FAILED: patch "[PATCH] dmaengine: qcom: bam_dma: Fix resource leak" failed to apply to 4.14-stable tree
The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7667819385457b4aeb5fac94f67f52ab52cc10d5 Mon Sep 17 00:00:00 2001
From: Jeffrey Hugo jeffrey.l.hugo@gmail.com Date: Thu, 17 Oct 2019 08:26:06 -0700 Subject: [PATCH] dmaengine: qcom: bam_dma: Fix resource leak
bam_dma_terminate_all() will leak resources if any of the transactions are committed to the hardware (present in the desc fifo), and not complete. Since bam_dma_terminate_all() does not cause the hardware to be updated, the hardware will still operate on any previously committed transactions. This can cause memory corruption if the memory for the transaction has been reassigned, and will cause a sync issue between the BAM and its client(s).
Fix this by properly updating the hardware in bam_dma_terminate_all().
Fixes: e7c0fe2a5c84 ("dmaengine: add Qualcomm BAM dma driver") Signed-off-by: Jeffrey Hugo jeffrey.l.hugo@gmail.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20191017152606.34120-1-jeffrey.l.hugo@gmail.com Signed-off-by: Vinod Koul vkoul@kernel.org
diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c index 8e90a405939d..ef73f65224b1 100644 --- a/drivers/dma/qcom/bam_dma.c +++ b/drivers/dma/qcom/bam_dma.c @@ -694,6 +694,25 @@ static int bam_dma_terminate_all(struct dma_chan *chan)
/* remove all transactions, including active transaction */ spin_lock_irqsave(&bchan->vc.lock, flag); + /* + * If we have transactions queued, then some might be committed to the + * hardware in the desc fifo. The only way to reset the desc fifo is + * to do a hardware reset (either by pipe or the entire block). + * bam_chan_init_hw() will trigger a pipe reset, and also reinit the + * pipe. If the pipe is left disabled (default state after pipe reset) + * and is accessed by a connected hardware engine, a fatal error in + * the BAM will occur. There is a small window where this could happen + * with bam_chan_init_hw(), but it is assumed that the caller has + * stopped activity on any attached hardware engine. Make sure to do + * this first so that the BAM hardware doesn't cause memory corruption + * by accessing freed resources. + */ + if (!list_empty(&bchan->desc_list)) { + async_desc = list_first_entry(&bchan->desc_list, + struct bam_async_desc, desc_node); + bam_chan_init_hw(bchan, async_desc->dir); + } + list_for_each_entry_safe(async_desc, tmp, &bchan->desc_list, desc_node) { list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
On Mon, Nov 04, 2019 at 10:35:26AM +0100, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7667819385457b4aeb5fac94f67f52ab52cc10d5 Mon Sep 17 00:00:00 2001 From: Jeffrey Hugo jeffrey.l.hugo@gmail.com Date: Thu, 17 Oct 2019 08:26:06 -0700 Subject: [PATCH] dmaengine: qcom: bam_dma: Fix resource leak
bam_dma_terminate_all() will leak resources if any of the transactions are committed to the hardware (present in the desc fifo), and not complete. Since bam_dma_terminate_all() does not cause the hardware to be updated, the hardware will still operate on any previously committed transactions. This can cause memory corruption if the memory for the transaction has been reassigned, and will cause a sync issue between the BAM and its client(s).
Fix this by properly updating the hardware in bam_dma_terminate_all().
Fixes: e7c0fe2a5c84 ("dmaengine: add Qualcomm BAM dma driver") Signed-off-by: Jeffrey Hugo jeffrey.l.hugo@gmail.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20191017152606.34120-1-jeffrey.l.hugo@gmail.com Signed-off-by: Vinod Koul vkoul@kernel.org
Is the "Fixes:" tag correct here? Is it an issue without 6b4faeac05bc ("dmaengine: qcom-bam: Process multiple pending descriptors")?
On Mon, Nov 4, 2019 at 7:07 AM Sasha Levin sashal@kernel.org wrote:
On Mon, Nov 04, 2019 at 10:35:26AM +0100, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7667819385457b4aeb5fac94f67f52ab52cc10d5 Mon Sep 17 00:00:00 2001 From: Jeffrey Hugo jeffrey.l.hugo@gmail.com Date: Thu, 17 Oct 2019 08:26:06 -0700 Subject: [PATCH] dmaengine: qcom: bam_dma: Fix resource leak
bam_dma_terminate_all() will leak resources if any of the transactions are committed to the hardware (present in the desc fifo), and not complete. Since bam_dma_terminate_all() does not cause the hardware to be updated, the hardware will still operate on any previously committed transactions. This can cause memory corruption if the memory for the transaction has been reassigned, and will cause a sync issue between the BAM and its client(s).
Fix this by properly updating the hardware in bam_dma_terminate_all().
Fixes: e7c0fe2a5c84 ("dmaengine: add Qualcomm BAM dma driver") Signed-off-by: Jeffrey Hugo jeffrey.l.hugo@gmail.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20191017152606.34120-1-jeffrey.l.hugo@gmail.com Signed-off-by: Vinod Koul vkoul@kernel.org
Is the "Fixes:" tag correct here? Is it an issue without 6b4faeac05bc ("dmaengine: qcom-bam: Process multiple pending descriptors")?
