From 679a7c6b30cb5961b6ae8204bfd02c0138af681c Mon Sep 17 00:00:00 2001
From: Jan-Simon Pendry <pendry@ucbvax.Berkeley.EDU>
Date: Wed, 15 Jun 1994 19:30:54 -0800
Subject: [PATCH] merge in netbsd changes. security fixes, curproc becomes
 symlink, misc other trash.

SCCS-vsn: sys/miscfs/procfs/procfs.h 8.7
SCCS-vsn: sys/miscfs/procfs/README 8.2
SCCS-vsn: sys/miscfs/procfs/procfs_ctl.c 8.4
SCCS-vsn: sys/miscfs/procfs/procfs_mem.c 8.5
SCCS-vsn: sys/miscfs/procfs/procfs_regs.c 8.4
SCCS-vsn: sys/miscfs/procfs/procfs_subr.c 8.5
SCCS-vsn: sys/miscfs/procfs/procfs_vnops.c 8.8
SCCS-vsn: sys/miscfs/procfs/procfs_status.c 8.4
SCCS-vsn: sys/miscfs/procfs/procfs_vfsops.c 8.5
SCCS-vsn: sys/miscfs/procfs/procfs_fpregs.c 8.2
---
 usr/src/sys/miscfs/procfs/procfs.h        |  50 ++--
 usr/src/sys/miscfs/procfs/procfs_ctl.c    |  20 +-
 usr/src/sys/miscfs/procfs/procfs_fpregs.c |  10 +-
 usr/src/sys/miscfs/procfs/procfs_mem.c    |   8 +-
 usr/src/sys/miscfs/procfs/procfs_regs.c   |  10 +-
 usr/src/sys/miscfs/procfs/procfs_status.c |   6 +-
 usr/src/sys/miscfs/procfs/procfs_subr.c   |  59 +++--
 usr/src/sys/miscfs/procfs/procfs_vfsops.c |  18 +-
 usr/src/sys/miscfs/procfs/procfs_vnops.c  | 273 +++++++++++++---------
 9 files changed, 253 insertions(+), 201 deletions(-)

diff --git a/usr/src/sys/miscfs/procfs/procfs.h b/usr/src/sys/miscfs/procfs/procfs.h
index d325a66acd..45b617c8bc 100644
--- a/usr/src/sys/miscfs/procfs/procfs.h
+++ b/usr/src/sys/miscfs/procfs/procfs.h
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
- *	@(#)procfs.h	8.6 (Berkeley) %G%
+ *	@(#)procfs.h	8.7 (Berkeley) %G%
  *
  * From:
  *	$Id: procfs.h,v 3.2 1993/12/15 09:40:17 jsp Exp $
@@ -19,6 +19,7 @@
  */
 typedef enum {
 	Proot,		/* the filesystem root */
+	Pcurproc,	/* symbolic link for curproc */
 	Pproc,		/* a process-specific sub-directory */
 	Pfile,		/* the executable file */
 	Pmem,		/* the process's memory image */
@@ -68,9 +69,9 @@ struct pfsdent {
 };
 #define UIO_MX sizeof(struct pfsdent)
 #define PROCFS_FILENO(pid, type) \
-	(((type) == Proot) ? \
-			2 : \
-			((((pid)+1) << 3) + ((int) (type))))
+	(((type) < Pproc) ? \
+			((type) + 2) : \
+			((((pid)+1) << 4) + ((int) (type))))
 
 /*
  * Convert between pfsnode vnode
@@ -84,29 +85,34 @@ struct vfs_namemap {
 	int nm_val;
 };
 
-extern int vfs_getuserstr __P((struct uio *, char *, int *));
-extern vfs_namemap_t *vfs_findname __P((vfs_namemap_t *, char *, int));
+int vfs_getuserstr __P((struct uio *, char *, int *));
+vfs_namemap_t *vfs_findname __P((vfs_namemap_t *, char *, int));
 
 /* <machine/reg.h> */
 struct reg;
 struct fpreg;
 
