.sf_uc.uc_sigmask = *mask;
        frame.sf_uc.uc_stack = td->td_sigstk;
        frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ?
            (onstack ? SS_ONSTACK : 0) : SS_DISABLE;
        mtx_unlock(&psp->ps_mtx);
        PROC_UNLOCK(td->td_proc);

        /* Copy the sigframe out to the user's stack. */
        if (copyout(&frame, fp, sizeof(*fp)) != 0) {
                /* Process has trashed its stack. Kill it. */
                CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp);
                PROC_LOCK(p);
                sigexit(td, SIGILL);
        }

        /*
         * Build context to run handler in.  We invoke the handler
         * directly, only returning via the trampoline.  Note the
         * trampoline version numbers are coordinated with machine-
         * dependent code in libc.
         */

        tf->tf_r0 = sig;
        tf->tf_r1 = (register_t)&fp->sf_si;
        tf->tf_r2 = (register_t)&fp->sf_uc;

        /* the trampoline uses r5 as the uc address */
        tf->tf_r5 = (register_t)&fp->sf_uc;
        tf->tf_pc = (register_t)catcher;
        tf->tf_usr_sp = (register_t)fp;
        sysent = p->p_sysent;
        if (PROC_HAS_SHP(p))
                tf->tf_usr_lr = (register_t)PROC_SIGCODE(p);
        else
                tf->tf_usr_lr = (register_t)(PROC_PS_STRINGS(p) -
                    *(sysent->sv_szsigcode));
        /* Set the mode to enter in the signal handler */
        if ((register_t)catcher & 1)
                tf->tf_spsr |= PSR_T;
        else
                tf->tf_spsr &= ~PSR_T;

        CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_usr_lr,
            tf->tf_usr_sp);

        PROC_LOCK(p);
        mtx_lock(&psp->ps_mtx);
}

int
sys_sigreturn(struct thread *td, struct sigreturn_args *uap)
{
        ucontext_t uc;
        int error;

        if (uap == NULL)
                return (EFAULT);
        if (copyin(uap->sigcntxp, &uc, sizeof(uc)))
                return (EFAULT);
        /* Restore register context. */
        error = set_mcontext(td, &uc.uc_mcontext);
        if (error != 0)
                return (error);

        /* Restore signal mask. */
        kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);

        return (EJUSTRETURN);
}