The patch below does not apply to the 4.19-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(a)vger.kernel.org>.
Possible dependencies:
6ba826cbb57d ("dmaengine: at_hdmac: Free the memset buf without holding the chan lock")
06988949df8c ("dmaengine: at_hdmac: Fix concurrency over descriptor")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6ba826cbb57d675f447b59323204d1473bbd5593 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:43 +0300
Subject: [PATCH] dmaengine: at_hdmac: Free the memset buf without holding the
chan lock
There's no need to hold the channel lock when freeing the memset buf, as
the operation has already completed. Free the memset buf without holding
the channel lock.
Fixes: 4d112426c344 ("dmaengine: hdmac: Add memset capabilities")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-10-tudor.ambarus@microchip.…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 2012ecc57826..0fb44f622d35 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -462,13 +462,6 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
if (!atc_chan_is_cyclic(atchan))
dma_cookie_complete(txd);
- /* If the transfer was a memset, free our temporary buffer */
- if (desc->memset_buffer) {
- dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
- desc->memset_paddr);
- desc->memset_buffer = false;
- }
-
/* Remove transfer node from the active list. */
list_del_init(&desc->desc_node);
spin_unlock_irqrestore(&atchan->lock, flags);
@@ -487,6 +480,13 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
/* add myself to free_list */
list_add(&desc->desc_node, &atchan->free_list);
spin_unlock_irqrestore(&atchan->lock, flags);
+
+ /* If the transfer was a memset, free our temporary buffer */
+ if (desc->memset_buffer) {
+ dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
+ desc->memset_paddr);
+ desc->memset_buffer = false;
+ }
}
/**
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(a)vger.kernel.org>.
Possible dependencies:
6ba826cbb57d ("dmaengine: at_hdmac: Free the memset buf without holding the chan lock")
06988949df8c ("dmaengine: at_hdmac: Fix concurrency over descriptor")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6ba826cbb57d675f447b59323204d1473bbd5593 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:43 +0300
Subject: [PATCH] dmaengine: at_hdmac: Free the memset buf without holding the
chan lock
There's no need to hold the channel lock when freeing the memset buf, as
the operation has already completed. Free the memset buf without holding
the channel lock.
Fixes: 4d112426c344 ("dmaengine: hdmac: Add memset capabilities")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-10-tudor.ambarus@microchip.…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 2012ecc57826..0fb44f622d35 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -462,13 +462,6 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
if (!atc_chan_is_cyclic(atchan))
dma_cookie_complete(txd);
- /* If the transfer was a memset, free our temporary buffer */
- if (desc->memset_buffer) {
- dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
- desc->memset_paddr);
- desc->memset_buffer = false;
- }
-
/* Remove transfer node from the active list. */
list_del_init(&desc->desc_node);
spin_unlock_irqrestore(&atchan->lock, flags);
@@ -487,6 +480,13 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
/* add myself to free_list */
list_add(&desc->desc_node, &atchan->free_list);
spin_unlock_irqrestore(&atchan->lock, flags);
+
+ /* If the transfer was a memset, free our temporary buffer */
+ if (desc->memset_buffer) {
+ dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
+ desc->memset_paddr);
+ desc->memset_buffer = false;
+ }
}
/**
The patch below does not apply to the 5.4-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(a)vger.kernel.org>.
Possible dependencies:
6ba826cbb57d ("dmaengine: at_hdmac: Free the memset buf without holding the chan lock")
06988949df8c ("dmaengine: at_hdmac: Fix concurrency over descriptor")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6ba826cbb57d675f447b59323204d1473bbd5593 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:43 +0300
Subject: [PATCH] dmaengine: at_hdmac: Free the memset buf without holding the
chan lock
There's no need to hold the channel lock when freeing the memset buf, as
the operation has already completed. Free the memset buf without holding
the channel lock.
