2 * Copyright (c) 1993, 1995 Jan-Simon Pendry
3 * Copyright (c) 1993, 1995
4 * The Regents of the University of California. All rights reserved.
6 * This code is derived from software contributed to Berkeley by
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10 * modification, are permitted provided that the following conditions
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13 * notice, this list of conditions and the following disclaimer.
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18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
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34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * @(#)procfs_vnops.c 8.18 (Berkeley) 5/21/95
39 * $FreeBSD: src/sys/miscfs/procfs/procfs_vnops.c,v 1.76.2.7 2002/01/22 17:22:59 nectar Exp $
40 * $DragonFly: src/sys/vfs/procfs/procfs_vnops.c,v 1.46 2007/11/20 21:03:50 dillon Exp $
44 * procfs vnode interface
47 #include <sys/param.h>
48 #include <sys/systm.h>
50 #include <sys/kernel.h>
52 #include <sys/fcntl.h>
55 #include <sys/signalvar.h>
56 #include <sys/vnode.h>
58 #include <sys/mount.h>
59 #include <sys/namei.h>
60 #include <sys/dirent.h>
61 #include <sys/malloc.h>
63 #include <vm/vm_zone.h>
64 #include <vfs/procfs/procfs.h>
65 #include <sys/pioctl.h>
67 #include <machine/limits.h>
69 static int procfs_access (struct vop_access_args *);
70 static int procfs_badop (struct vop_generic_args *);
71 static int procfs_bmap (struct vop_bmap_args *);
72 static int procfs_close (struct vop_close_args *);
73 static int procfs_getattr (struct vop_getattr_args *);
74 static int procfs_inactive (struct vop_inactive_args *);
75 static int procfs_ioctl (struct vop_ioctl_args *);
76 static int procfs_lookup (struct vop_old_lookup_args *);
77 static int procfs_open (struct vop_open_args *);
78 static int procfs_print (struct vop_print_args *);
79 static int procfs_readdir (struct vop_readdir_args *);
80 static int procfs_readlink (struct vop_readlink_args *);
81 static int procfs_reclaim (struct vop_reclaim_args *);
82 static int procfs_setattr (struct vop_setattr_args *);
84 static int procfs_readdir_proc(struct vop_readdir_args *);
85 static int procfs_readdir_root(struct vop_readdir_args *);
88 * procfs vnode operations.
90 struct vop_ops procfs_vnode_vops = {
91 .vop_default = vop_defaultop,
92 .vop_access = procfs_access,
93 .vop_advlock = (void *)procfs_badop,
94 .vop_bmap = procfs_bmap,
95 .vop_close = procfs_close,
96 .vop_old_create = (void *)procfs_badop,
97 .vop_getattr = procfs_getattr,
98 .vop_inactive = procfs_inactive,
99 .vop_old_link = (void *)procfs_badop,
100 .vop_old_lookup = procfs_lookup,
101 .vop_old_mkdir = (void *)procfs_badop,
102 .vop_old_mknod = (void *)procfs_badop,
103 .vop_open = procfs_open,
104 .vop_pathconf = vop_stdpathconf,
105 .vop_print = procfs_print,
106 .vop_read = procfs_rw,
107 .vop_readdir = procfs_readdir,
108 .vop_readlink = procfs_readlink,
109 .vop_reclaim = procfs_reclaim,
110 .vop_old_remove = (void *)procfs_badop,
111 .vop_old_rename = (void *)procfs_badop,
112 .vop_old_rmdir = (void *)procfs_badop,
113 .vop_setattr = procfs_setattr,
114 .vop_old_symlink = (void *)procfs_badop,
115 .vop_write = (void *)procfs_rw,
116 .vop_ioctl = procfs_ioctl
