From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 5.0 54/98] drm: Fix drm_release() and device unplug Date: Mon, 22 Apr 2019 15:41:21 -0400 Message-ID: <20190422194205.10404-54-sashal@kernel.org> References: <20190422194205.10404-1-sashal@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by gabe.freedesktop.org (Postfix) with ESMTPS id 64603891AB for ; Mon, 22 Apr 2019 19:43:54 +0000 (UTC) In-Reply-To: <20190422194205.10404-1-sashal@kernel.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sasha Levin , Dave Airlie , dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org RnJvbTogTm9yYWxmIFRyw7hubmVzIDxub3JhbGZAdHJvbm5lcy5vcmc+CgpbIFVwc3RyZWFtIGNv bW1pdCAzZjA0ZTBhNmNmZWJmNDgxNTJhYzY0NTAyMzQ2Y2RjMjU4ODExZjc5IF0KCklmIHVzZXJz cGFjZSBoYXMgb3BlbiBmZChzKSB3aGVuIGRybV9kZXZfdW5wbHVnKCkgaXMgcnVuLCBpdCB3aWxs IHJlc3VsdAppbiBkcm1fZGV2X3VucmVnaXN0ZXIoKSBiZWluZyBjYWxsZWQgdHdpY2UuIEZpcnN0 IGluIGRybV9kZXZfdW5wbHVnKCkgYW5kCnRoZW4gbGF0ZXIgaW4gZHJtX3JlbGVhc2UoKSB0aHJv dWdoIHRoZSBjYWxsIHRvIGRybV9wdXRfZGV2KCkuCgpTaW5jZSB1c2Vyc3BhY2UgYWxyZWFkeSBo b2xkcyBhIHJlZiBvbiBkcm1fZGV2aWNlIHRocm91Z2ggdGhlIGRybV9taW5vciwKaXQncyBub3Qg bmVjZXNzYXJ5IHRvIGFkZCBleHRyYSByZWYgY291bnRpbmcgYmFzZWQgb24gbm8gb3BlbiBmaWxl CmhhbmRsZXMuIEluc3RlYWQganVzdCBkcm1fZGV2X3B1dCgpIHVuY29uZGl0aW9uYWxseSBpbiBk cm1fZGV2X3VucGx1ZygpLgoKV2Ugbm93IGhhdmUgdGhpczoKLSBVc2VycGFjZSBob2xkcyBhIHJl ZiBvbiBkcm1fZGV2aWNlIGFzIGxvbmcgYXMgdGhlcmUncyBvcGVuIGZkKHMpCi0gVGhlIGRyaXZl ciBob2xkcyBhIHJlZiBvbiBkcm1fZGV2aWNlIGFzIGxvbmcgYXMgaXQncyBib3VuZCB0byB0aGUK ICBzdHJ1Y3QgZGV2aWNlCgpXaGVuIGJvdGggc2lkZXMgYXJlIGRvbmUgd2l0aCBkcm1fZGV2aWNl LCBpdCBpcyByZWxlYXNlZC4KClNpZ25lZC1vZmYtYnk6IE5vcmFsZiBUcsO4bm5lcyA8bm9yYWxm QHRyb25uZXMub3JnPgpSZXZpZXdlZC1ieTogT2xla3NhbmRyIEFuZHJ1c2hjaGVua28gPG9sZWtz YW5kcl9hbmRydXNoY2hlbmtvQGVwYW0uY29tPgpSZXZpZXdlZC1ieTogRGFuaWVsIFZldHRlciA8 ZGFuaWVsLnZldHRlckBmZndsbC5jaD4KUmV2aWV3ZWQtYnk6IFNlYW4gUGF1bCA8c2VhbkBwb29y bHkucnVuPgpTaWduZWQtb2ZmLWJ5OiBEYXZlIEFpcmxpZSA8YWlybGllZEByZWRoYXQuY29tPgpM aW5rOiBodHRwczovL3BhdGNod29yay5mcmVlZGVza3RvcC5vcmcvcGF0Y2gvbXNnaWQvMjAxOTAy MDgxNDAxMDMuMjg5MTktMi1ub3JhbGZAdHJvbm5lcy5vcmcKU2lnbmVkLW9mZi1ieTogU2FzaGEg TGV2aW4gKE1pY3Jvc29mdCkgPHNhc2hhbEBrZXJuZWwub3JnPgotLS0KIGRyaXZlcnMvZ3B1L2Ry bS9kcm1fZHJ2LmMgIHwgNiArLS0tLS0KIGRyaXZlcnMvZ3B1L2RybS9kcm1fZmlsZS5jIHwgNiAr Ky0tLS0KIDIgZmlsZXMgY2hhbmdlZCwgMyBpbnNlcnRpb25zKCspLCA5IGRlbGV0aW9ucygtKQoK ZGlmZiAtLWdpdCBhL2RyaXZlcnMvZ3B1L2RybS9kcm1fZHJ2LmMgYi9kcml2ZXJzL2dwdS9kcm0v ZHJtX2Rydi5jCmluZGV4IDEyZTVlMmJlNzg5MC4uN2E1OWI4YjNlZDVhIDEwMDY0NAotLS0gYS9k cml2ZXJzL2dwdS9kcm0vZHJtX2Rydi5jCisrKyBiL2RyaXZlcnMvZ3B1L2RybS9kcm1fZHJ2LmMK QEAgLTM4MSwxMSArMzgxLDcgQEAgdm9pZCBkcm1fZGV2X3VucGx1ZyhzdHJ1Y3QgZHJtX2Rldmlj ZSAqZGV2KQogCXN5bmNocm9uaXplX3NyY3UoJmRybV91bnBsdWdfc3JjdSk7CiAKIAlkcm1fZGV2 X3VucmVnaXN0ZXIoZGV2KTsKLQotCW11dGV4X2xvY2soJmRybV9nbG9iYWxfbXV0ZXgpOwotCWlm IChkZXYtPm9wZW5fY291bnQgPT0gMCkKLQkJZHJtX2Rldl9wdXQoZGV2KTsKLQltdXRleF91bmxv Y2soJmRybV9nbG9iYWxfbXV0ZXgpOworCWRybV9kZXZfcHV0KGRldik7CiB9CiBFWFBPUlRfU1lN Qk9MKGRybV9kZXZfdW5wbHVnKTsKIApkaWZmIC0tZ2l0IGEvZHJpdmVycy9ncHUvZHJtL2RybV9m aWxlLmMgYi9kcml2ZXJzL2dwdS9kcm0vZHJtX2ZpbGUuYwppbmRleCA0NmY0OGYyNDVlYjUuLjNm MjBmNTk4Y2Q3YyAxMDA2NDQKLS0tIGEvZHJpdmVycy9ncHUvZHJtL2RybV9maWxlLmMKKysrIGIv ZHJpdmVycy9ncHUvZHJtL2RybV9maWxlLmMKQEAgLTQ3OSwxMSArNDc5LDkgQEAgaW50IGRybV9y ZWxlYXNlKHN0cnVjdCBpbm9kZSAqaW5vZGUsIHN0cnVjdCBmaWxlICpmaWxwKQogCiAJZHJtX2Zp bGVfZnJlZShmaWxlX3ByaXYpOwogCi0JaWYgKCEtLWRldi0+b3Blbl9jb3VudCkgeworCWlmICgh