From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52278) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fezuu-0006AR-TU for qemu-devel@nongnu.org; Mon, 16 Jul 2018 05:35:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fezur-0006uQ-NH for qemu-devel@nongnu.org; Mon, 16 Jul 2018 05:35:40 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:42022 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fezur-0006tq-0z for qemu-devel@nongnu.org; Mon, 16 Jul 2018 05:35:37 -0400 Date: Mon, 16 Jul 2018 10:35:32 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Message-ID: <20180716093532.GK5616@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <20180710145557.12902-1-marcandre.lureau@redhat.com> <20180711144855.GE14423@vader> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180711144855.GE14423@vader> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] seccomp: allow sched_setscheduler() with SCHED_IDLE policy List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Otubo Cc: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , qemu-devel@nongnu.org, eskultet@redhat.com, kraxel@redhat.com, gschafer@gmail.com On Wed, Jul 11, 2018 at 04:48:55PM +0200, Eduardo Otubo wrote: > On 10/07/2018 - 16:55:57, Marc-Andr=C3=A9 Lureau wrote: > > Current and upcoming mesa releases rely on a shader disk cash. It use= s > > a thread job queue with low priority, set with > > sched_setscheduler(SCHED_IDLE). However, that syscall is rejected by > > the "resourcecontrol" seccomp qemu filter. > >=20 > > Since it should be safe to allow lowering thread priority, let's allo= w > > scheduling thread to idle policy. > >=20 > > Related to: > > https://bugzilla.redhat.com/show_bug.cgi?id=3D1594456 > >=20 > > Signed-off-by: Marc-Andr=C3=A9 Lureau > > --- > > qemu-seccomp.c | 12 ++++++++++-- > > 1 file changed, 10 insertions(+), 2 deletions(-) > >=20 > > diff --git a/qemu-seccomp.c b/qemu-seccomp.c > > index 148e4c6f24..9cd8eb9499 100644 > > --- a/qemu-seccomp.c > > +++ b/qemu-seccomp.c > > @@ -34,6 +34,12 @@ > > struct QemuSeccompSyscall { > > int32_t num; > > uint8_t set; > > + uint8_t narg; > > + const struct scmp_arg_cmp *arg_cmp; > > +}; > > + > > +const struct scmp_arg_cmp sched_setscheduler_arg[] =3D { > > + SCMP_A1(SCMP_CMP_NE, SCHED_IDLE) > > }; > > =20 > > static const struct QemuSeccompSyscall blacklist[] =3D { > > @@ -92,7 +98,8 @@ static const struct QemuSeccompSyscall blacklist[] = =3D { > > { SCMP_SYS(setpriority), QEMU_SECCOMP_SET_RESOURCECTL= }, > > { SCMP_SYS(sched_setparam), QEMU_SECCOMP_SET_RESOURCECTL= }, > > { SCMP_SYS(sched_getparam), QEMU_SECCOMP_SET_RESOURCECTL= }, > > - { SCMP_SYS(sched_setscheduler), QEMU_SECCOMP_SET_RESOURCECTL= }, > > + { SCMP_SYS(sched_setscheduler), QEMU_SECCOMP_SET_RESOURCECTL= , > > + ARRAY_SIZE(sched_setscheduler_arg), sched_setscheduler_arg }, > > { SCMP_SYS(sched_getscheduler), QEMU_SECCOMP_SET_RESOURCECTL= }, > > { SCMP_SYS(sched_setaffinity), QEMU_SECCOMP_SET_RESOURCECTL= }, > > { SCMP_SYS(sched_getaffinity), QEMU_SECCOMP_SET_RESOURCECTL= }, > > @@ -118,7 +125,8 @@ static int seccomp_start(uint32_t seccomp_opts) > > continue; > > } > > =20 > > - rc =3D seccomp_rule_add(ctx, SCMP_ACT_KILL, blacklist[i].num= , 0); > > + rc =3D seccomp_rule_add_array(ctx, SCMP_ACT_KILL, blacklist[= i].num, > > + blacklist[i].narg, blacklist[i].= arg_cmp); > > if (rc < 0) { > > goto seccomp_return; > > } > > --=20 > > 2.18.0.129.ge3331758f1 > >=20 >=20 > Acked-by: Eduardo Otubo >=20 > Patch looks safe enough for me. If everyone else is OK with this I'll s= end a > pull-request tomorrow morning. Reviewed-by: Daniel P. Berrang=C3=A9 Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|