On Sun, 2018-06-03 at 14:33 -0700, Rodney W. Grimes wrote: > > > > On Sat, Jun 2, 2018 at 11:08 PM, Eitan Adler <ead...@freebsd.org> wrote: > > > > > > > > On 2 June 2018 at 16:56, Rodney W. Grimes > > > <free...@pdx.rh.cn85.dnsmgr.net> wrote: > > > > > > > > > > > > > > Author: eadler > > > > > Date: Sat Jun 2 22:06:27 2018 > > > > > New Revision: 334543 > > > > > URL: https://svnweb.freebsd.org/changeset/base/334543 > > > > > > > > > > Log: > > > > > top(1): chdir to / as init; remove unneeded comment > > > > > > > > > > - chdir to / to allow unmounting of wd > > > > > - remove warning about running top(1) as setuid. If this is a > > > > > concern > > > we > > > > > > > > > > > > > > should just drop privs instead. > > > > > > > > > > Modified: > > > > > head/usr.bin/top/machine.c > > > > > head/usr.bin/top/top.c > > > > > > > > > > Modified: head/usr.bin/top/machine.c > > > > > ============================================================ > > > ================== > > > > > > > > > > > > > > --- head/usr.bin/top/machine.c Sat Jun 2 21:50:00 2018 > > > (r334542) > > > > > > > > > > > > > > +++ head/usr.bin/top/machine.c Sat Jun 2 22:06:27 2018 > > > (r334543) > > > > > > > > > > > > > > @@ -1613,11 +1613,6 @@ compare_ivcsw(const void *arg1, const void > > > > > *arg2) > > > > > /* > > > > > * proc_owner(pid) - returns the uid that owns process "pid", or -1 > > > > > if > > > > > * the process does not exist. > > > > > - * It is EXTREMELY IMPORTANT that this function work > > > correctly. > > > > > > > > > > > > > > - * If top runs setuid root (as in SVR4), then this function > > > > > - * is the only thing that stands in the way of a serious > > > > > - * security problem. It validates requests for the "kill" > > > > > - * and "renice" commands. > > > > > */ > > > > > > > > > > int > > > > > > > > > > Modified: head/usr.bin/top/top.c > > > > > ============================================================ > > > ================== > > > > > > > > > > > > > > --- head/usr.bin/top/top.c Sat Jun 2 21:50:00 2018 > > > > > (r334542) > > > > > +++ head/usr.bin/top/top.c Sat Jun 2 22:06:27 2018 > > > > > (r334543) > > > > > @@ -260,6 +260,15 @@ main(int argc, char *argv[]) > > > > > #define CMD_order 26 > > > > > #define CMD_pid 27 > > > > > > > > > > + /* > > > > > + * Since top(1) is often long running and > > > > > + * doesn't typically care about where its running from > > > > > + * chdir to the root to allow unmounting of its > > > > > + * originall wd. Failure is alright as this is > > > > > + * just a courtesy for users. > > > > > + */ > > > > > + chdir("/"); > > > > > + > > > > Bad side effect of doing that is it is not hard to get a "core" > > > > from top when run as a user, as it is going to try to write > > > > to /, and it probably does not have permission for that. > > > Another person made the point that other similar applications don't do > > > this, so I just reverted it. > > > > > Actually, it was a good change. > > > > I've had issues on other systems where I couldn't unmount a filesystem for > > reasons unknown. > lsof is your friend here. That is the tool of choice for finding > cwd of processes that are in directories you can not unmount. >
Actually, rather than lsof (which I never even bother to install anymore), I think the newer version of this advice is to use procstat(1) from base. For example, to see why you can't umount /foo: procstat -af | grep /foo -- Ian _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