 #define PFIND(pid) ((pid) ? pfind(pid) : &proc0)
-extern int procfs_freevp __P((struct vnode *));
-extern int procfs_allocvp __P((struct mount *, struct vnode **, long, pfstype));
-extern struct vnode *procfs_findtextvp __P((struct proc *));
-extern int procfs_sstep __P((struct proc *));
-extern void procfs_fix_sstep __P((struct proc *));
-extern int procfs_read_regs __P((struct proc *, struct reg *));
-extern int procfs_write_regs __P((struct proc *, struct reg *));
-extern int procfs_read_fpregs __P((struct proc *, struct fpreg *));
-extern int procfs_write_fpregs __P((struct proc *, struct fpreg *));
-extern int procfs_donote __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
-extern int procfs_doregs __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
-extern int procfs_dofpregs __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
-extern int procfs_domem __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
-extern int procfs_doctl __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
-extern int procfs_dostatus __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+int procfs_freevp __P((struct vnode *));
+int procfs_allocvp __P((struct mount *, struct vnode **, long, pfstype));
+struct vnode *procfs_findtextvp __P((struct proc *));
+int procfs_sstep __P((struct proc *, int));
+void procfs_fix_sstep __P((struct proc *));
+int procfs_read_regs __P((struct proc *, struct reg *));
+int procfs_write_regs __P((struct proc *, struct reg *));
+int procfs_read_fpregs __P((struct proc *, struct fpreg *));
+int procfs_write_fpregs __P((struct proc *, struct fpreg *));
+int procfs_donote __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+int procfs_doregs __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+int procfs_dofpregs __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+int procfs_domem __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+int procfs_doctl __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+int procfs_dostatus __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+
+/* functions to check whether or not files should be displayed */
+int procfs_validfile __P((struct proc *));
+int procfs_validfpregs __P((struct proc *));
+int procfs_validregs __P((struct proc *));
 
 #define PROCFS_LOCKED	0x01
 #define PROCFS_WANT	0x02
@@ -141,7 +147,7 @@ int	procfs_ioctl __P((struct vop_ioctl_args *));
 #define procfs_rmdir ((int (*) __P((struct vop_rmdir_args *))) procfs_badop)
 #define procfs_symlink ((int (*) __P((struct vop_symlink_args *))) procfs_badop)
 int	procfs_readdir __P((struct vop_readdir_args *));
-#define procfs_readlink ((int (*) __P((struct vop_readlink_args *))) procfs_badop)
+int	procfs_readlink __P((struct vop_readlink_args *));
 int	procfs_abortop __P((struct vop_abortop_args *));
 int	procfs_inactive __P((struct vop_inactive_args *));
 int	procfs_reclaim __P((struct vop_reclaim_args *));
diff --git a/usr/src/sys/miscfs/procfs/procfs_ctl.c b/usr/src/sys/miscfs/procfs/procfs_ctl.c
index 11123e81e7..cce6ca6c1b 100644
--- a/usr/src/sys/miscfs/procfs/procfs_ctl.c
+++ b/usr/src/sys/miscfs/procfs/procfs_ctl.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
- *	@(#)procfs_ctl.c	8.3 (Berkeley) %G%
+ *	@(#)procfs_ctl.c	8.4 (Berkeley) %G%
  *
  * From:
  *	$Id: procfs_ctl.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
@@ -24,8 +24,14 @@
 #include <sys/tty.h>
 #include <sys/resource.h>
 #include <sys/resourcevar.h>
+#include <sys/ptrace.h>
 #include <miscfs/procfs/procfs.h>
 
+#ifndef FIX_SSTEP
+#define FIX_SSTEP(p)
+#endif
+
+
 /*
  * True iff process (p) is in trace wait state
  * relative to process (curp)
@@ -35,15 +41,6 @@
 	 (p)->p_pptr == (curp) && \
 	 ((p)->p_flag & P_TRACED))
 
-#ifdef notdef
-#define FIX_SSTEP(p) { \
-		procfs_fix_sstep(p); \
-	} \
-}
-#else
-#define FIX_SSTEP(p)
-#endif
-
 #define PROCFS_CTL_ATTACH	1
 #define PROCFS_CTL_DETACH	2
 #define PROCFS_CTL_STEP		3
@@ -180,7 +177,8 @@ procfs_control(curp, p, op)
 	 * Step.  Let the target process execute a single instruction.
 	 */
 	case PROCFS_CTL_STEP:
-		procfs_sstep(p);
+		if (error = procfs_sstep(p, 1))
+			return (error);
 		break;
 
