shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-08 20:07:46 +09:00
Code Issues Packages Projects Releases Wiki Activity

dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list

Browse Source 
commit c33ee1301c upstream.

The interrupt handler puts a half-completed DMA descriptor on a free list
and then schedules tasklet to process bottom half of the descriptor that
executes client's callback, this creates possibility to pick up the busy
descriptor from the free list. Thus, let's disallow descriptor's re-use
until it is fully processed.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200209163356.6439-3-digetx@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dmitry Osipenko
2020-02-09 19:33:39 +03:00
committed by Chris
parent cdf071ecd9
commit 120fe63509
1 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/dma/tegra20-apb-dma.c
View File

@@ -288,7 +288,7 @@ static struct tegra_dma_desc *tegra_dma_desc_get(
/* Do not allocate if desc are waiting for ack */
list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
if (async_tx_test_ack(&dma_desc->txd)) {
if (async_tx_test_ack(&dma_desc->txd) && !dma_desc->cb_count) {
list_del(&dma_desc->node);
spin_unlock_irqrestore(&tdc->lock, flags);
dma_desc->txd.flags = 0;