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dmaengine: ti: k3-udma: Set r/tchan or rflow to NULL if request fail

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udma_get_*() checks if rchan/tchan/rflow is already allocated by checking
if it has a NON NULL value. For the error cases, rchan/tchan/rflow will
have error value and udma_get_*() considers this as already allocated
(PASS) since the error values are NON NULL. This results in NULL pointer
dereference error while de-referencing rchan/tchan/rflow.

Reset the value of rchan/tchan/rflow to NULL if a channel request fails.

CC: stable@vger.kernel.org
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/20211031032411.27235-3-kishon@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Kishon Vijay Abraham I 2021-10-31 08:54:11 +05:30 committed by Vinod Koul
parent 5c6c6d60e4
commit eb91224e47
1 changed files with 20 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
drivers/dma/ti/k3-udma.c
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@ -1380,6 +1380,7 @@ static int bcdma_get_bchan(struct udma_chan *uc)
static int udma_get_tchan(struct udma_chan *uc) static int udma_get_tchan(struct udma_chan *uc)
{ {
struct udma_dev *ud = uc->ud; struct udma_dev *ud = uc->ud;
int ret;
if (uc->tchan) { if (uc->tchan) {
dev_dbg(ud->dev, "chan%d: already have tchan%d allocated\n", dev_dbg(ud->dev, "chan%d: already have tchan%d allocated\n",
@ -1394,8 +1395,11 @@ static int udma_get_tchan(struct udma_chan *uc)
*/ */
uc->tchan = __udma_reserve_tchan(ud, uc->config.channel_tpl, uc->tchan = __udma_reserve_tchan(ud, uc->config.channel_tpl,
uc->config.mapped_channel_id); uc->config.mapped_channel_id);
if (IS_ERR(uc->tchan)) if (IS_ERR(uc->tchan)) {
return PTR_ERR(uc->tchan); ret = PTR_ERR(uc->tchan);
uc->tchan = NULL;
return ret;
}
if (ud->tflow_cnt) { if (ud->tflow_cnt) {
int tflow_id; int tflow_id;
@ -1425,6 +1429,7 @@ static int udma_get_tchan(struct udma_chan *uc)
static int udma_get_rchan(struct udma_chan *uc) static int udma_get_rchan(struct udma_chan *uc)
{ {
struct udma_dev *ud = uc->ud; struct udma_dev *ud = uc->ud;
int ret;
if (uc->rchan) { if (uc->rchan) {
dev_dbg(ud->dev, "chan%d: already have rchan%d allocated\n", dev_dbg(ud->dev, "chan%d: already have rchan%d allocated\n",
@ -1439,8 +1444,13 @@ static int udma_get_rchan(struct udma_chan *uc)
*/ */
uc->rchan = __udma_reserve_rchan(ud, uc->config.channel_tpl, uc->rchan = __udma_reserve_rchan(ud, uc->config.channel_tpl,
uc->config.mapped_channel_id); uc->config.mapped_channel_id);
if (IS_ERR(uc->rchan)) {
ret = PTR_ERR(uc->rchan);
uc->rchan = NULL;
return ret;
}
return PTR_ERR_OR_ZERO(uc->rchan); return 0;
} }
static int udma_get_chan_pair(struct udma_chan *uc) static int udma_get_chan_pair(struct udma_chan *uc)
@ -1494,6 +1504,7 @@ static int udma_get_chan_pair(struct udma_chan *uc)
static int udma_get_rflow(struct udma_chan *uc, int flow_id) static int udma_get_rflow(struct udma_chan *uc, int flow_id)
{ {
struct udma_dev *ud = uc->ud; struct udma_dev *ud = uc->ud;
int ret;
if (!uc->rchan) { if (!uc->rchan) {
dev_err(ud->dev, "chan%d: does not have rchan??\n", uc->id); dev_err(ud->dev, "chan%d: does not have rchan??\n", uc->id);
@ -1507,8 +1518,13 @@ static int udma_get_rflow(struct udma_chan *uc, int flow_id)
} }
uc->rflow = __udma_get_rflow(ud, flow_id); uc->rflow = __udma_get_rflow(ud, flow_id);
if (IS_ERR(uc->rflow)) {
ret = PTR_ERR(uc->rflow);
uc->rflow = NULL;
return ret;
}
return PTR_ERR_OR_ZERO(uc->rflow); return 0;
} }
static void bcdma_put_bchan(struct udma_chan *uc) static void bcdma_put_bchan(struct udma_chan *uc)