From: Tudor Ambarus <tudor.ambarus@microchip.com>
To: <vkoul@kernel.org>, <peda@axentia.se>, <du@axentia.se>,
<regressions@leemhuis.info>
Cc: <ludovic.desroches@microchip.com>, <maciej.sosnowski@intel.com>,
<tudor.ambarus@microchip.com>, <dan.j.williams@intel.com>,
<nicolas.ferre@microchip.com>, <mripard@kernel.org>,
<torfl6749@gmail.com>, <linux-kernel@vger.kernel.org>,
<dmaengine@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>, <stable@vger.kernel.org>
Subject: [PATCH 16/33] dmaengine: at_hdmac: Fix concurrency over the active list
Date: Sat, 20 Aug 2022 15:57:00 +0300 [thread overview]
Message-ID: <20220820125717.588722-17-tudor.ambarus@microchip.com> (raw)
In-Reply-To: <20220820125717.588722-1-tudor.ambarus@microchip.com>
The tasklet did not held the channel lock when retrieving the first active
descriptor, causing concurrency problems if issue_pending() was called in
between. If issue_pending() was called exactly after the lock was released
in the tasklet, atc_chain_complete() could complete a descriptor for which
the controller has not yet raised an interrupt.
Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda@axentia.se>
Cc: stable@vger.kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/
---
drivers/dma/at_hdmac.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index c2b3d7b63920..635c3be74399 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -897,8 +897,6 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
if (!atc_chan_is_cyclic(atchan))
dma_cookie_complete(txd);
- /* Remove transfer node from the active list. */
- list_del_init(&desc->desc_node);
spin_unlock_irqrestore(&atchan->lock, flags);
dma_descriptor_unmap(txd);
@@ -930,6 +928,7 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
*/
static void atc_advance_work(struct at_dma_chan *atchan)
{
+ struct at_desc *desc;
unsigned long flags;
dev_vdbg(chan2dev(&atchan->dma_chan), "advance_work\n");
@@ -937,9 +936,12 @@ static void atc_advance_work(struct at_dma_chan *atchan)
spin_lock_irqsave(&atchan->lock, flags);
if (atc_chan_is_enabled(atchan) || list_empty(&atchan->active_list))
return spin_unlock_irqrestore(&atchan->lock, flags);
- spin_unlock_irqrestore(&atchan->lock, flags);
- atc_chain_complete(atchan, atc_first_active(atchan));
+ desc = atc_first_active(atchan);
+ /* Remove the transfer node from the active list. */
+ list_del_init(&desc->desc_node);
+ spin_unlock_irqrestore(&atchan->lock, flags);
+ atc_chain_complete(atchan, desc);
/* advance work */
spin_lock_irqsave(&atchan->lock, flags);
--
2.25.1
next prev parent reply other threads:[~2022-08-20 12:59 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-20 12:56 [PATCH 00/33] dmaengine: at_hdmac: Fix concurrency bugs and then convert to virt-dma Tudor Ambarus
2022-08-20 12:56 ` [PATCH 01/33] dmaengine: at_hdmac: Keep register definitions and structures private to at_hdmac.c Tudor Ambarus
2022-08-20 12:56 ` [PATCH 02/33] dmaengine: at_hdmac: Use bitfield access macros Tudor Ambarus
2022-08-20 12:56 ` [PATCH 03/33] dmaengine: at_hdmac: Rename "dma_common" to "dma_device" Tudor Ambarus
2022-08-20 12:56 ` [PATCH 04/33] dmaengine: at_hdmac: Rename "chan_common" to "dma_chan" Tudor Ambarus
2022-08-20 12:56 ` [PATCH 05/33] dmaengine: at_hdmac: Remove unused member of at_dma_chan Tudor Ambarus
