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linux_misc.c revision 1.138
      1 /*	$NetBSD: linux_misc.c,v 1.138 2005/05/29 22:08:16 christos 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/cdefs.h>
     67 __KERNEL_RCSID(0, "$NetBSD: linux_misc.c,v 1.138 2005/05/29 22:08:16 christos Exp $");
     68 
     69 #include <sys/param.h>
     70 #include <sys/systm.h>
     71 #include <sys/namei.h>
     72 #include <sys/proc.h>
     73 #include <sys/dirent.h>
     74 #include <sys/file.h>
     75 #include <sys/stat.h>
     76 #include <sys/filedesc.h>
     77 #include <sys/ioctl.h>
     78 #include <sys/kernel.h>
     79 #include <sys/malloc.h>
     80 #include <sys/mbuf.h>
     81 #include <sys/mman.h>
     82 #include <sys/mount.h>
     83 #include <sys/reboot.h>
     84 #include <sys/resource.h>
     85 #include <sys/resourcevar.h>
     86 #include <sys/signal.h>
     87 #include <sys/signalvar.h>
     88 #include <sys/socket.h>
     89 #include <sys/time.h>
     90 #include <sys/times.h>
     91 #include <sys/vnode.h>
     92 #include <sys/uio.h>
     93 #include <sys/wait.h>
     94 #include <sys/utsname.h>
     95 #include <sys/unistd.h>
     96 #include <sys/swap.h>		/* for SWAP_ON */
     97 #include <sys/sysctl.h>		/* for KERN_DOMAINNAME */
     98 
     99 #include <sys/ptrace.h>
    100 #include <machine/ptrace.h>
    101 
    102 #include <sys/sa.h>
    103 #include <sys/syscallargs.h>
    104 
    105 #include <compat/linux/common/linux_types.h>
    106 #include <compat/linux/common/linux_signal.h>
    107 
    108 #include <compat/linux/linux_syscallargs.h>
    109 
    110 #include <compat/linux/common/linux_fcntl.h>
    111 #include <compat/linux/common/linux_mmap.h>
    112 #include <compat/linux/common/linux_dirent.h>
    113 #include <compat/linux/common/linux_util.h>
    114 #include <compat/linux/common/linux_misc.h>
    115 #include <compat/linux/common/linux_ptrace.h>
    116 #include <compat/linux/common/linux_reboot.h>
    117 #include <compat/linux/common/linux_emuldata.h>
    118 
    119 const int linux_ptrace_request_map[] = {
    120 	LINUX_PTRACE_TRACEME,	PT_TRACE_ME,
    121 	LINUX_PTRACE_PEEKTEXT,	PT_READ_I,
    122 	LINUX_PTRACE_PEEKDATA,	PT_READ_D,
    123 	LINUX_PTRACE_POKETEXT,	PT_WRITE_I,
    124 	LINUX_PTRACE_POKEDATA,	PT_WRITE_D,
    125 	LINUX_PTRACE_CONT,	PT_CONTINUE,
    126 	LINUX_PTRACE_KILL,	PT_KILL,
    127 	LINUX_PTRACE_ATTACH,	PT_ATTACH,
    128 	LINUX_PTRACE_DETACH,	PT_DETACH,
    129 #ifdef PT_STEP
    130 	LINUX_PTRACE_SINGLESTEP,	PT_STEP,
    131 #endif
    132 	-1
    133 };
    134 
    135 const struct linux_mnttypes linux_fstypes[] = {
    136 	{ MOUNT_FFS,		LINUX_DEFAULT_SUPER_MAGIC	},
    137 	{ MOUNT_NFS,		LINUX_NFS_SUPER_MAGIC 		},
    138 	{ MOUNT_MFS,		LINUX_DEFAULT_SUPER_MAGIC	},
    139 	{ MOUNT_MSDOS,		LINUX_MSDOS_SUPER_MAGIC		},
    140 	{ MOUNT_LFS,		LINUX_DEFAULT_SUPER_MAGIC	},
    141 	{ MOUNT_FDESC,		LINUX_DEFAULT_SUPER_MAGIC	},
    142 	{ MOUNT_PORTAL,		LINUX_DEFAULT_SUPER_MAGIC	},
    143 	{ MOUNT_NULL,		LINUX_DEFAULT_SUPER_MAGIC	},
    144 	{ MOUNT_OVERLAY,	LINUX_DEFAULT_SUPER_MAGIC	},
    145 	{ MOUNT_UMAP,		LINUX_DEFAULT_SUPER_MAGIC	},
    146 	{ MOUNT_KERNFS,		LINUX_DEFAULT_SUPER_MAGIC	},
    147 	{ MOUNT_PROCFS,		LINUX_PROC_SUPER_MAGIC		},
    148 	{ MOUNT_AFS,		LINUX_DEFAULT_SUPER_MAGIC	},
    149 	{ MOUNT_CD9660,		LINUX_ISOFS_SUPER_MAGIC		},
    150 	{ MOUNT_UNION,		LINUX_DEFAULT_SUPER_MAGIC	},
    151 	{ MOUNT_ADOSFS,		LINUX_ADFS_SUPER_MAGIC		},
    152 	{ MOUNT_EXT2FS,		LINUX_EXT2_SUPER_MAGIC		},
    153 	{ MOUNT_CFS,		LINUX_DEFAULT_SUPER_MAGIC	},
    154 	{ MOUNT_CODA,		LINUX_CODA_SUPER_MAGIC		},
    155 	{ MOUNT_FILECORE,	LINUX_DEFAULT_SUPER_MAGIC	},
    156 	{ MOUNT_NTFS,		LINUX_DEFAULT_SUPER_MAGIC	},
    157 	{ MOUNT_SMBFS,		LINUX_SMB_SUPER_MAGIC		},
    158 	{ MOUNT_PTYFS,		LINUX_DEVPTS_SUPER_MAGIC	}
    159 };
    160 const int linux_fstypes_cnt = sizeof(linux_fstypes) / sizeof(linux_fstypes[0]);
    161 
    162 #ifdef DEBUG_LINUX
    163 #define DPRINTF(a)	uprintf a
    164 #else
    165 #define DPRINTF(a)
    166 #endif
    167 
    168 /* Local linux_misc.c functions: */
    169 #ifndef __amd64__
    170 static void bsd_to_linux_statfs __P((const struct statvfs *,
    171     struct linux_statfs *));
    172 #endif
    173 static int linux_to_bsd_limit __P((int));
    174 static void linux_to_bsd_mmap_args __P((struct sys_mmap_args *,
    175     const struct linux_sys_mmap_args *));
    176 static int linux_mmap __P((struct lwp *, struct linux_sys_mmap_args *,
    177     register_t *, off_t));
    178 
    179 
    180 /*
    181  * The information on a terminated (or stopped) process needs
    182  * to be converted in order for Linux binaries to get a valid signal
    183  * number out of it.
    184  */
    185 void
    186 bsd_to_linux_wstat(st)
    187 	int *st;
    188 {
    189 
    190 	int sig;
    191 
    192 	if (WIFSIGNALED(*st)) {
    193 		sig = WTERMSIG(*st);
    194 		if (sig >= 0 && sig < NSIG)
    195 			*st= (*st& ~0177) | native_to_linux_signo[sig];
    196 	} else if (WIFSTOPPED(*st)) {
    197 		sig = WSTOPSIG(*st);
    198 		if (sig >= 0 && sig < NSIG)
    199 			*st = (*st & ~0xff00) |
    200 			    (native_to_linux_signo[sig] << 8);
    201 	}
    202 }
    203 
    204 /*
    205  * wait4(2).  Passed on to the NetBSD call, surrounded by code to
    206  * reserve some space for a NetBSD-style wait status, and converting
    207  * it to what Linux wants.
