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linux_machdep.c revision 1.36.2.1
      1 /*	$NetBSD: linux_machdep.c,v 1.36.2.1 2007/03/12 05:52:14 rmind Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Eric Haszlakiewicz.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the NetBSD
     21  *	Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  *
     38  * Based on sys/arch/i386/i386/linux_machdep.c:
     39  *	linux_machdep.c,v 1.42 1998/09/11 12:50:06 mycroft Exp
     40  *	written by Frank van der Linden
     41  *
     42  */
     43 
     44 #include <sys/cdefs.h>
     45 __KERNEL_RCSID(0, "$NetBSD: linux_machdep.c,v 1.36.2.1 2007/03/12 05:52:14 rmind Exp $");
     46 
     47 #include <sys/param.h>
     48 #include <sys/systm.h>
     49 #include <sys/signalvar.h>
     50 #include <sys/kernel.h>
     51 #include <sys/proc.h>
     52 #include <sys/user.h>
     53 #include <sys/buf.h>
     54 #include <sys/reboot.h>
     55 #include <sys/conf.h>
     56 #include <sys/exec.h>
     57 #include <sys/file.h>
     58 #include <sys/callout.h>
     59 #include <sys/malloc.h>
     60 #include <sys/mbuf.h>
     61 #include <sys/msgbuf.h>
     62 #include <sys/mount.h>
     63 #include <sys/vnode.h>
     64 #include <sys/device.h>
     65 #include <sys/syscallargs.h>
     66 #include <sys/filedesc.h>
     67 #include <sys/exec_elf.h>
     68 #include <sys/ioctl.h>
     69 #include <sys/kauth.h>
     70 
     71 #include <uvm/uvm_extern.h>
     72 
     73 #include <compat/linux/common/linux_types.h>
     74 #include <compat/linux/common/linux_signal.h>
     75 #include <compat/linux/common/linux_siginfo.h>
     76 #include <compat/linux/common/linux_util.h>
     77 #include <compat/linux/common/linux_ioctl.h>
     78 #include <compat/linux/common/linux_exec.h>
     79 #include <compat/linux/common/linux_machdep.h>
     80 #include <compat/linux/common/linux_emuldata.h>
     81 
     82 #include <compat/linux/linux_syscallargs.h>
     83 
     84 #include <machine/alpha.h>
     85 #include <machine/reg.h>
     86 
     87 #if defined(_KERNEL_OPT)
     88 #include "wsdisplay.h"
     89 #endif
     90 #if (NWSDISPLAY >0)
     91 #include <dev/wscons/wsdisplay_usl_io.h>
     92 #endif
     93 #ifdef DEBUG
     94 #include <machine/sigdebug.h>
     95 #endif
     96 
     97 /*
     98  * Deal with some alpha-specific things in the Linux emulation code.
     99  */
    100 
    101 void
    102 linux_setregs(l, epp, stack)
    103 	struct lwp *l;
    104 	struct exec_package *epp;
    105 	u_long stack;
    106 {
    107 #ifdef DEBUG
    108 	struct trapframe *tfp = l->l_md.md_tf;
    109 #endif
    110 
    111 	setregs(l, epp, stack);
    112 #ifdef DEBUG
    113 	/*
    114 	 * Linux has registers set to zero on entry; for DEBUG kernels
    115 	 * the alpha setregs() fills registers with 0xbabefacedeadbeef.
    116 	 */
    117 	memset(tfp->tf_regs, 0, FRAME_SIZE * sizeof tfp->tf_regs[0]);
    118 #endif
    119 }
    120 
    121 void
    122 setup_linux_rt_sigframe(struct trapframe *tf, int sig, const sigset_t *mask)
    123 {
    124 	struct lwp *l = curlwp;
    125 	struct proc *p = l->l_proc;
    126 	struct linux_rt_sigframe *sfp, sigframe;
    127 	int onstack, error;
    128 	int fsize, rndfsize;
    129 	extern char linux_rt_sigcode[], linux_rt_esigcode[];
    130 
    131 	/* Do we need to jump onto the signal stack? */
    132 	onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
    133 		  (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
    134 
    135 	/* Allocate space for the signal handler context.  */
    136 	fsize = sizeof(struct linux_rt_sigframe);
    137 	rndfsize = ((fsize + 15) / 16) * 16;
    138 
    139 	if (onstack)
    140 		sfp = (struct linux_rt_sigframe *)
    141 		    ((char *)l->l_sigstk.ss_sp + l->l_sigstk.ss_size);
    142 	else
    143 		sfp = (struct linux_rt_sigframe *)(alpha_pal_rdusp());
    144 	sfp = (struct linux_rt_sigframe *)((char *)sfp - rndfsize);
    145 
    146 #ifdef DEBUG
    147 	if ((sigdebug & SDB_KSTACK) && (p->p_pid == sigpid))
    148 		printf("linux_sendsig(%d): sig %d ssp %p usp %p\n", p->p_pid,
    149 		    sig, &onstack, sfp);
    150 #endif /* DEBUG */
    151 
    152 	/*
    153 	 * Build the signal context to be used by sigreturn.
