svn commit: r350116 - head/lib/libc/gen

[Konstantin Belousov]

On Thu, Jul 18, 2019 at 09:41:15PM +0000, Brooks Davis wrote:
> On Thu, Jul 18, 2019 at 09:33:56PM +0000, Brooks Davis wrote:
> > Author: brooks
> > Date: Thu Jul 18 21:33:55 2019
> > New Revision: 350116
> > URL: https://svnweb.freebsd.org/changeset/base/350116
> > 
> > Log:
> >   Document that setmode(3) is not thread safe.
> >   
> >   In some circumstances, setmode(3) may call umask(2) twice to retrieve
> >   the current mode and then restore it.  Between calls, the process will
> >   have a umask of 0.
> 
> This race isn't especially serious, since it only occurs when
> security.bsd.unprivileged_proc_debug=0, but it's probably something to
> fix.  The easiest solution would probably be to implement a getumask()
> syscall.

You can use pthread_suspend_all_np(3).