    208  */
    209 int
    210 linux_sys_wait4(l, v, retval)
    211 	struct lwp *l;
    212 	void *v;
    213 	register_t *retval;
    214 {
    215 	struct linux_sys_wait4_args /* {
    216 		syscallarg(int) pid;
    217 		syscallarg(int *) status;
    218 		syscallarg(int) options;
    219 		syscallarg(struct rusage *) rusage;
    220 	} */ *uap = v;
    221 	struct proc *p = l->l_proc;
    222 	struct sys_wait4_args w4a;
    223 	int error, *status, tstat, options, linux_options;
    224 	caddr_t sg;
    225 
    226 	if (SCARG(uap, status) != NULL) {
    227 		sg = stackgap_init(p, 0);
    228 		status = (int *) stackgap_alloc(p, &sg, sizeof *status);
    229 	} else
    230 		status = NULL;
    231 
    232 	linux_options = SCARG(uap, options);
    233 	options = 0;
    234 	if (linux_options & ~(LINUX_WAIT4_KNOWNFLAGS))
    235 		return (EINVAL);
    236 
    237 	if (linux_options & LINUX_WAIT4_WNOHANG)
    238 		options |= WNOHANG;
    239 	if (linux_options & LINUX_WAIT4_WUNTRACED)
    240 		options |= WUNTRACED;
    241 	if (linux_options & LINUX_WAIT4_WALL)
    242 		options |= WALLSIG;
    243 	if (linux_options & LINUX_WAIT4_WCLONE)
    244 		options |= WALTSIG;
    245 #ifdef DIAGNOSTIC
    246 	if (linux_options & LINUX_WAIT4_WNOTHREAD)
    247 		printf("WARNING: %s: linux process %d.%d called "
    248 		       "waitpid with __WNOTHREAD set!",
    249 		       __FILE__, p->p_pid, l->l_lid);
    250 
    251 #endif
    252 
    253 	SCARG(&w4a, pid) = SCARG(uap, pid);
    254 	SCARG(&w4a, status) = status;
    255 	SCARG(&w4a, options) = options;
    256 	SCARG(&w4a, rusage) = SCARG(uap, rusage);
    257 
    258 	if ((error = sys_wait4(l, &w4a, retval)))
    259 		return error;
    260 
    261 	sigdelset(&p->p_sigctx.ps_siglist, SIGCHLD);
    262 
    263 	if (status != NULL) {
    264 		if ((error = copyin(status, &tstat, sizeof tstat)))
    265 			return error;
    266 
    267 		bsd_to_linux_wstat(&tstat);
    268 		return copyout(&tstat, SCARG(uap, status), sizeof tstat);
    269 	}
    270 
    271 	return 0;
    272 }
    273 
    274 /*
    275  * Linux brk(2). The check if the new address is >= the old one is
    276  * done in the kernel in Linux. NetBSD does it in the library.
    277  */
    278 int
    279 linux_sys_brk(l, v, retval)
    280 	struct lwp *l;
    281 	void *v;
    282 	register_t *retval;
    283 {
    284 	struct linux_sys_brk_args /* {
    285 		syscallarg(char *) nsize;
    286 	} */ *uap = v;
    287 	struct proc *p = l->l_proc;
    288 	char *nbrk = SCARG(uap, nsize);
    289 	struct sys_obreak_args oba;
    290 	struct vmspace *vm = p->p_vmspace;
    291 	struct linux_emuldata *ed = (struct linux_emuldata*)p->p_emuldata;
    292 
    293 	SCARG(&oba, nsize) = nbrk;
    294 
    295 	if ((caddr_t) nbrk > vm->vm_daddr && sys_obreak(l, &oba, retval) == 0)
    296 		ed->s->p_break = (char*)nbrk;
    297 	else
    298 		nbrk = ed->s->p_break;
    299 
    300 	retval[0] = (register_t)nbrk;
    301 
    302 	return 0;
    303 }
    304 
    305 #ifndef __amd64__
    306 /*
    307  * Convert NetBSD statvfs structure to Linux statfs structure.
    308  * Linux doesn't have f_flag, and we can't set f_frsize due
    309  * to glibc statvfs() bug (see below).
    310  */
    311 static void
    312 bsd_to_linux_statfs(bsp, lsp)
    313 	const struct statvfs *bsp;
    314 	struct linux_statfs *lsp;
    315 {
    316 	int i;
    317 
    318 	for (i = 0; i < linux_fstypes_cnt; i++) {
    319 		if (strcmp(bsp->f_fstypename, linux_fstypes[i].bsd) == 0) {
    320 			lsp->l_ftype = linux_fstypes[i].linux;
    321 			break;
    322 		}
    323 	}
    324 
    325 	if (i == linux_fstypes_cnt) {
    326 		DPRINTF(("unhandled fstype in linux emulation: %s\n",
    327 		    bsp->f_fstypename));
    328 		lsp->l_ftype = LINUX_DEFAULT_SUPER_MAGIC;
    329 	}
    330 
    331 	/*
    332 	 * The sizes are expressed in number of blocks. The block
    333 	 * size used for the size is f_frsize for POSIX-compliant
    334 	 * statvfs. Linux statfs uses f_bsize as the block size
    335 	 * (f_frsize used to not be available in Linux struct statfs).
    336 	 * However, glibc 2.3.3 statvfs() wrapper fails to adjust the block
    337 	 * counts for different f_frsize if f_frsize is provided by the kernel.
    338 	 * POSIX conforming apps thus get wrong size if f_frsize
    339 	 * is different to f_bsize. Thus, we just pretend we don't
    340 	 * support f_frsize.
    341 	 */
    342 
    343 	lsp->l_fbsize = bsp->f_frsize;
    344 	lsp->l_ffrsize = 0;			/* compat */
    345 	lsp->l_fblocks = bsp->f_blocks;
    346 	lsp->l_fbfree = bsp->f_bfree;
    347 	lsp->l_fbavail = bsp->f_bavail;
    348 	lsp->l_ffiles = bsp->f_files;
    349 	lsp->l_fffree = bsp->f_ffree;
    350 	/* Linux sets the fsid to 0..., we don't */
    351 	lsp->l_ffsid.val[0] = bsp->f_fsidx.__fsid_val[0];
    352 	lsp->l_ffsid.val[1] = bsp->f_fsidx.__fsid_val[1];
    353 	lsp->l_fnamelen = bsp->f_namemax;
    354 	(void)memset(lsp->l_fspare, 0, sizeof(lsp->l_fspare));
    355 }
    356 
    357 /*
    358  * Implement the fs stat functions. Straightforward.
    359  */
    360 int
    361 linux_sys_statfs(l, v, retval)
    362 	struct lwp *l;
    363 	void *v;
    364 	register_t *retval;
    365 {
    366 	struct linux_sys_statfs_args /* {
    367 		syscallarg(const char *) path;
    368 		syscallarg(struct linux_statfs *) sp;
    369 	} */ *uap = v;
    370 	struct proc *p = l->l_proc;
    371 	struct statvfs btmp, *bsp;
    372 	struct linux_statfs ltmp;
    373 	struct sys_statvfs1_args bsa;
    374 	caddr_t sg;
    375 	int error;
    376 
    377 	sg = stackgap_init(p, 0);
    378 	bsp = (struct statvfs *) stackgap_alloc(p, &sg, sizeof (struct statvfs));
    379 
    380 	CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
    381 
    382 	SCARG(&bsa, path) = SCARG(uap, path);
    383 	SCARG(&bsa, buf) = bsp;
    384 	SCARG(&bsa, flags) = ST_WAIT;
    385 
    386 	if ((error = sys_statvfs1(l, &bsa, retval)))
    387 		return error;
    388 
    389 	if ((error = copyin((caddr_t) bsp, (caddr_t) &btmp, sizeof btmp)))
    390 		return error;
    391 
    392 	bsd_to_linux_statfs(&btmp, &ltmp);
    393 
    394 	return copyout((caddr_t) &ltmp, (caddr_t) SCARG(uap, sp), sizeof ltmp);
    395 }
    396 
    397 int
    398 linux_sys_fstatfs(l, v, retval)
    399 	struct lwp *l;
    400 	void *v;
    401 	register_t *retval;
    402 {
    403 	struct linux_sys_fstatfs_args /* {
    404 		syscallarg(int) fd;
    405 		syscallarg(struct linux_statfs *) sp;
    406 	} */ *uap = v;
    407 	struct proc *p = l->l_proc;
    408 	struct statvfs btmp, *bsp;
    409 	struct linux_statfs ltmp;
    410 	struct sys_fstatvfs1_args bsa;
    411 	caddr_t sg;
    412 	int error;
    413 
    414 	sg = stackgap_init(p, 0);
    415 	bsp = (struct statvfs *) stackgap_alloc(p, &sg, sizeof (struct statvfs));
    416 
    417 	SCARG(&bsa, fd) = SCARG(uap, fd);
    418 	SCARG(&bsa, buf) = bsp;
    419 	SCARG(&bsa, flags) = ST_WAIT;
    420 
    421 	if ((error = sys_fstatvfs1(l, &bsa, retval)))
    422 		return error;
    423 
    424 	if ((error = copyin((caddr_t) bsp, (caddr_t) &btmp, sizeof btmp)))
    425 		return error;
    426 
    427 	bsd_to_linux_statfs(&btmp, &ltmp);
    428 
    429 	return copyout((caddr_t) &ltmp, (caddr_t) SCARG(uap, sp), sizeof ltmp);
    430 }
    431 #endif /* __amd64__ */
    432 
    433 /*
    434  * uname(). Just copy the info from the various strings stored in the
    435  * kernel, and put it in the Linux utsname structure. That structure
    436  * is almost the same as the NetBSD one, only it has fields 65 characters
    437  * long, and an extra domainname field.
