Major fixes for procfs..

Implement a "variable" directory structure. Files that do not make
sense for the given process do not "appear" and cannot be opened.
For example, "system" processes do not have "file", "regs" or "fpregs",
because they do not have a user area.

"attempt" to fill in the user area of a given process when it is being
accessed via /proc/pid/mem (the user struct is just after
VM_MAXUSER_ADDRESS in the process address space.)

Dont do IO to the U area while it's swapped, hold it in place if possible.

Lock off access to the "ctl" file if it's done a setuid like the other
pseudo-files in there.

6 files changed, 88 insertions, 22 deletions

diff --git a/sys/fs/procfs/procfs.h b/sys/fs/procfs/procfs.h
index ddb5757..964c667 100644
--- a/sys/fs/procfs/procfs.h
+++ b/sys/fs/procfs/procfs.h
@@ -36,7 +36,7 @@
  *
  *	@(#)procfs.h	8.6 (Berkeley) 2/3/94
  *
- *	$Id: procfs.h,v 1.7 1995/11/09 08:16:01 bde Exp $
+ *	$Id: procfs.h,v 1.8 1995/11/16 11:39:09 bde Exp $
  */
 
 /*
@@ -134,6 +134,11 @@ extern int procfs_domem __P((struct proc *, struct proc *, struct pfsnode *pfsp,
 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));
 
+/* check to see if the process has the "items" (regs/file) */
+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
 
diff --git a/sys/fs/procfs/procfs_ctl.c b/sys/fs/procfs/procfs_ctl.c
index d11a296..78d4ac2 100644
--- a/sys/fs/procfs/procfs_ctl.c
+++ b/sys/fs/procfs/procfs_ctl.c
@@ -36,7 +36,7 @@
  *
  *	@(#)procfs_ctl.c	8.3 (Berkeley) 1/21/94
  *
- *	$Id: procfs_ctl.c,v 1.7 1995/12/03 14:54:34 bde Exp $
+ *	$Id: procfs_ctl.c,v 1.8 1995/12/07 12:47:14 davidg Exp $
  */
 
 #include <sys/param.h>
@@ -72,8 +72,6 @@
 		procfs_fix_sstep(p); \
 	} \
 }
-#else
-#define FIX_SSTEP(p)
 #endif
 
 #define PROCFS_CTL_ATTACH	1
@@ -171,10 +169,13 @@ procfs_control(curp, p, op)
 			return (EBUSY);
 	}
 
+
+#ifdef FIX_SSTEP
 	/*
 	 * do single-step fixup if needed
 	 */
 	FIX_SSTEP(p);
+#endif
 
 	/*
 	 * Don't deliver any signal by default.
@@ -218,7 +219,9 @@ procfs_control(curp, p, op)
 	 * Step.  Let the target process execute a single instruction.
 	 */
 	case PROCFS_CTL_STEP:
+		PHOLD(p);
 		procfs_sstep(p);
+		PRELE(p);
 		break;
 
 	/*
@@ -301,7 +304,9 @@ procfs_doctl(curp, p, pfs, uio)
 		if (nm) {
 			if (TRACE_WAIT_P(curp, p)) {
 				p->p_xstat = nm->nm_val;
+#ifdef FIX_SSTEP
 				FIX_SSTEP(p);
+#endif
 				setrunnable(p);
 			} else {
 				psignal(p, nm->nm_val);
diff --git a/sys/fs/procfs/procfs_fpregs.c b/sys/fs/procfs/procfs_fpregs.c
index 331a671..3f233bd 100644
--- a/sys/fs/procfs/procfs_fpregs.c
+++ b/sys/fs/procfs/procfs_fpregs.c
@@ -36,7 +36,7 @@
  *
  *	@(#)procfs_fpregs.c	8.1 (Berkeley) 1/27/94
  *
- *	$Id: procfs_fpregs.c,v 1.1.1.1 1994/05/24 10:05:09 rgrimes Exp $
+ *	$Id: procfs_fpregs.c,v 1.2 1994/08/02 07:45:12 davidg Exp $
  */
 