121 * This is a list of the valid names in the
122 * process-specific sub-directories. It is
123 * used in procfs_lookup and procfs_readdir
125 static struct proc_target {
130 int (*pt_valid) (struct lwp *p);
132 #define N(s) sizeof(s)-1, s
133 /* name type validp */
134 { DT_DIR, N("."), Pproc, NULL },
135 { DT_DIR, N(".."), Proot, NULL },
136 { DT_REG, N("mem"), Pmem, NULL },
137 { DT_REG, N("regs"), Pregs, procfs_validregs },
138 { DT_REG, N("fpregs"), Pfpregs, procfs_validfpregs },
139 { DT_REG, N("dbregs"), Pdbregs, procfs_validdbregs },
140 { DT_REG, N("ctl"), Pctl, NULL },
141 { DT_REG, N("status"), Pstatus, NULL },
142 { DT_REG, N("note"), Pnote, NULL },
143 { DT_REG, N("notepg"), Pnotepg, NULL },
144 { DT_REG, N("map"), Pmap, procfs_validmap },
145 { DT_REG, N("etype"), Ptype, procfs_validtype },
146 { DT_REG, N("cmdline"), Pcmdline, NULL },
147 { DT_REG, N("rlimit"), Prlimit, NULL },
148 { DT_LNK, N("file"), Pfile, NULL },
151 static const int nproc_targets = sizeof(proc_targets) / sizeof(proc_targets[0]);
153 static pid_t atopid (const char *, u_int);
156 * set things up for doing i/o on
157 * the pfsnode (vp). (vp) is locked
158 * on entry, and should be left locked
161 * for procfs we don't need to do anything
162 * in particular for i/o. all that is done
163 * is to support exclusive open on process
166 * procfs_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred,
170 procfs_open(struct vop_open_args *ap)
172 struct pfsnode *pfs = VTOPFS(ap->a_vp);
173 struct proc *p1, *p2;
175 p2 = PFIND(pfs->pfs_pid);
178 if (pfs->pfs_pid && !PRISON_CHECK(ap->a_cred, p2->p_ucred))
181 switch (pfs->pfs_type) {
183 if (((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL)) ||
184 ((pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE)))
189 /* Can't trace a process that's currently exec'ing. */
190 if ((p2->p_flag & P_INEXEC) != 0)
192 if (!CHECKIO(p1, p2) || p_trespass(ap->a_cred, p2->p_ucred))
195 if (ap->a_mode & FWRITE)
196 pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL);
204 return (vop_stdopen(ap));
208 * close the pfsnode (vp) after doing i/o.
209 * (vp) is not locked on entry or exit.
211 * nothing to do for procfs other than undo
212 * any exclusive open flag (see _open above).
214 * procfs_close(struct vnode *a_vp, int a_fflag, struct ucred *a_cred)
217 procfs_close(struct vop_close_args *ap)
219 struct pfsnode *pfs = VTOPFS(ap->a_vp);
222 switch (pfs->pfs_type) {
224 if ((ap->a_fflag & FWRITE) && (pfs->pfs_flags & O_EXCL))
225 pfs->pfs_flags &= ~(FWRITE|O_EXCL);
227 * v_opencount determines the last real close on the vnode.
229 * If this is the last close, then it checks to see if
230 * the target process has PF_LINGER set in p_pfsflags,
231 * if this is *not* the case, then the process' stop flags
232 * are cleared, and the process is woken up. This is
233 * to help prevent the case where a process has been
234 * told to stop on an event, but then the requesting process
235 * has gone away or forgotten about it.
237 if ((ap->a_vp->v_opencount < 2)
238 && (p = pfind(pfs->pfs_pid))
239 && !(p->p_pfsflags & PF_LINGER)) {
249 return (vop_stdclose(ap));
253 * do an ioctl operation on a pfsnode (vp).
254 * (vp) is not locked on entry or exit.