    438  */
    439 int
    440 linux_sys_uname(l, v, retval)
    441 	struct lwp *l;
    442 	void *v;
    443 	register_t *retval;
    444 {
    445 	struct linux_sys_uname_args /* {
    446 		syscallarg(struct linux_utsname *) up;
    447 	} */ *uap = v;
    448 	struct linux_utsname luts;
    449 
    450 	strncpy(luts.l_sysname, linux_sysname, sizeof(luts.l_sysname));
    451 	strncpy(luts.l_nodename, hostname, sizeof(luts.l_nodename));
    452 	strncpy(luts.l_release, linux_release, sizeof(luts.l_release));
    453 	strncpy(luts.l_version, linux_version, sizeof(luts.l_version));
    454 	strncpy(luts.l_machine, machine, sizeof(luts.l_machine));
    455 	strncpy(luts.l_domainname, domainname, sizeof(luts.l_domainname));
    456 
    457 	return copyout(&luts, SCARG(uap, up), sizeof(luts));
    458 }
    459 
    460 /* Used directly on: alpha, mips, ppc, sparc, sparc64 */
    461 /* Used indirectly on: arm, i386, m68k */
    462 
    463 /*
    464  * New type Linux mmap call.
    465  * Only called directly on machines with >= 6 free regs.
    466  */
    467 int
    468 linux_sys_mmap(l, v, retval)
    469 	struct lwp *l;
    470 	void *v;
    471 	register_t *retval;
    472 {
    473 	struct linux_sys_mmap_args /* {
    474 		syscallarg(unsigned long) addr;
    475 		syscallarg(size_t) len;
    476 		syscallarg(int) prot;
    477 		syscallarg(int) flags;
    478 		syscallarg(int) fd;
    479 		syscallarg(linux_off_t) offset;
    480 	} */ *uap = v;
    481 
    482 	if (SCARG(uap, offset) & PAGE_MASK)
    483 		return EINVAL;
    484 
    485 	return linux_mmap(l, uap, retval, SCARG(uap, offset));
    486 }
    487 
    488 /*
    489  * Guts of most architectures' mmap64() implementations.  This shares
    490  * its list of arguments with linux_sys_mmap().
    491  *
    492  * The difference in linux_sys_mmap2() is that "offset" is actually
    493  * (offset / pagesize), not an absolute byte count.  This translation
    494  * to pagesize offsets is done inside glibc between the mmap64() call
    495  * point, and the actual syscall.
    496  */
    497 int
    498 linux_sys_mmap2(l, v, retval)
    499 	struct lwp *l;
    500 	void *v;
    501 	register_t *retval;
    502 {
    503 	struct linux_sys_mmap2_args /* {
    504 		syscallarg(unsigned long) addr;
    505 		syscallarg(size_t) len;
    506 		syscallarg(int) prot;
    507 		syscallarg(int) flags;
    508 		syscallarg(int) fd;
    509 		syscallarg(linux_off_t) offset;
    510 	} */ *uap = v;
    511 
    512 	return linux_mmap(l, uap, retval,
    513 	    ((off_t)SCARG(uap, offset)) << PAGE_SHIFT);
    514 }
    515 
    516 /*
    517  * Massage arguments and call system mmap(2).
    518  */
    519 static int
    520 linux_mmap(l, uap, retval, offset)
    521 	struct lwp *l;
    522 	struct linux_sys_mmap_args *uap;
    523 	register_t *retval;
    524 	off_t offset;
    525 {
    526 	struct sys_mmap_args cma;
    527 	int error;
    528 	size_t mmoff=0;
    529 
    530 	if (SCARG(uap, flags) & LINUX_MAP_GROWSDOWN) {
    531 		/*
    532 		 * Request for stack-like memory segment. On linux, this
    533 		 * works by mmap()ping (small) segment, which is automatically
    534 		 * extended when page fault happens below the currently
    535 		 * allocated area. We emulate this by allocating (typically
    536 		 * bigger) segment sized at current stack size limit, and
    537 		 * offsetting the requested and returned address accordingly.
    538 		 * Since physical pages are only allocated on-demand, this
    539 		 * is effectively identical.
    540 		 */
    541 		rlim_t ssl = l->l_proc->p_rlimit[RLIMIT_STACK].rlim_cur;
    542 
    543 		if (SCARG(uap, len) < ssl) {
    544 			/* Compute the address offset */
    545 			mmoff = round_page(ssl) - SCARG(uap, len);
    546 
    547 			if (SCARG(uap, addr))
    548 				SCARG(uap, addr) -= mmoff;
    549 
    550 			SCARG(uap, len) = (size_t) ssl;
    551 		}
    552 	}
    553 
    554 	linux_to_bsd_mmap_args(&cma, uap);
    555 	SCARG(&cma, pos) = offset;
    556 
    557 	error = sys_mmap(l, &cma, retval);
    558 	if (error)
    559 		return (error);
    560 
    561 	/* Shift the returned address for stack-like segment if necessary */
    562 	if (SCARG(uap, flags) & LINUX_MAP_GROWSDOWN && mmoff)
    563 		retval[0] += mmoff;
    564 
    565 	return (0);
    566 }
    567 
    568 static void
    569 linux_to_bsd_mmap_args(cma, uap)
    570 	struct sys_mmap_args *cma;
    571 	const struct linux_sys_mmap_args *uap;
    572 {
    573 	int flags = MAP_TRYFIXED, fl = SCARG(uap, flags);
    574 
    575 	flags |= cvtto_bsd_mask(fl, LINUX_MAP_SHARED, MAP_SHARED);
    576 	flags |= cvtto_bsd_mask(fl, LINUX_MAP_PRIVATE, MAP_PRIVATE);
    577 	flags |= cvtto_bsd_mask(fl, LINUX_MAP_FIXED, MAP_FIXED);
    578 	flags |= cvtto_bsd_mask(fl, LINUX_MAP_ANON, MAP_ANON);
    579 	/* XXX XAX ERH: Any other flags here?  There are more defined... */
    580 
    581 	SCARG(cma, addr) = (void *)SCARG(uap, addr);
    582 	SCARG(cma, len) = SCARG(uap, len);
    583 	SCARG(cma, prot) = SCARG(uap, prot);
    584 	if (SCARG(cma, prot) & VM_PROT_WRITE) /* XXX */
    585 		SCARG(cma, prot) |= VM_PROT_READ;
    586 	SCARG(cma, flags) = flags;
    587 	SCARG(cma, fd) = flags & MAP_ANON ? -1 : SCARG(uap, fd);
    588 	SCARG(cma, pad) = 0;
    589 }
    590 
    591 int
    592 linux_sys_mremap(l, v, retval)
    593 	struct lwp *l;
    594 	void *v;
    595 	register_t *retval;
    596 {
    597 	struct linux_sys_mremap_args /* {
    598 		syscallarg(void *) old_address;
    599 		syscallarg(size_t) old_size;
    600 		syscallarg(size_t) new_size;
    601 		syscallarg(u_long) flags;
    602 	} */ *uap = v;
    603 	struct sys_munmap_args mua;
    604 	size_t old_size, new_size;
    605 	int error;
    606 
    607 	old_size = round_page(SCARG(uap, old_size));
    608 	new_size = round_page(SCARG(uap, new_size));
    609 
    610 	/*
    611 	 * Growing mapped region.
    612 	 */
    613 	if (new_size > old_size) {
    614 		/*
    615 		 * XXX Implement me.  What we probably want to do is
    616 		 * XXX dig out the guts of the old mapping, mmap that
    617 		 * XXX object again with the new size, then munmap
    618 		 * XXX the old mapping.
    619 		 */
    620 		*retval = 0;
    621 		return (ENOMEM);
    622 	}
    623 
    624 	/*
    625 	 * Shrinking mapped region.
    626 	 */
    627 	if (new_size < old_size) {
    628 		SCARG(&mua, addr) = (caddr_t)SCARG(uap, old_address) +
    629 		    new_size;
    630 		SCARG(&mua, len) = old_size - new_size;
    631 		error = sys_munmap(l, &mua, retval);
    632 		*retval = error ? 0 : (register_t)SCARG(uap, old_address);
    633 		return (error);
    634 	}
    635 
    636 	/*
    637 	 * No change.