 	/*
diff --git a/usr/src/sys/miscfs/procfs/procfs_fpregs.c b/usr/src/sys/miscfs/procfs/procfs_fpregs.c
index bf9b015b6f..71e665c4f2 100644
--- a/usr/src/sys/miscfs/procfs/procfs_fpregs.c
+++ b/usr/src/sys/miscfs/procfs/procfs_fpregs.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
- *	@(#)procfs_fpregs.c	8.1 (Berkeley) %G%
+ *	@(#)procfs_fpregs.c	8.2 (Berkeley) %G%
  *
  * From:
  *	$Id: procfs_regs.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
@@ -59,3 +59,11 @@ procfs_dofpregs(curp, p, pfs, uio)
 	uio->uio_offset = 0;
 	return (error);
 }
+
+int
+procfs_validfpregs(p)
+	struct proc *p;
+{
+
+	return ((p->p_flag & P_SYSTEM) == 0);
+}
diff --git a/usr/src/sys/miscfs/procfs/procfs_mem.c b/usr/src/sys/miscfs/procfs/procfs_mem.c
index ff4ca33a5b..ef8f24c3bc 100644
--- a/usr/src/sys/miscfs/procfs/procfs_mem.c
+++ b/usr/src/sys/miscfs/procfs/procfs_mem.c
@@ -9,7 +9,7 @@
  *
  * %sccs.include.redist.c%
  *
- *	@(#)procfs_mem.c	8.4 (Berkeley) %G%
+ *	@(#)procfs_mem.c	8.5 (Berkeley) %G%
  *
  * From:
  *	$Id: procfs_mem.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
@@ -180,14 +180,11 @@ procfs_domem(curp, p, pfs, uio)
 	struct pfsnode *pfs;
 	struct uio *uio;
 {
-	int error;
 
 	if (uio->uio_resid == 0)
 		return (0);
 
-	error = procfs_rwmem(p, uio);
-
-	return (error);
+	return (procfs_rwmem(p, uio));
 }
 
 /*
@@ -205,6 +202,7 @@ struct vnode *
 procfs_findtextvp(p)
 	struct proc *p;
 {
+
 	return (p->p_textvp);
 }
 
diff --git a/usr/src/sys/miscfs/procfs/procfs_regs.c b/usr/src/sys/miscfs/procfs/procfs_regs.c
index 05a9657386..34847bcec9 100644
--- a/usr/src/sys/miscfs/procfs/procfs_regs.c
+++ b/usr/src/sys/miscfs/procfs/procfs_regs.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
- *	@(#)procfs_regs.c	8.3 (Berkeley) %G%
+ *	@(#)procfs_regs.c	8.4 (Berkeley) %G%
  *
  * From:
  *	$Id: procfs_regs.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
@@ -59,3 +59,11 @@ procfs_doregs(curp, p, pfs, uio)
 	uio->uio_offset = 0;
 	return (error);
 }
+
+int
+procfs_validregs(p)
+	struct proc *p;
+{
+
+	return ((p->p_flag & P_SYSTEM) == 0);
+}
diff --git a/usr/src/sys/miscfs/procfs/procfs_status.c b/usr/src/sys/miscfs/procfs/procfs_status.c
index b3ff0717eb..f204664dd3 100644
--- a/usr/src/sys/miscfs/procfs/procfs_status.c
+++ b/usr/src/sys/miscfs/procfs/procfs_status.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
- *	@(#)procfs_status.c	8.3 (Berkeley) %G%
+ *	@(#)procfs_status.c	8.4 (Berkeley) %G%
  *
  * From:
  *	$Id: procfs_status.c,v 3.1 1993/12/15 09:40:17 jsp Exp $
@@ -101,7 +101,7 @@ procfs_dostatus(curp, p, pfs, uio)
 
 	cr = p->p_ucred;
 
-	ps += sprintf(ps, " %d", cr->cr_uid, cr->cr_gid);
+	ps += sprintf(ps, " %d", cr->cr_uid);
 	for (i = 0; i < cr->cr_ngroups; i++)
 		ps += sprintf(ps, ",%d", cr->cr_groups[i]);
 	ps += sprintf(ps, "\n");
@@ -109,7 +109,7 @@ procfs_dostatus(curp, p, pfs, uio)
 	xlen = ps - psbuf;
 	xlen -= uio->uio_offset;
 	ps = psbuf + uio->uio_offset;
-	xlen = min(xlen, uio->uio_resid);
+	xlen = imin(xlen, uio->uio_resid);
 	if (xlen <= 0)
 		error = 0;
 	else
diff --git a/usr/src/sys/miscfs/procfs/procfs_subr.c b/usr/src/sys/miscfs/procfs/procfs_subr.c
index 9505f33ee5..6c4b989692 100644
--- a/usr/src/sys/miscfs/procfs/procfs_subr.c
+++ b/usr/src/sys/miscfs/procfs/procfs_subr.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
- *	@(#)procfs_subr.c	8.4 (Berkeley) %G%
+ *	@(#)procfs_subr.c	8.5 (Berkeley) %G%
  *
  * From:
  *	$Id: procfs_subr.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
@@ -59,18 +59,20 @@ procfs_allocvp(mp, vpp, pid, pfs_type)
 	long pid;
 	pfstype pfs_type;
 {
-	int error;
 	struct pfsnode *pfs;
+	struct vnode *vp;
 	struct pfsnode **pp;
+	int error;
 