    154 	 */
    155 	memset(&sigframe.uc, 0, sizeof(struct linux_ucontext));
    156 	sigframe.uc.uc_mcontext.sc_onstack = onstack;
    157 
    158 	/* Setup potentially partial signal mask in sc_mask. */
    159 	/* But get all of it in uc_sigmask */
    160 	native_to_linux_old_sigset(&sigframe.uc.uc_mcontext.sc_mask, mask);
    161 	native_to_linux_sigset(&sigframe.uc.uc_sigmask, mask);
    162 
    163 	sigframe.uc.uc_mcontext.sc_pc = tf->tf_regs[FRAME_PC];
    164 	sigframe.uc.uc_mcontext.sc_ps = ALPHA_PSL_USERMODE;
    165 	frametoreg(tf, (struct reg *)sigframe.uc.uc_mcontext.sc_regs);
    166 	sigframe.uc.uc_mcontext.sc_regs[R_SP] = alpha_pal_rdusp();
    167 
    168 	alpha_enable_fp(l, 1);
    169 	sigframe.uc.uc_mcontext.sc_fpcr = alpha_read_fpcr();
    170 	sigframe.uc.uc_mcontext.sc_fp_control = alpha_read_fp_c(l);
    171 	alpha_pal_wrfen(0);
    172 
    173 	sigframe.uc.uc_mcontext.sc_traparg_a0 = tf->tf_regs[FRAME_A0];
    174 	sigframe.uc.uc_mcontext.sc_traparg_a1 = tf->tf_regs[FRAME_A1];
    175 	sigframe.uc.uc_mcontext.sc_traparg_a2 = tf->tf_regs[FRAME_A2];
    176 
    177 	/*
    178 	 * XXX XAX Create bogus siginfo data.  This can't really
    179 	 * XXX be fixed until NetBSD has realtime signals.
    180 	 * XXX Or we do the emuldata thing.
    181 	 * XXX -erh
    182 	 */
    183 	memset(&sigframe.info, 0, sizeof(struct linux_siginfo));
    184 	sigframe.info.lsi_signo = sig;
    185 	sigframe.info.lsi_code = LINUX_SI_USER;
    186 	sigframe.info.lsi_pid = p->p_pid;
    187 	sigframe.info.lsi_uid = kauth_cred_geteuid(l->l_cred);	/* Use real uid here? */
    188 
    189 	sendsig_reset(l, sig);
    190 	mutex_exit(&p->p_smutex);
    191 	error = copyout((void *)&sigframe, (void *)sfp, fsize);
    192 	mutex_enter(&p->p_smutex);
    193 
    194 	if (error != 0) {
    195 #ifdef DEBUG
    196 		if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
    197 			printf("sendsig(%d): copyout failed on sig %d\n",
    198 			    p->p_pid, sig);
    199 #endif
    200 		/*
    201 		 * Process has trashed its stack; give it an illegal
    202 		 * instruction to halt it in its tracks.