    638 	 */
    639 	*retval = (register_t)SCARG(uap, old_address);
    640 	return (0);
    641 }
    642 
    643 int
    644 linux_sys_msync(l, v, retval)
    645 	struct lwp *l;
    646 	void *v;
    647 	register_t *retval;
    648 {
    649 	struct linux_sys_msync_args /* {
    650 		syscallarg(caddr_t) addr;
    651 		syscallarg(int) len;
    652 		syscallarg(int) fl;
    653 	} */ *uap = v;
    654 
    655 	struct sys___msync13_args bma;
    656 
    657 	/* flags are ignored */
    658 	SCARG(&bma, addr) = SCARG(uap, addr);
    659 	SCARG(&bma, len) = SCARG(uap, len);
    660 	SCARG(&bma, flags) = SCARG(uap, fl);
    661 
    662 	return sys___msync13(l, &bma, retval);
    663 }
    664 
    665 int
    666 linux_sys_mprotect(l, v, retval)
    667 	struct lwp *l;
    668 	void *v;
    669 	register_t *retval;
    670 {
    671 	struct linux_sys_mprotect_args /* {
    672 		syscallarg(const void *) start;
    673 		syscallarg(unsigned long) len;
    674 		syscallarg(int) prot;
    675 	} */ *uap = v;
    676 	unsigned long end, start = (unsigned long)SCARG(uap, start), len;
    677 	int prot = SCARG(uap, prot);
    678 	struct vm_map_entry *entry;
    679 	struct vm_map *map = &l->l_proc->p_vmspace->vm_map;
    680 
    681 	if (start & PAGE_MASK)
    682 		return EINVAL;
    683 
    684 	len = round_page(SCARG(uap, len));
    685 	end = start + len;
    686 
    687 	if (end < start)
    688 		return EINVAL;
    689 	else if (end == start)
    690 		return 0;
    691 
    692 	if (SCARG(uap, prot) & ~(PROT_READ | PROT_WRITE | PROT_EXEC))
    693 		return EINVAL;
    694 
    695 	vm_map_lock(map);
    696 #ifdef notdef
    697 	VM_MAP_RANGE_CHECK(map, start, end);
    698 #endif
    699 	if (!uvm_map_lookup_entry(map, start, &entry) || entry->start > start) {
    700 		vm_map_unlock(map);
    701 		return ENOMEM;
    702 	}
    703 	vm_map_unlock(map);
    704 	return uvm_map_protect(map, start, end, prot, FALSE);
    705 }
    706 
    707 /*
    708  * This code is partly stolen from src/lib/libc/compat-43/times.c
    709  */
    710 
    711 #define	CONVTCK(r)	(r.tv_sec * hz + r.tv_usec / (1000000 / hz))
    712 
    713 int
    714 linux_sys_times(l, v, retval)
    715 	struct lwp *l;
    716 	void *v;
    717 	register_t *retval;
    718 {
    719 	struct linux_sys_times_args /* {
    720 		syscallarg(struct times *) tms;
    721 	} */ *uap = v;
    722 	struct proc *p = l->l_proc;
    723 	struct timeval t;
    724 	int error, s;
    725 
    726 	if (SCARG(uap, tms)) {
    727 		struct linux_tms ltms;
    728 		struct rusage ru;
    729 
    730 		calcru(p, &ru.ru_utime, &ru.ru_stime, NULL);
    731 		ltms.ltms_utime = CONVTCK(ru.ru_utime);
    732 		ltms.ltms_stime = CONVTCK(ru.ru_stime);
    733 
    734 		ltms.ltms_cutime = CONVTCK(p->p_stats->p_cru.ru_utime);
    735 		ltms.ltms_cstime = CONVTCK(p->p_stats->p_cru.ru_stime);
    736 
    737 		if ((error = copyout(&ltms, SCARG(uap, tms), sizeof ltms)))
    738 			return error;
    739 	}
    740 
    741 	s = splclock();
    742 	timersub(&time, &boottime, &t);
    743 	splx(s);
    744 
    745 	retval[0] = ((linux_clock_t)(CONVTCK(t)));
    746 	return 0;
    747 }
    748 
    749 #undef CONVTCK
    750 
    751 /*
    752  * Linux 'readdir' call. This code is mostly taken from the
    753  * SunOS getdents call (see compat/sunos/sunos_misc.c), though
    754  * an attempt has been made to keep it a little cleaner (failing
    755  * miserably, because of the cruft needed if count 1 is passed).
    756  *
    757  * The d_off field should contain the offset of the next valid entry,
    758  * but in Linux it has the offset of the entry itself. We emulate
    759  * that bug here.
    760  *
    761  * Read in BSD-style entries, convert them, and copy them out.
    762  *
    763  * Note that this doesn't handle union-mounted filesystems.
    764  */
    765 int
    766 linux_sys_getdents(l, v, retval)
    767 	struct lwp *l;
    768 	void *v;
    769 	register_t *retval;
    770 {
    771 	struct linux_sys_getdents_args /* {
    772 		syscallarg(int) fd;
    773 		syscallarg(struct linux_dirent *) dent;
    774 		syscallarg(unsigned int) count;
    775 	} */ *uap = v;
    776 	struct proc *p = l->l_proc;
    777 	struct dirent *bdp;
    778 	struct vnode *vp;
    779 	caddr_t	inp, tbuf;		/* BSD-format */
    780 	int len, reclen;		/* BSD-format */
    781 	caddr_t outp;			/* Linux-format */
    782 	int resid, linux_reclen = 0;	/* Linux-format */
    783 	struct file *fp;
    784 	struct uio auio;
    785 	struct iovec aiov;
    786 	struct linux_dirent idb;
    787 	off_t off;		/* true file offset */
    788 	int buflen, error, eofflag, nbytes, oldcall;
    789 	struct vattr va;
    790 	off_t *cookiebuf = NULL, *cookie;
    791 	int ncookies;
    792 
    793 	/* getvnode() will use the descriptor for us */
    794 	if ((error = getvnode(p->p_fd, SCARG(uap, fd), &fp)) != 0)
    795 		return (error);
    796 
    797 	if ((fp->f_flag & FREAD) == 0) {
    798 		error = EBADF;
    799 		goto out1;
    800 	}
    801 
    802 	vp = (struct vnode *)fp->f_data;
    803 	if (vp->v_type != VDIR) {
    804 		error = EINVAL;
    805 		goto out1;
    806 	}
    807 
    808 	if ((error = VOP_GETATTR(vp, &va, p->p_ucred, p)))
    809 		goto out1;
    810 
    811 	nbytes = SCARG(uap, count);
    812 	if (nbytes == 1) {	/* emulating old, broken behaviour */
    813 		nbytes = sizeof (idb);
    814 		buflen = max(va.va_blocksize, nbytes);
    815 		oldcall = 1;
    816 	} else {
    817 		buflen = min(MAXBSIZE, nbytes);
    818 		if (buflen < va.va_blocksize)
    819 			buflen = va.va_blocksize;
    820 		oldcall = 0;
    821 	}
    822 	tbuf = malloc(buflen, M_TEMP, M_WAITOK);
    823 
    824 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    825 	off = fp->f_offset;
    826 again:
    827 	aiov.iov_base = tbuf;
    828 	aiov.iov_len = buflen;
    829 	auio.uio_iov = &aiov;
    830 	auio.uio_iovcnt = 1;
    831 	auio.uio_rw = UIO_READ;
    832 	auio.uio_segflg = UIO_SYSSPACE;
    833 	auio.uio_procp = NULL;
    834 	auio.uio_resid = buflen;
    835 	auio.uio_offset = off;
    836 	/*
    837          * First we read into the malloc'ed buffer, then
    838          * we massage it into user space, one record at a time.
    839          */
    840 	error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf,
    841 	    &ncookies);
    842 	if (error)
    843 		goto out;
    844 
    845 	inp = tbuf;
    846 	outp = (caddr_t)SCARG(uap, dent);
    847 	resid = nbytes;
    848 	if ((len = buflen - auio.uio_resid) == 0)
    849 		goto eof;
    850 
    851 	for (cookie = cookiebuf; len > 0; len -= reclen) {
    852 		bdp = (struct dirent *)inp;
    853 		reclen = bdp->d_reclen;
    854 		if (reclen & 3)
    855 			panic("linux_readdir");
    856 		if (bdp->d_fileno == 0) {
    857 			inp += reclen;	/* it is a hole; squish it out */
    858 			if (cookie)
    859 				off = *cookie++;
    860 			else
    861 				off += reclen;
    862 			continue;
    863 		}
    864 		linux_reclen = LINUX_RECLEN(&idb, bdp->d_namlen);
    865 		if (reclen > len || resid < linux_reclen) {
    866 			/* entry too big for buffer, so just stop */
    867 			outp++;
    868 			break;
    869 		}
    870 		/*
    871 		 * Massage in place to make a Linux-shaped dirent (otherwise
    872 		 * we have to worry about touching user memory outside of
    873 		 * the copyout() call).
    874 		 */
    875 		idb.d_ino = bdp->d_fileno;
    876 		/*
    877 		 * The old readdir() call misuses the offset and reclen fields.
