text: /*
   * Copyright (c) 1998 Mark Newton
   * Copyright (c) 1994 Christos Zoulas
   * 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.
   * 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.
   *
   * $FreeBSD: src/sys/i386/svr4/svr4_machdep.c,v 1.26.2.1 2002/12/19 09:40:09 alfred Exp $
   */
  
  #include <sys/types.h>
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/exec.h>
  #include <sys/filedesc.h>
  #include <sys/lock.h>
  #include <sys/mutex.h>
  #include <sys/proc.h>
  #include <sys/signal.h>
  #include <sys/signalvar.h>
  
  #include <machine/cpu.h>
  #include <machine/cpufunc.h>
  #include <machine/psl.h>
  #include <machine/reg.h>
  #include <machine/specialreg.h>
  #include <machine/sysarch.h>
  #include <machine/vm86.h>
  #include <machine/vmparam.h>
  
  #include <vm/vm.h>
  #include <vm/pmap.h>
  
  #include <compat/svr4/svr4.h>
  #include <compat/svr4/svr4_types.h>
  #include <compat/svr4/svr4_signal.h>
  #include <i386/svr4/svr4_machdep.h>
  #include <compat/svr4/svr4_ucontext.h>
  #include <compat/svr4/svr4_proto.h>
  #include <compat/svr4/svr4_util.h>
  
  #undef sigcode
  #undef szsigcode
  
  extern int svr4_szsigcode;
  extern char svr4_sigcode[];
  extern int _udatasel, _ucodesel;
  
  static void svr4_getsiginfo(union svr4_siginfo *, int, u_long, caddr_t);
  
  #if !defined(__NetBSD__)
    /* taken from /sys/arch/i386/include/psl.h on NetBSD-1.3 */
  # define PSL_MBZ 0xffc08028
  # define PSL_USERSTATIC (PSL_USER | PSL_MBZ | PSL_IOPL | PSL_NT | PSL_VM | PSL_VIF | PSL_VIP)
  # define USERMODE(c, f) (ISPL(c) == SEL_UPL)
  #endif
  
  #if defined(__NetBSD__)
  void
  svr4_setregs(td, epp, stack)
  	struct thread *td;
  	struct exec_package *epp;
  	u_long stack;
  {
  	register struct pcb *pcb = td->td_pcb;
  
  	pcb->pcb_savefpu.sv_env.en_cw = __SVR4_NPXCW__;
  	setregs(td, epp, stack, 0UL);
  }
  #endif /* __NetBSD__ */
  
  void
  svr4_getcontext(td, uc, mask, oonstack)
  	struct thread *td;
  	struct svr4_ucontext *uc;
  	sigset_t *mask;
  	int oonstack;
  {
  	struct proc *p = td->td_proc;
  	struct trapframe *tf = td->td_frame;
  	svr4_greg_t *r = uc->uc_mcontext.greg;
  	struct svr4_sigaltstack *s = &uc->uc_stack;
  #if defined(DONE_MORE_SIGALTSTACK_WORK)
  	struct sigacts *psp;
  	struct sigaltstack *sf;
  #endif
  
  	PROC_LOCK(p);
  #if defined(DONE_MORE_SIGALTSTACK_WORK)
  	psp = p->p_sigacts;
  	sf = &p->p_sigstk;
  #endif
  
  	memset(uc, 0, sizeof(struct svr4_ucontext));
  
