/*      $NetBSD: netbsd32_machdep_16.c,v 1.6 2021/11/06 20:42:56 thorpej Exp $  */

/*
 * Copyright (c) 1998, 2001 Matthew R. Green
 * 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: netbsd32_machdep_16.c,v 1.6 2021/11/06 20:42:56 thorpej Exp $");

#ifdef _KERNEL_OPT
#include "opt_compat_netbsd.h"
#include "opt_modular.h"
#include "opt_execfmt.h"
#include "firm_events.h"
#endif

#include <sys/param.h>
#include <sys/exec.h>
#include <sys/exec_aout.h>
#include <sys/filedesc.h>
#include <sys/file.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/systm.h>
#include <sys/core.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/select.h>
#include <sys/socketvar.h>
#include <sys/ucontext.h>
#include <sys/ioctl.h>
#include <sys/kmem.h>

#include <dev/sun/event_var.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/igmp.h>
#include <netinet/igmp_var.h>
#include <netinet/ip_mroute.h>

#include <compat/netbsd32/netbsd32.h>
#include <compat/netbsd32/netbsd32_ioctl.h>
#include <compat/netbsd32/netbsd32_syscallargs.h>
#include <compat/netbsd32/netbsd32_exec.h>

#include <compat/sys/signal.h>
#include <compat/sys/signalvar.h>
#include <compat/sys/siginfo.h>
#include <compat/sys/ucontext.h>

#include <machine/frame.h>
#include <machine/pcb.h>
#include <machine/reg.h>
#include <machine/vmparam.h>
#include <machine/vuid_event.h>
#include <machine/netbsd32_machdep.h>
#include <machine/userret.h>

/*
 * NB: since this is a 32-bit address world, sf_scp and sf_sc
 *      can't be a pointer since those are 64-bits wide.
 */
struct sparc32_sigframe {
        int     sf_signo;               /* signal number */
        int     sf_code;                /* code */
        u_int   sf_scp;                 /* SunOS user addr of sigcontext */
        int     sf_addr;                /* SunOS compat, always 0 for now */
        struct  netbsd32_sigcontext sf_sc;      /* actual sigcontext */
};

#undef DEBUG
#ifdef DEBUG
extern int sigdebug;
#endif

static void
netbsd32_sendsig_sigcontext(const ksiginfo_t *ksi, const sigset_t *mask)
{
        int sig = ksi->ksi_signo;
        struct lwp *l = curlwp;
        struct proc *p = l->l_proc;
        struct sparc32_sigframe *fp;
        struct trapframe64 *tf;
        int addr, onstack, error;
        struct rwindow32 *oldsp, *newsp;
        register32_t sp;
        sig_t catcher = SIGACTION(p, sig).sa_handler;
        struct sparc32_sigframe sf;
        extern char netbsd32_sigcode[], netbsd32_esigcode[];
#define szsigcode       (netbsd32_esigcode - netbsd32_sigcode)

        tf = l->l_md.md_tf;
        /* Need to attempt to zero extend this 32-bit pointer */
        oldsp = (struct rwindow32 *)(u_long)(u_int)tf->tf_out[6];
        /* Do we need to jump onto the signal stack? */
        onstack =
            (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
            (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
        if (onstack) {
                fp = (struct sparc32_sigframe *)((char *)l->l_sigstk.ss_sp +
                                        l->l_sigstk.ss_size);
                l->l_sigstk.ss_flags |= SS_ONSTACK;
        } else
                fp = (struct sparc32_sigframe *)oldsp;
        fp = (struct sparc32_sigframe *)((u_long)(fp - 1) & ~7);

#ifdef DEBUG
        sigpid = p->p_pid;
        if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid) {
                printf("sendsig: %s[%d] sig %d newusp %p scp %p oldsp %p\n",
                    p->p_comm, p->p_pid, sig, fp, &fp->sf_sc, oldsp);
                if (sigdebug & SDB_DDB) Debugger();
        }
#endif
        /*
         * Now set up the signal frame.  We build it in kernel space
         * and then copy it out.  We probably ought to just build it
         * directly in user space....
         */
        memset(&sf, 0, sizeof(sf));
        sf.sf_signo = sig;
        sf.sf_code = (u_int)ksi->ksi_trap;
        sf.sf_scp = (u_long)&fp->sf_sc;
        sf.sf_addr = 0;                 /* XXX */

