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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15FA0C433FE for ; Sun, 13 Nov 2022 23:41:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235427AbiKMXlU (ORCPT ); Sun, 13 Nov 2022 18:41:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231252AbiKMXlS (ORCPT ); Sun, 13 Nov 2022 18:41:18 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04D4BD73 for ; Sun, 13 Nov 2022 15:41:18 -0800 (PST) Received: from dimapc.. (109-252-117-140.nat.spd-mgts.ru [109.252.117.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by madras.collabora.co.uk (Postfix) with ESMTPSA id 5E29B6601DEB; Sun, 13 Nov 2022 23:41:15 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1668382876; bh=gJizz7c+xyP2SpxmajSfdslozS7FNzwEJ2RHchPiu4I=; h=From:To:Cc:Subject:Date:From; b=b0cGLCM/etNSALXIWkniC99MFuBqjrhpw0/Ygks//v57zIgQO2PL5X9lHDEEqDXcf BtOII3ZZ2krf0YYC7rAKPHX+dHFLx4a0IWAAFujI84AKLplXsz3p+58kqwn7rU8bWR +kJV8K3jL2Aou8/55Tp5EY9YcgLAAda0GMpo3/uRAfvb7rGz2CJync8tNnWj38BcjO eyEaUTq7uR1UwreMHvSn3ALNOC1JsQf13dqmBjpnwCHQ8PugIVXYRsYbf9xCAfkr2m On8mKhjZIDo/l8IOiwuVVVR1RJOjO4NhrCNJURyYEywppctnkHPkIwFlg/5HQVUDyG /yikoMtDKK9vA== From: Dmitry Osipenko To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , =?UTF-8?q?Christian=20K=C3=B6nig?= , David Airlie , Daniel Vetter , Dmitry Vyukov Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v1] drm/gem-vram: Fix deadlock in drm_gem_vram_vmap() Date: Mon, 14 Nov 2022 02:38:50 +0300 Message-Id: <20221113233850.427704-1-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.37.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Recently DRM framebuffer core and all drivers were moved to unlocked vmapping functions that take the reservation lock. The drm_gem_vram_vmap() was missed out by accident and now deadlocks drivers that use drm_gem_vram helpers when framebuffer is updated, like Bochs driver. Remove the locking from drm_gem_vram_v[un]map() functions to fix the deadlock. Reported-by: Dmitry Vyukov Fixes: 79e2cf2e7a19 ("drm/gem: Take reservation lock for vmap/vunmap operations") Signed-off-by: Dmitry Osipenko --- drivers/gpu/drm/drm_gem_vram_helper.c | 18 +++--------------- 1 file changed, 3 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c index 125160b534be..b6c7e3803bb3 100644 --- a/drivers/gpu/drm/drm_gem_vram_helper.c +++ b/drivers/gpu/drm/drm_gem_vram_helper.c @@ -433,25 +433,19 @@ int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct iosys_map *map) { int ret; - ret = ttm_bo_reserve(&gbo->bo, true, false, NULL); - if (ret) - return ret; + dma_resv_assert_held(gbo->bo.base.resv); ret = drm_gem_vram_pin_locked(gbo, 0); if (ret) - goto err_ttm_bo_unreserve; + return ret; ret = drm_gem_vram_kmap_locked(gbo, map); if (ret) goto err_drm_gem_vram_unpin_locked; - ttm_bo_unreserve(&gbo->bo); - return 0; err_drm_gem_vram_unpin_locked: drm_gem_vram_unpin_locked(gbo); -err_ttm_bo_unreserve: - ttm_bo_unreserve(&gbo->bo); return ret; } EXPORT_SYMBOL(drm_gem_vram_vmap); @@ -467,16 +461,10 @@ EXPORT_SYMBOL(drm_gem_vram_vmap); void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct iosys_map *map) { - int ret; - - ret = ttm_bo_reserve(&gbo->bo, false, false, NULL); - if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret)) - return; + dma_resv_assert_held(gbo->bo.base.resv); drm_gem_vram_kunmap_locked(gbo, map); drm_gem_vram_unpin_locked(gbo); - - ttm_bo_unreserve(&gbo->bo); } EXPORT_SYMBOL(drm_gem_vram_vunmap); -- 2.37.3