 #include <sys/param.h>
@@ -47,6 +47,8 @@
 #include <sys/vnode.h>
 #include <machine/reg.h>
 #include <miscfs/procfs/procfs.h>
+#include <vm/vm.h>
+#include <vm/vm_extern.h>
 
 int
 procfs_dofpregs(curp, p, pfs, uio)
@@ -68,6 +70,8 @@ procfs_dofpregs(curp, p, pfs, uio)
 	if (kl > uio->uio_resid)
 		kl = uio->uio_resid;
 
+	PHOLD(p);
+
 	if (kl < 0)
 		error = EINVAL;
 	else
@@ -80,7 +84,15 @@ procfs_dofpregs(curp, p, pfs, uio)
 		else
 			error = procfs_write_fpregs(p, &r);
 	}
+	PRELE(p);
 
 	uio->uio_offset = 0;
 	return (error);
 }
+
+int
+procfs_validfpregs(p)
+	struct proc *p;
+{
+	return ((p->p_flag & P_SYSTEM) == 0);
+}
diff --git a/sys/fs/procfs/procfs_mem.c b/sys/fs/procfs/procfs_mem.c
index b536055..f772c4b 100644
--- a/sys/fs/procfs/procfs_mem.c
+++ b/sys/fs/procfs/procfs_mem.c
@@ -37,7 +37,7 @@
  *
  *	@(#)procfs_mem.c	8.4 (Berkeley) 1/21/94
  *
- *	$Id: procfs_mem.c,v 1.14 1995/12/17 07:19:24 bde Exp $
+ *	$Id: procfs_mem.c,v 1.15 1996/01/19 03:58:32 dyson Exp $
  */
 
 /*
@@ -62,6 +62,7 @@
 #include <vm/vm_object.h>
 #include <vm/vm_page.h>
 #include <vm/vm_extern.h>
+#include <sys/user.h>
 
 static int	procfs_rwmem __P((struct proc *p, struct uio *uio));
 
@@ -96,10 +97,18 @@ procfs_rwmem(p, uio)
 
 		uva = (vm_offset_t) uio->uio_offset;
 		if (uva >= VM_MAXUSER_ADDRESS) {
+			
 			if (writing || (uva >= (VM_MAXUSER_ADDRESS + UPAGES * PAGE_SIZE))) {
 				error = 0;
 				break;
 			}
+			/* we are reading the "U area", fill it in */
+			PHOLD(p);
+			if (p->p_flag & P_INMEM) {
+				p->p_addr->u_kproc.kp_proc = *p;
+				fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
+			}
+			PRELE(p);
 		}
 
 		/*
diff --git a/sys/fs/procfs/procfs_regs.c b/sys/fs/procfs/procfs_regs.c
index 8b0600a..bc5520c 100644
--- a/sys/fs/procfs/procfs_regs.c
+++ b/sys/fs/procfs/procfs_regs.c
@@ -36,7 +36,7 @@
  *
  *	@(#)procfs_regs.c	8.3 (Berkeley) 1/27/94
  *
- *	$Id: procfs_regs.c,v 1.1.1.1 1994/05/24 10:05:08 rgrimes Exp $
+ *	$Id: procfs_regs.c,v 1.2 1994/08/02 07:45:18 davidg Exp $
  */
 
 #include <sys/param.h>
@@ -47,6 +47,8 @@
 #include <sys/vnode.h>
 #include <machine/reg.h>
 #include <miscfs/procfs/procfs.h>
+#include <vm/vm.h>
+#include <vm/vm_extern.h>
 
 int
 procfs_doregs(curp, p, pfs, uio)
@@ -68,6 +70,8 @@ procfs_doregs(curp, p, pfs, uio)
 	if (kl > uio->uio_resid)
 		kl = uio->uio_resid;
 
