From patchwork Sat Oct 9 05:55:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Guangming.Cao" X-Patchwork-Id: 12547321 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 0D8E0C433F5 for ; Sat, 9 Oct 2021 06:03:35 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 C342B60F9C for ; Sat, 9 Oct 2021 06:03:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C342B60F9C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=VXppNF3ASh1//iDlES2QY5BFkCF4GtuGZUMewTVcycw=; b=JQlXDmMPOvDKHO hbpvaJmPzCgfce4+3P9pyHAqYPFcT7IdwbFOzLAi8ICBDoI+hvSSzE+iQm81MCWgXNNMsc2ShSomK X4VExpnb807xfCLYv69omJFVpObf/OUyXFkn+FEheZ4LYx3iIHG5vrG7QItHixOL6/iX5+ChqMb1G UzwX1Vd1+65ao+JBP/l2Mx/YQAzUf4IYPjKV/Ntp3TvOn/ceS2s9p16EF44pub1OmeitBYAwoh2an WvulfanDG6pxrQDdaGSIvjoXpldP5qiIFBcGS4SEqtObQmCnWKcXRGj2pB/2AZRpnDyZfV/UZBr8o br8TAkrjnOyB89m8QfIQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mZ5QN-005DCh-SO; Sat, 09 Oct 2021 06:01:35 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mZ5QJ-005DBS-M3; Sat, 09 Oct 2021 06:01:33 +0000 X-UUID: f7684f50d70c47e98968293e069d7b30-20211008 X-UUID: f7684f50d70c47e98968293e069d7b30-20211008 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 2068158737; Fri, 08 Oct 2021 23:01:27 -0700 Received: from mtkmbs10n1.mediatek.inc (172.21.101.34) by MTKMBS62N1.mediatek.inc (172.29.193.41) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 8 Oct 2021 22:53:19 -0700 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 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211008_230131_759143_55DAA5C1 X-CRM114-Status: GOOD ( 15.62 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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; }