From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Brezillon Subject: Re: [PATCH 6/8] drm/panfrost: Make sure imported/exported BOs are never purged Date: Fri, 29 Nov 2019 22:09:24 +0100 Message-ID: <20191129220924.7982a350@collabora.com> References: <20191129135908.2439529-1-boris.brezillon@collabora.com> <20191129135908.2439529-7-boris.brezillon@collabora.com> <20191129201213.GR624164@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20191129201213.GR624164@phenom.ffwll.local> Sender: stable-owner@vger.kernel.org To: Daniel Vetter Cc: Rob Herring , Tomeu Vizoso , Alyssa Rosenzweig , Steven Price , stable@vger.kernel.org, dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org On Fri, 29 Nov 2019 21:12:13 +0100 Daniel Vetter wrote: > On Fri, Nov 29, 2019 at 02:59:06PM +0100, Boris Brezillon wrote: > > We don't want imported/exported BOs to be purges, as those are shared > > with other processes that might still use them. We should also refuse > > to export a BO if it's been marked purgeable or has already been purged. > > > > Fixes: 013b65101315 ("drm/panfrost: Add madvise and shrinker support") > > Cc: > > Signed-off-by: Boris Brezillon > > --- > > drivers/gpu/drm/panfrost/panfrost_drv.c | 19 ++++++++++++++++- > > drivers/gpu/drm/panfrost/panfrost_gem.c | 27 +++++++++++++++++++++++++ > > 2 files changed, 45 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c > > index 1c67ac434e10..751df975534f 100644 > > --- a/drivers/gpu/drm/panfrost/panfrost_drv.c > > +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c > > @@ -343,6 +343,7 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data, > > struct drm_panfrost_madvise *args = data; > > struct panfrost_device *pfdev = dev->dev_private; > > struct drm_gem_object *gem_obj; > > + int ret; > > > > gem_obj = drm_gem_object_lookup(file_priv, args->handle); > > if (!gem_obj) { > > @@ -350,6 +351,19 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data, > > return -ENOENT; > > } > > > > + /* > > + * We don't want to mark exported/imported BOs as purgeable: we're not > > + * the only owner in that case. > > + */ > > + mutex_lock(&dev->object_name_lock); > > Kinda not awesome that you have to take this core lock here and encumber > core drm locking with random driver stuff. Looks like drm_gem_shmem_is_purgeable() already does the !imported && !exported check. For the imported case, I think we're good, since userspace can't change the madv value before ->import_attach has been set. For the exporter case, we need to make sure there's no race between the export and madvise operations, which I can probably do from the gem->export() hook by taking the shrinker or bo->mappings lock. > > Can't this be solved with your own locking only and some reasonable > ordering of checks? big locks because it's easy is endless long-term pain. > > Also exporting purgeable objects is kinda a userspace bug, all you have to > do is not oops in dma_buf_attachment_map. No need to prevent the damage > here imo. I feel like making sure an exported BO can't be purged or a purged BO can't be exported would be much simpler than making sure all importers are ready to have the sgt freed. 