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 1A18B1849DD; Wed, 3 Jul 2024 11:22:31 +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=1720005751; cv=none; b=b+GOwZvaL4VICYoXHvHfZSvdIX9hWYyusADAi1lyP82fthX4lR7nQ9ulEYxNknr2Eaoj5TRxvCs4RWfCRxtmj/w3jR1MQ9l3fjsGTPrlY/Wq/kgvC+gW9TGsHbWFHGW4ybo8KpwVyh/xguixwlAkV6ERTdPO3Pr/zpLwsD/Esi8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720005751; c=relaxed/simple; bh=8JeZz9flsRfJyLVlHgOgObtzIxH4lYhY0gzPgexdjOU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aVZ5A8CL7Yzv3sKve7g7HN7Z+pl4LijM15p4411iczMLR0Odko2VK/UE12Z+C5J5O+1ubdw+3jFItjpY2BpvFYFlsSitTR6x65wSZzSRgqU10BmuSAOGRErsL8aB0sFuJU6L/HX0XaMbu/iUD7XRCgIroa9nKXBTMT12YGqxUKw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AUPB8P/o; 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="AUPB8P/o" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95631C4AF0B; Wed, 3 Jul 2024 11:22:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720005751; bh=8JeZz9flsRfJyLVlHgOgObtzIxH4lYhY0gzPgexdjOU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AUPB8P/ozl6Nfme1yGzbL5MD+PIzFVhOmaVE7YT4j4UQydVbyTDtjSJ3Hufxu6ahM 5MIEWihhD96/xZnq9hxYdY84aYfP6Ss0VhUOrz4Cdcd2p2d6pp8ImR14vR7AC6zz3W RybZR2JT2hlAjHN4LFNx3xdqSXtdEAJj8/DCTeyw= 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 5.15 177/356] Avoid hw_desc array overrun in dw-axi-dmac Date: Wed, 3 Jul 2024 12:38:33 +0200 Message-ID: <20240703102919.800625080@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102913.093882413@linuxfoundation.org> References: <20240703102913.093882413@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 5.15-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 cfc47efcb5d93..6715ade391aa1 100644 --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c @@ -213,6 +213,7 @@ static struct axi_dma_desc *axi_desc_alloc(u32 num) kfree(desc); return NULL; } + desc->nr_hw_descs = num; return desc; } @@ -239,7 +240,7 @@ 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; @@ -1049,9 +1050,6 @@ 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 380005afde160..58fc6310ee364 100644 --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h @@ -101,6 +101,7 @@ struct axi_dma_desc { u32 completed_blocks; u32 length; u32 period_len; + u32 nr_hw_descs; }; static inline struct device *dchan2dev(struct dma_chan *dchan) -- 2.43.0