From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56919) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fdbba-0001nZ-Lo for qemu-devel@nongnu.org; Thu, 12 Jul 2018 09:25:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fdbbW-0001C0-RU for qemu-devel@nongnu.org; Thu, 12 Jul 2018 09:25:58 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:38632 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 1fdbbW-0001BN-LE for qemu-devel@nongnu.org; Thu, 12 Jul 2018 09:25:54 -0400 From: Eduardo Otubo Date: Thu, 12 Jul 2018 15:25:38 +0200 Message-Id: <20180712132538.21921-2-otubo@redhat.com> In-Reply-To: <20180712132538.21921-1-otubo@redhat.com> References: <20180712132538.21921-1-otubo@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PULL 1/1] seccomp: allow sched_setscheduler() with SCHED_IDLE policy List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, marcandre.lureau@redhat.com From: Marc-Andr=C3=A9 Lureau Current and upcoming mesa releases rely on a shader disk cash. It uses a thread job queue with low priority, set with sched_setscheduler(SCHED_IDLE). However, that syscall is rejected by the "resourcecontrol" seccomp qemu filter. Since it should be safe to allow lowering thread priority, let's allow scheduling thread to idle policy. Related to: https://bugzilla.redhat.com/show_bug.cgi?id=3D1594456 Signed-off-by: Marc-Andr=C3=A9 Lureau Acked-by: Eduardo Otubo --- qemu-seccomp.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) 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].n= um, + blacklist[i].narg, blacklist[i].arg_= cmp); if (rc < 0) { goto seccomp_return; } --=20 2.17.1