Thanks for your reply.
On 2024/1/22 19:25, Vinod Koul wrote:
On 18-01-24, 11:30, Kunwu Chan wrote:
kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.
Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>
---
drivers/dma/dmaengine.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 491b22240221..a6f808d13aa4 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -856,6 +856,8 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name)
#ifdef CONFIG_DEBUG_FS
chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev),
name);
+ if (!chan->dbg_client_name)
+ return chan;
That is wrong, you cant return a half done channel here
Pls see rest of the code for reference
I handle the error path like line 862 in 'dma_request_chan', though i
think it's not so perfect. Why it just return chan in line 862 when in
error? I would be very grateful if it could help me solve this puzzle
dma_request_chan find and return the ``name`` DMA channel associated
with the 'dev' device. The association is done via DT, ACPI or board
file based dma_slave_map matching table.
So when error occurs, just do the opposite, like in 'dma_release_channel'.
look likes:
---
chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s",
dev_name(dev),
name);
+ if (!chan->dbg_client_name) {
+ dma_cap_clear(DMA_SLAVE, chan->device->cap_mask);
+ dma_cap_zero(chan->device->cap_mask);
+ dma_chan_put(chan);
+ chan->slave = NULL;
+ chan = NULL;
+ return chan;
+ }
---
It's that right by clear the cap and set chan to NULL？
#endif
chan->name = kasprintf(GFP_KERNEL, "dma:%s", name);
--
2.39.2
--
Thanks,
Kunwu