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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 819D2C43215 for ; Fri, 29 Nov 2019 21:09:34 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5FAFC2086A for ; Fri, 29 Nov 2019 21:09:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5FAFC2086A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9D7236E94E; Fri, 29 Nov 2019 21:09:33 +0000 (UTC) Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by gabe.freedesktop.org (Postfix) with ESMTPS id 57ADA6E94E for ; Fri, 29 Nov 2019 21:09:32 +0000 (UTC) Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:b93f:9fae:b276:a89a]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 18C6029299B; Fri, 29 Nov 2019 21:09:28 +0000 (GMT) Date: Fri, 29 Nov 2019 22:09:24 +0100 From: Boris Brezillon To: Daniel Vetter Subject: Re: [PATCH 6/8] drm/panfrost: Make sure imported/exported BOs are never purged Message-ID: <20191129220924.7982a350@collabora.com> In-Reply-To: <20191129201213.GR624164@phenom.ffwll.local> References: <20191129135908.2439529-1-boris.brezillon@collabora.com> <20191129135908.2439529-7-boris.brezillon@collabora.com> <20191129201213.GR624164@phenom.ffwll.local> Organization: Collabora X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stable@vger.kernel.org, Steven Price , Rob Herring , dri-devel@lists.freedesktop.org, Alyssa Rosenzweig Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Message-ID: <20191129210924.j3cXbjv9lAg2y6f7o5AJlYNlc10IBVOE-VLYaCPo_H4@z> T24gRnJpLCAyOSBOb3YgMjAxOSAyMToxMjoxMyArMDEwMApEYW5pZWwgVmV0dGVyIDxkYW5pZWxA ZmZ3bGwuY2g+IHdyb3RlOgoKPiBPbiBGcmksIE5vdiAyOSwgMjAxOSBhdCAwMjo1OTowNlBNICsw MTAwLCBCb3JpcyBCcmV6aWxsb24gd3JvdGU6Cj4gPiBXZSBkb24ndCB3YW50IGltcG9ydGVkL2V4 cG9ydGVkIEJPcyB0byBiZSBwdXJnZXMsIGFzIHRob3NlIGFyZSBzaGFyZWQKPiA+IHdpdGggb3Ro ZXIgcHJvY2Vzc2VzIHRoYXQgbWlnaHQgc3RpbGwgdXNlIHRoZW0uIFdlIHNob3VsZCBhbHNvIHJl ZnVzZQo+ID4gdG8gZXhwb3J0IGEgQk8gaWYgaXQncyBiZWVuIG1hcmtlZCBwdXJnZWFibGUgb3Ig aGFzIGFscmVhZHkgYmVlbiBwdXJnZWQuCj4gPiAKPiA+IEZpeGVzOiAwMTNiNjUxMDEzMTUgKCJk cm0vcGFuZnJvc3Q6IEFkZCBtYWR2aXNlIGFuZCBzaHJpbmtlciBzdXBwb3J0IikKPiA+IENjOiA8 c3RhYmxlQHZnZXIua2VybmVsLm9yZz4KPiA+IFNpZ25lZC1vZmYtYnk6IEJvcmlzIEJyZXppbGxv biA8Ym9yaXMuYnJlemlsbG9uQGNvbGxhYm9yYS5jb20+Cj4gPiAtLS0KPiA+ICBkcml2ZXJzL2dw dS9kcm0vcGFuZnJvc3QvcGFuZnJvc3RfZHJ2LmMgfCAxOSArKysrKysrKysrKysrKysrLQo+ID4g IGRyaXZlcnMvZ3B1L2RybS9wYW5mcm9zdC9wYW5mcm9zdF9nZW0uYyB8IDI3ICsrKysrKysrKysr KysrKysrKysrKysrKysKPiA+ICAyIGZpbGVzIGNoYW5nZWQsIDQ1IGluc2VydGlvbnMoKyksIDEg