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linux_misc.c revision 1.70
      1 /*	$NetBSD: linux_misc.c,v 1.70 2000/06/26 14:38:57 mrg Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1995, 1998, 1999 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Frank van der Linden and Eric Haszlakiewicz; by Jason R. Thorpe
      9  * of the Numerical Aerospace Simulation Facility, NASA Ames Research Center.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the NetBSD
     22  *	Foundation, Inc. and its contributors.
     23  * 4. Neither the name of The NetBSD Foundation nor the names of its
     24  *    contributors may be used to endorse or promote products derived
     25  *    from this software without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     37  * POSSIBILITY OF SUCH DAMAGE.
     38  */
     39 
     40 /*
     41  * Linux compatibility module. Try to deal with various Linux system calls.
     42  */
     43 
     44 /*
     45  * These functions have been moved to multiarch to allow
     46  * selection of which machines include them to be
     47  * determined by the individual files.linux_<arch> files.
     48  *
     49  * Function in multiarch:
     50  *	linux_sys_break			: linux_break.c
     51  *	linux_sys_alarm			: linux_misc_notalpha.c
     52  *	linux_sys_getresgid		: linux_misc_notalpha.c
     53  *	linux_sys_nice			: linux_misc_notalpha.c
     54  *	linux_sys_readdir		: linux_misc_notalpha.c
     55  *	linux_sys_setresgid		: linux_misc_notalpha.c
     56  *	linux_sys_time			: linux_misc_notalpha.c
     57  *	linux_sys_utime			: linux_misc_notalpha.c
     58  *	linux_sys_waitpid		: linux_misc_notalpha.c
     59  *	linux_sys_old_mmap		: linux_oldmmap.c
     60  *	linux_sys_oldolduname		: linux_oldolduname.c
     61  *	linux_sys_oldselect		: linux_oldselect.c
     62  *	linux_sys_olduname		: linux_olduname.c
     63  *	linux_sys_pipe			: linux_pipe.c
     64  */
     65 
     66 #include <sys/param.h>
     67 #include <sys/systm.h>
     68 #include <sys/namei.h>
     69 #include <sys/proc.h>
     70 #include <sys/dirent.h>
     71 #include <sys/file.h>
     72 #include <sys/stat.h>
     73 #include <sys/filedesc.h>
     74 #include <sys/ioctl.h>
     75 #include <sys/kernel.h>
     76 #include <sys/malloc.h>
     77 #include <sys/mbuf.h>
     78 #include <sys/mman.h>
     79 #include <sys/mount.h>
     80 #include <sys/ptrace.h>
     81 #include <sys/reboot.h>
     82 #include <sys/resource.h>
     83 #include <sys/resourcevar.h>
     84 #include <sys/signal.h>
     85 #include <sys/signalvar.h>
     86 #include <sys/socket.h>
     87 #include <sys/time.h>
     88 #include <sys/times.h>
     89 #include <sys/vnode.h>
     90 #include <sys/uio.h>
     91 #include <sys/wait.h>
     92 #include <sys/utsname.h>
     93 #include <sys/unistd.h>
     94 
     95 #include <sys/syscallargs.h>
     96 
     97 #include <vm/vm.h>
     98 
     99 #include <compat/linux/common/linux_types.h>
    100 #include <compat/linux/common/linux_signal.h>
    101 
    102 #include <compat/linux/linux_syscallargs.h>
    103 
    104 #include <compat/linux/common/linux_fcntl.h>
    105 #include <compat/linux/common/linux_mmap.h>
    106 #include <compat/linux/common/linux_dirent.h>
    107 #include <compat/linux/common/linux_util.h>
    108 #include <compat/linux/common/linux_misc.h>
    109 #include <compat/linux/common/linux_ptrace.h>
    110 #include <compat/linux/common/linux_reboot.h>
    111 
    112 int linux_ptrace_request_map[] = {
    113 	LINUX_PTRACE_TRACEME,	PT_TRACE_ME,
    114 	LINUX_PTRACE_PEEKTEXT,	PT_READ_I,
    115 	LINUX_PTRACE_PEEKDATA,	PT_READ_D,
    116 	LINUX_PTRACE_POKETEXT,	PT_WRITE_I,
    117 	LINUX_PTRACE_POKEDATA,	PT_WRITE_D,
    118 	LINUX_PTRACE_CONT,	PT_CONTINUE,
    119 	LINUX_PTRACE_KILL,	PT_KILL,
    120 	LINUX_PTRACE_ATTACH,	PT_ATTACH,
    121 	LINUX_PTRACE_DETACH,	PT_DETACH,
    122 	-1
    123 };
    124 
    125 /* Local linux_misc.c functions: */
    126 static void bsd_to_linux_statfs __P((struct statfs *, struct linux_statfs *));
    127 
    128 /*
    129  * The information on a terminated (or stopped) process needs
    130  * to be converted in order for Linux binaries to get a valid signal
    131  * number out of it.