        /*
         * Build the signal context to be used by sigreturn.
         */
        sf.sf_sc.sc_onstack = onstack;
        sf.sf_sc.sc_mask = *mask;
        sf.sf_sc.sc_sp = (u_long)oldsp;
        sf.sf_sc.sc_pc = tf->tf_pc;
        sf.sf_sc.sc_npc = tf->tf_npc;
        sf.sf_sc.sc_psr = TSTATECCR_TO_PSR(tf->tf_tstate); /* XXX */
        sf.sf_sc.sc_g1 = tf->tf_global[1];
        sf.sf_sc.sc_o0 = tf->tf_out[0];

        /*
         * Put the stack in a consistent state before we whack away
         * at it.  Note that write_user_windows may just dump the
         * registers into the pcb; we need them in the process's memory.
         * We also need to make sure that when we start the signal handler,
         * its %i6 (%fp), which is loaded from the newly allocated stack area,
         * joins seamlessly with the frame it was in when the signal occurred,
         * so that the debugger and _longjmp code can back up through it.
         */
        sendsig_reset(l, sig);
        mutex_exit(p->p_lock);
        newsp = (struct rwindow32 *)((long)fp - sizeof(struct rwindow32));
        write_user_windows();
#ifdef DEBUG
        if ((sigdebug & SDB_KSTACK))
            printf("sendsig: saving sf to %p, setting stack pointer %p to %p\n",
                   fp, &(((struct rwindow32 *)newsp)->rw_in[6]), oldsp);
#endif
        sp = NETBSD32PTR32I(oldsp);
        error = (rwindow_save(l) || 
            copyout(&sf, fp, sizeof sf) || 
            copyout(&sp, &(((struct rwindow32 *)newsp)->rw_in[6]),
                sizeof(sp)));
        mutex_enter(p->p_lock);
        if (error) {
                /*
                 * Process has trashed its stack; give it an illegal
                 * instruction to halt it in its tracks.
                 */
#ifdef DEBUG
                mutex_exit(p->p_lock);
                if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
                        printf("sendsig: window save or copyout error\n");
                printf("sendsig: stack was trashed trying to send sig %d, sending SIGILL\n", sig);
                if (sigdebug & SDB_DDB) Debugger();
                mutex_enter(p->p_lock);
#endif
                sigexit(l, SIGILL);
                /* NOTREACHED */
        }

#ifdef DEBUG
        if (sigdebug & SDB_FOLLOW) {
                printf("sendsig: %s[%d] sig %d scp %p\n",
                       p->p_comm, p->p_pid, sig, &fp->sf_sc);
        }
#endif
        /*
         * Arrange to continue execution at the code copied out in exec().
         * It needs the function to call in %g1, and a new stack pointer.
         */
        addr = p->p_psstrp - szsigcode;
        tf->tf_global[1] = (long)catcher;
        tf->tf_pc = addr;
        tf->tf_npc = addr + 4;
        tf->tf_out[6] = (uint64_t)(u_int)(u_long)newsp;

        /* Remember that we're now on the signal stack. */
        if (onstack)
                l->l_sigstk.ss_flags |= SS_ONSTACK;

#ifdef DEBUG
        if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid) {
                mutex_exit(p->p_lock);
                printf("sendsig: about to return to catcher %p thru %p\n", 
                       catcher, addr);
                if (sigdebug & SDB_DDB) Debugger();
                mutex_enter(p->p_lock);
        }
#endif
}

struct sparc32_sigframe_siginfo {
        siginfo32_t sf_si;
        ucontext32_t sf_uc;
};