Fixes: 4d112426c344 ("dmaengine: hdmac: Add memset capabilities")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-10-tudor.ambarus@microchip.…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 2012ecc57826..0fb44f622d35 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -462,13 +462,6 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
if (!atc_chan_is_cyclic(atchan))
dma_cookie_complete(txd);
- /* If the transfer was a memset, free our temporary buffer */
- if (desc->memset_buffer) {
- dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
- desc->memset_paddr);
- desc->memset_buffer = false;
- }
-
/* Remove transfer node from the active list. */
list_del_init(&desc->desc_node);
spin_unlock_irqrestore(&atchan->lock, flags);
@@ -487,6 +480,13 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
/* add myself to free_list */
list_add(&desc->desc_node, &atchan->free_list);
spin_unlock_irqrestore(&atchan->lock, flags);
+
+ /* If the transfer was a memset, free our temporary buffer */
+ if (desc->memset_buffer) {
+ dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
+ desc->memset_paddr);
+ desc->memset_buffer = false;
+ }
}
/**
The patch below does not apply to the 4.9-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(a)vger.kernel.org>.
Possible dependencies:
06988949df8c ("dmaengine: at_hdmac: Fix concurrency over descriptor")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 06988949df8c3007ad82036d3606d8ae72ed9000 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:42 +0300
Subject: [PATCH] dmaengine: at_hdmac: Fix concurrency over descriptor
The descriptor was added to the free_list before calling the callback,
which could result in reissuing of the same descriptor and calling of a
single callback for both. Move the decriptor to the free list after the
callback is invoked.
Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-9-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index f1e6fa6af6c2..2012ecc57826 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -469,11 +469,8 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
desc->memset_buffer = false;
}
- /* move children to free_list */
- list_splice_init(&desc->tx_list, &atchan->free_list);
- /* move myself to free_list */
- list_move(&desc->desc_node, &atchan->free_list);
-
+ /* Remove transfer node from the active list. */
+ list_del_init(&desc->desc_node);
spin_unlock_irqrestore(&atchan->lock, flags);
dma_descriptor_unmap(txd);
@@ -483,6 +480,13 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
dmaengine_desc_get_callback_invoke(txd, NULL);
dma_run_dependencies(txd);
+
+ spin_lock_irqsave(&atchan->lock, flags);
+ /* move children to free_list */
+ list_splice_init(&desc->tx_list, &atchan->free_list);
+ /* add myself to free_list */
+ list_add(&desc->desc_node, &atchan->free_list);
+ spin_unlock_irqrestore(&atchan->lock, flags);
}
/**
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(a)vger.kernel.org>.
Possible dependencies:
06988949df8c ("dmaengine: at_hdmac: Fix concurrency over descriptor")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 06988949df8c3007ad82036d3606d8ae72ed9000 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:42 +0300
Subject: [PATCH] dmaengine: at_hdmac: Fix concurrency over descriptor
The descriptor was added to the free_list before calling the callback,
which could result in reissuing of the same descriptor and calling of a
single callback for both. Move the decriptor to the free list after the
callback is invoked.
Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-9-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index f1e6fa6af6c2..2012ecc57826 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -469,11 +469,8 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
desc->memset_buffer = false;
}
- /* move children to free_list */
- list_splice_init(&desc->tx_list, &atchan->free_list);
- /* move myself to free_list */
- list_move(&desc->desc_node, &atchan->free_list);
-
+ /* Remove transfer node from the active list. */
+ list_del_init(&desc->desc_node);
spin_unlock_irqrestore(&atchan->lock, flags);
dma_descriptor_unmap(txd);
@@ -483,6 +480,13 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
dmaengine_desc_get_callback_invoke(txd, NULL);
dma_run_dependencies(txd);
+
+ spin_lock_irqsave(&atchan->lock, flags);
+ /* move children to free_list */
+ list_splice_init(&desc->tx_list, &atchan->free_list);
+ /* add myself to free_list */
+ list_add(&desc->desc_node, &atchan->free_list);
+ spin_unlock_irqrestore(&atchan->lock, flags);
}
/**
The patch below does not apply to the 4.19-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(a)vger.kernel.org>.
Possible dependencies:
06988949df8c ("dmaengine: at_hdmac: Fix concurrency over descriptor")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 06988949df8c3007ad82036d3606d8ae72ed9000 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:42 +0300
Subject: [PATCH] dmaengine: at_hdmac: Fix concurrency over descriptor
The descriptor was added to the free_list before calling the callback,
which could result in reissuing of the same descriptor and calling of a
single callback for both. Move the decriptor to the free list after the
callback is invoked.
Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-9-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index f1e6fa6af6c2..2012ecc57826 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -469,11 +469,8 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
desc->memset_buffer = false;
}
- /* move children to free_list */
- list_splice_init(&desc->tx_list, &atchan->free_list);
- /* move myself to free_list */
- list_move(&desc->desc_node, &atchan->free_list);
-
+ /* Remove transfer node from the active list. */
+ list_del_init(&desc->desc_node);
spin_unlock_irqrestore(&atchan->lock, flags);
dma_descriptor_unmap(txd);
@@ -483,6 +480,13 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
dmaengine_desc_get_callback_invoke(txd, NULL);
dma_run_dependencies(txd);
+
+ spin_lock_irqsave(&atchan->lock, flags);
+ /* move children to free_list */
+ list_splice_init(&desc->tx_list, &atchan->free_list);
+ /* add myself to free_list */
+ list_add(&desc->desc_node, &atchan->free_list);
+ spin_unlock_irqrestore(&atchan->lock, flags);
}
/**
The patch below does not apply to the 5.4-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(a)vger.kernel.org>.
Possible dependencies:
06988949df8c ("dmaengine: at_hdmac: Fix concurrency over descriptor")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 06988949df8c3007ad82036d3606d8ae72ed9000 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:42 +0300
Subject: [PATCH] dmaengine: at_hdmac: Fix concurrency over descriptor
The descriptor was added to the free_list before calling the callback,
which could result in reissuing of the same descriptor and calling of a
single callback for both. Move the decriptor to the free list after the
callback is invoked.
Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-9-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index f1e6fa6af6c2..2012ecc57826 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -469,11 +469,8 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
desc->memset_buffer = false;
}
- /* move children to free_list */
- list_splice_init(&desc->tx_list, &atchan->free_list);
- /* move myself to free_list */
- list_move(&desc->desc_node, &atchan->free_list);
-
+ /* Remove transfer node from the active list. */
+ list_del_init(&desc->desc_node);
spin_unlock_irqrestore(&atchan->lock, flags);
dma_descriptor_unmap(txd);
@@ -483,6 +480,13 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
dmaengine_desc_get_callback_invoke(txd, NULL);
dma_run_dependencies(txd);
+
+ spin_lock_irqsave(&atchan->lock, flags);
+ /* move children to free_list */
+ list_splice_init(&desc->tx_list, &atchan->free_list);
+ /* add myself to free_list */
+ list_add(&desc->desc_node, &atchan->free_list);
+ spin_unlock_irqrestore(&atchan->lock, flags);
}
/**
The patch below does not apply to the 4.9-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(a)vger.kernel.org>.
Possible dependencies:
c6babed879fb ("dmaengine: at_hdmac: Fix concurrency problems by removing atc_complete_all()")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c6babed879fbe82796a601bf097649e07382db46 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:41 +0300
Subject: [PATCH] dmaengine: at_hdmac: Fix concurrency problems by removing
atc_complete_all()
atc_complete_all() had concurrency bugs, thus remove it:
1/ atc_complete_all() in its entirety was buggy, as when the atchan->queue
list (the one that contains descriptors that are not yet issued to the
hardware) contained descriptors, it fired just the first from the
atchan->queue, but moved all the desc from atchan->queue to
atchan->active_list and considered them all as fired. This could result in
calling the completion of a descriptor that was not yet issued to the
hardware.
2/ when in tasklet at atc_advance_work() time, atchan->active_list was
queried without holding the lock of the chan. This can result in
atchan->active_list concurrency problems between the tasklet and
issue_pending().
Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-8-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index deb4c6027436..f1e6fa6af6c2 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -485,42 +485,6 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
dma_run_dependencies(txd);
}
-/**
- * atc_complete_all - finish work for all transactions
- * @atchan: channel to complete transactions for
- *
- * Eventually submit queued descriptors if any
- *
- * Assume channel is idle while calling this function
- * Called with atchan->lock held and bh disabled
- */
-static void atc_complete_all(struct at_dma_chan *atchan)
-{
- struct at_desc *desc, *_desc;
- LIST_HEAD(list);
- unsigned long flags;
-
- dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n");
-
- spin_lock_irqsave(&atchan->lock, flags);
-
- /*
- * Submit queued descriptors ASAP, i.e. before we go through
- * the completed ones.