    203 		 */
    204 		sigexit(l, SIGILL);
    205 		/* NOTREACHED */
    206 	}
    207 
    208 	/* Pass pointers to siginfo and ucontext in the regs */
    209 	tf->tf_regs[FRAME_A1] = (unsigned long)&sfp->info;
    210 	tf->tf_regs[FRAME_A2] = (unsigned long)&sfp->uc;
    211 
    212 	/* Address of trampoline code.  End up at this PC after mi_switch */
    213 	tf->tf_regs[FRAME_PC] =
    214 	    (u_int64_t)(p->p_psstr - (linux_rt_esigcode - linux_rt_sigcode));
    215 
    216 	/* Adjust the stack */
    217 	alpha_pal_wrusp((unsigned long)sfp);
    218 
    219 	/* Remember that we're now on the signal stack. */
    220 	if (onstack)
    221 		l->l_sigstk.ss_flags |= SS_ONSTACK;
    222 }
    223 
    224 void setup_linux_sigframe(tf, sig, mask)
    225 	struct trapframe *tf;
    226 	int sig;
    227 	const sigset_t *mask;
    228 {
    229 	struct lwp *l = curlwp;
    230 	struct proc *p = l->l_proc;
    231 	struct linux_sigframe *sfp, sigframe;
    232 	int onstack, error;
    233 	int fsize, rndfsize;
    234 	extern char linux_sigcode[], linux_esigcode[];
    235 
    236 	/* Do we need to jump onto the signal stack? */
    237 	onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
    238 		  (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
    239 
    240 	/* Allocate space for the signal handler context.  */
    241 	fsize = sizeof(struct linux_sigframe);
    242 	rndfsize = ((fsize + 15) / 16) * 16;
    243 
    244 	if (onstack)
    245 		sfp = (struct linux_sigframe *)
    246 		    ((char *)l->l_sigstk.ss_sp + l->l_sigstk.ss_size);
    247 	else
    248 		sfp = (struct linux_sigframe *)(alpha_pal_rdusp());
    249 	sfp = (struct linux_sigframe *)((char *)sfp - rndfsize);
    250 
    251 #ifdef DEBUG
    252 	if ((sigdebug & SDB_KSTACK) && (p->p_pid == sigpid))
    253 		printf("linux_sendsig(%d): sig %d ssp %p usp %p\n", p->p_pid,
    254 		    sig, &onstack, sfp);
    255 #endif /* DEBUG */
    256 
    257 	/*
    258 	 * Build the signal context to be used by sigreturn.
    259 	 */
    260 	memset(&sigframe.sf_sc, 0, sizeof(struct linux_ucontext));
    261 	sigframe.sf_sc.sc_onstack = onstack;
    262 	native_to_linux_old_sigset(&sigframe.sf_sc.sc_mask, mask);
    263 	sigframe.sf_sc.sc_pc = tf->tf_regs[FRAME_PC];
    264 	sigframe.sf_sc.sc_ps = ALPHA_PSL_USERMODE;
    265 	frametoreg(tf, (struct reg *)sigframe.sf_sc.sc_regs);
    266 	sigframe.sf_sc.sc_regs[R_SP] = alpha_pal_rdusp();
    267 
    268 	if (l == fpcurlwp) {
    269 	    alpha_pal_wrfen(1);
    270 	    savefpstate(&l->l_addr->u_pcb.pcb_fp);
    271 	    alpha_pal_wrfen(0);
    272 	    sigframe.sf_sc.sc_fpcr = l->l_addr->u_pcb.pcb_fp.fpr_cr;
    273 	    fpcurlwp = NULL;
    274 	}
    275 	/* XXX ownedfp ? etc...? */
    276 
    277 	sigframe.sf_sc.sc_traparg_a0 = tf->tf_regs[FRAME_A0];
    278 	sigframe.sf_sc.sc_traparg_a1 = tf->tf_regs[FRAME_A1];
    279 	sigframe.sf_sc.sc_traparg_a2 = tf->tf_regs[FRAME_A2];
    280 
    281 	sendsig_reset(l, sig);
    282 	mutex_exit(&p->p_smutex);
    283 	error = copyout((void *)&sigframe, (void *)sfp, fsize);
    284 	mutex_enter(&p->p_smutex);
    285 
    286 	if (error != 0) {
    287 #ifdef DEBUG
    288 		if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
    289 			printf("sendsig(%d): copyout failed on sig %d\n",
    290 			    p->p_pid, sig);
    291 #endif
    292 		/*
    293 		 * Process has trashed its stack; give it an illegal
    294 		 * instruction to halt it in its tracks.
    295 		 */
    296 		sigexit(l, SIGILL);
    297 		/* NOTREACHED */
    298 	}
    299 
    300 	/* Pass pointers to sigcontext in the regs */
    301 	tf->tf_regs[FRAME_A1] = 0;
    302 	tf->tf_regs[FRAME_A2] = (unsigned long)&sfp->sf_sc;
    303 
    304 	/* Address of trampoline code.  End up at this PC after mi_switch */
    305 	tf->tf_regs[FRAME_PC] =
    306 	    (u_int64_t)(p->p_psstr - (linux_esigcode - linux_sigcode));
    307 
    308 	/* Adjust the stack */
    309 	alpha_pal_wrusp((unsigned long)sfp);
    310 
    311 	/* Remember that we're now on the signal stack. */
    312 	if (onstack)
    313 		l->l_sigstk.ss_flags |= SS_ONSTACK;
    314 }
    315 
    316 /*
    317  * Send an interrupt to process.
    318  *
    319  * Stack is set up to allow sigcode stored
    320  * in u. to call routine, followed by kcall
    321  * to sigreturn routine below.  After sigreturn
    322  * resets the signal mask, the stack, and the
    323  * frame pointer, it returns to the user
    324  * specified pc, psl.
