[src/trunk]: src/usr.bin/vmstat Drop setgid kmem, simplify nlist setup.

[simonb <simonb%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/2d28652ed93a
branches:  trunk
changeset: 982124:2d28652ed93a
user:      simonb <simonb%NetBSD.org@localhost>
date:      Fri Apr 02 06:28:55 2021 +0000

description:
Drop setgid kmem, simplify nlist setup.

diffstat:

 usr.bin/vmstat/Makefile |   7 +---
 usr.bin/vmstat/vmstat.c |  78 ++++++++++++++++--------------------------------
 2 files changed, 28 insertions(+), 57 deletions(-)

diffs (174 lines):

diff -r 0a25a7ea6a97 -r 2d28652ed93a usr.bin/vmstat/Makefile
--- a/usr.bin/vmstat/Makefile   Fri Apr 02 03:20:53 2021 +0000
+++ b/usr.bin/vmstat/Makefile   Fri Apr 02 06:28:55 2021 +0000
@@ -1,8 +1,7 @@
-#      $NetBSD: Makefile,v 1.34 2016/12/29 23:42:39 mrg Exp $
+#      $NetBSD: Makefile,v 1.35 2021/04/02 06:28:55 simonb Exp $
 #      @(#)Makefile    8.1 (Berkeley) 6/6/93
 
 .include <bsd.own.mk>
-USE_FORT?= yes # setgid
 PROG=  vmstat
 
 CPPFLAGS+=-D_KMEMUSER -I${NETBSDSRCDIR}/sys
@@ -10,8 +9,6 @@
 MAN=   vmstat.1
 DPADD= ${LIBKVM}
 LDADD= -lkvm
-BINGRP=        kmem
-BINMODE=2555
 
 CWARNFLAGS.clang+=     -Wno-format-extra-args
 COPTS.vmstat.c += -Wno-format-nonliteral
@@ -19,6 +16,4 @@
 # sparc64 is broken!
 COPTS.vmstat.c += -Wno-error=stack-protector
 
-.include "../../compat/exec.mk"
-
 .include <bsd.prog.mk>
diff -r 0a25a7ea6a97 -r 2d28652ed93a usr.bin/vmstat/vmstat.c
--- a/usr.bin/vmstat/vmstat.c   Fri Apr 02 03:20:53 2021 +0000
+++ b/usr.bin/vmstat/vmstat.c   Fri Apr 02 06:28:55 2021 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: vmstat.c,v 1.245 2021/04/01 06:23:14 simonb Exp $ */
+/* $NetBSD: vmstat.c,v 1.246 2021/04/02 06:28:55 simonb Exp $ */
 
 /*-
  * Copyright (c) 1998, 2000, 2001, 2007, 2019, 2020
@@ -71,7 +71,7 @@
 #if 0
 static char sccsid[] = "@(#)vmstat.c   8.2 (Berkeley) 3/1/95";
 #else
-__RCSID("$NetBSD: vmstat.c,v 1.245 2021/04/01 06:23:14 simonb Exp $");
+__RCSID("$NetBSD: vmstat.c,v 1.246 2021/04/02 06:28:55 simonb Exp $");
 #endif
 #endif /* not lint */
 
@@ -328,7 +328,6 @@
 static const int vmmeter_mib[] = { CTL_VM, VM_METER };
 static const int uvmexp2_mib[] = { CTL_VM, VM_UVMEXP2 };
 static const int boottime_mib[] = { CTL_KERN, KERN_BOOTTIME };
-static char kvm_errbuf[_POSIX2_LINE_MAX];
 
 int
 main(int argc, char *argv[])
@@ -336,11 +335,10 @@
        int c, todo, verbose, wide;
        struct timespec interval;
        int reps;
-       gid_t egid = getegid();
        const char *histname, *hashname;
+       char errbuf[_POSIX2_LINE_MAX];
 
        histname = hashname = NULL;
-       (void)setegid(getgid());
        memf = nlistf = NULL;
        reps = todo = verbose = wide = 0;
        interval.tv_sec = 0;
@@ -415,35 +413,21 @@
        if (todo == 0)
                todo = VMSTAT;
 