    878 		 */
    879 		if (oldcall) {
    880 			idb.d_off = (linux_off_t)linux_reclen;
    881 			idb.d_reclen = (u_short)bdp->d_namlen;
    882 		} else {
    883 			if (sizeof (idb.d_off) <= 4 && (off >> 32) != 0) {
    884 				compat_offseterr(vp, "linux_getdents");
    885 				error = EINVAL;
    886 				goto out;
    887 			}
    888 			idb.d_off = (linux_off_t)off;
    889 			idb.d_reclen = (u_short)linux_reclen;
    890 		}
    891 		strcpy(idb.d_name, bdp->d_name);
    892 		if ((error = copyout((caddr_t)&idb, outp, linux_reclen)))
    893 			goto out;
    894 		/* advance past this real entry */
    895 		inp += reclen;
    896 		if (cookie)
    897 			off = *cookie++; /* each entry points to itself */
    898 		else
    899 			off += reclen;
    900 		/* advance output past Linux-shaped entry */
    901 		outp += linux_reclen;
    902 		resid -= linux_reclen;
    903 		if (oldcall)
    904 			break;
    905 	}
    906 
    907 	/* if we squished out the whole block, try again */
    908 	if (outp == (caddr_t)SCARG(uap, dent))
    909 		goto again;
    910 	fp->f_offset = off;	/* update the vnode offset */
    911 
    912 	if (oldcall)
    913 		nbytes = resid + linux_reclen;
    914 
    915 eof:
    916 	*retval = nbytes - resid;
    917 out:
    918 	VOP_UNLOCK(vp, 0);
    919 	if (cookiebuf)
    920 		free(cookiebuf, M_TEMP);
    921 	free(tbuf, M_TEMP);
    922 out1:
    923 	FILE_UNUSE(fp, p);
    924 	return error;
    925 }
    926 
    927 /*
    928  * Even when just using registers to pass arguments to syscalls you can
    929  * have 5 of them on the i386. So this newer version of select() does
    930  * this.
    931  */
    932 int
    933 linux_sys_select(l, v, retval)
    934 	struct lwp *l;
    935 	void *v;
    936 	register_t *retval;
    937 {
    938 	struct linux_sys_select_args /* {
    939 		syscallarg(int) nfds;
    940 		syscallarg(fd_set *) readfds;
    941 		syscallarg(fd_set *) writefds;
    942 		syscallarg(fd_set *) exceptfds;
    943 		syscallarg(struct timeval *) timeout;
    944 	} */ *uap = v;
    945 
    946 	return linux_select1(l, retval, SCARG(uap, nfds), SCARG(uap, readfds),
    947 	    SCARG(uap, writefds), SCARG(uap, exceptfds), SCARG(uap, timeout));
    948 }
    949 
    950 /*
    951  * Common code for the old and new versions of select(). A couple of
    952  * things are important:
    953  * 1) return the amount of time left in the 'timeout' parameter
    954  * 2) select never returns ERESTART on Linux, always return EINTR
    955  */
    956 int
    957 linux_select1(l, retval, nfds, readfds, writefds, exceptfds, timeout)
    958 	struct lwp *l;
    959 	register_t *retval;
    960 	int nfds;
    961 	fd_set *readfds, *writefds, *exceptfds;
    962 	struct timeval *timeout;
    963 {
    964 	struct sys_select_args bsa;
    965 	struct proc *p = l->l_proc;
    966 	struct timeval tv0, tv1, utv, *tvp;
    967 	caddr_t sg;
    968 	int error;
    969 
    970 	SCARG(&bsa, nd) = nfds;
    971 	SCARG(&bsa, in) = readfds;
    972 	SCARG(&bsa, ou) = writefds;
    973 	SCARG(&bsa, ex) = exceptfds;
    974 	SCARG(&bsa, tv) = timeout;
    975 
    976 	/*
    977 	 * Store current time for computation of the amount of
    978 	 * time left.
    979 	 */
    980 	if (timeout) {
    981 		if ((error = copyin(timeout, &utv, sizeof(utv))))
    982 			return error;
    983 		if (itimerfix(&utv)) {
    984 			/*
    985 			 * The timeval was invalid.  Convert it to something
    986 			 * valid that will act as it does under Linux.
    987 			 */
    988 			sg = stackgap_init(p, 0);
    989 			tvp = stackgap_alloc(p, &sg, sizeof(utv));
    990 			utv.tv_sec += utv.tv_usec / 1000000;
    991 			utv.tv_usec %= 1000000;
    992 			if (utv.tv_usec < 0) {
    993 				utv.tv_sec -= 1;
    994 				utv.tv_usec += 1000000;
    995 			}
    996 			if (utv.tv_sec < 0)
    997 				timerclear(&utv);
    998 			if ((error = copyout(&utv, tvp, sizeof(utv))))
    999 				return error;
   1000 			SCARG(&bsa, tv) = tvp;
   1001 		}
   1002 		microtime(&tv0);
   1003 	}
   1004 
   1005 	error = sys_select(l, &bsa, retval);
   1006 	if (error) {
   1007 		/*
   1008 		 * See fs/select.c in the Linux kernel.  Without this,
   1009 		 * Maelstrom doesn't work.
   1010 		 */
   1011 		if (error == ERESTART)
   1012 			error = EINTR;
   1013 		return error;
   1014 	}
   1015 
   1016 	if (timeout) {
   1017 		if (*retval) {
   1018 			/*
   1019 			 * Compute how much time was left of the timeout,
   1020 			 * by subtracting the current time and the time
   1021 			 * before we started the call, and subtracting
   1022 			 * that result from the user-supplied value.
   1023 			 */
   1024 			microtime(&tv1);
   1025 			timersub(&tv1, &tv0, &tv1);
   1026 			timersub(&utv, &tv1, &utv);
   1027 			if (utv.tv_sec < 0)
   1028 				timerclear(&utv);
   1029 		} else
   1030 			timerclear(&utv);
   1031 		if ((error = copyout(&utv, timeout, sizeof(utv))))
   1032 			return error;
   1033 	}
   1034 
   1035 	return 0;
   1036 }
   1037 
   1038 /*
   1039  * Get the process group of a certain process. Look it up
   1040  * and return the value.
   1041  */
   1042 int
   1043 linux_sys_getpgid(l, v, retval)
   1044 	struct lwp *l;
   1045 	void *v;
   1046 	register_t *retval;
   1047 {
   1048 	struct linux_sys_getpgid_args /* {
   1049 		syscallarg(int) pid;
   1050 	} */ *uap = v;
   1051 	struct proc *p = l->l_proc;
   1052 	struct proc *targp;
   1053 
   1054 	if (SCARG(uap, pid) != 0 && SCARG(uap, pid) != p->p_pid) {
   1055 		if ((targp = pfind(SCARG(uap, pid))) == 0)
   1056 			return ESRCH;
   1057 	}
   1058 	else
   1059 		targp = p;
   1060 
   1061 	retval[0] = targp->p_pgid;
   1062 	return 0;
   1063 }
   1064 
   1065 /*
   1066  * Set the 'personality' (emulation mode) for the current process. Only
   1067  * accept the Linux personality here (0). This call is needed because
   1068  * the Linux ELF crt0 issues it in an ugly kludge to make sure that
   1069  * ELF binaries run in Linux mode, not SVR4 mode.
   1070  */
   1071 int
   1072 linux_sys_personality(l, v, retval)
   1073 	struct lwp *l;
   1074 	void *v;
   1075 	register_t *retval;
   1076 {
   1077 	struct linux_sys_personality_args /* {
   1078 		syscallarg(int) per;
   1079 	} */ *uap = v;
   1080 
   1081 	if (SCARG(uap, per) != 0)
   1082 		return EINVAL;
   1083 	retval[0] = 0;
   1084 	return 0;
   1085 }
   1086 
   1087 #if defined(__i386__) || defined(__m68k__)
   1088 /*
   1089  * The calls are here because of type conversions.