    132  */
    133 void
    134 bsd_to_linux_wstat(st)
    135 	int *st;
    136 {
    137 
    138 	int sig;
    139 
    140 	if (WIFSIGNALED(*st)) {
    141 		sig = WTERMSIG(*st);
    142 		if (sig >= 0 && sig < NSIG)
    143 			*st= (*st& ~0177) | native_to_linux_sig[sig];
    144 	} else if (WIFSTOPPED(*st)) {
    145 		sig = WSTOPSIG(*st);
    146 		if (sig >= 0 && sig < NSIG)
    147 			*st = (*st & ~0xff00) | (native_to_linux_sig[sig] << 8);
    148 	}
    149 }
    150 
    151 /*
    152  * This is very much the same as waitpid()
    153  */
    154 int
    155 linux_sys_wait4(p, v, retval)
    156 	struct proc *p;
    157 	void *v;
    158 	register_t *retval;
    159 {
    160 	struct linux_sys_wait4_args /* {
    161 		syscallarg(int) pid;
    162 		syscallarg(int *) status;
    163 		syscallarg(int) options;
    164 		syscallarg(struct rusage *) rusage;
    165 	} */ *uap = v;
    166 	struct sys_wait4_args w4a;
    167 	int error, *status, tstat, options, linux_options;
    168 	caddr_t sg;
    169 
    170 	if (SCARG(uap, status) != NULL) {
    171 		sg = stackgap_init(p->p_emul);
    172 		status = (int *) stackgap_alloc(&sg, sizeof *status);
    173 	} else
    174 		status = NULL;
    175 
    176 	linux_options = SCARG(uap, options);
    177 	options = 0;
    178 	if (linux_options &
    179 	    ~(LINUX_WAIT4_WNOHANG|LINUX_WAIT4_WUNTRACED|LINUX_WAIT4_WCLONE))
    180 		return (EINVAL);
    181 
    182 	if (linux_options & LINUX_WAIT4_WNOHANG)
    183 		options |= WNOHANG;
    184 	if (linux_options & LINUX_WAIT4_WUNTRACED)
    185 		options |= WUNTRACED;
    186 	if (linux_options & LINUX_WAIT4_WCLONE)
    187 		options |= WALTSIG;
    188 
    189 	SCARG(&w4a, pid) = SCARG(uap, pid);
    190 	SCARG(&w4a, status) = status;
    191 	SCARG(&w4a, options) = options;
    192 	SCARG(&w4a, rusage) = SCARG(uap, rusage);
    193 
    194 	if ((error = sys_wait4(p, &w4a, retval)))
    195 		return error;
    196 
    197 	sigdelset(&p->p_siglist, SIGCHLD);
    198 
    199 	if (status != NULL) {
    200 		if ((error = copyin(status, &tstat, sizeof tstat)))
    201 			return error;
    202 
    203 		bsd_to_linux_wstat(&tstat);
    204 		return copyout(&tstat, SCARG(uap, status), sizeof tstat);
    205 	}
    206 
    207 	return 0;
    208 }
    209 
    210 /*
    211  * Linux brk(2). The check if the new address is >= the old one is
    212  * done in the kernel in Linux. NetBSD does it in the library.
    213  */
    214 int
    215 linux_sys_brk(p, v, retval)
    216 	struct proc *p;
    217 	void *v;
    218 	register_t *retval;
    219 {
    220 	struct linux_sys_brk_args /* {
    221 		syscallarg(char *) nsize;
    222 	} */ *uap = v;
    223 	char *nbrk = SCARG(uap, nsize);
    224 	struct sys_obreak_args oba;
    225 	struct vmspace *vm = p->p_vmspace;
    226 	caddr_t oldbrk;
    227 
    228 	oldbrk = vm->vm_daddr + ctob(vm->vm_dsize);
    229 	/*
    230 	 * XXX inconsistent.. Linux always returns at least the old
    231 	 * brk value, but it will be page-aligned if this fails,
    232 	 * and possibly not page aligned if it succeeds (the user
    233 	 * supplied pointer is returned).
    234 	 */
    235 	SCARG(&oba, nsize) = nbrk;
    236 
    237 	if ((caddr_t) nbrk > vm->vm_daddr && sys_obreak(p, &oba, retval) == 0)
    238 		retval[0] = (register_t)nbrk;
    239 	else
    240 		retval[0] = (register_t)oldbrk;
    241 
    242 	return 0;
    243 }
    244 
    245 /*
    246  * Convert BSD statfs structure to Linux statfs structure.
    247  * The Linux structure has less fields, and it also wants
    248  * the length of a name in a dir entry in a field, which
    249  * we fake (probably the wrong way).
    250  */
    251 static void
    252 bsd_to_linux_statfs(bsp, lsp)
    253 	struct statfs *bsp;
    254 	struct linux_statfs *lsp;
    255 {
    256 
    257 	lsp->l_ftype = bsp->f_type;
    258 	lsp->l_fbsize = bsp->f_bsize;
    259 	lsp->l_fblocks = bsp->f_blocks;
    260 	lsp->l_fbfree = bsp->f_bfree;
    261 	lsp->l_fbavail = bsp->f_bavail;
    262 	lsp->l_ffiles = bsp->f_files;
    263 	lsp->l_fffree = bsp->f_ffree;
    264 	lsp->l_ffsid.val[0] = bsp->f_fsid.val[0];
    265 	lsp->l_ffsid.val[1] = bsp->f_fsid.val[1];
    266 	lsp->l_fnamelen = MAXNAMLEN;	/* XXX */
    267 }
    268 
    269 /*
    270  * Implement the fs stat functions. Straightforward.