 loop:
 	for (pfs = pfshead; pfs != 0; pfs = pfs->pfs_next) {
+		vp = PFSTOV(pfs);
 		if (pfs->pfs_pid == pid &&
 		    pfs->pfs_type == pfs_type &&
-		    PFSTOV(pfs)->v_mount == mp) {
-			if (vget(pfs->pfs_vnode, 0))
+		    vp->v_mount == mp) {
+			if (vget(vp, 0))
 				goto loop;
-			*vpp = pfs->pfs_vnode;
+			*vpp = vp;
 			return (0);
 		}
 	}
@@ -86,18 +88,17 @@ loop:
 	}
 	pfsvplock |= PROCFS_LOCKED;
 
-	error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp);
-	if (error)
+	if (error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp))
 		goto out;
+	vp = *vpp;
 
-	MALLOC((*vpp)->v_data, void *, sizeof(struct pfsnode),
-		M_TEMP, M_WAITOK);
+	MALLOC(pfs, void *, sizeof(struct pfsnode), M_TEMP, M_WAITOK);
+	vp->v_data = pfs;
 
-	pfs = VTOPFS(*vpp);
 	pfs->pfs_next = 0;
 	pfs->pfs_pid = (pid_t) pid;
 	pfs->pfs_type = pfs_type;
-	pfs->pfs_vnode = *vpp;
+	pfs->pfs_vnode = vp;
 	pfs->pfs_flags = 0;
 	pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type);
 
@@ -106,46 +107,44 @@ loop:
 		pfs->pfs_mode = (VREAD|VEXEC) |
 				(VREAD|VEXEC) >> 3 |
 				(VREAD|VEXEC) >> 6;
+		vp->v_type = VDIR;
+		vp->v_flag = VROOT;
+		break;
+
+	case Pcurproc:	/* /proc/curproc = lr--r--r-- */
+		pfs->pfs_mode = (VREAD) |
+				(VREAD >> 3) |
+				(VREAD >> 6);
+		vp->v_type = VLNK;
 		break;
 
 	case Pproc:
 		pfs->pfs_mode = (VREAD|VEXEC) |
 				(VREAD|VEXEC) >> 3 |
 				(VREAD|VEXEC) >> 6;
+		vp->v_type = VDIR;
 		break;
 
 	case Pfile:
-		pfs->pfs_mode = (VREAD|VWRITE);
-		break;
-
 	case Pmem:
-		pfs->pfs_mode = (VREAD|VWRITE);
-		break;
-
 	case Pregs:
-		pfs->pfs_mode = (VREAD|VWRITE);
-		break;
-
 	case Pfpregs:
 		pfs->pfs_mode = (VREAD|VWRITE);
+		vp->v_type = VREG;
 		break;
 
 	case Pctl:
+	case Pnote:
+	case Pnotepg:
 		pfs->pfs_mode = (VWRITE);
+		vp->v_type = VREG;
 		break;
 
 	case Pstatus:
 		pfs->pfs_mode = (VREAD) |
 				(VREAD >> 3) |
 				(VREAD >> 6);
-		break;
-
-	case Pnote:
-		pfs->pfs_mode = (VWRITE);
-		break;
-
-	case Pnotepg:
-		pfs->pfs_mode = (VWRITE);
+		vp->v_type = VREG;
 		break;
 
 	default:
@@ -257,8 +256,7 @@ vfs_getuserstr(uio, buf, buflenp)
 		return (EMSGSIZE);
 	xlen = uio->uio_resid;
 
-	error = uiomove(buf, xlen, uio);
-	if (error)
+	if (error = uiomove(buf, xlen, uio))
 		return (error);
 