   1090  */
   1091 int
   1092 linux_sys_setreuid16(l, v, retval)
   1093 	struct lwp *l;
   1094 	void *v;
   1095 	register_t *retval;
   1096 {
   1097 	struct linux_sys_setreuid16_args /* {
   1098 		syscallarg(int) ruid;
   1099 		syscallarg(int) euid;
   1100 	} */ *uap = v;
   1101 	struct sys_setreuid_args bsa;
   1102 
   1103 	SCARG(&bsa, ruid) = ((linux_uid_t)SCARG(uap, ruid) == (linux_uid_t)-1) ?
   1104 		(uid_t)-1 : SCARG(uap, ruid);
   1105 	SCARG(&bsa, euid) = ((linux_uid_t)SCARG(uap, euid) == (linux_uid_t)-1) ?
   1106 		(uid_t)-1 : SCARG(uap, euid);
   1107 
   1108 	return sys_setreuid(l, &bsa, retval);
   1109 }
   1110 
   1111 int
   1112 linux_sys_setregid16(l, v, retval)
   1113 	struct lwp *l;
   1114 	void *v;
   1115 	register_t *retval;
   1116 {
   1117 	struct linux_sys_setregid16_args /* {
   1118 		syscallarg(int) rgid;
   1119 		syscallarg(int) egid;
   1120 	} */ *uap = v;
   1121 	struct sys_setregid_args bsa;
   1122 
   1123 	SCARG(&bsa, rgid) = ((linux_gid_t)SCARG(uap, rgid) == (linux_gid_t)-1) ?
   1124 		(uid_t)-1 : SCARG(uap, rgid);
   1125 	SCARG(&bsa, egid) = ((linux_gid_t)SCARG(uap, egid) == (linux_gid_t)-1) ?
   1126 		(uid_t)-1 : SCARG(uap, egid);
   1127 
   1128 	return sys_setregid(l, &bsa, retval);
   1129 }
   1130 
   1131 int
   1132 linux_sys_setresuid16(l, v, retval)
   1133 	struct lwp *l;
   1134 	void *v;
   1135 	register_t *retval;
   1136 {
   1137 	struct linux_sys_setresuid16_args /* {
   1138 		syscallarg(uid_t) ruid;
   1139 		syscallarg(uid_t) euid;
   1140 		syscallarg(uid_t) suid;
   1141 	} */ *uap = v;
   1142 	struct linux_sys_setresuid16_args lsa;
   1143 
   1144 	SCARG(&lsa, ruid) = ((linux_uid_t)SCARG(uap, ruid) == (linux_uid_t)-1) ?
   1145 		(uid_t)-1 : SCARG(uap, ruid);
   1146 	SCARG(&lsa, euid) = ((linux_uid_t)SCARG(uap, euid) == (linux_uid_t)-1) ?
   1147 		(uid_t)-1 : SCARG(uap, euid);
   1148 	SCARG(&lsa, suid) = ((linux_uid_t)SCARG(uap, suid) == (linux_uid_t)-1) ?
   1149 		(uid_t)-1 : SCARG(uap, suid);
   1150 
   1151 	return linux_sys_setresuid(l, &lsa, retval);
   1152 }
   1153 
   1154 int
   1155 linux_sys_setresgid16(l, v, retval)
   1156 	struct lwp *l;
   1157 	void *v;
   1158 	register_t *retval;
   1159 {
   1160 	struct linux_sys_setresgid16_args /* {
   1161 		syscallarg(gid_t) rgid;
   1162 		syscallarg(gid_t) egid;
   1163 		syscallarg(gid_t) sgid;
   1164 	} */ *uap = v;
   1165 	struct linux_sys_setresgid16_args lsa;
   1166 
   1167 	SCARG(&lsa, rgid) = ((linux_gid_t)SCARG(uap, rgid) == (linux_gid_t)-1) ?
   1168 		(gid_t)-1 : SCARG(uap, rgid);
   1169 	SCARG(&lsa, egid) = ((linux_gid_t)SCARG(uap, egid) == (linux_gid_t)-1) ?
   1170 		(gid_t)-1 : SCARG(uap, egid);
   1171 	SCARG(&lsa, sgid) = ((linux_gid_t)SCARG(uap, sgid) == (linux_gid_t)-1) ?
   1172 		(gid_t)-1 : SCARG(uap, sgid);
   1173 
   1174 	return linux_sys_setresgid(l, &lsa, retval);
   1175 }
   1176 
   1177 int
   1178 linux_sys_getgroups16(l, v, retval)
   1179 	struct lwp *l;
   1180 	void *v;
   1181 	register_t *retval;
   1182 {
   1183 	struct linux_sys_getgroups16_args /* {
   1184 		syscallarg(int) gidsetsize;
   1185 		syscallarg(linux_gid_t *) gidset;
   1186 	} */ *uap = v;
   1187 	struct proc *p = l->l_proc;
   1188 	caddr_t sg;
   1189 	int n, error, i;
   1190 	struct sys_getgroups_args bsa;
   1191 	gid_t *bset, *kbset;
   1192 	linux_gid_t *lset;
   1193 	struct pcred *pc = p->p_cred;
   1194 
   1195 	n = SCARG(uap, gidsetsize);
   1196 	if (n < 0)
   1197 		return EINVAL;
   1198 	error = 0;
   1199 	bset = kbset = NULL;
   1200 	lset = NULL;
   1201 	if (n > 0) {
   1202 		n = min(pc->pc_ucred->cr_ngroups, n);
   1203 		sg = stackgap_init(p, 0);
   1204 		bset = stackgap_alloc(p, &sg, n * sizeof (gid_t));
   1205 		kbset = malloc(n * sizeof (gid_t), M_TEMP, M_WAITOK);
   1206 		lset = malloc(n * sizeof (linux_gid_t), M_TEMP, M_WAITOK);
   1207 		if (bset == NULL || kbset == NULL || lset == NULL)
   1208 			return ENOMEM;
   1209 		SCARG(&bsa, gidsetsize) = n;
   1210 		SCARG(&bsa, gidset) = bset;
   1211 		error = sys_getgroups(l, &bsa, retval);
   1212 		if (error != 0)
   1213 			goto out;
   1214 		error = copyin(bset, kbset, n * sizeof (gid_t));
   1215 		if (error != 0)
   1216 			goto out;
   1217 		for (i = 0; i < n; i++)
   1218 			lset[i] = (linux_gid_t)kbset[i];
   1219 		error = copyout(lset, SCARG(uap, gidset),
   1220 		    n * sizeof (linux_gid_t));
   1221 	} else
   1222 		*retval = pc->pc_ucred->cr_ngroups;
   1223 out:
   1224 	if (kbset != NULL)
   1225 		free(kbset, M_TEMP);
   1226 	if (lset != NULL)
   1227 		free(lset, M_TEMP);
   1228 	return error;
   1229 }
   1230 
   1231 int
   1232 linux_sys_setgroups16(l, v, retval)
   1233 	struct lwp *l;
   1234 	void *v;
   1235 	register_t *retval;
   1236 {
   1237 	struct linux_sys_setgroups16_args /* {
   1238 		syscallarg(int) gidsetsize;
   1239 		syscallarg(linux_gid_t *) gidset;
   1240 	} */ *uap = v;
   1241 	struct proc *p = l->l_proc;
   1242 	caddr_t sg;
   1243 	int n;
   1244 	int error, i;
   1245 	struct sys_setgroups_args bsa;
   1246 	gid_t *bset, *kbset;
   1247 	linux_gid_t *lset;
   1248 
   1249 	n = SCARG(uap, gidsetsize);
   1250 	if (n < 0 || n > NGROUPS)
   1251 		return EINVAL;
   1252 	sg = stackgap_init(p, 0);
   1253 	bset = stackgap_alloc(p, &sg, n * sizeof (gid_t));
   1254 	lset = malloc(n * sizeof (linux_gid_t), M_TEMP, M_WAITOK);
   1255 	kbset = malloc(n * sizeof (gid_t), M_TEMP, M_WAITOK);
   1256 	if (lset == NULL || bset == NULL)
   1257 		return ENOMEM;
   1258 	error = copyin(SCARG(uap, gidset), lset, n * sizeof (linux_gid_t));
   1259 	if (error != 0)
   1260 		goto out;
   1261 	for (i = 0; i < n; i++)
   1262 		kbset[i] = (gid_t)lset[i];
   1263 	error = copyout(kbset, bset, n * sizeof (gid_t));
   1264 	if (error != 0)
   1265 		goto out;
   1266 	SCARG(&bsa, gidsetsize) = n;
   1267 	SCARG(&bsa, gidset) = bset;
   1268 	error = sys_setgroups(l, &bsa, retval);
   1269 
   1270 out:
   1271 	if (lset != NULL)
   1272 		free(lset, M_TEMP);
   1273 	if (kbset != NULL)
   1274 		free(kbset, M_TEMP);
   1275 
   1276 	return error;
   1277 }
   1278 
   1279 #endif /* __i386__ || __m68k__ || __amd64__ */
   1280 
   1281 /*
   1282  * We have nonexistent fsuid equal to uid.
   1283  * If modification is requested, refuse.
   1284  */
   1285 int
   1286 linux_sys_setfsuid(l, v, retval)
   1287 	 struct lwp *l;
   1288 	 void *v;
   1289 	 register_t *retval;
   1290 {
   1291 	 struct linux_sys_setfsuid_args /* {
   1292 		 syscallarg(uid_t) uid;
   1293 	 } */ *uap = v;
   1294 	 struct proc *p = l->l_proc;
   1295 	 uid_t uid;
   1296 
   1297 	 uid = SCARG(uap, uid);
   1298 	 if (p->p_cred->p_ruid != uid)
   1299 		 return sys_nosys(l, v, retval);
   1300 	 else
   1301 		 return (0);
   1302 }
   1303 
   1304 /* XXX XXX XXX */
   1305 #ifndef alpha
   1306 int
   1307 linux_sys_getfsuid(l, v, retval)
   1308 	struct lwp *l;
   1309 	void *v;
   1310 	register_t *retval;
   1311 {
   1312 	return sys_getuid(l, v, retval);
   1313 }
   1314 #endif
   1315 
   1316 int
   1317 linux_sys_setresuid(l, v, retval)
   1318 	struct lwp *l;
   1319 	void *v;
   1320 	register_t *retval;
   1321 {
   1322 	struct linux_sys_setresuid_args /* {
   1323 		syscallarg(uid_t) ruid;
   1324 		syscallarg(uid_t) euid;
   1325 		syscallarg(uid_t) suid;
   1326 	} */ *uap = v;
   1327 
   1328 	/*
   1329 	 * Note: These checks are a little different than the NetBSD
   1330 	 * setreuid(2) call performs.  This precisely follows the
   1331 	 * behavior of the Linux kernel.