    271  */
    272 int
    273 linux_sys_statfs(p, v, retval)
    274 	struct proc *p;
    275 	void *v;
    276 	register_t *retval;
    277 {
    278 	struct linux_sys_statfs_args /* {
    279 		syscallarg(const char *) path;
    280 		syscallarg(struct linux_statfs *) sp;
    281 	} */ *uap = v;
    282 	struct statfs btmp, *bsp;
    283 	struct linux_statfs ltmp;
    284 	struct sys_statfs_args bsa;
    285 	caddr_t sg;
    286 	int error;
    287 
    288 	sg = stackgap_init(p->p_emul);
    289 	bsp = (struct statfs *) stackgap_alloc(&sg, sizeof (struct statfs));
    290 
    291 	LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
    292 
    293 	SCARG(&bsa, path) = SCARG(uap, path);
    294 	SCARG(&bsa, buf) = bsp;
    295 
    296 	if ((error = sys_statfs(p, &bsa, retval)))
    297 		return error;
    298 
    299 	if ((error = copyin((caddr_t) bsp, (caddr_t) &btmp, sizeof btmp)))
    300 		return error;
    301 
    302 	bsd_to_linux_statfs(&btmp, &ltmp);
    303 
    304 	return copyout((caddr_t) &ltmp, (caddr_t) SCARG(uap, sp), sizeof ltmp);
    305 }
    306 
    307 int
    308 linux_sys_fstatfs(p, v, retval)
    309 	struct proc *p;
    310 	void *v;
    311 	register_t *retval;
    312 {
    313 	struct linux_sys_fstatfs_args /* {
    314 		syscallarg(int) fd;
    315 		syscallarg(struct linux_statfs *) sp;
    316 	} */ *uap = v;
    317 	struct statfs btmp, *bsp;
    318 	struct linux_statfs ltmp;
    319 	struct sys_fstatfs_args bsa;
    320 	caddr_t sg;
    321 	int error;
    322 
    323 	sg = stackgap_init(p->p_emul);
    324 	bsp = (struct statfs *) stackgap_alloc(&sg, sizeof (struct statfs));
    325 
    326 	SCARG(&bsa, fd) = SCARG(uap, fd);
    327 	SCARG(&bsa, buf) = bsp;
    328 
    329 	if ((error = sys_fstatfs(p, &bsa, retval)))
    330 		return error;
    331 
    332 	if ((error = copyin((caddr_t) bsp, (caddr_t) &btmp, sizeof btmp)))
    333 		return error;
    334 
    335 	bsd_to_linux_statfs(&btmp, &ltmp);
    336 
    337 	return copyout((caddr_t) &ltmp, (caddr_t) SCARG(uap, sp), sizeof ltmp);
    338 }
    339 
    340 /*
    341  * uname(). Just copy the info from the various strings stored in the
    342  * kernel, and put it in the Linux utsname structure. That structure
    343  * is almost the same as the NetBSD one, only it has fields 65 characters
    344  * long, and an extra domainname field.
    345  */
    346 int
    347 linux_sys_uname(p, v, retval)
    348 	struct proc *p;
    349 	void *v;
    350 	register_t *retval;
    351 {
    352 	struct linux_sys_uname_args /* {
    353 		syscallarg(struct linux_utsname *) up;
    354 	} */ *uap = v;
    355 	struct linux_utsname luts;
    356 	int len;
    357 	char *cp;
    358 
    359 	strncpy(luts.l_sysname, ostype, sizeof(luts.l_sysname));
    360 	strncpy(luts.l_nodename, hostname, sizeof(luts.l_nodename));
    361 	strncpy(luts.l_release, osrelease, sizeof(luts.l_release));
    362 	strncpy(luts.l_version, version, sizeof(luts.l_version));
    363 	strncpy(luts.l_machine, machine, sizeof(luts.l_machine));
    364 	strncpy(luts.l_domainname, domainname, sizeof(luts.l_domainname));
    365 
    366 	/* This part taken from the uname() in libc */
    367 	len = sizeof(luts.l_version);
    368 	for (cp = luts.l_version; len--; ++cp) {
    369 		if (*cp == '\n' || *cp == '\t') {
    370 			if (len > 1)
    371 				*cp = ' ';
    372 			else
    373 				*cp = '\0';
    374 		}
    375 	}
    376 
    377 	return copyout(&luts, SCARG(uap, up), sizeof(luts));
    378 }
    379 
    380 /* Used directly on: alpha, mips, ppc, sparc, sparc64 */
    381 /* Used indirectly on: arm, i386, m68k */
    382 
    383 /*
    384  * New type Linux mmap call.
    385  * Only called directly on machines with >= 6 free regs.
    386  */
    387 int
    388 linux_sys_mmap(p, v, retval)
    389 	struct proc *p;
    390 	void *v;
    391 	register_t *retval;
    392 {
    393 	struct linux_sys_mmap_args /* {
    394 		syscallarg(unsigned long) addr;
    395 		syscallarg(size_t) len;
    396 		syscallarg(int) prot;
    397 		syscallarg(int) flags;
    398 		syscallarg(int) fd;
    399 		syscallarg(off_t) offset;
    400 	} */ *uap = v;
    401 	struct sys_mmap_args cma;
    402 	int flags;
    403 
    404 	flags = 0;
    405 	flags |= cvtto_bsd_mask(SCARG(uap,flags), LINUX_MAP_SHARED, MAP_SHARED);
    406 	flags |= cvtto_bsd_mask(SCARG(uap,flags), LINUX_MAP_PRIVATE, MAP_PRIVATE);
    407 	flags |= cvtto_bsd_mask(SCARG(uap,flags), LINUX_MAP_FIXED, MAP_FIXED);
    408 	flags |= cvtto_bsd_mask(SCARG(uap,flags), LINUX_MAP_ANON, MAP_ANON);
    409 	/* XXX XAX ERH: Any other flags here?  There are more defined... */
    410 
    411 	SCARG(&cma,addr) = (void *)SCARG(uap, addr);
    412 	SCARG(&cma,len) = SCARG(uap, len);
    413 	SCARG(&cma,prot) = SCARG(uap, prot);
    414 	if (SCARG(&cma,prot) & VM_PROT_WRITE) /* XXX */
    415 		SCARG(&cma,prot) |= VM_PROT_READ;
    416 	SCARG(&cma,flags) = flags;
    417 	SCARG(&cma,fd) = SCARG(uap, fd);
    418 	SCARG(&cma,pad) = 0;
    419 	SCARG(&cma,pos) = SCARG(uap, offset);
    420 
    421 	return sys_mmap(p, &cma, retval);
    422 }
    423 
    424 int
    425 linux_sys_mremap(p, v, retval)
    426 	struct proc *p;
    427 	void *v;
    428 	register_t *retval;
    429 {
    430 	struct linux_sys_mremap_args /* {
    431 		syscallarg(void *) old_address;
    432 		syscallarg(size_t) old_size;
    433 		syscallarg(size_t) new_size;
    434 		syscallarg(u_long) flags;
    435 	} */ *uap = v;
    436 	struct sys_munmap_args mua;
    437 	size_t old_size, new_size;
    438 	int error;
    439 
    440 	old_size = round_page(SCARG(uap, old_size));
    441 	new_size = round_page(SCARG(uap, new_size));
    442 
    443 	/*
    444 	 * Growing mapped region.
