From patchwork Mon Mar 9 12:15:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11426879 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9268F921 for ; Mon, 9 Mar 2020 12:15:56 +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 7A90E205ED for ; Mon, 9 Mar 2020 12:15:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A90E205ED Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk 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 B8CB86E439; Mon, 9 Mar 2020 12:15:51 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2C2596E436; Mon, 9 Mar 2020 12:15:49 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from build.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 20494660-1500050 for multiple; Mon, 09 Mar 2020 12:15:31 +0000 From: Chris Wilson To: dri-devel@lists.freedesktop.org Subject: [PATCH] drm/mm: Allow drm_mm_initialized() to be used outside of the locks Date: Mon, 9 Mar 2020 12:15:29 +0000 Message-Id: <20200309121529.16497-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mika.kuoppala@linux.intel.com, intel-gfx@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Mark up the potential racy read in drm_mm_initialized(), as we want a cheap and cheerful check: [ 121.098731] BUG: KCSAN: data-race in _i915_gem_object_create_stolen [i915] / rm_hole [ 121.098766] [ 121.098789] write (marked) to 0xffff8881f01ed330 of 8 bytes by task 3568 on cpu 3: [ 121.098831] rm_hole+0x64/0x140 [ 121.098860] drm_mm_insert_node_in_range+0x3d3/0x6c0 [ 121.099254] i915_gem_stolen_insert_node_in_range+0x91/0xe0 [i915] [ 121.099646] _i915_gem_object_create_stolen+0x9d/0x100 [i915] [ 121.100047] i915_gem_object_create_region+0x7a/0xa0 [i915] [ 121.100451] i915_gem_object_create_stolen+0x33/0x50 [i915] [ 121.100849] intel_engine_create_ring+0x1af/0x280 [i915] [ 121.101242] __execlists_context_alloc+0xce/0x3d0 [i915] [ 121.101635] execlists_context_alloc+0x25/0x40 [i915] [ 121.102030] intel_context_alloc_state+0xb6/0xf0 [i915] [ 121.102420] __intel_context_do_pin+0x1ff/0x220 [i915] [ 121.102815] i915_gem_do_execbuffer+0x46b4/0x4c20 [i915] [ 121.103211] i915_gem_execbuffer2_ioctl+0x2c3/0x580 [i915] [ 121.103244] drm_ioctl_kernel+0xe4/0x120 [ 121.103269] drm_ioctl+0x297/0x4c7 [ 121.103296] ksys_ioctl+0x89/0xb0 [ 121.103321] __x64_sys_ioctl+0x42/0x60 [ 121.103349] do_syscall_64+0x6e/0x2c0 [ 121.103377] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 121.103403] [ 121.103426] read to 0xffff8881f01ed330 of 8 bytes by task 3109 on cpu 1: [ 121.103819] _i915_gem_object_create_stolen+0x30/0x100 [i915] [ 121.104228] i915_gem_object_create_region+0x7a/0xa0 [i915] [ 121.104631] i915_gem_object_create_stolen+0x33/0x50 [i915] [ 121.105025] intel_engine_create_ring+0x1af/0x280 [i915] [ 121.105420] __execlists_context_alloc+0xce/0x3d0 [i915] [ 121.105818] execlists_context_alloc+0x25/0x40 [i915] [ 121.106202] intel_context_alloc_state+0xb6/0xf0 [i915] [ 121.106595] __intel_context_do_pin+0x1ff/0x220 [i915] [ 121.106985] i915_gem_do_execbuffer+0x46b4/0x4c20 [i915] [ 121.107375] i915_gem_execbuffer2_ioctl+0x2c3/0x580 [i915] [ 121.107409] drm_ioctl_kernel+0xe4/0x120 [ 121.107437] drm_ioctl+0x297/0x4c7 [ 121.107464] ksys_ioctl+0x89/0xb0 [ 121.107489] __x64_sys_ioctl+0x42/0x60 [ 121.107511] do_syscall_64+0x6e/0x2c0 [ 121.107535] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Chris Wilson Reviewed-by: Daniel Vetter --- include/drm/drm_mm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h index d7939c054259..ee8b0e80ca90 100644 --- a/include/drm/drm_mm.h +++ b/include/drm/drm_mm.h @@ -272,7 +272,7 @@ static inline bool drm_mm_node_allocated(const struct drm_mm_node *node) */ static inline bool drm_mm_initialized(const struct drm_mm *mm) { - return mm->hole_stack.next; + return READ_ONCE(mm->hole_stack.next); } /**