   1332 	 */
   1333 
   1334 	return do_setresuid(l, SCARG(uap, ruid), SCARG(uap, euid),
   1335 			    SCARG(uap, suid),
   1336 			    ID_R_EQ_R | ID_R_EQ_E | ID_R_EQ_S |
   1337 			    ID_E_EQ_R | ID_E_EQ_E | ID_E_EQ_S |
   1338 			    ID_S_EQ_R | ID_S_EQ_E | ID_S_EQ_S );
   1339 }
   1340 
   1341 int
   1342 linux_sys_getresuid(l, v, retval)
   1343 	struct lwp *l;
   1344 	void *v;
   1345 	register_t *retval;
   1346 {
   1347 	struct linux_sys_getresuid_args /* {
   1348 		syscallarg(uid_t *) ruid;
   1349 		syscallarg(uid_t *) euid;
   1350 		syscallarg(uid_t *) suid;
   1351 	} */ *uap = v;
   1352 	struct proc *p = l->l_proc;
   1353 	struct pcred *pc = p->p_cred;
   1354 	int error;
   1355 
   1356 	/*
   1357 	 * Linux copies these values out to userspace like so:
   1358 	 *
   1359 	 *	1. Copy out ruid.
   1360 	 *	2. If that succeeds, copy out euid.
   1361 	 *	3. If both of those succeed, copy out suid.
   1362 	 */
   1363 	if ((error = copyout(&pc->p_ruid, SCARG(uap, ruid),
   1364 			     sizeof(uid_t))) != 0)
   1365 		return (error);
   1366 
   1367 	if ((error = copyout(&pc->pc_ucred->cr_uid, SCARG(uap, euid),
   1368 			     sizeof(uid_t))) != 0)
   1369 		return (error);
   1370 
   1371 	return (copyout(&pc->p_svuid, SCARG(uap, suid), sizeof(uid_t)));
   1372 }
   1373 
   1374 int
   1375 linux_sys_ptrace(l, v, retval)
   1376 	struct lwp *l;
   1377 	void *v;
   1378 	register_t *retval;
   1379 {
   1380 	struct linux_sys_ptrace_args /* {
   1381 		i386, m68k, powerpc: T=int
   1382 		alpha, amd64: T=long
   1383 		syscallarg(T) request;
   1384 		syscallarg(T) pid;
   1385 		syscallarg(T) addr;
   1386 		syscallarg(T) data;
   1387 	} */ *uap = v;
   1388 	const int *ptr;
   1389 	int request;
   1390 	int error;
   1391 
   1392 	ptr = linux_ptrace_request_map;
   1393 	request = SCARG(uap, request);
   1394 	while (*ptr != -1)
   1395 		if (*ptr++ == request) {
   1396 			struct sys_ptrace_args pta;
   1397 
   1398 			SCARG(&pta, req) = *ptr;
   1399 			SCARG(&pta, pid) = SCARG(uap, pid);
   1400 			SCARG(&pta, addr) = (caddr_t)SCARG(uap, addr);
   1401 			SCARG(&pta, data) = SCARG(uap, data);
   1402 
   1403 			/*
   1404 			 * Linux ptrace(PTRACE_CONT, pid, 0, 0) means actually
   1405 			 * to continue where the process left off previously.
   1406 			 * The same thing is achieved by addr == (caddr_t) 1
   1407 			 * on NetBSD, so rewrite 'addr' appropriately.
   1408 			 */
   1409 			if (request == LINUX_PTRACE_CONT && SCARG(uap, addr)==0)
   1410 				SCARG(&pta, addr) = (caddr_t) 1;
   1411 
   1412 			error = sys_ptrace(l, &pta, retval);
   1413 			if (error)
   1414 				return error;
   1415 			switch (request) {
   1416 			case LINUX_PTRACE_PEEKTEXT:
   1417 			case LINUX_PTRACE_PEEKDATA:
   1418 				error = copyout (retval,
   1419 				    (caddr_t)SCARG(uap, data),
   1420 				    sizeof *retval);
   1421 				*retval = SCARG(uap, data);
   1422 				break;
   1423 			default:
   1424 				break;
   1425 			}
   1426 			return error;
   1427 		}
   1428 		else
   1429 			ptr++;
   1430 
   1431 	return LINUX_SYS_PTRACE_ARCH(l, uap, retval);
   1432 }
   1433 
   1434 int
   1435 linux_sys_reboot(struct lwp *l, void *v, register_t *retval)
   1436 {
   1437 	struct linux_sys_reboot_args /* {
   1438 		syscallarg(int) magic1;
   1439 		syscallarg(int) magic2;
   1440 		syscallarg(int) cmd;
   1441 		syscallarg(void *) arg;
   1442 	} */ *uap = v;
   1443 	struct sys_reboot_args /* {
   1444 		syscallarg(int) opt;
   1445 		syscallarg(char *) bootstr;
   1446 	} */ sra;
   1447 	struct proc *p = l->l_proc;
   1448 	int error;
   1449 
   1450 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
   1451 		return(error);
   1452 
   1453 	if (SCARG(uap, magic1) != LINUX_REBOOT_MAGIC1)
   1454 		return(EINVAL);
   1455 	if (SCARG(uap, magic2) != LINUX_REBOOT_MAGIC2 &&
   1456 	    SCARG(uap, magic2) != LINUX_REBOOT_MAGIC2A &&
   1457 	    SCARG(uap, magic2) != LINUX_REBOOT_MAGIC2B)
   1458 		return(EINVAL);
   1459 
   1460 	switch (SCARG(uap, cmd)) {
   1461 	case LINUX_REBOOT_CMD_RESTART:
   1462 		SCARG(&sra, opt) = RB_AUTOBOOT;
   1463 		break;
   1464 	case LINUX_REBOOT_CMD_HALT:
   1465 		SCARG(&sra, opt) = RB_HALT;
   1466 		break;
   1467 	case LINUX_REBOOT_CMD_POWER_OFF:
   1468 		SCARG(&sra, opt) = RB_HALT|RB_POWERDOWN;
   1469 		break;
   1470 	case LINUX_REBOOT_CMD_RESTART2:
   1471 		/* Reboot with an argument. */
   1472 		SCARG(&sra, opt) = RB_AUTOBOOT|RB_STRING;
   1473 		SCARG(&sra, bootstr) = SCARG(uap, arg);
   1474 		break;
   1475 	case LINUX_REBOOT_CMD_CAD_ON:
   1476 		return(EINVAL);	/* We don't implement ctrl-alt-delete */
   1477 	case LINUX_REBOOT_CMD_CAD_OFF:
   1478 		return(0);
   1479 	default:
   1480 		return(EINVAL);
   1481 	}
   1482 
   1483 	return(sys_reboot(l, &sra, retval));
   1484 }
   1485 
   1486 /*
   1487  * Copy of compat_12_sys_swapon().
   1488  */
   1489 int
   1490 linux_sys_swapon(l, v, retval)
   1491 	struct lwp *l;
   1492 	void *v;
   1493 	register_t *retval;
   1494 {
   1495 	struct sys_swapctl_args ua;
   1496 	struct linux_sys_swapon_args /* {
   1497 		syscallarg(const char *) name;
   1498 	} */ *uap = v;
   1499 
   1500 	SCARG(&ua, cmd) = SWAP_ON;
   1501 	SCARG(&ua, arg) = (void *)SCARG(uap, name);
   1502 	SCARG(&ua, misc) = 0;	/* priority */
   1503 	return (sys_swapctl(l, &ua, retval));
   1504 }
   1505 
   1506 /*
   1507  * Stop swapping to the file or block device specified by path.