    445 	 */
    446 	if (new_size > old_size) {
    447 		/*
    448 		 * XXX Implement me.  What we probably want to do is
    449 		 * XXX dig out the guts of the old mapping, mmap that
    450 		 * XXX object again with the new size, then munmap
    451 		 * XXX the old mapping.
    452 		 */
    453 		*retval = 0;
    454 		return (ENOMEM);
    455 	}
    456 
    457 	/*
    458 	 * Shrinking mapped region.
    459 	 */
    460 	if (new_size < old_size) {
    461 		SCARG(&mua, addr) = (caddr_t)SCARG(uap, old_address) +
    462 		    new_size;
    463 		SCARG(&mua, len) = old_size - new_size;
    464 		error = sys_munmap(p, &mua, retval);
    465 		*retval = error ? 0 : (register_t)SCARG(uap, old_address);
    466 		return (error);
    467 	}
    468 
    469 	/*
    470 	 * No change.
    471 	 */
    472 	*retval = (register_t)SCARG(uap, old_address);
    473 	return (0);
    474 }
    475 
    476 int
    477 linux_sys_msync(p, v, retval)
    478 	struct proc *p;
    479 	void *v;
    480 	register_t *retval;
    481 {
    482 	struct linux_sys_msync_args /* {
    483 		syscallarg(caddr_t) addr;
    484 		syscallarg(int) len;
    485 		syscallarg(int) fl;
    486 	} */ *uap = v;
    487 
    488 	struct sys___msync13_args bma;
    489 
    490 	/* flags are ignored */
    491 	SCARG(&bma, addr) = SCARG(uap, addr);
    492 	SCARG(&bma, len) = SCARG(uap, len);
    493 	SCARG(&bma, flags) = SCARG(uap, fl);
    494 
    495 	return sys___msync13(p, &bma, retval);
    496 }
    497 
    498 /*
    499  * This code is partly stolen from src/lib/libc/compat-43/times.c
    500  * XXX - CLK_TCK isn't declared in /sys, just in <time.h>, done here
    501  */
    502 
    503 #define CLK_TCK 100
    504 #define	CONVTCK(r)	(r.tv_sec * CLK_TCK + r.tv_usec / (1000000 / CLK_TCK))
    505 
    506 int
    507 linux_sys_times(p, v, retval)
    508 	struct proc *p;
    509 	void *v;
    510 	register_t *retval;
    511 {
    512 	struct linux_sys_times_args /* {
    513 		syscallarg(struct times *) tms;
    514 	} */ *uap = v;
    515 	struct timeval t;
    516 	struct linux_tms ltms;
    517 	struct rusage ru;
    518 	int error, s;
    519 
    520 	calcru(p, &ru.ru_utime, &ru.ru_stime, NULL);
    521 	ltms.ltms_utime = CONVTCK(ru.ru_utime);
    522 	ltms.ltms_stime = CONVTCK(ru.ru_stime);
    523 
    524 	ltms.ltms_cutime = CONVTCK(p->p_stats->p_cru.ru_utime);
    525 	ltms.ltms_cstime = CONVTCK(p->p_stats->p_cru.ru_stime);
    526 
    527 	if ((error = copyout(&ltms, SCARG(uap, tms), sizeof ltms)))
    528 		return error;
    529 
    530 	s = splclock();
    531 	timersub(&time, &boottime, &t);
    532 	splx(s);
    533 
    534 	retval[0] = ((linux_clock_t)(CONVTCK(t)));
    535 	return 0;
    536 }
    537 
    538 /*
    539  * Linux 'readdir' call. This code is mostly taken from the
    540  * SunOS getdents call (see compat/sunos/sunos_misc.c), though
    541  * an attempt has been made to keep it a little cleaner (failing
    542  * miserably, because of the cruft needed if count 1 is passed).
    543  *
    544  * The d_off field should contain the offset of the next valid entry,
    545  * but in Linux it has the offset of the entry itself. We emulate
    546  * that bug here.
    547  *
    548  * Read in BSD-style entries, convert them, and copy them out.
    549  *
    550  * Note that this doesn't handle union-mounted filesystems.