- */
- if (!list_empty(&atchan->queue))
- atc_dostart(atchan, atc_first_queued(atchan));
- /* empty active_list now it is completed */
- list_splice_init(&atchan->active_list, &list);
- /* empty queue list by moving descriptors (if any) to active_list */
- list_splice_init(&atchan->queue, &atchan->active_list);
-
- spin_unlock_irqrestore(&atchan->lock, flags);
-
- list_for_each_entry_safe(desc, _desc, &list, desc_node)
- atc_chain_complete(atchan, desc);
-}
-
/**
* atc_advance_work - at the end of a transaction, move forward
* @atchan: channel where the transaction ended
@@ -528,25 +492,20 @@ static void atc_complete_all(struct at_dma_chan *atchan)
static void atc_advance_work(struct at_dma_chan *atchan)
{
unsigned long flags;
- int ret;
dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
spin_lock_irqsave(&atchan->lock, flags);
- ret = atc_chan_is_enabled(atchan);
+ if (atc_chan_is_enabled(atchan) || list_empty(&atchan->active_list))
+ return spin_unlock_irqrestore(&atchan->lock, flags);
spin_unlock_irqrestore(&atchan->lock, flags);
- if (ret)
- return;
-
- if (list_empty(&atchan->active_list) ||
- list_is_singular(&atchan->active_list))
- return atc_complete_all(atchan);
atc_chain_complete(atchan, atc_first_active(atchan));
/* advance work */
spin_lock_irqsave(&atchan->lock, flags);
- atc_dostart(atchan, atc_first_active(atchan));
+ if (!list_empty(&atchan->active_list))
+ atc_dostart(atchan, atc_first_active(atchan));
spin_unlock_irqrestore(&atchan->lock, flags);
}
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(a)vger.kernel.org>.
Possible dependencies:
c6babed879fb ("dmaengine: at_hdmac: Fix concurrency problems by removing atc_complete_all()")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c6babed879fbe82796a601bf097649e07382db46 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:41 +0300
Subject: [PATCH] dmaengine: at_hdmac: Fix concurrency problems by removing
atc_complete_all()
atc_complete_all() had concurrency bugs, thus remove it:
1/ atc_complete_all() in its entirety was buggy, as when the atchan->queue
list (the one that contains descriptors that are not yet issued to the
hardware) contained descriptors, it fired just the first from the
atchan->queue, but moved all the desc from atchan->queue to
atchan->active_list and considered them all as fired. This could result in
calling the completion of a descriptor that was not yet issued to the
hardware.
2/ when in tasklet at atc_advance_work() time, atchan->active_list was
queried without holding the lock of the chan. This can result in
atchan->active_list concurrency problems between the tasklet and
issue_pending().
Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-8-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index deb4c6027436..f1e6fa6af6c2 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -485,42 +485,6 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
dma_run_dependencies(txd);
}
-/**
- * atc_complete_all - finish work for all transactions
- * @atchan: channel to complete transactions for
- *
- * Eventually submit queued descriptors if any
- *
- * Assume channel is idle while calling this function
- * Called with atchan->lock held and bh disabled
- */
-static void atc_complete_all(struct at_dma_chan *atchan)
-{
- struct at_desc *desc, *_desc;
- LIST_HEAD(list);
- unsigned long flags;
-
- dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n");
-
- spin_lock_irqsave(&atchan->lock, flags);
-
- /*
- * Submit queued descriptors ASAP, i.e. before we go through
- * the completed ones.
- */
- if (!list_empty(&atchan->queue))
- atc_dostart(atchan, atc_first_queued(atchan));
- /* empty active_list now it is completed */
- list_splice_init(&atchan->active_list, &list);
- /* empty queue list by moving descriptors (if any) to active_list */
- list_splice_init(&atchan->queue, &atchan->active_list);
-
- spin_unlock_irqrestore(&atchan->lock, flags);
-
- list_for_each_entry_safe(desc, _desc, &list, desc_node)
- atc_chain_complete(atchan, desc);
-}
-
/**
* atc_advance_work - at the end of a transaction, move forward
* @atchan: channel where the transaction ended
@@ -528,25 +492,20 @@ static void atc_complete_all(struct at_dma_chan *atchan)
static void atc_advance_work(struct at_dma_chan *atchan)
{
unsigned long flags;
- int ret;
dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
spin_lock_irqsave(&atchan->lock, flags);
- ret = atc_chan_is_enabled(atchan);
+ if (atc_chan_is_enabled(atchan) || list_empty(&atchan->active_list))
+ return spin_unlock_irqrestore(&atchan->lock, flags);
spin_unlock_irqrestore(&atchan->lock, flags);
- if (ret)
- return;
-
- if (list_empty(&atchan->active_list) ||
- list_is_singular(&atchan->active_list))
- return atc_complete_all(atchan);
atc_chain_complete(atchan, atc_first_active(atchan));
/* advance work */
spin_lock_irqsave(&atchan->lock, flags);
- atc_dostart(atchan, atc_first_active(atchan));
+ if (!list_empty(&atchan->active_list))
+ atc_dostart(atchan, atc_first_active(atchan));
spin_unlock_irqrestore(&atchan->lock, flags);
}
The patch below does not apply to the 4.19-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(a)vger.kernel.org>.
