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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id C45F4C4332F for ; Tue, 29 Nov 2022 20:03:09 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CAEAD10E35F; Tue, 29 Nov 2022 20:03:08 +0000 (UTC) Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1290D10E367 for ; Tue, 29 Nov 2022 20:03:00 +0000 (UTC) Received: by mail-pj1-x1032.google.com with SMTP id k5so13694556pjo.5 for ; Tue, 29 Nov 2022 12:03:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=KmLZiaEVkjJr8RiYF6yToHXQoLPPBZhOHiujuwoMMv8=; b=Dz7C3calMnoC2yh0ZC4zZ18Y3+Fg658tq9lsj9p0WciuPXjgUd+tVvWl0Lc62p6jVW r2Bd5aY2VRPWULHTa6j95JU+cnKHKPHnhokZ8HHRUkXMxDRfKyho4TJOBtfLMgnN+jtk 6qX+OzHN0jn37opP0t8b0WA97hE2SX19L9NufPseOkLxo9fx3ln3D27ws/2/FmFfLWBs 2QiVp247MYChRznqD8zQlY1Lq6+md5jBcmE2ngOip1Im7cI9Rx6uQL1xuibovEpkTLY9 POfy1S6VtEZK9vsQvB5mLbG+0CGKZwNmlz/ChDoSF5CaH+QBXV5gMYFobvOGJ+Jp5ez7 mLzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=KmLZiaEVkjJr8RiYF6yToHXQoLPPBZhOHiujuwoMMv8=; b=TBZKygFrrAh5t2uNN7ls0VxIQ3kKtmdhUt9rnYAi1TGE3IpoJlkbDJxzoHBLtkXZRx qnhbnBMebC6HHA8OScBLBvOjNE+CGSNGFsONNRoOAgKjkaT4uVJIsVRm5MdrZS1Q7yca PlwjOTl5TXasp9FTVN5VOONWun7P4gVhPsFOZq4kAPEfCmetiDk1yswbDtQ+gQS8XDxj dIrGyE/zACH/mQESsn/N4rOj9U3dMRUkjdZbKLZ6DotEcKRgNQ8wb+78YtPHo+t7W4AZ NIQUvciXS7vPfxq7dHfiPzjfRcbQjb5TkabVkdRIoWQ85K6xL+FoXh4y8vzsHdOzcPbN g4Ow== X-Gm-Message-State: ANoB5pl5N0sdsdYDI3RNfpsdR4tN5xl2nqpNHJxjPnW5lHnWxjDh8A79 dYBDXzRX93cfB/ohgRqaZcYwM9z6JcQ= X-Google-Smtp-Source: AA0mqf58iGfyCo4hDR+2yRciiyJd2DTGXcfQcykl7GdRzbd7PwYHNjjcg3PQcDS5ZyQve/9BqimogA== X-Received: by 2002:a17:902:dac6:b0:189:7105:59e8 with SMTP id q6-20020a170902dac600b00189710559e8mr19846111plx.50.1669752179326; Tue, 29 Nov 2022 12:02:59 -0800 (PST) Received: from localhost ([2a00:79e1:abd:4a00:2703:3c72:eb1a:cffd]) by smtp.gmail.com with ESMTPSA id q5-20020a17090311c500b00186985198a4sm11337838plh.169.2022.11.29.12.02.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Nov 2022 12:02:58 -0800 (PST) From: Rob Clark To: dri-devel@lists.freedesktop.org Subject: [PATCH 2/2] drm/shmem-helper: Avoid vm_open error paths Date: Tue, 29 Nov 2022 12:02:42 -0800 Message-Id: <20221129200242.298120-3-robdclark@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221129200242.298120-1-robdclark@gmail.com> References: <20221129200242.298120-1-robdclark@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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: Rob Clark , open list , stable@vger.kernel.org, Eric Anholt , =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= , Thomas Zimmermann Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Rob Clark vm_open() is not allowed to fail. Fortunately we are guaranteed that the pages are already pinned, and only need to increment the refcnt. So just increment it directly. Fixes: 2194a63a818d ("drm: Add library for shmem backed GEM objects") Cc: stable@vger.kernel.org Signed-off-by: Rob Clark --- drivers/gpu/drm/drm_gem_shmem_helper.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 110a9eac2af8..9885ba64127f 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -571,12 +571,20 @@ static void drm_gem_shmem_vm_open(struct vm_area_struct *vma) { struct drm_gem_object *obj = vma->vm_private_data; struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); - int ret; WARN_ON(shmem->base.import_attach); - ret = drm_gem_shmem_get_pages(shmem); - WARN_ON_ONCE(ret != 0); + mutex_lock(&shmem->pages_lock); + + /* + * We should have already pinned the pages, vm_open() just grabs + * an additional reference for the new mm the vma is getting + * copied into. + */ + WARN_ON_ONCE(!shmem->pages_use_count); + + shmem->pages_use_count++; + mutex_unlock(&shmem->pages_lock); drm_gem_vm_open(vma); } -- 2.38.1