On Tuesday, February 28, 2012 1:34:25 am Julian Elischer wrote: > On 2/27/12 1:29 AM, Konstantin Belousov wrote: > > On Mon, Feb 27, 2012 at 10:49:59AM +0200, Mikolaj Golub wrote: > >> On Mon, 27 Feb 2012 09:28:11 +0100 Pawel Jakub Dawidek wrote: > >> > >> PJD> On Sun, Feb 26, 2012 at 02:25:48PM +0000, Mikolaj Golub wrote: > >> >> Author: trociny > >> >> Date: Sun Feb 26 14:25:48 2012 > >> >> New Revision: 232181 > >> >> URL: http://svn.freebsd.org/changeset/base/232181 > >> >> > >> >> Log: > >> >> Add sysctl to retrieve or set umask of another process. > >> > >> PJD> "set umask of another process"? This seems... weird. What's the > >> purpose > >> PJD> of this change? > >> > >> When we were discussing this with Kostik and Robert, and I asked if it > >> could > >> be useful to have the sysctl rw, Kostik described a real situation when he > >> had > >> had to change umask of another process: umask had not been set properly on > >> an > >> aplication start but it could not be restarted until the end of the day. > >> Kostik was able to fix it using gdb but having an easier way looked useful. > > kgdb, not gdb. > > > > It is indeed possible to write a ptrace-based utility that inject a code > > payload that would change umask. Since this is very risky but indeed > > possible, > > having the straighforward kernel facility is justified. > Why not have a sysctl to change a process' uid, cwd, memory limits, > etc. etc.
uid and cwd would be rediculous to change. However, we recently added sysctls to allow a sysadmin to read and write the limits of other processes (and that is a very useful feature indeed since it is not unusual for a long-running process to require more resources than it was initially allocated, as is the ability to easily query the limits that a given process is subject to). > I don't think this belongs in the kernel by default. It's not exactl a > call for backout but It's teh next thing short of that. a call for "do > you REALLY think we need this particular specific case catered for?" That said, the umask bit does strike me as a bit more odd than the limits case. I would have more need of a tool to let me adjust the listen queue length of a socket than to adjust umask (I've had to do that multiple times via kgdb). -- John Baldwin _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