257 procfs_ioctl(struct vop_ioctl_args *ap)
259 struct pfsnode *pfs = VTOPFS(ap->a_vp);
264 struct procfs_status *psp;
267 procp = pfind(pfs->pfs_pid);
274 /* Can't trace a process that's currently exec'ing. */
275 if ((procp->p_flag & P_INEXEC) != 0)
277 if (!CHECKIO(p, procp) || p_trespass(ap->a_cred, procp->p_ucred))
280 switch (ap->a_command) {
282 procp->p_stops |= *(unsigned int*)ap->a_data;
285 procp->p_stops &= ~*(unsigned int*)ap->a_data;
289 * NFLAGS is "non-suser_xxx flags" -- currently, only
290 * PFS_ISUGID ("ignore set u/g id");
292 #define NFLAGS (PF_ISUGID)
293 flags = (unsigned char)*(unsigned int*)ap->a_data;
294 if (flags & NFLAGS && (error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0)))
296 procp->p_pfsflags = flags;
299 *(unsigned int*)ap->a_data = (unsigned int)procp->p_pfsflags;
302 psp = (struct procfs_status *)ap->a_data;
303 psp->state = (procp->p_step == 0);
304 psp->flags = procp->p_pfsflags;
305 psp->events = procp->p_stops;
307 psp->why = procp->p_stype;
308 psp->val = procp->p_xstat;
310 psp->why = psp->val = 0; /* Not defined values */
314 psp = (struct procfs_status *)ap->a_data;
315 if (procp->p_step == 0) {
316 error = tsleep(&procp->p_stype, PCATCH, "piocwait", 0);
320 psp->state = 1; /* It stopped */
321 psp->flags = procp->p_pfsflags;
322 psp->events = procp->p_stops;
323 psp->why = procp->p_stype; /* why it stopped */
324 psp->val = procp->p_xstat; /* any extra info */
326 case PIOCCONT: /* Restart a proc */
327 if (procp->p_step == 0)
328 return EINVAL; /* Can only start a stopped process */
329 if ((signo = *(int*)ap->a_data) != 0) {
330 if (signo >= NSIG || signo <= 0)
332 ksignal(procp, signo);
335 wakeup(&procp->p_step);
344 * do block mapping for pfsnode (vp).
345 * since we don't use the buffer cache
346 * for procfs this function should never
347 * be called. in any case, it's not clear
348 * what part of the kernel ever makes use
349 * of this function. for sanity, this is the
350 * usual no-op bmap, although returning
351 * (EIO) would be a reasonable alternative.
353 * XXX mmap assumes buffer cache operation
355 * procfs_bmap(struct vnode *a_vp, off_t a_loffset,
356 * off_t *a_doffsetp, int *a_runp, int *a_runb)
359 procfs_bmap(struct vop_bmap_args *ap)
361 if (ap->a_doffsetp != NULL)
362 *ap->a_doffsetp = ap->a_loffset;
363 if (ap->a_runp != NULL)
365 if (ap->a_runb != NULL)
371 * procfs_inactive is called when the pfsnode
372 * is vrele'd and the reference count goes
373 * to zero. (vp) will be on the vnode free
374 * list, so to get it back vget() must be
377 * (vp) is locked on entry, but must be unlocked on exit.
379 * procfs_inactive(struct vnode *a_vp)
382 procfs_inactive(struct vop_inactive_args *ap)
384 /*struct vnode *vp = ap->a_vp;*/
390 * _reclaim is called when getnewvnode()
391 * wants to make use of an entry on the vnode
392 * free list. at this time the filesystem needs
393 * to free any private data and remove the node
394 * from any private lists.
396 * procfs_reclaim(struct vnode *a_vp)
399 procfs_reclaim(struct vop_reclaim_args *ap)
401 return (procfs_freevp(ap->a_vp));
405 * _print is used for debugging.
406 * just print a readable description
409 * procfs_print(struct vnode *a_vp)
412 procfs_print(struct vop_print_args *ap)
414 struct pfsnode *pfs = VTOPFS(ap->a_vp);
416 kprintf("tag VT_PROCFS, type %d, pid %ld, mode %x, flags %lx\n",
417 pfs->pfs_type, (long)pfs->pfs_pid, pfs->pfs_mode, pfs->pfs_flags);
422 * generic entry point for unsupported operations
425 procfs_badop(struct vop_generic_args *ap)
431 * Invent attributes for pfsnode (vp) and store
433 * Directories lengths are returned as zero since
434 * any real length would require the genuine size
435 * to be computed, and nothing cares anyway.