  	uc->uc_link = p->p_emuldata;
  	/*
  	 * Set the general purpose registers
  	 */
  #ifdef VM86
  	if (tf->tf_eflags & PSL_VM) {
  		r[SVR4_X86_GS] = tf->tf_vm86_gs;
  		r[SVR4_X86_FS] = tf->tf_vm86_fs;
  		r[SVR4_X86_ES] = tf->tf_vm86_es;
  		r[SVR4_X86_DS] = tf->tf_vm86_ds;
  		r[SVR4_X86_EFL] = get_vflags(td);
  	} else
  #endif
  	{
  #if defined(__NetBSD__)
  	        __asm("movl %%gs,%w0" : "=r" (r[SVR4_X86_GS]));
  		__asm("movl %%fs,%w0" : "=r" (r[SVR4_X86_FS]));
  #else
  	        r[SVR4_X86_GS] = rgs();
  		r[SVR4_X86_FS] = tf->tf_fs;
  #endif
  		r[SVR4_X86_ES] = tf->tf_es;
  		r[SVR4_X86_DS] = tf->tf_ds;
  		r[SVR4_X86_EFL] = tf->tf_eflags;
  	}
  	r[SVR4_X86_EDI] = tf->tf_edi;
  	r[SVR4_X86_ESI] = tf->tf_esi;
  	r[SVR4_X86_EBP] = tf->tf_ebp;
  	r[SVR4_X86_ESP] = tf->tf_esp;
  	r[SVR4_X86_EBX] = tf->tf_ebx;
  	r[SVR4_X86_EDX] = tf->tf_edx;
  	r[SVR4_X86_ECX] = tf->tf_ecx;
  	r[SVR4_X86_EAX] = tf->tf_eax;
  	r[SVR4_X86_TRAPNO] = tf->tf_trapno;
  	r[SVR4_X86_ERR] = tf->tf_err;
  	r[SVR4_X86_EIP] = tf->tf_eip;
  	r[SVR4_X86_CS] = tf->tf_cs;
  	r[SVR4_X86_UESP] = 0;
  	r[SVR4_X86_SS] = tf->tf_ss;
  
  	/*
  	 * Set the signal stack
  	 */
  #if defined(DONE_MORE_SIGALTSTACK_WORK)
  	bsd_to_svr4_sigaltstack(sf, s);
  #else
  	s->ss_sp = (void *)(((u_long) tf->tf_esp) & ~(16384 - 1));
  	s->ss_size = 16384;
  	s->ss_flags = 0;
  #endif
  	PROC_UNLOCK(p);
  
  	/*
  	 * Set the signal mask
  	 */
  	bsd_to_svr4_sigset(mask, &uc->uc_sigmask);
  
  	/*
  	 * Set the flags
  	 */
  	uc->uc_flags = SVR4_UC_SIGMASK|SVR4_UC_CPU|SVR4_UC_STACK;
  }
  
  
  /*
   * Set to ucontext specified. Reset signal mask and
   * stack state from context.
   * Return to previous pc and psl as specified by
   * context left by sendsig. Check carefully to
   * make sure that the user has not modified the
   * psl to gain improper privileges or to cause
   * a machine fault.
   */
  int
  svr4_setcontext(td, uc)
  	struct thread *td;
  	struct svr4_ucontext *uc;
  {
  #if defined(DONE_MORE_SIGALTSTACK_WORK)
  	struct sigacts *psp;
  #endif
  	struct proc *p = td->td_proc;
  	register struct trapframe *tf;
  	svr4_greg_t *r = uc->uc_mcontext.greg;
  	struct svr4_sigaltstack *s = &uc->uc_stack;
  	struct sigaltstack *sf;
  	sigset_t mask;
  
  	PROC_LOCK(p);
  #if defined(DONE_MORE_SIGALTSTACK_WORK)
  	psp = p->p_sigacts;
  #endif
  	sf = &p->p_sigstk;
  
  	/*
  	 * XXX:
  	 * Should we check the value of flags to determine what to restore?
  	 * What to do with uc_link?
  	 * What to do with floating point stuff?
  	 * Should we bother with the rest of the registers that we
  	 * set to 0 right now?
  	 */
  
  	if ((uc->uc_flags & SVR4_UC_CPU) == 0)
  		return 0;
  
  	DPRINTF(("svr4_setcontext(%d)\n", p->p_pid));
  
  	tf = td->td_frame;
  
  	/*
  	 * Restore register context.
  	 */
  #ifdef VM86
  #warning "VM86 doesn't work yet, please don't try to use it."
  	if (r[SVR4_X86_EFL] & PSL_VM) {
  		tf->tf_vm86_gs = r[SVR4_X86_GS];
  		tf->tf_vm86_fs = r[SVR4_X86_FS];
  		tf->tf_vm86_es = r[SVR4_X86_ES];
  		tf->tf_vm86_ds = r[SVR4_X86_DS];
  		set_vflags(td, r[SVR4_X86_EFL]);
  	} else
  #endif
  	{
  		/*
  		 * Check for security violations.  If we're returning to
  		 * protected mode, the CPU will validate the segment registers
  		 * automatically and generate a trap on violations.  We handle
  		 * the trap, rather than doing all of the checking here.
  		 */
  		if (((r[SVR4_X86_EFL] ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 ||
  		    !USERMODE(r[SVR4_X86_CS], r[SVR4_X86_EFL]))
  			return (EINVAL);
  