    551  */
    552 int
    553 linux_sys_getdents(p, v, retval)
    554 	struct proc *p;
    555 	void *v;
    556 	register_t *retval;
    557 {
    558 	struct linux_sys_getdents_args /* {
    559 		syscallarg(int) fd;
    560 		syscallarg(struct linux_dirent *) dent;
    561 		syscallarg(unsigned int) count;
    562 	} */ *uap = v;
    563 	struct dirent *bdp;
    564 	struct vnode *vp;
    565 	caddr_t	inp, buf;		/* BSD-format */
    566 	int len, reclen;		/* BSD-format */
    567 	caddr_t outp;			/* Linux-format */
    568 	int resid, linux_reclen = 0;	/* Linux-format */
    569 	struct file *fp;
    570 	struct uio auio;
    571 	struct iovec aiov;
    572 	struct linux_dirent idb;
    573 	off_t off;		/* true file offset */
    574 	int buflen, error, eofflag, nbytes, oldcall;
    575 	struct vattr va;
    576 	off_t *cookiebuf = NULL, *cookie;
    577 	int ncookies;
    578 
    579 	/* getvnode() will use the descriptor for us */
    580 	if ((error = getvnode(p->p_fd, SCARG(uap, fd), &fp)) != 0)
    581 		return (error);
    582 
    583 	if ((fp->f_flag & FREAD) == 0) {
    584 		error = EBADF;
    585 		goto out1;
    586 	}
    587 
    588 	vp = (struct vnode *)fp->f_data;
    589 	if (vp->v_type != VDIR) {
    590 		error = EINVAL;
    591 		goto out1;
    592 	}
    593 
    594 	if ((error = VOP_GETATTR(vp, &va, p->p_ucred, p)))
    595 		goto out1;
    596 
    597 	nbytes = SCARG(uap, count);
    598 	if (nbytes == 1) {	/* emulating old, broken behaviour */
    599 		nbytes = sizeof (struct linux_dirent);
    600 		buflen = max(va.va_blocksize, nbytes);
    601 		oldcall = 1;
    602 	} else {
    603 		buflen = min(MAXBSIZE, nbytes);
    604 		if (buflen < va.va_blocksize)
    605 			buflen = va.va_blocksize;
    606 		oldcall = 0;
    607 	}
    608 	buf = malloc(buflen, M_TEMP, M_WAITOK);
    609 
    610 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    611 	off = fp->f_offset;
    612 again:
    613 	aiov.iov_base = buf;
    614 	aiov.iov_len = buflen;
    615 	auio.uio_iov = &aiov;
    616 	auio.uio_iovcnt = 1;
    617 	auio.uio_rw = UIO_READ;
    618 	auio.uio_segflg = UIO_SYSSPACE;
    619 	auio.uio_procp = p;
    620 	auio.uio_resid = buflen;
    621 	auio.uio_offset = off;
    622 	/*
    623          * First we read into the malloc'ed buffer, then
    624          * we massage it into user space, one record at a time.
    625          */
    626 	error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf,
    627 	    &ncookies);
    628 	if (error)
    629 		goto out;
    630 
    631 	inp = buf;
    632 	outp = (caddr_t)SCARG(uap, dent);
    633 	resid = nbytes;
    634 	if ((len = buflen - auio.uio_resid) == 0)
    635 		goto eof;
    636 
    637 	for (cookie = cookiebuf; len > 0; len -= reclen) {
    638 		bdp = (struct dirent *)inp;
    639 		reclen = bdp->d_reclen;
    640 		if (reclen & 3)
    641 			panic("linux_readdir");
    642 		if (bdp->d_fileno == 0) {
    643 			inp += reclen;	/* it is a hole; squish it out */
    644 			off = *cookie++;
    645 			continue;
    646 		}
    647 		linux_reclen = LINUX_RECLEN(&idb, bdp->d_namlen);
    648 		if (reclen > len || resid < linux_reclen) {
    649 			/* entry too big for buffer, so just stop */
    650 			outp++;
    651 			break;
    652 		}
    653 		/*
    654 		 * Massage in place to make a Linux-shaped dirent (otherwise
    655 		 * we have to worry about touching user memory outside of
    656 		 * the copyout() call).
    657 		 */
    658 		idb.d_ino = (linux_ino_t)bdp->d_fileno;
    659 		/*
    660 		 * The old readdir() call misuses the offset and reclen fields.
    661 		 */
    662 		if (oldcall) {
    663 			idb.d_off = (linux_off_t)linux_reclen;
    664 			idb.d_reclen = (u_short)bdp->d_namlen;
    665 		} else {
    666 			if (sizeof (linux_off_t) < 4 && (off >> 32) != 0) {
    667 				compat_offseterr(vp, "linux_getdents");
    668 				error = EINVAL;
    669 				goto out;
    670 			}
    671 			idb.d_off = (linux_off_t)off;
    672 			idb.d_reclen = (u_short)linux_reclen;
    673 		}
    674 		strcpy(idb.d_name, bdp->d_name);
    675 		if ((error = copyout((caddr_t)&idb, outp, linux_reclen)))
    676 			goto out;
    677 		/* advance past this real entry */
    678 		inp += reclen;
    679 		off = *cookie++;	/* each entry points to itself */
    680 		/* advance output past Linux-shaped entry */
    681 		outp += linux_reclen;
    682 		resid -= linux_reclen;
    683 		if (oldcall)
    684 			break;
    685 	}
    686 
    687 	/* if we squished out the whole block, try again */
    688 	if (outp == (caddr_t)SCARG(uap, dent))
    689 		goto again;
    690 	fp->f_offset = off;	/* update the vnode offset */
    691 
    692 	if (oldcall)
    693 		nbytes = resid + linux_reclen;
    694 
    695 eof:
    696 	*retval = nbytes - resid;
    697 out:
    698 	VOP_UNLOCK(vp, 0);
    699 	if (cookiebuf)
    700 		free(cookiebuf, M_TEMP);
    701 	free(buf, M_TEMP);
    702  out1:
    703 	FILE_UNUSE(fp, p);
    704 	return error;
    705 }
    706 
    707 /*
    708  * Even when just using registers to pass arguments to syscalls you can
    709  * have 5 of them on the i386. So this newer version of select() does
    710  * this.