437 * this is relatively minimal for procfs.
439 * procfs_getattr(struct vnode *a_vp, struct vattr *a_vap)
442 procfs_getattr(struct vop_getattr_args *ap)
444 struct pfsnode *pfs = VTOPFS(ap->a_vp);
445 struct vattr *vap = ap->a_vap;
450 * First make sure that the process and its credentials
453 switch (pfs->pfs_type) {
460 procp = PFIND(pfs->pfs_pid);
461 if (procp == NULL || procp->p_ucred == NULL)
467 /* start by zeroing out the attributes */
470 /* next do all the common fields */
471 vap->va_type = ap->a_vp->v_type;
472 vap->va_mode = pfs->pfs_mode;
473 vap->va_fileid = pfs->pfs_fileno;
475 vap->va_blocksize = PAGE_SIZE;
476 vap->va_bytes = vap->va_size = 0;
477 vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
480 * Make all times be current TOD.
481 * It would be possible to get the process start
482 * time from the p_stat structure, but there's
483 * no "file creation" time stamp anyway, and the
484 * p_stat structure is not addressible if u. gets
485 * swapped out for that process.
487 nanotime(&vap->va_ctime);
488 vap->va_atime = vap->va_mtime = vap->va_ctime;
491 * If the process has exercised some setuid or setgid
492 * privilege, then rip away read/write permission so
493 * that only root can gain access.
495 switch (pfs->pfs_type) {
501 if (procp->p_flag & P_SUGID)
502 vap->va_mode &= ~((VREAD|VWRITE)|
504 ((VREAD|VWRITE)>>6));
511 * now do the object specific fields
513 * The size could be set from struct reg, but it's hardly
514 * worth the trouble, and it puts some (potentially) machine
515 * dependent data into this machine-independent code. If it
516 * becomes important then this function should break out into
517 * a per-file stat function in the corresponding .c file.
522 vap->va_uid = procp->p_ucred->cr_uid;
523 vap->va_gid = procp->p_ucred->cr_gid;
526 switch (pfs->pfs_type) {
529 * Set nlink to 1 to tell fts(3) we don't actually know.
534 vap->va_size = vap->va_bytes = DEV_BSIZE;
538 char buf[16]; /* should be enough */
541 vap->va_size = vap->va_bytes =
542 ksnprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid);
547 vap->va_nlink = nproc_targets;
548 vap->va_size = vap->va_bytes = DEV_BSIZE;
552 char *fullpath, *freepath;
553 error = vn_fullpath(procp, NULL, &fullpath, &freepath);
555 vap->va_size = strlen(fullpath);
556 kfree(freepath, M_TEMP);
558 vap->va_size = sizeof("unknown") - 1;
561 vap->va_bytes = vap->va_size;
567 * If we denied owner access earlier, then we have to
568 * change the owner to root - otherwise 'ps' and friends
569 * will break even though they are setgid kmem. *SIGH*
571 if (procp->p_flag & P_SUGID)
574 vap->va_uid = procp->p_ucred->cr_uid;
578 vap->va_bytes = vap->va_size = sizeof(struct reg);
582 vap->va_bytes = vap->va_size = sizeof(struct fpreg);
586 vap->va_bytes = vap->va_size = sizeof(struct dbreg);
600 panic("procfs_getattr");
607 * procfs_setattr(struct vnode *a_vp, struct vattr *a_vap,
608 * struct ucred *a_cred)
611 procfs_setattr(struct vop_setattr_args *ap)
613 if (ap->a_vap->va_flags != VNOVAL)
617 * just fake out attribute setting
618 * it's not good to generate an error
619 * return, otherwise things like creat()
620 * will fail when they try to set the
621 * file length to 0. worse, this means
622 * that echo $note > /proc/$pid/note will fail.
629 * implement access checking.