Yes. The issue will occur, even if you submit only one descriptor. The uart_dm driver which exposed this issue (msm_serial), only uses one descriptor at a time, despite the hardware and some versions of the bam driver allowing more than that.
A trivial way to trigger this would be to queue a descriptor to receive data from some peripheral that is attached to the BAM dma engine, but the peripheral never sends that data - ie if you had a NIC and you wanted to prequeue a receive buffer to accept an incoming packet. If you then invoke terminate_all(), perhaps you need to renegotiate the link speed of the NIC, you'll hit the same issue - with or without "Process multiple pending descriptors".
-- Thanks, Sasha
On Mon, Nov 04, 2019 at 07:39:58AM -0700, Jeffrey Hugo wrote:
On Mon, Nov 4, 2019 at 7:07 AM Sasha Levin sashal@kernel.org wrote:
On Mon, Nov 04, 2019 at 10:35:26AM +0100, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7667819385457b4aeb5fac94f67f52ab52cc10d5 Mon Sep 17 00:00:00 2001 From: Jeffrey Hugo jeffrey.l.hugo@gmail.com Date: Thu, 17 Oct 2019 08:26:06 -0700 Subject: [PATCH] dmaengine: qcom: bam_dma: Fix resource leak
bam_dma_terminate_all() will leak resources if any of the transactions are committed to the hardware (present in the desc fifo), and not complete. Since bam_dma_terminate_all() does not cause the hardware to be updated, the hardware will still operate on any previously committed transactions. This can cause memory corruption if the memory for the transaction has been reassigned, and will cause a sync issue between the BAM and its client(s).
Fix this by properly updating the hardware in bam_dma_terminate_all().
Fixes: e7c0fe2a5c84 ("dmaengine: add Qualcomm BAM dma driver") Signed-off-by: Jeffrey Hugo jeffrey.l.hugo@gmail.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20191017152606.34120-1-jeffrey.l.hugo@gmail.com Signed-off-by: Vinod Koul vkoul@kernel.org
Is the "Fixes:" tag correct here? Is it an issue without 6b4faeac05bc ("dmaengine: qcom-bam: Process multiple pending descriptors")?
Yes. The issue will occur, even if you submit only one descriptor. The uart_dm driver which exposed this issue (msm_serial), only uses one descriptor at a time, despite the hardware and some versions of the bam driver allowing more than that.
A trivial way to trigger this would be to queue a descriptor to receive data from some peripheral that is attached to the BAM dma engine, but the peripheral never sends that data - ie if you had a NIC and you wanted to prequeue a receive buffer to accept an incoming packet. If you then invoke terminate_all(), perhaps you need to renegotiate the link speed of the NIC, you'll hit the same issue - with or without "Process multiple pending descriptors".
In this case I'll happily take a backport of this patch :)
On Mon, Nov 4, 2019 at 10:12 AM Sasha Levin sashal@kernel.org wrote:
On Mon, Nov 04, 2019 at 07:39:58AM -0700, Jeffrey Hugo wrote:
On Mon, Nov 4, 2019 at 7:07 AM Sasha Levin sashal@kernel.org wrote:
On Mon, Nov 04, 2019 at 10:35:26AM +0100, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7667819385457b4aeb5fac94f67f52ab52cc10d5 Mon Sep 17 00:00:00 2001 From: Jeffrey Hugo jeffrey.l.hugo@gmail.com Date: Thu, 17 Oct 2019 08:26:06 -0700 Subject: [PATCH] dmaengine: qcom: bam_dma: Fix resource leak
bam_dma_terminate_all() will leak resources if any of the transactions are committed to the hardware (present in the desc fifo), and not complete. Since bam_dma_terminate_all() does not cause the hardware to be updated, the hardware will still operate on any previously committed transactions. This can cause memory corruption if the memory for the transaction has been reassigned, and will cause a sync issue between the BAM and its client(s).
Fix this by properly updating the hardware in bam_dma_terminate_all().
Fixes: e7c0fe2a5c84 ("dmaengine: add Qualcomm BAM dma driver") Signed-off-by: Jeffrey Hugo jeffrey.l.hugo@gmail.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20191017152606.34120-1-jeffrey.l.hugo@gmail.com Signed-off-by: Vinod Koul vkoul@kernel.org
Is the "Fixes:" tag correct here? Is it an issue without 6b4faeac05bc ("dmaengine: qcom-bam: Process multiple pending descriptors")?
Yes. The issue will occur, even if you submit only one descriptor. The uart_dm driver which exposed this issue (msm_serial), only uses one descriptor at a time, despite the hardware and some versions of the bam driver allowing more than that.
A trivial way to trigger this would be to queue a descriptor to receive data from some peripheral that is attached to the BAM dma engine, but the peripheral never sends that data - ie if you had a NIC and you wanted to prequeue a receive buffer to accept an incoming packet. If you then invoke terminate_all(), perhaps you need to renegotiate the link speed of the NIC, you'll hit the same issue - with or without "Process multiple pending descriptors".
In this case I'll happily take a backport of this patch :)
I'll see what I can do in the next few days.
linux-stable-mirror@lists.linaro.org
-
gregkh＠linuxfoundation.org -
Jeffrey Hugo -
Sasha Levin