    325  */
    326 void
    327 linux_sendsig(const ksiginfo_t *ksi, const sigset_t *mask)
    328 {
    329 	struct lwp *l = curlwp;
    330 	struct proc *p = l->l_proc;
    331 	struct trapframe *tf = l->l_md.md_tf;
    332 	const int sig = ksi->ksi_signo;
    333 	sig_t catcher = SIGACTION(p, sig).sa_handler;
    334 #ifdef notyet
    335 	struct linux_emuldata *edp;
    336 
    337 	/* Setup the signal frame (and part of the trapframe) */
    338 	/*OLD: if (p->p_sigacts->ps_siginfo & sigmask(sig))*/
    339 /*	XXX XAX this is broken now.  need someplace to store what
    340 	XXX XAX kind of signal handler a signal has.*/
    341 #if 0
    342 	edp = (struct linux_emuldata *)p->p_emuldata;
    343 #else
    344 	edp = 0;
    345 #endif
    346 	if (edp && sigismember(&edp->ps_siginfo, sig))
    347 		setup_linux_rt_sigframe(tf, sig, mask);
    348 	else
    349 #endif /* notyet */
    350 		setup_linux_sigframe(tf, sig, mask);
    351 
    352 	/* Signal handler for trampoline code */
    353 	tf->tf_regs[FRAME_T12] = (u_int64_t)catcher;
    354 	tf->tf_regs[FRAME_A0] = native_to_linux_signo[sig];
    355 
    356 	/*
    357 	 * Linux has a custom restorer option.  To support it we would
    358 	 * need to store an array of restorers and a sigcode block
    359 	 * which knew to use it.  Doesn't seem worth the trouble.
    360 	 * -erh
    361 	 */
    362 
    363 #ifdef DEBUG
    364 	if (sigdebug & SDB_FOLLOW)
    365 		printf("sendsig(%d): pc %lx, catcher %lx\n", l->l_proc->p_pid,
    366 		    tf->tf_regs[FRAME_PC], tf->tf_regs[FRAME_A3]);
    367 	if ((sigdebug & SDB_KSTACK) && l->l_proc->p_pid == sigpid)
    368 		printf("sendsig(%d): sig %d returns\n", l->l_proc->p_pid, sig);
    369 #endif
    370 }
    371 
    372 /*
    373  * System call to cleanup state after a signal
    374  * has been taken.  Reset signal mask and
    375  * stack state from context left by sendsig (above).
    376  * Return to previous pc as specified by context
    377  * left by sendsig.
    378  * Linux real-time signals use a different sigframe,
    379  * but the sigcontext is the same.
    380  */
    381 
    382 int
    383 linux_restore_sigcontext(struct lwp *l, struct linux_sigcontext context,
    384 			 sigset_t *mask)
    385 {
    386 	struct proc *p = l->l_proc;
    387 
    388 	/*
    389 	 * Linux doesn't (yet) have alternate signal stacks.
    390 	 * However, the OSF/1 sigcontext which they use has
    391 	 * an onstack member.  This could be needed in the future.
    392 	 */
    393 	mutex_enter(&p->p_smutex);
    394 	if (context.sc_onstack & LINUX_SA_ONSTACK)
    395 	    l->l_sigstk.ss_flags |= SS_ONSTACK;
    396 	else
    397 	    l->l_sigstk.ss_flags &= ~SS_ONSTACK;
    398 
    399 	/* Reset the signal mask */
    400 	(void) sigprocmask1(l, SIG_SETMASK, mask, 0);
    401 	mutex_exit(&p->p_smutex);
    402 
    403 	/*
    404 	 * Check for security violations.
    405 	 * Linux doesn't allow any changes to the PSL.