631 * procfs_access(struct vnode *a_vp, int a_mode, struct ucred *a_cred)
634 procfs_access(struct vop_access_args *ap)
639 error = VOP_GETATTR(ap->a_vp, &vattr);
641 error = vop_helper_access(ap, vattr.va_uid, vattr.va_gid,
647 * lookup. this is incredibly complicated in the general case, however
648 * for most pseudo-filesystems very little needs to be done.
650 * procfs_lookup(struct vnode *a_dvp, struct vnode **a_vpp,
651 * struct componentname *a_cnp)
654 procfs_lookup(struct vop_old_lookup_args *ap)
656 struct componentname *cnp = ap->a_cnp;
657 struct vnode **vpp = ap->a_vpp;
658 struct vnode *dvp = ap->a_dvp;
659 char *pname = cnp->cn_nameptr;
660 /* struct proc *curp = cnp->cn_proc; */
661 struct proc_target *pt;
671 if (cnp->cn_nameiop == NAMEI_DELETE || cnp->cn_nameiop == NAMEI_RENAME)
675 if (cnp->cn_namelen == 1 && *pname == '.') {
682 switch (pfs->pfs_type) {
684 if (cnp->cn_flags & CNP_ISDOTDOT)
687 if (CNEQ(cnp, "curproc", 7)) {
688 error = procfs_allocvp(dvp->v_mount, vpp, 0, Pcurproc);
692 pid = atopid(pname, cnp->cn_namelen);
700 if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred))
703 if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 &&
704 ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid)
707 error = procfs_allocvp(dvp->v_mount, vpp, pid, Pproc);
711 if (cnp->cn_flags & CNP_ISDOTDOT) {
712 error = procfs_root(dvp->v_mount, vpp);
716 p = PFIND(pfs->pfs_pid);
720 lp = FIRST_LWP_IN_PROC(p);
722 if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred))
725 if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 &&
726 ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid)
729 for (pt = proc_targets, i = 0; i < nproc_targets; pt++, i++) {
730 if (cnp->cn_namelen == pt->pt_namlen &&
731 bcmp(pt->pt_name, pname, cnp->cn_namelen) == 0 &&
732 (pt->pt_valid == NULL || (*pt->pt_valid)(lp)))
737 error = procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid,
745 if (cnp->cn_nameiop == NAMEI_LOOKUP)
750 * If no error occured *vpp will hold a referenced locked vnode.
751 * dvp was passed to us locked and *vpp must be returned locked.
752 * If *vpp != dvp then we should unlock dvp if (1) this is not the
753 * last component or (2) CNP_LOCKPARENT is not set.
756 if (error == 0 && *vpp != dvp) {
757 if ((cnp->cn_flags & CNP_LOCKPARENT) == 0) {
758 cnp->cn_flags |= CNP_PDIRUNLOCK;
766 * Does this process have a text file?
769 procfs_validfile(struct lwp *lp)
771 return (procfs_findtextvp(lp->lwp_proc) != NULLVP);
775 * readdir() returns directory entries from pfsnode (vp).
777 * We generate just one directory entry at a time, as it would probably
778 * not pay off to buffer several entries locally to save uiomove calls.
780 * procfs_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred,
781 * int *a_eofflag, int *a_ncookies, off_t **a_cookies)
784 procfs_readdir(struct vop_readdir_args *ap)
789 if (ap->a_uio->uio_offset < 0 || ap->a_uio->uio_offset > INT_MAX)
791 if ((error = vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY)) != 0)
793 pfs = VTOPFS(ap->a_vp);
795 switch (pfs->pfs_type) {
798 * this is for the process-specific sub-directories.
799 * all that is needed to is copy out all the entries
800 * from the procent[] table (top of this file).
