From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C9CEC33CAA for ; Tue, 21 Jan 2020 16:10:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 144BF217F4 for ; Tue, 21 Jan 2020 16:10:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729336AbgAUQKL (ORCPT ); Tue, 21 Jan 2020 11:10:11 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:50579 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726555AbgAUQKL (ORCPT ); Tue, 21 Jan 2020 11:10:11 -0500 Received: from kresse.hi.pengutronix.de ([2001:67c:670:100:1d::2a]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1itw6K-00023c-2Z; Tue, 21 Jan 2020 17:10:00 +0100 Message-ID: <1971902c68ff805ee0b4a66f558afe06e6edf0c5.camel@pengutronix.de> Subject: Re: [PATCH] drm/etnaviv: only reject timeouts with tv_nsec >= 2 seconds From: Lucas Stach To: Guido =?ISO-8859-1?Q?G=FCnther?= , Arnd Bergmann Cc: Russell King , Christian Gmeiner , David Airlie , Daniel Vetter , Philipp Zabel , Sam Ravnborg , Rob Herring , Emil Velikov , etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Date: Tue, 21 Jan 2020 17:09:56 +0100 In-Reply-To: <20200121125546.GA71415@bogon.m.sigxcpu.org> References: <20200121114553.2667556-1-arnd@arndb.de> <20200121125546.GA71415@bogon.m.sigxcpu.org> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5-1.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::2a X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Guido, On Di, 2020-01-21 at 13:55 +0100, Guido Günther wrote: > Hi, > On Tue, Jan 21, 2020 at 12:45:25PM +0100, Arnd Bergmann wrote: > > As Guido Günther reported, get_abs_timeout() in the etnaviv user space > > sometimes passes timeouts with nanosecond values larger than 1000000000, > > which gets rejected after my first patch. > > > > To avoid breaking this, while also not allowing completely arbitrary > > values, set the limit to 1999999999 and use set_normalized_timespec64() > > to get the correct format before comparing it. > > I'm seeing values up to 5 seconds so I need > > if (args->timeout.tv_nsec > (5 * NSEC_PER_SEC)) > > to unbreak rendering. Which seems to match what mesa's get_abs_timeout() > does and how it's invoked. I have not tested this myself yet, only looked at the code. From the code I quoted earlier, I don't see how we end up with 5 * NSEC_PER_SEC in the tv_nsec member, even if the timeout passed to get_abs_timeout() is 5 seconds. Regards, Lucas > with that: > > Tested-by: Guido Günther > > Cheers, > -- Guido > > > This also addresses the off-by-1 glitch reported by Ben Hutchings. > > > > Fixes: 172a216ff334 ("drm/etnaviv: reject timeouts with tv_nsec >= NSEC_PER_SEC") > > Cc: Guido Günther > > Link: https://patchwork.kernel.org/patch/11291089/ > > Signed-off-by: Arnd Bergmann > > --- > > drivers/gpu/drm/etnaviv/etnaviv_drv.c | 10 +++++++--- > > drivers/gpu/drm/etnaviv/etnaviv_drv.h | 6 ++---- > > 2 files changed, 9 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c > > index 3eb0f9223bea..d94740c123d3 100644 > > --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.c > > +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.c > > @@ -292,7 +292,11 @@ static int etnaviv_ioctl_gem_cpu_prep(struct drm_device *dev, void *data, > > if (args->op & ~(ETNA_PREP_READ | ETNA_PREP_WRITE | ETNA_PREP_NOSYNC)) > > return -EINVAL; > > > > - if (args->timeout.tv_nsec > NSEC_PER_SEC) > > + /* > > + * existing user space passes non-normalized timespecs, but never > > + * more than 2 seconds worth of nanoseconds > > + */ > > + if (args->timeout.tv_nsec >= (2 * NSEC_PER_SEC)) > > return -EINVAL; > > > > obj = drm_gem_object_lookup(file, args->handle); > > @@ -358,7 +362,7 @@ static int etnaviv_ioctl_wait_fence(struct drm_device *dev, void *data, > > if (args->flags & ~(ETNA_WAIT_NONBLOCK)) > > return -EINVAL; > > > > - if (args->timeout.tv_nsec > NSEC_PER_SEC) > > + if (args->timeout.tv_nsec >= (2 * NSEC_PER_SEC)) > > return -EINVAL; > > > > if (args->pipe >= ETNA_MAX_PIPES) > > @@ -412,7 +416,7 @@ static int etnaviv_ioctl_gem_wait(struct drm_device *dev, void *data, > > if (args->flags & ~(ETNA_WAIT_NONBLOCK)) > > return -EINVAL; > > > > - if (args->timeout.tv_nsec > NSEC_PER_SEC) > > + if (args->timeout.tv_nsec >= (2 * NSEC_PER_SEC)) > > return -EINVAL; > > > > if (args->pipe >= ETNA_MAX_PIPES) > > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.h b/drivers/gpu/drm/etnaviv/etnaviv_drv.h > > index efc656efeb0f..3e47050af706 100644 > > --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.h > > +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.h > > @@ -109,12 +109,10 @@ static inline size_t size_vstruct(size_t nelem, size_t elem_size, size_t base) > > static inline unsigned long etnaviv_timeout_to_jiffies( > > const struct drm_etnaviv_timespec *timeout) > > { > > - struct timespec64 ts, to = { > > - .tv_sec = timeout->tv_sec, > > - .tv_nsec = timeout->tv_nsec, > > - }; > > + struct timespec64 ts, to; > > > > ktime_get_ts64(&ts); > > + set_normalized_timespec64(&to, timeout->tv_sec, timeout->tv_nsec); > > > > /* timeouts before "now" have already expired */ > > if (timespec64_compare(&to, &ts) <= 0) > > -- > > 2.25.0 > >