LS1kZXYtPm9wZW5fY291bnQpCiAJCWRybV9sYXN0Y2xvc2UoZGV2KTsKLQkJaWYgKGRybV9kZXZf aXNfdW5wbHVnZ2VkKGRldikpCi0JCQlkcm1fcHV0X2RldihkZXYpOwotCX0KKwogCW11dGV4X3Vu bG9jaygmZHJtX2dsb2JhbF9tdXRleCk7CiAKIAlkcm1fbWlub3JfcmVsZWFzZShtaW5vcik7Ci0t IAoyLjE5LjEKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f CmRyaS1kZXZlbCBtYWlsaW5nIGxpc3QKZHJpLWRldmVsQGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpo dHRwczovL2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2RyaS1kZXZlbA== 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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 418A7C282E1 for ; 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Mon, 22 Apr 2019 19:43:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555962234; bh=B9hfitLqx3c6/Qrr9wS8Ka+HLiv37qnrs9TxLrLSLG8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=czY76zCXwD/JCM5SBg9kJmsNjY5Dr5CKRxj7Vr4WIT3h7PVihZHk6KTL/zJXnE4No QAJwpLX2oShi+OlhXaIZHrlvndd8BRaL5PsZGKwTiaTwHqH/Kz8kBwXZ/MEehIEKgv jt3dGU6ZRY7cRKZ8/heWZAjRV6xcYjsN+l/TYjUo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= , Dave Airlie , Sasha Levin , dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.0 54/98] drm: Fix drm_release() and device unplug Date: Mon, 22 Apr 2019 15:41:21 -0400 Message-Id: <20190422194205.10404-54-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190422194205.10404-1-sashal@kernel.org> References: <20190422194205.10404-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Noralf Trønnes [ Upstream commit 3f04e0a6cfebf48152ac64502346cdc258811f79 ] If userspace has open fd(s) when drm_dev_unplug() is run, it will result in drm_dev_unregister() being called twice. First in drm_dev_unplug() and then later in drm_release() through the call to drm_put_dev(). Since userspace already holds a ref on drm_device through the drm_minor, it's not necessary to add extra ref counting based on no open file handles. Instead just drm_dev_put() unconditionally in drm_dev_unplug(). We now have this: - Userpace holds a ref on drm_device as long as there's open fd(s) - The driver holds a ref on drm_device as long as it's bound to the struct device When both sides are done with drm_device, it is released. Signed-off-by: Noralf Trønnes Reviewed-by: Oleksandr Andrushchenko Reviewed-by: Daniel Vetter Reviewed-by: Sean Paul Signed-off-by: Dave Airlie Link: https://patchwork.freedesktop.org/patch/msgid/20190208140103.28919-2-noralf@tronnes.org Signed-off-by: Sasha Levin (Microsoft) --- drivers/gpu/drm/drm_drv.c | 6 +----- drivers/gpu/drm/drm_file.c | 6 ++---- 2 files changed, 3 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 12e5e2be7890..7a59b8b3ed5a 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -381,11 +381,7 @@ void drm_dev_unplug(struct drm_device *dev) synchronize_srcu(&drm_unplug_srcu); drm_dev_unregister(dev); - - mutex_lock(&drm_global_mutex); - if (dev->open_count == 0) - drm_dev_put(dev); - mutex_unlock(&drm_global_mutex); + drm_dev_put(dev); } EXPORT_SYMBOL(drm_dev_unplug); diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c index 46f48f245eb5..3f20f598cd7c 100644 --- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -479,11 +479,9 @@ int drm_release(struct inode *inode, struct file *filp) drm_file_free(file_priv); - if (!--dev->open_count) { + if (!--dev->open_count) drm_lastclose(dev); - if (drm_dev_is_unplugged(dev)) - drm_put_dev(dev); - } + mutex_unlock(&drm_global_mutex); drm_minor_release(minor); -- 2.19.1