ZGVsZXRpb24oLSkKPiA+IAo+ID4gZGlmZiAtLWdpdCBhL2RyaXZlcnMvZ3B1L2RybS9wYW5mcm9z dC9wYW5mcm9zdF9kcnYuYyBiL2RyaXZlcnMvZ3B1L2RybS9wYW5mcm9zdC9wYW5mcm9zdF9kcnYu Ywo+ID4gaW5kZXggMWM2N2FjNDM0ZTEwLi43NTFkZjk3NTUzNGYgMTAwNjQ0Cj4gPiAtLS0gYS9k cml2ZXJzL2dwdS9kcm0vcGFuZnJvc3QvcGFuZnJvc3RfZHJ2LmMKPiA+ICsrKyBiL2RyaXZlcnMv Z3B1L2RybS9wYW5mcm9zdC9wYW5mcm9zdF9kcnYuYwo+ID4gQEAgLTM0Myw2ICszNDMsNyBAQCBz dGF0aWMgaW50IHBhbmZyb3N0X2lvY3RsX21hZHZpc2Uoc3RydWN0IGRybV9kZXZpY2UgKmRldiwg dm9pZCAqZGF0YSwKPiA+ICAJc3RydWN0IGRybV9wYW5mcm9zdF9tYWR2aXNlICphcmdzID0gZGF0 YTsKPiA+ICAJc3RydWN0IHBhbmZyb3N0X2RldmljZSAqcGZkZXYgPSBkZXYtPmRldl9wcml2YXRl Owo+ID4gIAlzdHJ1Y3QgZHJtX2dlbV9vYmplY3QgKmdlbV9vYmo7Cj4gPiArCWludCByZXQ7Cj4g PiAgCj4gPiAgCWdlbV9vYmogPSBkcm1fZ2VtX29iamVjdF9sb29rdXAoZmlsZV9wcml2LCBhcmdz LT5oYW5kbGUpOwo+ID4gIAlpZiAoIWdlbV9vYmopIHsKPiA+IEBAIC0zNTAsNiArMzUxLDE5IEBA IHN0YXRpYyBpbnQgcGFuZnJvc3RfaW9jdGxfbWFkdmlzZShzdHJ1Y3QgZHJtX2RldmljZSAqZGV2 LCB2b2lkICpkYXRhLAo+ID4gIAkJcmV0dXJuIC1FTk9FTlQ7Cj4gPiAgCX0KPiA+ICAKPiA+ICsJ LyoKPiA+ICsJICogV2UgZG9uJ3Qgd2FudCB0byBtYXJrIGV4cG9ydGVkL2ltcG9ydGVkIEJPcyBh cyBwdXJnZWFibGU6IHdlJ3JlIG5vdAo+ID4gKwkgKiB0aGUgb25seSBvd25lciBpbiB0aGF0IGNh c2UuCj4gPiArCSAqLwo+ID4gKwltdXRleF9sb2NrKCZkZXYtPm9iamVjdF9uYW1lX2xvY2spOyAg Cj4gCj4gS2luZGEgbm90IGF3ZXNvbWUgdGhhdCB5b3UgaGF2ZSB0byB0YWtlIHRoaXMgY29yZSBs b2NrIGhlcmUgYW5kIGVuY3VtYmVyCj4gY29yZSBkcm0gbG9ja2luZyB3aXRoIHJhbmRvbSBkcml2 ZXIgc3R1ZmYuCgpMb29rcyBsaWtlIGRybV9nZW1fc2htZW1faXNfcHVyZ2VhYmxlKCkgYWxyZWFk eSBkb2VzIHRoZSAhaW1wb3J0ZWQgJiYKIWV4cG9ydGVkIGNoZWNrLiBGb3IgdGhlIGltcG9ydGVk IGNhc2UsIEkgdGhpbmsgd2UncmUgZ29vZCwgc2luY2UKdXNlcnNwYWNlIGNhbid0IGNoYW5nZSB0 aGUgbWFkdiB2YWx1ZSBiZWZvcmUgLT5pbXBvcnRfYXR0YWNoIGhhcyBiZWVuCnNldC4gRm9yIHRo ZSBleHBvcnRlciBjYXNlLCB3ZSBuZWVkIHRvIG1ha2Ugc3VyZSB0aGVyZSdzIG5vIHJhY2UKYmV0 d2VlbiB0aGUgZXhwb3J0IGFuZCBtYWR2aXNlIG9wZXJhdGlvbnMsIHdoaWNoIEkgY2FuIHByb2Jh Ymx5IGRvIGZyb20KdGhlIGdlbS0+ZXhwb3J0KCkgaG9vayBieSB0YWtpbmcgdGhlIHNocmlua2Vy IG9yIGJvLT5tYXBwaW5ncyBsb2NrLgoKPiAKPiBDYW4ndCB0aGlzIGJlIHNvbHZlZCB3aXRoIHlv dXIgb3duIGxvY2tpbmcgb25seSBhbmQgc29tZSByZWFzb25hYmxlCj4gb3JkZXJpbmcgb2YgY2hl Y2tzPyBiaWcgbG9ja3MgYmVjYXVzZSBpdCdzIGVhc3kgaXMgZW5kbGVzcyBsb25nLXRlcm0gcGFp bi4KPiAKPiBBbHNvIGV4cG9ydGluZyBwdXJnZWFibGUgb2JqZWN0cyBpcyBraW5kYSBhIHVzZXJz cGFjZSBidWcsIGFsbCB5b3UgaGF2ZSB0bwo+IGRvIGlzIG5vdCBvb3BzIGluIGRtYV9idWZfYXR0 YWNobWVudF9tYXAuIE5vIG5lZWQgdG8gcHJldmVudCB0aGUgZGFtYWdlCj4gaGVyZSBpbW8uCgpJ IGZlZWwgbGlrZSBtYWtpbmcgc3VyZSBhbiBleHBvcnRlZCBCTyBjYW4ndCBiZSBwdXJnZWQgb3Ig YSBwdXJnZWQgQk8KY2FuJ3QgYmUgZXhwb3J0ZWQgd291bGQgYmUgbXVjaCBzaW1wbGVyIHRoYW4g bWFraW5nIHN1cmUgYWxsIGltcG9ydGVycwphcmUgcmVhZHkgdG8gaGF2ZSB0aGUgc2d0IGZyZWVk LgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpkcmktZGV2 ZWwgbWFpbGluZyBsaXN0CmRyaS1kZXZlbEBsaXN0cy5mcmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9s aXN0cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0aW5mby9kcmktZGV2ZWw=