2022-08-20 12:56 ` [PATCH 06/33] dmaengine: at_hdmac: Return dma_cookie_status()'s ret code when txstate is NULL Tudor Ambarus
2022-08-20 12:56 ` [PATCH 07/33] dmaengine: at_hdmac: Fix at_lli struct definition Tudor Ambarus
2022-10-19 16:38 ` Vinod Koul
2022-10-20 7:08 ` Tudor.Ambarus
2022-08-20 12:56 ` [PATCH 08/33] dmaengine: at_hdmac: Don't start transactions at tx_submit level Tudor Ambarus
2022-08-20 12:56 ` [PATCH 09/33] dmaengine: at_hdmac: Start transfer for cyclic channels in issue_pending Tudor Ambarus
2022-08-20 12:56 ` [PATCH 10/33] dmaengine: at_hdmac: Fix premature completion of desc " Tudor Ambarus
2022-08-20 12:56 ` [PATCH 11/33] dmaengine: at_hdmac: Do not call the complete callback on device_terminate_all Tudor Ambarus
2022-08-20 12:56 ` [PATCH 12/33] dmaengine: at_hdmac: Protect atchan->status with the channel lock Tudor Ambarus
2022-08-20 12:56 ` [PATCH 13/33] dmaengine: at_hdmac: Fix concurrency problems by removing atc_complete_all() Tudor Ambarus
2022-08-20 12:56 ` [PATCH 14/33] dmaengine: at_hdmac: Fix concurrency over descriptor Tudor Ambarus
2022-08-20 12:56 ` [PATCH 15/33] dmaengine: at_hdmac: Free the memset buf without holding the chan lock Tudor Ambarus
2022-08-20 12:57 ` Tudor Ambarus [this message]
2022-08-20 12:57 ` [PATCH 17/33] dmaengine: at_hdmac: Fix descriptor handling when issuing it to hardware Tudor Ambarus
2022-08-20 12:57 ` [PATCH 18/33] dmaengine: at_hdmac: Fix completion of unissued descriptor in case of errors Tudor Ambarus
2022-08-20 12:57 ` [PATCH 19/33] dmaengine: at_hdmac: Don't allow CPU to reorder channel enable Tudor Ambarus
2022-08-20 12:57 ` [PATCH 20/33] dmaengine: at_hdmac: Do not print messages on console while holding the lock Tudor Ambarus
2022-08-20 12:57 ` [PATCH 21/33] dmaengine: at_hdmac: Fix impossible condition Tudor Ambarus
2022-08-20 12:57 ` [PATCH 22/33] dmaengine: at_hdmac: Pass residue by address to avoid unneccessary implicit casts Tudor Ambarus
2022-08-20 12:57 ` [PATCH 23/33] dmaengine: at_hdmac: s/atc_get_bytes_left/atc_get_residue Tudor Ambarus
2022-08-20 12:57 ` [PATCH 24/33] dmaengine: at_hdmac: Introduce atc_get_llis_residue() Tudor Ambarus
2022-08-20 12:57 ` [PATCH 25/33] dmaengine: at_hdmac: Remove superfluous cast Tudor Ambarus
2022-08-20 12:57 ` [PATCH 26/33] dmaengine: at_hdmac: Use devm_kzalloc() and struct_size() Tudor Ambarus
2022-08-20 12:57 ` [PATCH 27/33] dmaengine: at_hdmac: Use devm_platform_ioremap_resource Tudor Ambarus
2022-08-20 12:57 ` [PATCH 28/33] dmaengine: at_hdmac: Use devm_request_irq() Tudor Ambarus
2022-10-19 16:49 ` Vinod Koul
2022-10-20 7:24 ` Tudor.Ambarus
2022-08-20 12:57 ` [PATCH 29/33] dmaengine: at_hdmac: Use devm_clk_get() Tudor Ambarus
2022-08-20 12:57 ` [PATCH 30/33] dmaengine: at_hdmac: Check return code of dma_async_device_register Tudor Ambarus
2022-08-20 12:57 ` [PATCH 31/33] dmaengine: at_hdmac: Use pm_ptr() Tudor Ambarus
2022-10-19 16:50 ` Vinod Koul
2022-10-20 7:10 ` Tudor.Ambarus
2022-08-20 12:57 ` [PATCH 32/33] dmaengine: at_hdmac: Set include entries in alphabetic order Tudor Ambarus
2022-08-20 12:57 ` [PATCH 33/33] dmaengine: at_hdmac: Convert driver to use virt-dma Tudor Ambarus
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