  #if defined(__NetBSD__)
  		/* %fs and %gs were restored by the trampoline. */
  #else
  		/* %gs was restored by the trampoline. */
  		tf->tf_fs = r[SVR4_X86_FS];
  #endif
  		tf->tf_es = r[SVR4_X86_ES];
  		tf->tf_ds = r[SVR4_X86_DS];
  		tf->tf_eflags = r[SVR4_X86_EFL];
  	}
  	tf->tf_edi = r[SVR4_X86_EDI];
  	tf->tf_esi = r[SVR4_X86_ESI];
  	tf->tf_ebp = r[SVR4_X86_EBP];
  	tf->tf_ebx = r[SVR4_X86_EBX];
  	tf->tf_edx = r[SVR4_X86_EDX];
  	tf->tf_ecx = r[SVR4_X86_ECX];
  	tf->tf_eax = r[SVR4_X86_EAX];
  	tf->tf_trapno = r[SVR4_X86_TRAPNO];
  	tf->tf_err = r[SVR4_X86_ERR];
  	tf->tf_eip = r[SVR4_X86_EIP];
  	tf->tf_cs = r[SVR4_X86_CS];
  	tf->tf_ss = r[SVR4_X86_SS];
  	tf->tf_esp = r[SVR4_X86_ESP];
  
  	p->p_emuldata = uc->uc_link;
  	/*
  	 * restore signal stack
  	 */
  	if (uc->uc_flags & SVR4_UC_STACK) {
  		svr4_to_bsd_sigaltstack(s, sf);
  	}
  
  	/*
  	 * restore signal mask
  	 */
  	if (uc->uc_flags & SVR4_UC_SIGMASK) {
  #if defined(DEBUG_SVR4)
  		{
  			int i;
  			for (i = 0; i < 4; i++)
  				DPRINTF(("\tuc_sigmask[%d] = %lx\n", i,
  						uc->uc_sigmask.bits[i]));
  		}
  #endif
  		svr4_to_bsd_sigset(&uc->uc_sigmask, &mask);
  		SIG_CANTMASK(mask);
  		p->p_sigmask = mask;
  		signotify(p);
  	}
  	PROC_UNLOCK(p);
  
  	return 0; /*EJUSTRETURN;*/
  }
  
  
  static void
  svr4_getsiginfo(si, sig, code, addr)
  	union svr4_siginfo	*si;
  	int			 sig;
  	u_long			 code;
  	caddr_t			 addr;
  {
  	si->si_signo = bsd_to_svr4_sig[sig];
  	si->si_errno = 0;
  	si->si_addr  = addr;
  
  	switch (code) {
  	case T_PRIVINFLT:
  		si->si_code = SVR4_ILL_PRVOPC;
  		si->si_trap = SVR4_T_PRIVINFLT;
  		break;
  
  	case T_BPTFLT:
  		si->si_code = SVR4_TRAP_BRKPT;
  		si->si_trap = SVR4_T_BPTFLT;
  		break;
  
  	case T_ARITHTRAP:
  		si->si_code = SVR4_FPE_INTOVF;
  		si->si_trap = SVR4_T_DIVIDE;
  		break;
  
  	case T_PROTFLT:
  		si->si_code = SVR4_SEGV_ACCERR;
  		si->si_trap = SVR4_T_PROTFLT;
  		break;
  
  	case T_TRCTRAP:
  		si->si_code = SVR4_TRAP_TRACE;
  		si->si_trap = SVR4_T_TRCTRAP;
  		break;
  
  	case T_PAGEFLT:
  		si->si_code = SVR4_SEGV_ACCERR;
  		si->si_trap = SVR4_T_PAGEFLT;
  		break;
  
  	case T_ALIGNFLT:
  		si->si_code = SVR4_BUS_ADRALN;
  		si->si_trap = SVR4_T_ALIGNFLT;
  		break;
  
  	case T_DIVIDE:
  		si->si_code = SVR4_FPE_FLTDIV;
  		si->si_trap = SVR4_T_DIVIDE;
  		break;
  
  	case T_OFLOW:
  		si->si_code = SVR4_FPE_FLTOVF;
  		si->si_trap = SVR4_T_DIVIDE;
  		break;
  