 	/* allow multiple writes without seeks */
@@ -280,6 +278,7 @@ vfs_findname(nm, buf, buflen)
 	char *buf;
 	int buflen;
 {
+
 	for (; nm->nm_name; nm++)
 		if (bcmp(buf, (char *) nm->nm_name, buflen+1) == 0)
 			return (nm);
diff --git a/usr/src/sys/miscfs/procfs/procfs_vfsops.c b/usr/src/sys/miscfs/procfs/procfs_vfsops.c
index ea6b6d5cfe..c60f093eae 100644
--- a/usr/src/sys/miscfs/procfs/procfs_vfsops.c
+++ b/usr/src/sys/miscfs/procfs/procfs_vfsops.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
- *	@(#)procfs_vfsops.c	8.4 (Berkeley) %G%
+ *	@(#)procfs_vfsops.c	8.5 (Berkeley) %G%
  *
  * From:
  *	$Id: procfs_vfsops.c,v 3.1 1993/12/15 09:40:17 jsp Exp $
@@ -96,24 +96,10 @@ procfs_root(mp, vpp)
 	struct mount *mp;
 	struct vnode **vpp;
 {
-	struct pfsnode *pfs;
-	struct vnode *vp;
-	int error;
-
-	error = procfs_allocvp(mp, &vp, (pid_t) 0, Proot);
-	if (error)
-		return (error);
 
-	vp->v_type = VDIR;
-	vp->v_flag = VROOT;
-	pfs = VTOPFS(vp);
-
-	*vpp = vp;
-	return (0);
+	return (procfs_allocvp(mp, vpp, 0, Proot));
 }
 
-/*
- */
 /* ARGSUSED */
 procfs_start(mp, flags, p)
 	struct mount *mp;
diff --git a/usr/src/sys/miscfs/procfs/procfs_vnops.c b/usr/src/sys/miscfs/procfs/procfs_vnops.c
index 1d6a95d9c1..1294d34ddd 100644
--- a/usr/src/sys/miscfs/procfs/procfs_vnops.c
+++ b/usr/src/sys/miscfs/procfs/procfs_vnops.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
- *	@(#)procfs_vnops.c	8.7 (Berkeley) %G%
+ *	@(#)procfs_vnops.c	8.8 (Berkeley) %G%
  *
  * From:
  *	$Id: procfs_vnops.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
@@ -29,8 +29,9 @@
 #include <sys/malloc.h>
 #include <sys/dirent.h>
 #include <sys/resourcevar.h>
-#include <miscfs/procfs/procfs.h>
 #include <vm/vm.h>	/* for PAGE_SIZE */
+#include <machine/reg.h>
+#include <miscfs/procfs/procfs.h>
 
 /*
  * Vnode Operations.
@@ -43,20 +44,24 @@
  * used in procfs_lookup and procfs_readdir
  */
 static struct pfsnames {
-	u_short	d_namlen;
+	u_char	d_type;
+	u_char	d_namlen;
 	char	d_name[PROCFS_NAMELEN];
 	pfstype	d_pfstype;
+	int	(*d_valid) __P((struct proc *p));
 } procent[] = {
 #define N(s) sizeof(s)-1, s
 	/* namlen, nam, type */
-	{  N("file"),	Pfile },
-	{  N("mem"),	Pmem },
-	{  N("regs"),	Pregs },
-	{  N("fpregs"),	Pfpregs },
-	{  N("ctl"),	Pctl },
-	{  N("status"),	Pstatus },
-	{  N("note"),	Pnote },
-	{  N("notepg"),	Pnotepg },
+	{ DT_DIR, N("."),	Pproc,		NULL },
+	{ DT_DIR, N(".."),	Proot,		NULL },
+	{ DT_REG, N("file"),	Pfile,		procfs_validfile },
+	{ DT_REG, N("mem"),	Pmem,		NULL },
+	{ DT_REG, N("regs"),	Pregs,		procfs_validregs },
+	{ DT_REG, N("fpregs"),	Pfpregs,	procfs_validfpregs },
+	{ DT_REG, N("ctl"),	Pctl,		NULL },
+	{ DT_REG, N("status"),	Pstatus,	NULL },
+	{ DT_REG, N("note"),	Pnote,		NULL },
+	{ DT_REG, N("notepg"),	Pnotepg,	NULL },
 #undef N
 };
 #define Nprocent (sizeof(procent)/sizeof(procent[0]))
@@ -90,10 +95,9 @@ procfs_open(ap)
 			return (ENOENT);	/* was ESRCH, jsp */
 
 		if ((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL) ||
-				(pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE))
+		    (pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE))
 			return (EBUSY);
 
-
 		if (ap->a_mode & FWRITE)
 			pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL);
 
@@ -218,10 +222,8 @@ procfs_reclaim(ap)
 		struct vnode *a_vp;
 	} */ *ap;
 {
-	int error;
 
-	error = procfs_freevp(ap->a_vp);
-	return (error);
+	return (procfs_freevp(ap->a_vp));
 }
 
 /*
@@ -272,9 +274,8 @@ procfs_print(ap)
 {
 	struct pfsnode *pfs = VTOPFS(ap->a_vp);
 