    711  */
    712 int
    713 linux_sys_select(p, v, retval)
    714 	struct proc *p;
    715 	void *v;
    716 	register_t *retval;
    717 {
    718 	struct linux_sys_select_args /* {
    719 		syscallarg(int) nfds;
    720 		syscallarg(fd_set *) readfds;
    721 		syscallarg(fd_set *) writefds;
    722 		syscallarg(fd_set *) exceptfds;
    723 		syscallarg(struct timeval *) timeout;
    724 	} */ *uap = v;
    725 
    726 	return linux_select1(p, retval, SCARG(uap, nfds), SCARG(uap, readfds),
    727 	    SCARG(uap, writefds), SCARG(uap, exceptfds), SCARG(uap, timeout));
    728 }
    729 
    730 /*
    731  * Common code for the old and new versions of select(). A couple of
    732  * things are important:
    733  * 1) return the amount of time left in the 'timeout' parameter
    734  * 2) select never returns ERESTART on Linux, always return EINTR
    735  */
    736 int
    737 linux_select1(p, retval, nfds, readfds, writefds, exceptfds, timeout)
    738 	struct proc *p;
    739 	register_t *retval;
    740 	int nfds;
    741 	fd_set *readfds, *writefds, *exceptfds;
    742 	struct timeval *timeout;
    743 {
    744 	struct sys_select_args bsa;
    745 	struct timeval tv0, tv1, utv, *tvp;
    746 	caddr_t sg;
    747 	int error;
    748 
    749 	SCARG(&bsa, nd) = nfds;
    750 	SCARG(&bsa, in) = readfds;
    751 	SCARG(&bsa, ou) = writefds;
    752 	SCARG(&bsa, ex) = exceptfds;
    753 	SCARG(&bsa, tv) = timeout;
    754 
    755 	/*
    756 	 * Store current time for computation of the amount of
    757 	 * time left.
    758 	 */
    759 	if (timeout) {
    760 		if ((error = copyin(timeout, &utv, sizeof(utv))))
    761 			return error;
    762 		if (itimerfix(&utv)) {
    763 			/*
    764 			 * The timeval was invalid.  Convert it to something
    765 			 * valid that will act as it does under Linux.
    766 			 */
    767 			sg = stackgap_init(p->p_emul);
    768 			tvp = stackgap_alloc(&sg, sizeof(utv));
    769 			utv.tv_sec += utv.tv_usec / 1000000;
    770 			utv.tv_usec %= 1000000;
    771 			if (utv.tv_usec < 0) {
    772 				utv.tv_sec -= 1;
    773 				utv.tv_usec += 1000000;
    774 			}
    775 			if (utv.tv_sec < 0)
    776 				timerclear(&utv);
    777 			if ((error = copyout(&utv, tvp, sizeof(utv))))
    778 				return error;
    779 			SCARG(&bsa, tv) = tvp;
    780 		}
    781 		microtime(&tv0);
    782 	}
    783 
    784 	error = sys_select(p, &bsa, retval);
    785 	if (error) {
    786 		/*
    787 		 * See fs/select.c in the Linux kernel.  Without this,
    788 		 * Maelstrom doesn't work.
    789 		 */
    790 		if (error == ERESTART)
    791 			error = EINTR;
    792 		return error;
    793 	}
    794 
    795 	if (timeout) {
    796 		if (*retval) {
    797 			/*
    798 			 * Compute how much time was left of the timeout,
    799 			 * by subtracting the current time and the time
    800 			 * before we started the call, and subtracting
    801 			 * that result from the user-supplied value.
    802 			 */
    803 			microtime(&tv1);
    804 			timersub(&tv1, &tv0, &tv1);
    805 			timersub(&utv, &tv1, &utv);
    806 			if (utv.tv_sec < 0)
    807 				timerclear(&utv);
    808 		} else
    809 			timerclear(&utv);
    810 		if ((error = copyout(&utv, timeout, sizeof(utv))))
    811 			return error;
    812 	}
    813 
    814 	return 0;
    815 }
    816 
    817 /*
    818  * Get the process group of a certain process. Look it up
    819  * and return the value.
    820  */
    821 int
    822 linux_sys_getpgid(p, v, retval)
    823 	struct proc *p;
    824 	void *v;
    825 	register_t *retval;
    826 {
    827 	struct linux_sys_getpgid_args /* {
    828 		syscallarg(int) pid;
    829 	} */ *uap = v;
    830 	struct proc *targp;
    831 
    832 	if (SCARG(uap, pid) != 0 && SCARG(uap, pid) != p->p_pid) {
    833 		if ((targp = pfind(SCARG(uap, pid))) == 0)
    834 			return ESRCH;
    835 	}
    836 	else
    837 		targp = p;
    838 
    839 	retval[0] = targp->p_pgid;
    840 	return 0;
    841 }
    842 
    843 /*
    844  * Set the 'personality' (emulation mode) for the current process. Only
    845  * accept the Linux personality here (0). This call is needed because
    846  * the Linux ELF crt0 issues it in an ugly kludge to make sure that
    847  * ELF binaries run in Linux mode, not SVR4 mode.
    848  */
    849 int
    850 linux_sys_personality(p, v, retval)
    851 	struct proc *p;
    852 	void *v;
    853 	register_t *retval;
    854 {
    855 	struct linux_sys_personality_args /* {
    856 		syscallarg(int) per;
    857 	} */ *uap = v;
    858 
    859 	if (SCARG(uap, per) != 0)
    860 		return EINVAL;
    861 	retval[0] = 0;
    862 	return 0;
    863 }
    864 
    865 /*
    866  * The calls are here because of type conversions.