  	case T_BOUND:
  		si->si_code = SVR4_FPE_FLTSUB;
  		si->si_trap = SVR4_T_BOUND;
  		break;
  
  	case T_DNA:
  		si->si_code = SVR4_FPE_FLTINV;
  		si->si_trap = SVR4_T_DNA;
  		break;
  
  	case T_FPOPFLT:
  		si->si_code = SVR4_FPE_FLTINV;
  		si->si_trap = SVR4_T_FPOPFLT;
  		break;
  
  	case T_SEGNPFLT:
  		si->si_code = SVR4_SEGV_MAPERR;
  		si->si_trap = SVR4_T_SEGNPFLT;
  		break;
  
  	case T_STKFLT:
  		si->si_code = SVR4_ILL_BADSTK;
  		si->si_trap = SVR4_T_STKFLT;
  		break;
  
  	default:
  		si->si_code = 0;
  		si->si_trap = 0;
  #if defined(DEBUG_SVR4)
  		printf("sig %d code %ld\n", sig, code);
  /*		panic("svr4_getsiginfo");*/
  #endif
  		break;
  	}
  }
  
  
  /*
   * Send an interrupt to process.
   *
   * Stack is set up to allow sigcode stored
   * in u. to call routine. After the handler is
   * done svr4 will call setcontext for us
   * with the user context we just set up, and we
   * will return to the user pc, psl.
   */
  void
  svr4_sendsig(catcher, sig, mask, code)
  	sig_t catcher;
  	int sig;
  	sigset_t *mask;
  	u_long code;
  {
  	register struct thread *td = curthread;
  	struct proc *p = td->td_proc;
  	register struct trapframe *tf;
  	struct svr4_sigframe *fp, frame;
  	struct sigacts *psp;
  	int oonstack;
  
  #if defined(DEBUG_SVR4)
  	printf("svr4_sendsig(%d)\n", sig);
  #endif
  	PROC_LOCK_ASSERT(p, MA_OWNED);
  	psp = p->p_sigacts;
  
  	tf = td->td_frame;
  	oonstack = sigonstack(tf->tf_esp);
  
  	/*
  	 * Allocate space for the signal handler context.
  	 */
  	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
  	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
  		fp = (struct svr4_sigframe *)(p->p_sigstk.ss_sp +
  		    p->p_sigstk.ss_size - sizeof(struct svr4_sigframe));
  		p->p_sigstk.ss_flags |= SS_ONSTACK;
  	} else {
  		fp = (struct svr4_sigframe *)tf->tf_esp - 1;
  	}
  	PROC_UNLOCK(p);
  
  	/* 
  	 * Build the argument list for the signal handler.
  	 * Notes:
  	 * 	- we always build the whole argument list, even when we
  	 *	  don't need to [when SA_SIGINFO is not set, we don't need
  	 *	  to pass all sf_si and sf_uc]
  	 *	- we don't pass the correct signal address [we need to
  	 *	  modify many kernel files to enable that]
  	 */
  
  	svr4_getcontext(td, &frame.sf_uc, mask, oonstack);
  #if defined(DEBUG_SVR4)
  	printf("obtained ucontext\n");
  #endif
  	svr4_getsiginfo(&frame.sf_si, sig, code, (caddr_t) tf->tf_eip);
  #if defined(DEBUG_SVR4)
  	printf("obtained siginfo\n");
  #endif
  	frame.sf_signum = frame.sf_si.si_signo;
  	frame.sf_sip = &fp->sf_si;
  	frame.sf_ucp = &fp->sf_uc;
  	frame.sf_handler = catcher;
  #if defined(DEBUG_SVR4)
  	printf("sig = %d, sip %p, ucp = %p, handler = %p\n", 
  	       frame.sf_signum, frame.sf_sip, frame.sf_ucp, frame.sf_handler);
  #endif
  
  	if (copyout(&frame, fp, sizeof(frame)) != 0) {
  		/*
  		 * Process has trashed its stack; give it an illegal
  		 * instruction to halt it in its tracks.
  		 */
  		PROC_LOCK(p);
  		sigexit(td, SIGILL);
  		/* NOTREACHED */
  	}
  #if defined(__NetBSD__)
  	/*
  	 * Build context to run handler in.
  	 */
  	tf->tf_es = GSEL(GUSERLDT_SEL, SEL_UPL);
  	tf->tf_ds = GSEL(GUSERLDT_SEL, SEL_UPL);
  	tf->tf_eip = (int)(((char *)PS_STRINGS) -
  	     svr4_szsigcode);
  	tf->tf_cs = GSEL(GUSERLDT_SEL, SEL_UPL);
  
