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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2D9FC433FE for ; Sat, 9 Oct 2021 05:53:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8AA4D60F5B for ; Sat, 9 Oct 2021 05:53:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244286AbhJIFzZ (ORCPT ); Sat, 9 Oct 2021 01:55:25 -0400 Received: from mailgw01.mediatek.com ([60.244.123.138]:37822 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S232529AbhJIFzW (ORCPT ); Sat, 9 Oct 2021 01:55:22 -0400 X-UUID: bb78f1369c79463db52dfa763b5575e2-20211009 X-UUID: bb78f1369c79463db52dfa763b5575e2-20211009 Received: from mtkmbs10n2.mediatek.inc [(172.21.101.183)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 211365005; Sat, 09 Oct 2021 13:53:19 +0800 Received: from mtkcas10.mediatek.inc (172.21.101.39) by mtkmbs10n1.mediatek.inc (172.21.101.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.15; Sat, 9 Oct 2021 13:53:18 +0800 Received: from mszswglt01.gcn.mediatek.inc (10.16.20.20) by mtkcas10.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Sat, 9 Oct 2021 13:53:17 +0800 From: To: CC: , , , , , , , , , , , Guangming Cao Subject: [PATCH v2] dma-buf: remove restriction of IOCTL:DMA_BUF_SET_NAME Date: Sat, 9 Oct 2021 13:55:04 +0800 Message-ID: <20211009055504.68272-1-guangming.cao@mediatek.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Guangming Cao If dma-buf don't want userspace users to touch the dmabuf buffer, it seems we should add this restriction into dma_buf_ops.mmap, not in this IOCTL:DMA_BUF_SET_NAME. With this restriction, we can only know the kernel users of the dmabuf by attachments. However, for many userspace users, such as userpsace users of dma_heap, they also need to mark the usage of dma-buf, and they don't care about who attached to this dmabuf, and seems it's no meaning to be waiting for IOCTL:DMA_BUF_SET_NAME rather than mmap. Signed-off-by: Guangming Cao --- drivers/dma-buf/dma-buf.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 511fe0d217a0..db2f4efdec32 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -325,10 +325,8 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll) /** * dma_buf_set_name - Set a name to a specific dma_buf to track the usage. - * The name of the dma-buf buffer can only be set when the dma-buf is not - * attached to any devices. It could theoritically support changing the - * name of the dma-buf if the same piece of memory is used for multiple - * purpose between different devices. + * It could theoretically support changing the name of the dma-buf if the same + * piece of memory is used for multiple purpose between different devices. * * @dmabuf: [in] dmabuf buffer that will be renamed. * @buf: [in] A piece of userspace memory that contains the name of @@ -346,19 +344,11 @@ static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf) if (IS_ERR(name)) return PTR_ERR(name); - dma_resv_lock(dmabuf->resv, NULL); - if (!list_empty(&dmabuf->attachments)) { - ret = -EBUSY; - kfree(name); - goto out_unlock; - } spin_lock(&dmabuf->name_lock); kfree(dmabuf->name); dmabuf->name = name; spin_unlock(&dmabuf->name_lock); -out_unlock: - dma_resv_unlock(dmabuf->resv); return ret; } -- 2.17.1