#undef DEBUG

/*
 * System call to cleanup state after a signal
 * has been taken.  Reset signal mask and
 * stack state from context left by sendsig (above),
 * and return to the given trap frame (if there is one).
 * Check carefully to make sure that the user has not
 * modified the state to gain improper privileges or to cause
 * a machine fault.
 */
/* ARGSUSED */
int
compat_16_netbsd32___sigreturn14(struct lwp *l, const struct compat_16_netbsd32___sigreturn14_args *uap, register_t *retval)
{
        /* {
                syscallarg(struct sigcontext *) sigcntxp;
        } */
        struct netbsd32_sigcontext sc, *scp;
        struct trapframe64 *tf;
        struct proc *p = l->l_proc;

        /* First ensure consistent stack state (see sendsig). */
        write_user_windows();
        if (rwindow_save(l)) {
#ifdef DEBUG
                printf("netbsd32_sigreturn14: rwindow_save(%p) failed, sending SIGILL\n", p);
                Debugger();
#endif
                mutex_enter(p->p_lock);
                sigexit(l, SIGILL);
        }
#ifdef DEBUG
        if (sigdebug & SDB_FOLLOW) {
                printf("netbsd32_sigreturn14: %s[%d], sigcntxp %p\n",
                    p->p_comm, p->p_pid, SCARG(uap, sigcntxp));
                if (sigdebug & SDB_DDB) Debugger();
        }
#endif
        scp = (struct netbsd32_sigcontext *)(u_long)SCARG(uap, sigcntxp);
        if ((vaddr_t)scp & 3 || (copyin((void *)scp, &sc, sizeof sc) != 0))
        {
#ifdef DEBUG
                printf("netbsd32_sigreturn14: copyin failed: scp=%p\n", scp);
                Debugger();
#endif
                return (EINVAL);
        }
        scp = &sc;

        tf = l->l_md.md_tf;
        /*
         * Only the icc bits in the psr are used, so it need not be
         * verified.  pc and npc must be multiples of 4.  This is all
         * that is required; if it holds, just do it.
         */
        if (((sc.sc_pc | sc.sc_npc) & 3) != 0 || (sc.sc_pc == 0) || (sc.sc_npc == 0))
#ifdef DEBUG
        {
                printf("netbsd32_sigreturn14: pc %p or npc %p invalid\n", sc.sc_pc, sc.sc_npc);
                Debugger();
                return (EINVAL);
        }
#else
                return (EINVAL);
#endif
        /* take only psr ICC field */
        tf->tf_tstate = (int64_t)(tf->tf_tstate & ~TSTATE_CCR) | PSRCC_TO_TSTATE(sc.sc_psr);
        tf->tf_pc = (int64_t)sc.sc_pc;
        tf->tf_npc = (int64_t)sc.sc_npc;
        tf->tf_global[1] = (int64_t)sc.sc_g1;
        tf->tf_out[0] = (int64_t)sc.sc_o0;
        tf->tf_out[6] = (int64_t)sc.sc_sp;
#ifdef DEBUG
        if (sigdebug & SDB_FOLLOW) {
                printf("netbsd32_sigreturn14: return trapframe pc=%p sp=%p tstate=%llx\n",
                       (vaddr_t)tf->tf_pc, (vaddr_t)tf->tf_out[6], tf->tf_tstate);
                if (sigdebug & SDB_DDB) Debugger();
        }
#endif

        /* Restore signal stack. */
        mutex_enter(p->p_lock);
        if (sc.sc_onstack & SS_ONSTACK)
                l->l_sigstk.ss_flags |= SS_ONSTACK;
        else
                l->l_sigstk.ss_flags &= ~SS_ONSTACK;
        /* Restore signal mask. */
        (void) sigprocmask1(l, SIG_SETMASK, &sc.sc_mask, 0);
        mutex_exit(p->p_lock);

        return (EJUSTRETURN);
}

void
netbsd32_machdep_md_16_init(void)
{

        MODULE_HOOK_SET(netbsd32_sendsig_sigcontext_16_hook,
            netbsd32_sendsig_sigcontext);
}
 
void    
netbsd32_machdep_md_16_fini(void)  
{
        
        MODULE_HOOK_UNSET(netbsd32_sendsig_sigcontext_16_hook);
}