    867  */
    868 int
    869 linux_sys_setreuid(p, v, retval)
    870 	struct proc *p;
    871 	void *v;
    872 	register_t *retval;
    873 {
    874 	struct linux_sys_setreuid_args /* {
    875 		syscallarg(int) ruid;
    876 		syscallarg(int) euid;
    877 	} */ *uap = v;
    878 	struct sys_setreuid_args bsa;
    879 
    880 	SCARG(&bsa, ruid) = ((linux_uid_t)SCARG(uap, ruid) == (linux_uid_t)-1) ?
    881 		(uid_t)-1 : SCARG(uap, ruid);
    882 	SCARG(&bsa, euid) = ((linux_uid_t)SCARG(uap, euid) == (linux_uid_t)-1) ?
    883 		(uid_t)-1 : SCARG(uap, euid);
    884 
    885 	return sys_setreuid(p, &bsa, retval);
    886 }
    887 
    888 int
    889 linux_sys_setregid(p, v, retval)
    890 	struct proc *p;
    891 	void *v;
    892 	register_t *retval;
    893 {
    894 	struct linux_sys_setregid_args /* {
    895 		syscallarg(int) rgid;
    896 		syscallarg(int) egid;
    897 	} */ *uap = v;
    898 	struct sys_setregid_args bsa;
    899 
    900 	SCARG(&bsa, rgid) = ((linux_gid_t)SCARG(uap, rgid) == (linux_gid_t)-1) ?
    901 		(uid_t)-1 : SCARG(uap, rgid);
    902 	SCARG(&bsa, egid) = ((linux_gid_t)SCARG(uap, egid) == (linux_gid_t)-1) ?
    903 		(uid_t)-1 : SCARG(uap, egid);
    904 
    905 	return sys_setregid(p, &bsa, retval);
    906 }
    907 
    908 /*
    909  * We have nonexistent fsuid equal to uid.
    910  * If modification is requested, refuse.
    911  */
    912 int
    913 linux_sys_setfsuid(p, v, retval)
    914 	 struct proc *p;
    915 	 void *v;
    916 	 register_t *retval;
    917 {
    918 	 struct linux_sys_setfsuid_args /* {
    919 		 syscallarg(uid_t) uid;
    920 	 } */ *uap = v;
    921 	 uid_t uid;
    922 
    923 	 uid = SCARG(uap, uid);
    924 	 if (p->p_cred->p_ruid != uid)
    925 		 return sys_nosys(p, v, retval);
    926 	 else
    927 		 return (0);
    928 }
    929 
    930 /* XXX XXX XXX */
    931 #ifndef alpha
    932 int
    933 linux_sys_getfsuid(p, v, retval)
    934 	struct proc *p;
    935 	void *v;
    936 	register_t *retval;
    937 {
    938 	return sys_getuid(p, v, retval);
    939 }
    940 #endif
    941 
    942 int
    943 linux_sys___sysctl(p, v, retval)
    944 	struct proc *p;
    945 	void *v;
    946 	register_t *retval;
    947 {
    948 	struct linux_sys___sysctl_args /* {
    949 		syscallarg(struct linux___sysctl *) lsp;
    950 	} */ *uap = v;
    951 	struct linux___sysctl ls;
    952 	struct sys___sysctl_args bsa;
    953 	int error;
    954 
    955 	if ((error = copyin(SCARG(uap, lsp), &ls, sizeof ls)))
    956 		return error;
    957 	SCARG(&bsa, name) = ls.name;
    958 	SCARG(&bsa, namelen) = ls.namelen;
    959 	SCARG(&bsa, old) = ls.old;
    960 	SCARG(&bsa, oldlenp) = ls.oldlenp;
    961 	SCARG(&bsa, new) = ls.new;
    962 	SCARG(&bsa, newlen) = ls.newlen;
    963 
    964 	return sys___sysctl(p, &bsa, retval);
    965 }
    966 
    967 int
    968 linux_sys_setresuid(p, v, retval)
    969 	struct proc *p;
    970 	void *v;
    971 	register_t *retval;
    972 {
    973 	struct linux_sys_setresuid_args /* {
    974 		syscallarg(uid_t) ruid;
    975 		syscallarg(uid_t) euid;
    976 		syscallarg(uid_t) suid;
    977 	} */ *uap = v;
    978 	struct pcred *pc = p->p_cred;
    979 	uid_t ruid, euid, suid;
    980 	int error;
    981 
    982 	ruid = SCARG(uap, ruid);
    983 	euid = SCARG(uap, euid);
    984 	suid = SCARG(uap, suid);
    985 
    986 	/*
    987 	 * Note: These checks are a little different than the NetBSD
    988 	 * setreuid(2) call performs.  This precisely follows the
    989 	 * behavior of the Linux kernel.
    990 	 */
    991 	if (ruid != (uid_t)-1 &&
    992 	    ruid != pc->p_ruid &&
    993 	    ruid != pc->pc_ucred->cr_uid &&
    994 	    ruid != pc->p_svuid &&
    995 	    (error = suser(pc->pc_ucred, &p->p_acflag)))
    996 		return (error);
    997 
    998 	if (euid != (uid_t)-1 &&
    999 	    euid != pc->p_ruid &&
   1000 	    euid != pc->pc_ucred->cr_uid &&
   1001 	    euid != pc->p_svuid &&
   1002 	    (error = suser(pc->pc_ucred, &p->p_acflag)))
   1003 		return (error);
   1004 
   1005 	if (suid != (uid_t)-1 &&
   1006 	    suid != pc->p_ruid &&
   1007 	    suid != pc->pc_ucred->cr_uid &&
   1008 	    suid != pc->p_svuid &&
   1009 	    (error = suser(pc->pc_ucred, &p->p_acflag)))
   1010 		return (error);
   1011 
   1012 	/*
   1013 	 * Now assign the new real, effective, and saved UIDs.
   1014 	 * Note that Linux, unlike NetBSD in setreuid(2), does not
   1015 	 * set the saved UID in this call unless the user specifies
   1016 	 * it.
