From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C068D149C62; Tue, 25 Jun 2024 09:38:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719308300; cv=none; b=QcgntTln8Z7rciU8TCgfdmW2ozt2946YhceI1uecITifjg/lxy+sPZdeFgTwcBYH6MWcl4j30c05oen8EfTMoOuxk6bTD15sdMJpWS4HzELPPBXol+Yb82l+ChJzMbxgwYrRKe+JoqgbWVKtnx0NFrzZ7/iGSXBKya2Fk950RQc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719308300; c=relaxed/simple; bh=utoAPpkInd+2MPVEJCbdUVBK+cy6+GIT6hi4SyY8P60=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ltJNT3rmAB5ytDad7flKR7jRvNIRCfThhfkgr9ipTPsRYwPYxChs8C+ZZOPPDmvdZsu7uRjRC+9wGjGtZeBPh+5wHPYlsDaSn+LFTYO+9s0uUg6GhYtiRleCRGJzBPw91VKCglV197neiamF9vNN4QPd/PmuxjIyjJH8uQCkuBE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eFb7SvgU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="eFb7SvgU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 46AA8C4AF09; Tue, 25 Jun 2024 09:38:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1719308300; bh=utoAPpkInd+2MPVEJCbdUVBK+cy6+GIT6hi4SyY8P60=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eFb7SvgUP8T831a/wsUxruxjn7vfn91iEIwUj0r9yjPGmPk5xSacKCzpG0kBe0kpZ SJWSCEYIntFVcrI9r38jykXmp0zQoOCIuGd4h8uLt6R2FvFGKceEkSoyqi0P7MRqdr 5+JthxFZNKdZOeBAGulq5WsAx5vJEhxTCfGYkhd0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Joao Pinto , Vinod Koul , Sasha Levin Subject: [PATCH 6.9 075/250] Avoid hw_desc array overrun in dw-axi-dmac Date: Tue, 25 Jun 2024 11:30:33 +0200 Message-ID: <20240625085550.944378624@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240625085548.033507125@linuxfoundation.org> References: <20240625085548.033507125@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joao Pinto [ Upstream commit 333e11bf47fa8d477db90e2900b1ed3c9ae9b697 ] I have a use case where nr_buffers = 3 and in which each descriptor is composed by 3 segments, resulting in the DMA channel descs_allocated to be 9. Since axi_desc_put() handles the hw_desc considering the descs_allocated, this scenario would result in a kernel panic (hw_desc array will be overrun). To fix this, the proposal is to add a new member to the axi_dma_desc structure, where we keep the number of allocated hw_descs (axi_desc_alloc()) and use it in axi_desc_put() to handle the hw_desc array correctly. Additionally I propose to remove the axi_chan_start_first_queued() call after completing the transfer, since it was identified that unbalance can occur (started descriptors can be interrupted and transfer ignored due to DMA channel not being enabled). Signed-off-by: Joao Pinto Link: https://lore.kernel.org/r/1711536564-12919-1-git-send-email-jpinto@synopsys.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 6 ++---- drivers/dma/dw-axi-dmac/dw-axi-dmac.h | 1 + 2 files changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c index a86a81ff0caa6..321446fdddbd7 100644 --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c @@ -302,6 +302,7 @@ static struct axi_dma_desc *axi_desc_alloc(u32 num) kfree(desc); return NULL; } + desc->nr_hw_descs = num; return desc; } @@ -328,7 +329,7 @@ static struct axi_dma_lli *axi_desc_get(struct axi_dma_chan *chan, static void axi_desc_put(struct axi_dma_desc *desc) { struct axi_dma_chan *chan = desc->chan; - int count = atomic_read(&chan->descs_allocated); + int count = desc->nr_hw_descs; struct axi_dma_hw_desc *hw_desc; int descs_put; @@ -1139,9 +1140,6 @@ static void axi_chan_block_xfer_complete(struct axi_dma_chan *chan) /* Remove the completed descriptor from issued list before completing */ list_del(&vd->node); vchan_cookie_complete(vd); - - /* Submit queued descriptors after processing the completed ones */ - axi_chan_start_first_queued(chan); } out: diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h index 454904d996540..ac571b413b21c 100644 --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h @@ -104,6 +104,7 @@ struct axi_dma_desc { u32 completed_blocks; u32 length; u32 period_len; + u32 nr_hw_descs; }; struct axi_dma_chan_config { -- 2.43.0