-       /*
-        * Discard setgid privileges.  If not the running kernel, we toss
-        * them away totally so that bad guys can't print interesting stuff
-        * from kernel memory, otherwise switch back to kmem for the
-        * duration of the kvm_openfiles() call.
-        */
-       if (nlistf != NULL || memf != NULL)
-               (void)setgid(getgid());
-       else
-               (void)setegid(egid);
-
-       kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, kvm_errbuf);
-       if (kd == NULL) {
-               if (nlistf != NULL || memf != NULL) {
-                       errx(1, "kvm_openfiles: %s", kvm_errbuf);
-               }
+       if (memf == NULL) {
+               kd = kvm_openfiles(NULL, NULL, NULL, KVM_NO_FILES, errbuf);
+       } else {
+               kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf);
+               getnlist(todo);
        }
 
-       if (nlistf == NULL && memf == NULL)
-               (void)setgid(getgid());
-
+       if (kd == NULL)
+               errx(EXIT_FAILURE, "%s", errbuf);
 
        if (todo & VMSTAT) {
                struct winsize winsize;
 
                (void)drvinit(0);/* Initialize disk stats, no disks selected. */
 
-               (void)setgid(getgid()); /* don't need privs anymore */
-
                argv = choosedrives(argv);      /* Select disks. */
                winsize.ws_row = 0;
                (void)ioctl(STDOUT_FILENO, TIOCGWINSZ, &winsize);
@@ -466,8 +450,6 @@
        } else if (reps)
                interval.tv_sec = 1;
 
-
-       getnlist(todo);
        /*
         * Statistics dumping is incompatible with the default
         * VMSTAT/dovmstat() output. So perform the interval/reps handling
@@ -539,36 +521,30 @@
 void
 getnlist(int todo)
 {
-       static int namelist_done = 0;
        static int done = 0;
        int c;
        size_t i;
 
-       if (kd == NULL)
-               errx(1, "kvm_openfiles: %s", kvm_errbuf);
-
-       if (!namelist_done) {
-               namelist_done = 1;
-               if ((c = kvm_nlist(kd, namelist)) != 0) {
-                       int doexit = 0;
-                       if (c == -1)
-                               errx(1, "kvm_nlist: %s %s",
-                                   "namelist", kvm_geterr(kd));
-                       for (i = 0; i < __arraycount(namelist)-1; i++)
-                               if (namelist[i].n_type == 0) {
-                                       if (doexit++ == 0)
-                                               (void)fprintf(stderr,
-                                                   "%s: undefined symbols:",
-                                                   getprogname());
-                                       (void)fprintf(stderr, " %s",
-                                           namelist[i].n_name);
-                               }
-                       if (doexit) {
-                               (void)fputc('\n', stderr);
-                               exit(1);
+       if ((c = kvm_nlist(kd, namelist)) != 0) {
+               int doexit = 0;
+               if (c == -1)
+                       errx(1, "kvm_nlist: %s %s",
+                           "namelist", kvm_geterr(kd));
+               for (i = 0; i < __arraycount(namelist)-1; i++)
+                       if (namelist[i].n_type == 0) {
+                               if (doexit++ == 0)
+                                       (void)fprintf(stderr,
+                                           "%s: undefined symbols:",
+                                           getprogname());
+                               (void)fprintf(stderr, " %s",
+                                   namelist[i].n_name);
                        }
+               if (doexit) {
+                       (void)fputc('\n', stderr);
+                       exit(1);
                }
        }
+
        if ((todo & (VMSTAT|INTRSTAT)) && !(done & (VMSTAT))) {
                done |= VMSTAT;
                if ((c = kvm_nlist(kd, timenl)) == -1 || c == X_TIMENL_SIZE)