   1017 	 */
   1018 	if (ruid != (uid_t)-1) {
   1019 		(void)chgproccnt(pc->p_ruid, -1);
   1020 		(void)chgproccnt(ruid, 1);
   1021 		pc->p_ruid = ruid;
   1022 	}
   1023 
   1024 	if (euid != (uid_t)-1) {
   1025 		pc->pc_ucred = crcopy(pc->pc_ucred);
   1026 		pc->pc_ucred->cr_uid = euid;
   1027 	}
   1028 
   1029 	if (suid != (uid_t)-1)
   1030 		pc->p_svuid = suid;
   1031 
   1032 	if (ruid != (uid_t)-1 && euid != (uid_t)-1 && suid != (uid_t)-1)
   1033 		p->p_flag |= P_SUGID;
   1034 	return (0);
   1035 }
   1036 
   1037 int
   1038 linux_sys_getresuid(p, v, retval)
   1039 	struct proc *p;
   1040 	void *v;
   1041 	register_t *retval;
   1042 {
   1043 	struct linux_sys_getresuid_args /* {
   1044 		syscallarg(uid_t *) ruid;
   1045 		syscallarg(uid_t *) euid;
   1046 		syscallarg(uid_t *) suid;
   1047 	} */ *uap = v;
   1048 	struct pcred *pc = p->p_cred;
   1049 	int error;
   1050 
   1051 	/*
   1052 	 * Linux copies these values out to userspace like so:
   1053 	 *
   1054 	 *	1. Copy out ruid.
   1055 	 *	2. If that succeeds, copy out euid.
   1056 	 *	3. If both of those succeed, copy out suid.
   1057 	 */
   1058 	if ((error = copyout(&pc->p_ruid, SCARG(uap, ruid),
   1059 			     sizeof(uid_t))) != 0)
   1060 		return (error);
   1061 
   1062 	if ((error = copyout(&pc->pc_ucred->cr_uid, SCARG(uap, euid),
   1063 			     sizeof(uid_t))) != 0)
   1064 		return (error);
   1065 
   1066 	return (copyout(&pc->p_svuid, SCARG(uap, suid), sizeof(uid_t)));
   1067 }
   1068 
   1069 int
   1070 linux_sys_ptrace(p, v, retval)
   1071 	struct proc *p;
   1072 	void *v;
   1073 	register_t *retval;
   1074 {
   1075 	struct linux_sys_ptrace_args /* {
   1076 		i386, m68k: T=int
   1077 		alpha: T=long
   1078 		syscallarg(T) request;
   1079 		syscallarg(T) pid;
   1080 		syscallarg(T) addr;
   1081 		syscallarg(T) data;
   1082 	} */ *uap = v;
   1083 	int *ptr, request;
   1084 
   1085 	ptr = linux_ptrace_request_map;
   1086 	request = SCARG(uap, request);
   1087 	while (*ptr != -1)
   1088 		if (*ptr++ == request) {
   1089 			struct sys_ptrace_args pta;
   1090 			caddr_t sg;
   1091 
   1092 			sg = stackgap_init(p->p_emul);
   1093 
   1094 			SCARG(&pta, req) = *ptr;
   1095 			SCARG(&pta, pid) = SCARG(uap, pid);
   1096 			SCARG(&pta, addr) = (caddr_t)SCARG(uap, addr);
   1097 			SCARG(&pta, data) = SCARG(uap, data);
   1098 
   1099 			return sys_ptrace(p, &pta, retval);
   1100 		}
   1101 		else
   1102 			ptr++;
   1103 
   1104 	return LINUX_SYS_PTRACE_ARCH(p, uap, retval);
   1105 }
   1106 
   1107 int
   1108 linux_sys_reboot(struct proc *p, void *v, register_t *retval)
   1109 {
   1110 	struct linux_sys_reboot_args /* {
   1111 		syscallarg(int) magic1;
   1112 		syscallarg(int) magic2;
   1113 		syscallarg(int) cmd;
   1114 		syscallarg(void *) arg;
   1115 	} */ *uap = v;
   1116 	struct sys_reboot_args /* {
   1117 		syscallarg(int) opt;
   1118 		syscallarg(char *) bootstr;
   1119 	} */ sra;
   1120 	int error;
   1121 
   1122 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
   1123 		return(error);
   1124 
   1125 	if (SCARG(uap, magic1) != LINUX_REBOOT_MAGIC1)
   1126 		return(EINVAL);
   1127 	if (SCARG(uap, magic2) != LINUX_REBOOT_MAGIC2 &&
   1128 	    SCARG(uap, magic2) != LINUX_REBOOT_MAGIC2A &&
   1129 	    SCARG(uap, magic2) != LINUX_REBOOT_MAGIC2B)
   1130 		return(EINVAL);
   1131 
   1132 	switch (SCARG(uap, cmd)) {
   1133 	case LINUX_REBOOT_CMD_RESTART:
   1134 		SCARG(&sra, opt) = RB_AUTOBOOT;
   1135 		break;
   1136 	case LINUX_REBOOT_CMD_HALT:
   1137 		SCARG(&sra, opt) = RB_HALT;
   1138 		break;
   1139 	case LINUX_REBOOT_CMD_POWER_OFF:
   1140 		SCARG(&sra, opt) = RB_HALT|RB_POWERDOWN;
   1141 		break;
   1142 	case LINUX_REBOOT_CMD_RESTART2:
   1143 		/* Reboot with an argument. */
   1144 		SCARG(&sra, opt) = RB_AUTOBOOT|RB_STRING;
   1145 		SCARG(&sra, bootstr) = SCARG(uap, arg);
   1146 		break;
   1147 	case LINUX_REBOOT_CMD_CAD_ON:
   1148 		return(EINVAL);	/* We don't implement ctrl-alt-delete */
   1149 	case LINUX_REBOOT_CMD_CAD_OFF:
   1150 		return(0);
   1151 	default:
   1152 		return(EINVAL);
   1153 	}
   1154 
   1155 	return(sys_reboot(p, &sra, retval));
   1156 }
   1157