  	tf->tf_eflags &= ~(PSL_T|PSL_VM|PSL_AC);
  	tf->tf_esp = (int)fp;
  	tf->tf_ss = GSEL(GUSERLDT_SEL, SEL_UPL);
  #else
  	tf->tf_esp = (int)fp;
  	tf->tf_eip = (int)(((char *)PS_STRINGS) - *(p->p_sysent->sv_szsigcode));
  	tf->tf_eflags &= ~PSL_T;
  	tf->tf_cs = _ucodesel;
  	tf->tf_ds = _udatasel;
  	tf->tf_es = _udatasel;
  	tf->tf_fs = _udatasel;
  	load_gs(_udatasel);
  	tf->tf_ss = _udatasel;
  	PROC_LOCK(p);
  #endif
  }
  
  
  
  int
  svr4_sys_sysarch(td, v)
  	struct thread *td;
  	struct svr4_sys_sysarch_args *v;
  {
  	struct svr4_sys_sysarch_args *uap = v;
  #if 0	/* USER_LDT */
  #if defined(__NetBSD__)
  	caddr_t sg = stackgap_init(p->p_emul);
  #else
  	caddr_t sg = stackgap_init();
  #endif
  	int error;
  #endif
  
  	switch (uap->op) {
  	case SVR4_SYSARCH_FPHW:
  		return 0;
  
  	case SVR4_SYSARCH_DSCR:
  #if 0	/* USER_LDT */
  #warning "USER_LDT doesn't work - are you sure you want this?"
  		{
  			struct i386_set_ldt_args sa, *sap;
  			struct sys_sysarch_args ua;
  
  			struct svr4_ssd ssd;
  			union descriptor bsd;
  
  			if ((error = copyin(uap->a1, &ssd,
  					    sizeof(ssd))) != 0) {
  				printf("Cannot copy arg1\n");
  				return error;
  			}
  
  			printf("s=%x, b=%x, l=%x, a1=%x a2=%x\n",
  			       ssd.selector, ssd.base, ssd.limit,
  			       ssd.access1, ssd.access2);
  
  			/* We can only set ldt's for now. */
  			if (!ISLDT(ssd.selector)) {
  				printf("Not an ldt\n");
  				return EPERM;
  			}
  
  			/* Oh, well we don't cleanup either */
  			if (ssd.access1 == 0)
  				return 0;
  
  			bsd.sd.sd_lobase = ssd.base & 0xffffff;
  			bsd.sd.sd_hibase = (ssd.base >> 24) & 0xff;
  
  			bsd.sd.sd_lolimit = ssd.limit & 0xffff;
  			bsd.sd.sd_hilimit = (ssd.limit >> 16) & 0xf;
  
  			bsd.sd.sd_type = ssd.access1 & 0x1f;
  			bsd.sd.sd_dpl =  (ssd.access1 >> 5) & 0x3;
  			bsd.sd.sd_p = (ssd.access1 >> 7) & 0x1;
  
  			bsd.sd.sd_xx = ssd.access2 & 0x3;
  			bsd.sd.sd_def32 = (ssd.access2 >> 2) & 0x1;
  			bsd.sd.sd_gran = (ssd.access2 >> 3)& 0x1;
  
  			sa.start = IDXSEL(ssd.selector);
  			sa.desc = stackgap_alloc(&sg, sizeof(union descriptor));
  			sa.num = 1;
  			sap = stackgap_alloc(&sg,
  					     sizeof(struct i386_set_ldt_args));
  
  			if ((error = copyout(&sa, sap, sizeof(sa))) != 0) {
  				printf("Cannot copyout args\n");
  				return error;
  			}
  
  			ua.op = I386_SET_LDT;
  			ua.parms = (char *) sap;
  
  			if ((error = copyout(&bsd, sa.desc, sizeof(bsd))) != 0) {
  				printf("Cannot copyout desc\n");
  				return error;
  			}
  
  			return sys_sysarch(td, &ua, retval);
  		}
  #endif
  
  	default:
  		printf("svr4_sysarch(%d), a1 %p\n", uap->op,
  		       uap->a1);
  		return 0;
  	}
  }
  