Possible dependencies:
c6babed879fb ("dmaengine: at_hdmac: Fix concurrency problems by removing atc_complete_all()")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c6babed879fbe82796a601bf097649e07382db46 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:41 +0300
Subject: [PATCH] dmaengine: at_hdmac: Fix concurrency problems by removing
atc_complete_all()
atc_complete_all() had concurrency bugs, thus remove it:
1/ atc_complete_all() in its entirety was buggy, as when the atchan->queue
list (the one that contains descriptors that are not yet issued to the
hardware) contained descriptors, it fired just the first from the
atchan->queue, but moved all the desc from atchan->queue to
atchan->active_list and considered them all as fired. This could result in
calling the completion of a descriptor that was not yet issued to the
hardware.
2/ when in tasklet at atc_advance_work() time, atchan->active_list was
queried without holding the lock of the chan. This can result in
atchan->active_list concurrency problems between the tasklet and
issue_pending().
Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-8-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index deb4c6027436..f1e6fa6af6c2 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -485,42 +485,6 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
dma_run_dependencies(txd);
}
-/**
- * atc_complete_all - finish work for all transactions
- * @atchan: channel to complete transactions for
- *
- * Eventually submit queued descriptors if any
- *
- * Assume channel is idle while calling this function
- * Called with atchan->lock held and bh disabled
- */
-static void atc_complete_all(struct at_dma_chan *atchan)
-{
- struct at_desc *desc, *_desc;
- LIST_HEAD(list);
- unsigned long flags;
-
- dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n");
-
- spin_lock_irqsave(&atchan->lock, flags);
-
- /*
- * Submit queued descriptors ASAP, i.e. before we go through
- * the completed ones.
- */
- if (!list_empty(&atchan->queue))
- atc_dostart(atchan, atc_first_queued(atchan));
- /* empty active_list now it is completed */
- list_splice_init(&atchan->active_list, &list);
- /* empty queue list by moving descriptors (if any) to active_list */
- list_splice_init(&atchan->queue, &atchan->active_list);
-
- spin_unlock_irqrestore(&atchan->lock, flags);
-
- list_for_each_entry_safe(desc, _desc, &list, desc_node)
- atc_chain_complete(atchan, desc);
-}
-
/**
* atc_advance_work - at the end of a transaction, move forward
* @atchan: channel where the transaction ended
@@ -528,25 +492,20 @@ static void atc_complete_all(struct at_dma_chan *atchan)
static void atc_advance_work(struct at_dma_chan *atchan)
{
unsigned long flags;
- int ret;
dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
spin_lock_irqsave(&atchan->lock, flags);
- ret = atc_chan_is_enabled(atchan);
+ if (atc_chan_is_enabled(atchan) || list_empty(&atchan->active_list))
+ return spin_unlock_irqrestore(&atchan->lock, flags);
spin_unlock_irqrestore(&atchan->lock, flags);
- if (ret)
- return;
-
- if (list_empty(&atchan->active_list) ||
- list_is_singular(&atchan->active_list))
- return atc_complete_all(atchan);
atc_chain_complete(atchan, atc_first_active(atchan));
/* advance work */
spin_lock_irqsave(&atchan->lock, flags);
- atc_dostart(atchan, atc_first_active(atchan));
+ if (!list_empty(&atchan->active_list))
+ atc_dostart(atchan, atc_first_active(atchan));
spin_unlock_irqrestore(&atchan->lock, flags);
}