While this patch avoids the bug, it isn't quite right: pstat -ft should
be equivalent to "pstat -f && pstat -t" but...
$ pstat -ft
pstat: kvm_openfiles: /dev/mem: Permission denied
The actual problem is in ttymode(): if kd != NULL (which is the case if
-f is combined with -t), there are accesses of the kvm datastructures
without them being properly initialized:
879 if (kd != NULL)
880 KGET(TTY_NTTY, ntty);
and
896 KGET(TTY_TTYLIST, tty_head);
897 for (tp = TAILQ_FIRST(&tty_head); tp;
898 tp = TAILQ_NEXT(&tty, tty_link)) {
899 KGET2(tp, &tty, sizeof tty, "tty struct");
900 tty2itty(&tty, &itty);
901 ttyprt(&itty);
902 }
These code paths must not be hit unless need_nlist is true, so expose it
globally and replace 'kd != NULL' with the proper condition need_nlist
The following patch works in all affected cases, pstat -t, pstat -f,
pstat -tf, both as root and non-root as well as pstat -tv as root
(combinations with -d aren't interesting since pstat exits before
doing anything else but -d).
Index: pstat.c
===================================================================
RCS file: /var/cvs/src/usr.sbin/pstat/pstat.c,v
retrieving revision 1.108
diff -u -p -r1.108 pstat.c
--- pstat.c 14 Aug 2016 22:47:26 -0000 1.108
+++ pstat.c 17 Sep 2016 17:57:38 -0000
@@ -89,6 +89,7 @@ struct e_vnode {
struct vnode vnode;
};
+int need_nlist;
int usenumflag;
int totalflag;
int kflag;
@@ -141,7 +142,7 @@ main(int argc, char *argv[])
const char *dformat = NULL;
extern char *optarg;
extern int optind;
- int i, need_nlist;
+ int i;
hideroot = getuid();
@@ -869,7 +870,7 @@ ttymode(void)
struct itty itty, *itp;
size_t nlen;
- if (kd == 0) {
+ if (!need_nlist) {
mib[0] = CTL_KERN;
mib[1] = KERN_TTYCOUNT;
nlen = sizeof(ntty);
@@ -879,7 +880,7 @@ ttymode(void)
KGET(TTY_NTTY, ntty);
(void)printf("%d terminal device%s\n", ntty, ntty == 1 ? "" : "s");
(void)printf("%s", hdr);
- if (kd == 0) {
+ if (!need_nlist) {
mib[0] = CTL_KERN;
mib[1] = KERN_TTY;
mib[2] = KERN_TTY_INFO;
