Re: CVS commit: src/sys/uvm

[coypu%sdf.org@localhost]

On Fri, May 19, 2017 at 03:30:19PM +0000, Chuck Silvers wrote:
> Module Name:	src
> Committed By:	chs
> Date:		Fri May 19 15:30:19 UTC 2017
> 
> Modified Files:
> 	src/sys/uvm: uvm_map.c uvm_mmap.c
> 
> Log Message:
> make MAP_FIXED mapping operations atomic. fixes PR 52239.
> previously, unmapping any entries being replaced was done separately
> from entering the new mapping, which allowed another thread doing
> a non-MAP_FIXED mapping to allocate the range out from under the
> MAP_FIXED thread.

Does that have security ramifications? it sounds like something that
won't be good if not atomic, but I don't know enough to tell if it can
be abused.

Thanks.