-	printf("tag VT_PROCFS, pid %d, mode %x, flags %x\n",
-		pfs->pfs_pid,
-		pfs->pfs_mode, pfs->pfs_flags);
+	printf("tag VT_PROCFS, type %s, pid %d, mode %x, flags %x\n",
+	    pfs->pfs_type, pfs->pfs_pid, pfs->pfs_mode, pfs->pfs_flags);
 }
 
 /*
@@ -329,6 +330,7 @@ procfs_getattr(ap)
 	/* first check the process still exists */
 	switch (pfs->pfs_type) {
 	case Proot:
+	case Pcurproc:
 		procp = 0;
 		break;
 
@@ -351,33 +353,43 @@ procfs_getattr(ap)
 	vap->va_blocksize = PAGE_SIZE;
 	vap->va_bytes = vap->va_size = 0;
 
+	/*
+	 * Make all times be current TOD.
+	 * It would be possible to get the process start
+	 * time from the p_stat structure, but there's
+	 * no "file creation" time stamp anyway, and the
+	 * p_stat structure is not addressible if u. gets
+	 * swapped out for that process.
+	 *
+	 * XXX
+	 * Note that microtime() returns a timeval, not a timespec.
+	 */
+	microtime(&vap->va_ctime);
+	vap->va_atime = vap->va_mtime = vap->va_ctime;
+
 	/*
 	 * If the process has exercised some setuid or setgid
 	 * privilege, then rip away read/write permission so
 	 * that only root can gain access.
 	 */
 	switch (pfs->pfs_type) {
+	case Pmem:
 	case Pregs:
 	case Pfpregs:
-	case Pmem:
 		if (procp->p_flag & P_SUGID)
 			vap->va_mode &= ~((VREAD|VWRITE)|
 					  ((VREAD|VWRITE)>>3)|
 					  ((VREAD|VWRITE)>>6));
+	case Pctl:
+	case Pstatus:
+	case Pnote:
+	case Pnotepg:
+		vap->va_nlink = 1;
+		vap->va_uid = procp->p_ucred->cr_uid;
+		vap->va_gid = procp->p_ucred->cr_gid;
 		break;
 	}
 
-	/*
-	 * Make all times be current TOD.
-	 * It would be possible to get the process start
-	 * time from the p_stat structure, but there's
-	 * no "file creation" time stamp anyway, and the
-	 * p_stat structure is not addressible if u. gets
-	 * swapped out for that process.
-	 */
-	microtime(&vap->va_ctime);
-	vap->va_atime = vap->va_mtime = vap->va_ctime;
-
 	/*
 	 * now do the object specific fields
 	 *
@@ -390,15 +402,30 @@ procfs_getattr(ap)
 
 	switch (pfs->pfs_type) {
 	case Proot:
-		vap->va_nlink = 2;
+		/*
+		 * Set nlink to 1 to tell fts(3) we don't actually know.
+		 */
+		vap->va_nlink = 1;
+		vap->va_uid = 0;
+		vap->va_gid = 0;
+		vap->va_size = vap->va_bytes = DEV_BSIZE;
+		break;
+
+	case Pcurproc: {
+		char buf[16];		/* should be enough */
+		vap->va_nlink = 1;
 		vap->va_uid = 0;
 		vap->va_gid = 0;
+		vap->va_size = vap->va_bytes =
+		    sprintf(buf, "%ld", (long)curproc->p_pid);
 		break;
+	}
 
 	case Pproc:
 		vap->va_nlink = 2;
 		vap->va_uid = procp->p_ucred->cr_uid;
 		vap->va_gid = procp->p_ucred->cr_gid;
+		vap->va_size = vap->va_bytes = DEV_BSIZE;
 		break;
 
 	case Pfile:
@@ -406,24 +433,24 @@ procfs_getattr(ap)
 		break;
 
 	case Pmem:
-		vap->va_nlink = 1;
 		vap->va_bytes = vap->va_size =
 			ctob(procp->p_vmspace->vm_tsize +
 				    procp->p_vmspace->vm_dsize +
 				    procp->p_vmspace->vm_ssize);
-		vap->va_uid = procp->p_ucred->cr_uid;
-		vap->va_gid = procp->p_ucred->cr_gid;
 		break;
 
 	case Pregs:
+		vap->va_bytes = vap->va_size = sizeof(struct reg);
+		break;
+
 	case Pfpregs:
+		vap->va_bytes = vap->va_size = sizeof(struct fpreg);
+		break;
+
 	case Pctl:
 	case Pstatus:
 	case Pnote:
 	case Pnotepg:
-		vap->va_nlink = 1;
-		vap->va_uid = procp->p_ucred->cr_uid;
-		vap->va_gid = procp->p_ucred->cr_gid;
 		break;
 