   1508  */
   1509 int
   1510 linux_sys_swapoff(l, v, retval)
   1511 	struct lwp *l;
   1512 	void *v;
   1513 	register_t *retval;
   1514 {
   1515 	struct sys_swapctl_args ua;
   1516 	struct linux_sys_swapoff_args /* {
   1517 		syscallarg(const char *) path;
   1518 	} */ *uap = v;
   1519 
   1520 	SCARG(&ua, cmd) = SWAP_OFF;
   1521 	SCARG(&ua, arg) = __UNCONST(SCARG(uap, path)); /*XXXUNCONST*/
   1522 	return (sys_swapctl(l, &ua, retval));
   1523 }
   1524 
   1525 /*
   1526  * Copy of compat_09_sys_setdomainname()
   1527  */
   1528 /* ARGSUSED */
   1529 int
   1530 linux_sys_setdomainname(l, v, retval)
   1531 	struct lwp *l;
   1532 	void *v;
   1533 	register_t *retval;
   1534 {
   1535 	struct linux_sys_setdomainname_args /* {
   1536 		syscallarg(char *) domainname;
   1537 		syscallarg(int) len;
   1538 	} */ *uap = v;
   1539 	int name[2];
   1540 
   1541 	name[0] = CTL_KERN;
   1542 	name[1] = KERN_DOMAINNAME;
   1543 	return (old_sysctl(&name[0], 2, 0, 0, SCARG(uap, domainname),
   1544 			    SCARG(uap, len), l));
   1545 }
   1546 
   1547 /*
   1548  * sysinfo()
   1549  */
   1550 /* ARGSUSED */
   1551 int
   1552 linux_sys_sysinfo(l, v, retval)
   1553 	struct lwp *l;
   1554 	void *v;
   1555 	register_t *retval;
   1556 {
   1557 	struct linux_sys_sysinfo_args /* {
   1558 		syscallarg(struct linux_sysinfo *) arg;
   1559 	} */ *uap = v;
   1560 	struct linux_sysinfo si;
   1561 	struct loadavg *la;
   1562 
   1563 	si.uptime = time.tv_sec - boottime.tv_sec;
   1564 	la = &averunnable;
   1565 	si.loads[0] = la->ldavg[0] * LINUX_SYSINFO_LOADS_SCALE / la->fscale;
   1566 	si.loads[1] = la->ldavg[1] * LINUX_SYSINFO_LOADS_SCALE / la->fscale;
   1567 	si.loads[2] = la->ldavg[2] * LINUX_SYSINFO_LOADS_SCALE / la->fscale;
   1568 	si.totalram = ctob(physmem);
   1569 	si.freeram = uvmexp.free * uvmexp.pagesize;
   1570 	si.sharedram = 0;	/* XXX */
   1571 	si.bufferram = uvmexp.filepages * uvmexp.pagesize;
   1572 	si.totalswap = uvmexp.swpages * uvmexp.pagesize;
   1573 	si.freeswap = (uvmexp.swpages - uvmexp.swpginuse) * uvmexp.pagesize;
   1574 	si.procs = nprocs;
   1575 
   1576 	/* The following are only present in newer Linux kernels. */
   1577 	si.totalbig = 0;
   1578 	si.freebig = 0;
   1579 	si.mem_unit = 1;
   1580 
   1581 	return (copyout(&si, SCARG(uap, arg), sizeof si));
   1582 }
   1583 
   1584 #define bsd_to_linux_rlimit1(l, b, f) \
   1585     (l)->f = ((b)->f == RLIM_INFINITY || \
   1586 	     ((b)->f & 0xffffffff00000000ULL) != 0) ? \
   1587     LINUX_RLIM_INFINITY : (int32_t)(b)->f
   1588 #define bsd_to_linux_rlimit(l, b) \
   1589     bsd_to_linux_rlimit1(l, b, rlim_cur); \
   1590     bsd_to_linux_rlimit1(l, b, rlim_max)
   1591 
   1592 #define linux_to_bsd_rlimit1(b, l, f) \
   1593     (b)->f = (l)->f == LINUX_RLIM_INFINITY ? RLIM_INFINITY : (l)->f
   1594 #define linux_to_bsd_rlimit(b, l) \
   1595     linux_to_bsd_rlimit1(b, l, rlim_cur); \
   1596     linux_to_bsd_rlimit1(b, l, rlim_max)
   1597 
   1598 static int
   1599 linux_to_bsd_limit(lim)
   1600 	int lim;
   1601 {
   1602 	switch (lim) {
   1603 	case LINUX_RLIMIT_CPU:
   1604 		return RLIMIT_CPU;
   1605 	case LINUX_RLIMIT_FSIZE:
   1606 		return RLIMIT_FSIZE;
   1607 	case LINUX_RLIMIT_DATA:
   1608 		return RLIMIT_DATA;
   1609 	case LINUX_RLIMIT_STACK:
   1610 		return RLIMIT_STACK;
   1611 	case LINUX_RLIMIT_CORE:
   1612 		return RLIMIT_CORE;
   1613 	case LINUX_RLIMIT_RSS:
   1614 		return RLIMIT_RSS;
   1615 	case LINUX_RLIMIT_NPROC:
   1616 		return RLIMIT_NPROC;
   1617 	case LINUX_RLIMIT_NOFILE:
   1618 		return RLIMIT_NOFILE;
   1619 	case LINUX_RLIMIT_MEMLOCK:
   1620 		return RLIMIT_MEMLOCK;
   1621 	case LINUX_RLIMIT_AS:
   1622 	case LINUX_RLIMIT_LOCKS:
   1623 		return -EOPNOTSUPP;
   1624 	default:
   1625 		return -EINVAL;
   1626 	}
   1627 }
   1628 
   1629 
   1630 int
   1631 linux_sys_getrlimit(l, v, retval)
   1632 	struct lwp *l;
   1633 	void *v;
   1634 	register_t *retval;
   1635 {
   1636 	struct linux_sys_getrlimit_args /* {
   1637 		syscallarg(int) which;
   1638 		syscallarg(struct orlimit *) rlp;
   1639 	} */ *uap = v;
   1640 	struct proc *p = l->l_proc;
   1641 	caddr_t sg = stackgap_init(p, 0);
   1642 	struct sys_getrlimit_args ap;
   1643 	struct rlimit rl;
   1644 	struct orlimit orl;
   1645 	int error;
   1646 
   1647 	SCARG(&ap, which) = linux_to_bsd_limit(SCARG(uap, which));
   1648 	if ((error = SCARG(&ap, which)) < 0)
   1649 		return -error;
   1650 	SCARG(&ap, rlp) = stackgap_alloc(p, &sg, sizeof rl);
   1651 	if ((error = sys_getrlimit(l, &ap, retval)) != 0)
   1652 		return error;
   1653 	if ((error = copyin(SCARG(&ap, rlp), &rl, sizeof(rl))) != 0)
   1654 		return error;
   1655 	bsd_to_linux_rlimit(&orl, &rl);
   1656 	return copyout(&orl, SCARG(uap, rlp), sizeof(orl));
   1657 }
   1658 
   1659 int
   1660 linux_sys_setrlimit(l, v, retval)
   1661 	struct lwp *l;
   1662 	void *v;
   1663 	register_t *retval;
   1664 {
   1665 	struct linux_sys_setrlimit_args /* {
   1666 		syscallarg(int) which;
   1667 		syscallarg(struct orlimit *) rlp;
   1668 	} */ *uap = v;
   1669 	struct proc *p = l->l_proc;
   1670 	caddr_t sg = stackgap_init(p, 0);
   1671 	struct sys_getrlimit_args ap;
   1672 	struct rlimit rl;
   1673 	struct orlimit orl;
   1674 	int error;
   1675 
   1676 	SCARG(&ap, which) = linux_to_bsd_limit(SCARG(uap, which));
   1677 	SCARG(&ap, rlp) = stackgap_alloc(p, &sg, sizeof rl);
   1678 	if ((error = SCARG(&ap, which)) < 0)
   1679 		return -error;
   1680 	if ((error = copyin(SCARG(uap, rlp), &orl, sizeof(orl))) != 0)
   1681 		return error;
   1682 	linux_to_bsd_rlimit(&rl, &orl);
   1683 	if ((error = copyout(&rl, SCARG(&ap, rlp), sizeof(rl))) != 0)
   1684 		return error;
   1685 	return sys_setrlimit(l, &ap, retval);
   1686 }
   1687 
   1688 #if !defined(__mips__) && !defined(__amd64__)
   1689 /* XXX: this doesn't look 100% common, at least mips doesn't have it */
   1690 int
   1691 linux_sys_ugetrlimit(l, v, retval)
   1692 	struct lwp *l;
   1693 	void *v;
   1694 	register_t *retval;
   1695 {
   1696 	return linux_sys_getrlimit(l, v, retval);
   1697 }
   1698 #endif
   1699 
   1700 /*
   1701  * This gets called for unsupported syscalls. The difference to sys_nosys()
   1702  * is that process does not get SIGSYS, the call just returns with ENOSYS.
   1703  * This is the way Linux does it and glibc depends on this behaviour.
   1704  */
   1705 int
   1706 linux_sys_nosys(l, v, retval)
   1707 	struct lwp *l;
   1708 	void *v;
   1709 	register_t *retval;
   1710 {
   1711 	return (ENOSYS);
   1712 }
   1713