On 2/29/12 7:33 AM, Konstantin Belousov wrote:
On Wed, Feb 29, 2012 at 09:36:02AM -0500, John Baldwin wrote:
On Wednesday, February 29, 2012 8:25:07 am Konstantin Belousov wrote:
On Wed, Feb 29, 2012 at 02:37:25PM +0200, Mikolaj Golub wrote:
On Wed, 29 Feb 2012 12:03:00 +0000 Robert N. M. Watson wrote:
RNMW> I think the monitoring aspect of the patch is fine.
RNMW> The bit I was worried about was external umask changes. This can cause
RNMW> race conditions for applications that manage their umask -- for
RNMW> example, bsdtar, if I recall correctly. It's one thing to use a
RNMW> debugger to force an application to change its umask -- the developer
RNMW> needs to know they are changing application behaviour. But exposing a
RNMW> feature that can lead to correct applications but incorrect results is
RNMW> a risky thing to do, hence my objection.
RNMW> I think given the other objections, it would be wise to remove write
RNMW> access to process umasks, but retain read access for procstat (which is
RNMW> quite useful, I agree).
I still don't see why having a sysctl RW is worse than asking users to run
something like in the attach when they need to change umask for another
process, but ok, if people don't like RW I will remove it.
What is done is attach is much worse then the sysctl, just because
debugger attach often causes spurious EINTR, indeed seriously disrupting
applications, as opposed to some uncertain damage that could be done in
theory.
kgdb doesn't though, and presumably for umask you would change it via kgdb, so
from the running process' perspective it would look the same as changing it via
sysctl.
Right, but an idea of the change was to allow to do this for somebody who
does not know how to perform it in kgdb. Not to mention that kgdb -w
is risky, e.g. because filedesc might have changed under kgdb, so you would
write over freed memory.
but it's lowering the bar TOO much I think,
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