    406 	 */
    407 	if (context.sc_ps != ALPHA_PSL_USERMODE)
    408 	    return(EINVAL);
    409 
    410 	l->l_md.md_tf->tf_regs[FRAME_PC] = context.sc_pc;
    411 	l->l_md.md_tf->tf_regs[FRAME_PS] = context.sc_ps;
    412 
    413 	regtoframe((struct reg *)context.sc_regs, l->l_md.md_tf);
    414 	alpha_pal_wrusp(context.sc_regs[R_SP]);
    415 
    416 	if (l == fpcurlwp)
    417 	    fpcurlwp = NULL;
    418 
    419 	/* Restore fp regs and fpr_cr */
    420 	bcopy((struct fpreg *)context.sc_fpregs, &l->l_addr->u_pcb.pcb_fp,
    421 	    sizeof(struct fpreg));
    422 	/* XXX sc_ownedfp ? */
    423 	/* XXX sc_fp_control ? */
    424 
    425 #ifdef DEBUG
    426 	if (sigdebug & SDB_FOLLOW)
    427 		printf("linux_rt_sigreturn(%d): returns\n", p->p_pid);
    428 #endif
    429 	return (EJUSTRETURN);
    430 }
    431 
    432 int
    433 linux_sys_rt_sigreturn(l, v, retval)
    434 	struct lwp *l;
    435 	void *v;
    436 	register_t *retval;
    437 {
    438 	struct linux_sys_rt_sigreturn_args /* {
    439 		syscallarg(struct linux_rt_sigframe *) sfp;
    440 	} */ *uap = v;
    441 	struct linux_rt_sigframe *sfp, sigframe;
    442 	sigset_t mask;
    443 
    444 	/*
    445 	 * The trampoline code hands us the context.
    446 	 * It is unsafe to keep track of it ourselves, in the event that a
    447 	 * program jumps out of a signal handler.
    448 	 */
    449 
    450 	sfp = SCARG(uap, sfp);
    451 
    452 	if (ALIGN(sfp) != (u_int64_t)sfp)
    453 		return(EINVAL);
    454 
    455 	/*
    456 	 * Fetch the frame structure.
    457 	 */
    458 	if (copyin((void *)sfp, &sigframe,
    459 			sizeof(struct linux_rt_sigframe)) != 0)
    460 		return (EFAULT);
    461 
    462 	/* Grab the signal mask */
    463 	linux_to_native_sigset(&mask, &sigframe.uc.uc_sigmask);
    464 
    465 	return(linux_restore_sigcontext(l, sigframe.uc.uc_mcontext, &mask));
    466 }
    467 
    468 
    469 int
    470 linux_sys_sigreturn(l, v, retval)
    471 	struct lwp *l;
    472 	void *v;
    473 	register_t *retval;
    474 {
    475 	struct linux_sys_sigreturn_args /* {
    476 		syscallarg(struct linux_sigframe *) sfp;
    477 	} */ *uap = v;
    478 	struct linux_sigframe *sfp, frame;
    479 	sigset_t mask;
    480 
    481 	/*
    482 	 * The trampoline code hands us the context.
    483 	 * It is unsafe to keep track of it ourselves, in the event that a
    484 	 * program jumps out of a signal handler.
    485 	 */
    486 
    487 	sfp = SCARG(uap, sfp);
    488 	if (ALIGN(sfp) != (u_int64_t)sfp)
    489 		return(EINVAL);
    490 
    491 	/*
    492 	 * Fetch the frame structure.
    493 	 */
    494 	if (copyin((void *)sfp, &frame, sizeof(struct linux_sigframe)) != 0)
    495 		return(EFAULT);
    496 
    497 	/* Grab the signal mask. */
    498 	/* XXX use frame.extramask */
    499 	linux_old_to_native_sigset(&mask, frame.sf_sc.sc_mask);
    500 
    501 	return(linux_restore_sigcontext(l, frame.sf_sc, &mask));
    502 }
    503 
    504 /*
    505  * We come here in a last attempt to satisfy a Linux ioctl() call
    506  */
    507 /* XXX XAX update this, add maps, etc... */
    508 int
    509 linux_machdepioctl(l, v, retval)
    510 	struct lwp *l;
    511 	void *v;
    512 	register_t *retval;
    513 {
    514 	struct linux_sys_ioctl_args /* {
    515 		syscallarg(int) fd;
    516 		syscallarg(u_long) com;
    517 		syscallarg(void *) data;
    518 	} */ *uap = v;
    519 	struct sys_ioctl_args bia;
    520 	u_long com;
    521 
    522 	SCARG(&bia, fd) = SCARG(uap, fd);
    523 	SCARG(&bia, data) = SCARG(uap, data);
    524 	com = SCARG(uap, com);
    525 
    526 	switch (com) {
    527 	default:
    528 		printf("linux_machdepioctl: invalid ioctl %08lx\n", com);
    529 		return EINVAL;
    530 	}
    531 	SCARG(&bia, com) = com;
    532 	return sys_ioctl(l, &bia, retval);
    533 }
    534 
    535 /* XXX XAX fix this */
    536 dev_t
    537 linux_fakedev(dev, raw)
    538 	dev_t dev;
    539 	int raw;
    540 {
    541 	return dev;
    542 }
    543 
    544 int
    545 linux_usertrap(struct lwp *l, vaddr_t trapaddr, void *arg)
    546 {
    547 	return 0;
    548 }
    549