 	default:
@@ -482,8 +509,9 @@ procfs_access(ap)
 	 * If you're the super-user,
 	 * you always get access.
 	 */
-	if (ap->a_cred->cr_uid == (uid_t) 0)
+	if (ap->a_cred->cr_uid == 0)
 		return (0);
+
 	vap = &vattr;
 	if (error = VOP_GETATTR(ap->a_vp, vap, ap->a_cred, ap->a_p))
 		return (error);
@@ -497,7 +525,7 @@ procfs_access(ap)
 		gid_t *gp;
 		int i;
 
-		(ap->a_mode) >>= 3;
+		ap->a_mode >>= 3;
 		gp = ap->a_cred->cr_groups;
 		for (i = 0; i < ap->a_cred->cr_ngroups; i++, gp++)
 			if (vap->va_gid == *gp)
@@ -557,9 +585,9 @@ procfs_lookup(ap)
 			return (EIO);
 
 		if (CNEQ(cnp, "curproc", 7))
-			pid = cnp->cn_proc->p_pid;
-		else
-			pid = atopid(pname, cnp->cn_namelen);
+			return (procfs_allocvp(dvp->v_mount, vpp, 0, Pcurproc));
+
+		pid = atopid(pname, cnp->cn_namelen);
 		if (pid == NO_PID)
 			return (ENOENT);
 
@@ -567,15 +595,7 @@ procfs_lookup(ap)
 		if (procp == 0)
 			return (ENOENT);
 
-		error = procfs_allocvp(dvp->v_mount, &nvp, pid, Pproc);
-		if (error)
-			return (error);
-
-		nvp->v_type = VDIR;
-		pfs = VTOPFS(nvp);
-
-		*vpp = nvp;
-		return (0);
+		return (procfs_allocvp(dvp->v_mount, vpp, pid, Pproc));
 
 	case Pproc:
 		if (cnp->cn_flags & ISDOTDOT) {
@@ -591,7 +611,8 @@ procfs_lookup(ap)
 			struct pfsnames *dp = &procent[i];
 
 			if (cnp->cn_namelen == dp->d_namlen &&
-			    bcmp(pname, dp->d_name, dp->d_namlen) == 0) {
+			    bcmp(pname, dp->d_name, dp->d_namlen) == 0 &&
+			    (dp->d_valid == NULL || (*dp->d_valid)(procp))) {
 			    	pfs_type = dp->d_pfstype;
 				goto found;
 			}
@@ -601,29 +622,30 @@ procfs_lookup(ap)
 	found:
 		if (pfs_type == Pfile) {
 			nvp = procfs_findtextvp(procp);
-			if (nvp) {
-				VREF(nvp);
-				VOP_LOCK(nvp);
-			} else {
-				error = ENXIO;
-			}
-		} else {
-			error = procfs_allocvp(dvp->v_mount, &nvp,
-					pfs->pfs_pid, pfs_type);
-			if (error)
-				return (error);
-
-			nvp->v_type = VREG;
-			pfs = VTOPFS(nvp);
+			if (nvp == NULLVP)
+				return (ENXIO);
+			VREF(nvp);
+			VOP_LOCK(nvp);
+			*vpp = nvp;
+			return (0);
 		}
-		*vpp = nvp;
-		return (error);
+
+		return (procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid,
+		    pfs_type));
 
 	default:
 		return (ENOTDIR);
 	}
 }
 
+int
+procfs_validfile(p)
+	struct proc *p;
+{
+
+	return (procfs_findtextvp(p) != NULLVP);
+}
+
 /*
  * readdir returns directory entries from pfsnode (vp).
  *
@@ -681,24 +703,27 @@ procfs_readdir(ap)
 	 * from the procent[] table (top of this file).
 	 */
 	case Pproc: {
-		while (uio->uio_resid >= UIO_MX) {
-			struct pfsnames *dt;
+		pid_t pid = pfs->pfs_pid;
+		struct pfsnames *dt;
+
+		for (dt = &procent[i]; i < Nprocent && uio->uio_resid >= UIO_MX;
+		     dt++, i++) {
+			struct proc *p = PFIND(pid);
 
-			if (i >= Nprocent)
+			if (p == NULL)
 				break;
 
