From 3ac5e95583e70eb01604b8976dfcde2ccfbd4d7d Mon Sep 17 00:00:00 2001
From: John Dyson <dyson@FreeBSD.org>
Date: Fri, 5 Dec 1997 07:33:40 +0000
Subject: [PATCH] Add an option to building PS, so that the upages are
 explicitly paged in only for users who are root, or in group wheel.  This is
 useful on large timesharing systems where a PS command can cause the system
 to grind to a halt.  The ability to get the information isn't diminished for
 those who really need the additional detail (administrators.)  Normal users
 won't see any difference unless the processes are swapped out.  The "really
 get it mode" is invoked by the use of an additional flag in the command
 string "-f".  New/old behavior is selectable with a compile option.

PR:		5196
Submitted by:	Matt Dillon <dillon@best.net>
---
 bin/ps/Makefile | 10 ++++++++--
 bin/ps/ps.c     | 47 ++++++++++++++++++++++++++++++++++++-----------
 2 files changed, 44 insertions(+), 13 deletions(-)

diff --git a/bin/ps/Makefile b/bin/ps/Makefile
index 8d797bcd3b1..4e8d954d799 100644
--- a/bin/ps/Makefile
+++ b/bin/ps/Makefile
@@ -1,9 +1,15 @@
-#	$Id: Makefile,v 1.9 1997/08/11 02:36:09 steve Exp $
+#	$Id: Makefile,v 1.10 1997/08/13 17:35:00 steve Exp $
 #	@(#)Makefile	8.1 (Berkeley) 6/2/93
 
 PROG=	ps
 SRCS=	fmt.c keyword.c nlist.c print.c ps.c
-CFLAGS+=-I${.CURDIR}/../../sys
+#
+# To support "lazy" ps for non root/wheel users
+# add -DLAZY_PS to the cflags.  This helps
+# keep ps from being an unnecessary load
+# on large systems.
+#
+CFLAGS+=-I${.CURDIR}/../../sys -DLAZY_PS
 DPADD=	${LIBM} ${LIBKVM}
 LDADD=	-lm -lkvm
 BINGRP=	kmem
diff --git a/bin/ps/ps.c b/bin/ps/ps.c
index c854e8ecf95..091a97e0444 100644
--- a/bin/ps/ps.c
+++ b/bin/ps/ps.c
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: ps.c,v 1.20 1997/06/06 06:40:06 charnier Exp $
+ *	$Id: ps.c,v 1.21 1997/08/03 08:25:01 peter Exp $
  */
 
 #ifndef lint
@@ -79,6 +79,11 @@ int	termwidth;		/* width of screen (0 == infinity) */
 int	totwidth;		/* calculated width of requested variables */
 
 static int needuser, needcomm, needenv;
+#if defined(LAZY_PS)
+static int forceuread=0;
+#else
+static int forceuread=1;
+#endif
 
 enum sort { DEFAULT, SORTMEM, SORTCPU } sortby = DEFAULT;
 
@@ -137,7 +142,11 @@ main(argc, argv)
 	ttydev = NODEV;
 	memf = nlistf = swapf = NULL;
 	while ((ch = getopt(argc, argv,
+#if defined(LAZY_PS)
+	    "aCcfeghjLlM:mN:O:o:p:rSTt:U:uvW:wx")) != -1)
+#else
 	    "aCceghjLlM:mN:O:o:p:rSTt:U:uvW:wx")) != -1)
+#endif
 		switch((char)ch) {
 		case 'a':
 			all = 1;
@@ -189,6 +198,12 @@ main(argc, argv)
 			parsefmt(optarg);
 			fmt = 1;
 			break;
+#if defined(LAZY_PS)
+		case 'f':
+			if (getuid() == 0 || getgid() == 0)
+			    forceuread = 1;
+			break;
+#endif
 		case 'p':
 			pid = atol(optarg);
 			xflg = 1;
@@ -430,6 +445,8 @@ fmt(fn, ki, comm, maxlen)
 	return (s);
 }
 
+#define UREADOK(ki)	(forceuread || (KI_PROC(ki)->p_flag & P_INMEM))
+
 static void
 saveuser(ki)
 	KINFO *ki;
@@ -439,7 +456,7 @@ saveuser(ki)
 	struct user *u_addr = (struct user *)USRSTACK;
 
 	usp = &ki->ki_u;
-	if (kvm_uread(kd, KI_PROC(ki), (unsigned long)&u_addr->u_stats,
+	if (UREADOK(ki) && kvm_uread(kd, KI_PROC(ki), (unsigned long)&u_addr->u_stats,
 	    (char *)&pstats, sizeof(pstats)) == sizeof(pstats)) {
 		/*
 		 * The u-area might be swapped out, and we can't get
@@ -456,15 +473,23 @@ saveuser(ki)
 	/*
 	 * save arguments if needed
 	 */
-	if (needcomm)
-		ki->ki_args = fmt(kvm_getargv, ki, KI_PROC(ki)->p_comm,
-		    MAXCOMLEN);
-	else
-		ki->ki_args = NULL;
-	if (needenv)
-		ki->ki_env = fmt(kvm_getenvv, ki, (char *)NULL, 0);
-	else
-		ki->ki_env = NULL;
+	if (needcomm && UREADOK(ki)) {
+	    ki->ki_args = fmt(kvm_getargv, ki, KI_PROC(ki)->p_comm,
+		MAXCOMLEN);
+	} else if (needcomm) {
+	    ki->ki_args = malloc(strlen(KI_PROC(ki)->p_comm) + 3);
+	    sprintf(ki->ki_args, "(%s)", KI_PROC(ki)->p_comm);
+    } else {
+	    ki->ki_args = NULL;
+    }
+    if (needenv && UREADOK(ki)) {
+	    ki->ki_env = fmt(kvm_getenvv, ki, (char *)NULL, 0);
+    } else if (needenv) {
+	    ki->ki_env = malloc(3);
+	    strcpy(ki->ki_env, "()");
+    } else {
+	    ki->ki_env = NULL;
+    }
 }
 
 static int