802 error = procfs_readdir_proc(ap);
806 * this is for the root of the procfs filesystem
807 * what is needed is a special entry for "curproc"
808 * followed by an entry for each process on allproc
810 error = procfs_readdir_root(ap);
822 procfs_readdir_proc(struct vop_readdir_args *ap)
825 int error, i, retval;
828 struct proc_target *pt;
829 struct uio *uio = ap->a_uio;
831 pfs = VTOPFS(ap->a_vp);
832 p = PFIND(pfs->pfs_pid);
835 if (!PRISON_CHECK(ap->a_cred, p->p_ucred))
838 lp = FIRST_LWP_IN_PROC(p);
841 i = (int)uio->uio_offset;
845 for (pt = &proc_targets[i];
846 !error && uio->uio_resid > 0 && i < nproc_targets; pt++, i++) {
847 if (pt->pt_valid && (*pt->pt_valid)(lp) == 0)
850 retval = vop_write_dirent(&error, uio,
851 PROCFS_FILENO(pfs->pfs_pid, pt->pt_pfstype), pt->pt_type,
852 pt->pt_namlen, pt->pt_name);
857 uio->uio_offset = (off_t)i;
862 struct procfs_readdir_root_info {
870 static int procfs_readdir_root_callback(struct proc *p, void *data);
873 procfs_readdir_root(struct vop_readdir_args *ap)
875 struct procfs_readdir_root_info info;
876 struct uio *uio = ap->a_uio;
880 info.i = (int)uio->uio_offset;
887 info.cred = ap->a_cred;
888 while (info.pcnt < 3) {
889 res = procfs_readdir_root_callback(NULL, &info);
894 allproc_scan(procfs_readdir_root_callback, &info);
895 uio->uio_offset = (off_t)info.i;
901 procfs_readdir_root_callback(struct proc *p, void *data)
903 struct procfs_readdir_root_info *info = data;
914 if (uio->uio_resid <= 0 || info->error)
917 switch (info->pcnt) {
919 d_ino = PROCFS_FILENO(0, Proot);
925 d_ino = PROCFS_FILENO(0, Proot);
932 d_ino = PROCFS_FILENO(0, Pcurproc);
940 if (!PRISON_CHECK(info->cred, p->p_ucred))
942 if (ps_showallprocs == 0 &&
943 info->cred->cr_uid != 0 &&
944 info->cred->cr_uid != p->p_ucred->cr_uid) {
949 * Skip entries we have already returned (optimization)
951 if (info->pcnt < info->i) {
956 d_ino = PROCFS_FILENO(p->p_pid, Pproc);
957 d_namlen = ksnprintf(d_name_pid, sizeof(d_name_pid),
958 "%ld", (long)p->p_pid);
965 * Skip entries we have already returned (optimization)
967 if (info->pcnt < info->i) {
972 retval = vop_write_dirent(&info->error, uio,
973 d_ino, d_type, d_namlen, d_name);
982 * readlink reads the link of `curproc' or `file'
985 procfs_readlink(struct vop_readlink_args *ap)
987 char buf[16]; /* should be enough */
989 struct vnode *vp = ap->a_vp;
990 struct pfsnode *pfs = VTOPFS(vp);
991 char *fullpath, *freepath;
994 switch (pfs->pfs_type) {
996 if (pfs->pfs_fileno != PROCFS_FILENO(0, Pcurproc))
999 len = ksnprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid);
1001 return (uiomove(buf, len, ap->a_uio));
1003 * There _should_ be no way for an entire process to disappear
1007 procp = PFIND(pfs->pfs_pid);
1008 if (procp == NULL || procp->p_ucred == NULL) {
1009 kprintf("procfs_readlink: pid %d disappeared\n",
1011 return (uiomove("unknown", sizeof("unknown") - 1,
1014 error = vn_fullpath(procp, NULL, &fullpath, &freepath);
1016 return (uiomove("unknown", sizeof("unknown") - 1,
1018 error = uiomove(fullpath, strlen(fullpath), ap->a_uio);
1019 kfree(freepath, M_TEMP);
1027 * convert decimal ascii to pid_t
1030 atopid(const char *b, u_int len)
1036 if (c < '0' || c > '9')
1038 p = 10 * p + (c - '0');