From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [Cbe-oss-dev] [PATCH 14/22] spufs: use SPU master control to prevent wild SPU execution From: Michael Ellerman To: Arnd Bergmann In-Reply-To: <200703050202.59596.arnd@arndb.de> References: <20061120174454.067872000@arndb.de> <200703011450.50935.arnd@arndb.de> <1172830438.16533.6.camel@concordia.ozlabs.ibm.com> <200703050202.59596.arnd@arndb.de> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-qrNX51q/o/d+4nSZESZc" Date: Wed, 07 Mar 2007 09:58:25 +0100 Message-Id: <1173257905.5101.18.camel@concordia.ozlabs.ibm.com> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, cbe-oss-dev@ozlabs.org, linux-kernel@vger.kernel.org Reply-To: michael@ellerman.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-qrNX51q/o/d+4nSZESZc Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Mon, 2007-03-05 at 02:02 +0100, Arnd Bergmann wrote: > On Friday 02 March 2007, Michael Ellerman wrote: > > There's also the error case for spu_run_init() which skips the master > > stop. I guess that's ok because we've only set the master control in th= e > > backing store, and the only way that will ever get propagated to an > > actual spu is by coming back thorough spufs_run_spu(). >=20 > Hmm, the correct way would be to switch off the master control in there, > afaics. Fixing it only in spu_run_init would mean that we also handle > the case of spu_reacquire_runnable along with it. >=20 > > What originally caught my eye on this was the output from xmon. When we > > drop into xmon with no spu programs running and stop the spus, it > > reports that they _all_ have the master run enabled, >=20 > That looks right, there is no problem to have master control enabled, > as long as user space can't access the spu through a context that is > bound to it. >=20 > > and some of them=20 > > have the runcntl enabled (those that have had spu programs run on them > > since boot it seems). >=20 > While this sounds wrong. Maybe the runcntl is active on those that have > _not_ run since boot, which would make more sense. We should investigate > this. No I'm pretty sure it's enabled on the ones that _have_ run since boot. I'm booting up fresh, running two spu programs, and then I see two spus with master and runcntl set. cheers --=20 Michael Ellerman OzLabs, IBM Australia Development Lab wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183) We do not inherit the earth from our ancestors, we borrow it from our children. - S.M.A.R.T Person --=-qrNX51q/o/d+4nSZESZc Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (GNU/Linux) iD8DBQBF7n6xdSjSd0sB4dIRAlGvAJ9H8AY6oCaMXVxfgfTW4C7CphSfbACfZzKD xAm7Xo0L/MMAmshhX5YwgOQ= =awir -----END PGP SIGNATURE----- --=-qrNX51q/o/d+4nSZESZc--