+	PHOLD(p);
+
 	if (kl < 0)
 		error = EINVAL;
 	else
@@ -80,7 +84,15 @@ procfs_doregs(curp, p, pfs, uio)
 		else
 			error = procfs_write_regs(p, &r);
 	}
+	PRELE(p);
 
 	uio->uio_offset = 0;
 	return (error);
 }
+
+int
+procfs_validregs(p)
+	struct proc *p;
+{
+	return ((p->p_flag & P_SYSTEM) == 0);
+}
diff --git a/sys/fs/procfs/procfs_vnops.c b/sys/fs/procfs/procfs_vnops.c
index 24638fe..df57932 100644
--- a/sys/fs/procfs/procfs_vnops.c
+++ b/sys/fs/procfs/procfs_vnops.c
@@ -36,7 +36,7 @@
  *
  *	@(#)procfs_vnops.c	8.6 (Berkeley) 2/7/94
  *
- *	$Id: procfs_vnops.c,v 1.18 1995/11/09 08:16:04 bde Exp $
+ *	$Id: procfs_vnops.c,v 1.19 1995/11/16 11:39:11 bde Exp $
  */
 
 /*
@@ -81,21 +81,20 @@ static struct pfsnames {
 	u_short	d_namlen;
 	char	d_name[PROCFS_NAMELEN];
 	pfstype	d_pfstype;
+	int	(*d_valid) __P((struct proc *));
 } procent[] = {
 #define N(s) sizeof(s)-1, s
-	/* namlen, nam, type */
-	{  N("."),	Pproc },
-	{  N(".."),	Proot },
-#if 0
-	{  N("file"),	Pfile },
-#endif
-	{  N("mem"),	Pmem },
-	{  N("regs"),	Pregs },
-	{  N("fpregs"),	Pfpregs },
-	{  N("ctl"),	Pctl },
-	{  N("status"),	Pstatus },
-	{  N("note"),	Pnote },
-	{  N("notepg"),	Pnotepg },
+	/* namlen, nam, type	 validp */
+	{  N("."),	Pproc,	 NULL },
+	{  N(".."),	Proot,	 NULL },
+	{  N("file"),	Pfile,	 procfs_validfile },
+	{  N("mem"),	Pmem,	 NULL },
+	{  N("regs"),	Pregs,	 procfs_validregs },
+	{  N("fpregs"),	Pfpregs, procfs_validfpregs },
+	{  N("ctl"),	Pctl,	 NULL },
+	{  N("status"),	Pstatus, NULL },
+	{  N("note"),	Pnote,	 NULL },
+	{  N("notepg"),	Pnotepg, NULL },
 #undef N
 };
 #define Nprocent (sizeof(procent)/sizeof(procent[0]))
@@ -356,6 +355,7 @@ procfs_getattr(ap)
 	 * that only root can gain access.
 	 */
 	switch (pfs->pfs_type) {
+	case Pctl:
 	case Pregs:
 	case Pfpregs:
 		if (procp->p_flag & P_SUGID)
@@ -599,7 +599,8 @@ 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;
 			}
@@ -633,6 +634,16 @@ procfs_lookup(ap)
 }
 
 /*
+ * Does this process have a text file?
+ */
+int
+procfs_validfile(p)
+	struct proc *p;
+{
+	return (procfs_findtextvp(p) != NULLVP);
+}
+
+/*
  * readdir returns directory entries from pfsnode (vp).
  *
  * the strategy here with procfs is to generate a single
@@ -676,6 +687,12 @@ procfs_readdir(ap)
 	 * from the procent[] table (top of this file).
 	 */
 	case Pproc: {
+		struct proc *p;
+
+		p = PFIND(pfs->pfs_pid);
+		if (p == NULL)
+			break;
+
 		while (uio->uio_resid >= UIO_MX) {
 			struct pfsnames *dt;
 
@@ -684,6 +701,12 @@ procfs_readdir(ap)
 
 			dt = &procent[i];
 
+			/* see if we should show this one. */
+			if (dt->d_valid && (*dt->d_valid)(p) == 0) {
+				i++;
+				continue;
+			}
+
 			dp->d_reclen = UIO_MX;
 			dp->d_fileno = PROCFS_FILENO(pfs->pfs_pid, dt->d_pfstype);
 			dp->d_type = DT_REG;