Hi Stephen Isard!

 On 2015.03.22 at 08:48:43 -0500, Stephen Isard wrote next:

> I am using the elrepo fglrx driver and kmod packages (14.12-1.el6) with
> Scientific Linux SL6x.  Just recently, rkhunter has started to complain
> about a file /dev/shm/sem.__AMD_GL_CACHE__0016fe1386291f1d_20.  From the
> name, it looks as if the file is related to the driver and the file looks
> pretty innocent - 32 bytes consisting of a 1 and 31 0s.  If I delete the
> file, it eventually regenerates, although I don't know what triggers the
> regeneration.  Googling on the file name produces no results, but the
> documentation for the closed source driver says that you need /dev/shm for
> 3D effects.  I can't find any filenames in that documentation and I'm not
> consciously using any 3D effects.
> 
> The one thing that has changed recently is that I have added a second screen
> (without xinerama).  The second screen was there for about a week before the
> first rkhunter warning.
> 
> Can someone reassure me that the fglrx driver does put files with that kind
> of name in /dev/shm so that I can whitelist them for rkhunter?

/dev/shm/sem.* files are POSIX semaphores, these file names are used in
Linux implementation. I generally don't see any point in forbidding
any application to use these forms of IPC. So to answer your question -
yes, some part of catalyst (not the driver, the drivers don't use IPC -
it must be some userspace communication related to AMD OpenGL
implementation) use semaphores and in Linux that causes /dev/shm/sem.*
files to be created.

-- 

Vladimir