-			dt = &procent[i];
+			if (dt->d_valid && (*dt->d_valid)(p) == 0)
+				continue;
 			
 			dp->d_reclen = UIO_MX;
-			dp->d_fileno = PROCFS_FILENO(pfs->pfs_pid, dt->d_pfstype);
-			dp->d_type = DT_REG;
+			dp->d_fileno = PROCFS_FILENO(pid, dt->d_pfstype);
 			dp->d_namlen = dt->d_namlen;
-			bcopy(dt->d_name, dp->d_name, sizeof(dt->d_name)-1);
-			error = uiomove((caddr_t) dp, UIO_MX, uio);
-			if (error)
+			bcopy(dt->d_name, dp->d_name, dt->d_namlen + 1);
+			dp->d_type = dt->d_type;
+
+			if (error = uiomove((caddr_t)dp, UIO_MX, uio))
 				break;
-			count += UIO_MX;
-			i++;
 		}
 
 	    	break;
@@ -715,55 +740,61 @@ procfs_readdir(ap)
 	 */
 
 	case Proot: {
-		int pcnt;
 #ifdef PROCFS_ZOMBIE
 		int doingzomb = 0;
 #endif
-		volatile struct proc *p;
-
-		p = allproc;
-
-#define PROCFS_XFILES	1	/* number of other entries, like "curproc" */
-		pcnt = PROCFS_XFILES;
+		int pcnt = 0;
+		volatile struct proc *p = allproc;
 
-		while (p && uio->uio_resid >= UIO_MX) {
+	again:
+		for (; p && uio->uio_resid >= UIO_MX; i++, pcnt++) {
 			bzero((char *) dp, UIO_MX);
-			dp->d_type = DT_DIR;
 			dp->d_reclen = UIO_MX;
 
 			switch (i) {
-			case 0:
-				/* ship out entry for "curproc" */
-				dp->d_fileno = PROCFS_FILENO(PID_MAX+1, Pproc);
-				dp->d_namlen = sprintf(dp->d_name, "curproc");
+			case 0:		/* `.' */
+			case 1:		/* `..' */
+				dp->d_fileno = PROCFS_FILENO(0, Proot);
+				dp->d_namlen = i + 1;
+				bcopy("..", dp->d_name, dp->d_namlen);
+				dp->d_name[i + 1] = '\0';
+				dp->d_type = DT_DIR;
+				break;
+
+			case 2:
+				dp->d_fileno = PROCFS_FILENO(0, Pcurproc);
+				dp->d_namlen = 7;
+				bcopy("curproc", dp->d_name, 8);
+				dp->d_type = DT_LNK;
 				break;
 
 			default:
-				if (pcnt >= i) {
-					dp->d_fileno = PROCFS_FILENO(p->p_pid, Pproc);
-					dp->d_namlen = sprintf(dp->d_name, "%ld", (long) p->p_pid);
+				while (pcnt < i) {
+					pcnt++;
+					p = p->p_next;
+					if (!p)
+						goto done;
 				}
-
+				dp->d_fileno = PROCFS_FILENO(p->p_pid, Pproc);
+				dp->d_namlen = sprintf(dp->d_name, "%ld",
+				    (long)p->p_pid);
+				dp->d_type = DT_REG;
 				p = p->p_next;
-
-#ifdef PROCFS_ZOMBIE
-				if (p == 0 && doingzomb == 0) {
-					doingzomb = 1;
-					p = zombproc;
-				}
-#endif
-
-				if (pcnt++ < i)
-					continue;
-
 				break;
 			}
-			error = uiomove((caddr_t) dp, UIO_MX, uio);
-			if (error)
+
+			if (error = uiomove((caddr_t)dp, UIO_MX, uio))
 				break;
-			count += UIO_MX;
-			i++;
 		}
+	done:
+
+#ifdef PROCFS_ZOMBIE
+		if (p == 0 && doingzomb == 0) {
+			doingzomb = 1;
+			p = zombproc;
+			goto again;
+		}
+#endif
 
 		break;
 
@@ -779,6 +810,24 @@ procfs_readdir(ap)
 	return (error);
 }
 
+/*
+ * readlink reads the link of `curproc'
+ */
+procfs_readlink(ap)
+	struct vop_readlink_args *ap;
+{
+	struct uio *uio = ap->a_uio;
+	char buf[16];		/* should be enough */
+	int len;
+
+	if (VTOPFS(ap->a_vp)->pfs_fileno != PROCFS_FILENO(0, Pcurproc))
+		return (EINVAL);
+
+	len = sprintf(buf, "%ld", (long)curproc->p_pid);
+
+	return (uiomove((caddr_t)buf, len, ap->a_uio));
+}
+
 /*
  * convert decimal ascii to pid_t
  */
-- 
2.20.1