[PATCH][linux-next] dmaengine: dw-axi-dmac: Fix uninitialized variable in axi_chan_block_xfer_start()

[PATCH][linux-next] dmaengine: dw-axi-dmac: Fix uninitialized variable in axi_chan_block_xfer_start()

[Tim Gardner]

Coverity complains of an uninitialized variable:

5. uninit_use_in_call: Using uninitialized value config.dst_per when calling axi_chan_config_write. [show details]
6. uninit_use_in_call: Using uninitialized value config.hs_sel_src when calling axi_chan_config_write. [show details]
CID 121164 (#1-3 of 3): Uninitialized scalar variable (UNINIT)
7. uninit_use_in_call: Using uninitialized value config.src_per when calling axi_chan_config_write. [show details]
418        axi_chan_config_write(chan, &config);

Fix this by clearing the structure which should at least be benign in axi_chan_config_write(). Also fix
what looks like a cut-n-paste error when initializing config.hs_sel_dst.

Fixes: 824351668a413 ("dmaengine: dw-axi-dmac: support DMAX_NUM_CHANNELS > 8")
Cc: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index 79572ec532ef..f47116e77ea1 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -386,12 +386,13 @@ static void axi_chan_block_xfer_start(struct axi_dma_chan *chan,
 
 	axi_dma_enable(chan->chip);
 
+	memset(&config, 0, sizeof(config));
 	config.dst_multblk_type = DWAXIDMAC_MBLK_TYPE_LL;
 	config.src_multblk_type = DWAXIDMAC_MBLK_TYPE_LL;
 	config.tt_fc = DWAXIDMAC_TT_FC_MEM_TO_MEM_DMAC;
 	config.prior = priority;
 	config.hs_sel_dst = DWAXIDMAC_HS_SEL_HW;
-	config.hs_sel_dst = DWAXIDMAC_HS_SEL_HW;
+	config.hs_sel_src = DWAXIDMAC_HS_SEL_HW;
 	switch (chan->direction) {
 	case DMA_MEM_TO_DEV:
 		dw_axi_dma_set_byte_halfword(chan, true);
-- 
2.33.1

Re: [PATCH][linux-next] dmaengine: dw-axi-dmac: Fix uninitialized variable in axi_chan_block_xfer_start()

[Vinod Koul]

On 19-10-21, 13:07, Tim Gardner wrote:
> Coverity complains of an uninitialized variable:
> 
> 5. uninit_use_in_call: Using uninitialized value config.dst_per when calling axi_chan_config_write. [show details]
> 6. uninit_use_in_call: Using uninitialized value config.hs_sel_src when calling axi_chan_config_write. [show details]
> CID 121164 (#1-3 of 3): Uninitialized scalar variable (UNINIT)
> 7. uninit_use_in_call: Using uninitialized value config.src_per when calling axi_chan_config_write. [show details]
> 418        axi_chan_config_write(chan, &config);
> 
> Fix this by clearing the structure which should at least be benign in axi_chan_config_write(). Also fix
> what looks like a cut-n-paste error when initializing config.hs_sel_dst.

Eugeniy?

> 
> Fixes: 824351668a413 ("dmaengine: dw-axi-dmac: support DMAX_NUM_CHANNELS > 8")
> Cc: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
> Cc: Vinod Koul <vkoul@kernel.org>
> Cc: dmaengine@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
> ---
>  drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> index 79572ec532ef..f47116e77ea1 100644
> --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> @@ -386,12 +386,13 @@ static void axi_chan_block_xfer_start(struct axi_dma_chan *chan,
>  
>  	axi_dma_enable(chan->chip);
>  
> +	memset(&config, 0, sizeof(config));

pls init config while defining instead

        struct axi_dma_chan_config config = {};

>  	config.dst_multblk_type = DWAXIDMAC_MBLK_TYPE_LL;
>  	config.src_multblk_type = DWAXIDMAC_MBLK_TYPE_LL;
>  	config.tt_fc = DWAXIDMAC_TT_FC_MEM_TO_MEM_DMAC;
>  	config.prior = priority;
>  	config.hs_sel_dst = DWAXIDMAC_HS_SEL_HW;
> -	config.hs_sel_dst = DWAXIDMAC_HS_SEL_HW;
> +	config.hs_sel_src = DWAXIDMAC_HS_SEL_HW;
>  	switch (chan->direction) {
>  	case DMA_MEM_TO_DEV:
>  		dw_axi_dma_set_byte_halfword(chan, true);
> -- 
> 2.33.1

-- 
~Vinod

[PATCH v2][linux-next] dmaengine: dw-axi-dmac: Fix uninitialized variable in axi_chan_block_xfer_start()

[Tim Gardner]

Coverity complains of an uninitialized variable:

5. uninit_use_in_call: Using uninitialized value config.dst_per when calling axi_chan_config_write. [show details]
6. uninit_use_in_call: Using uninitialized value config.hs_sel_src when calling axi_chan_config_write. [show details]
CID 121164 (#1-3 of 3): Uninitialized scalar variable (UNINIT)
7. uninit_use_in_call: Using uninitialized value config.src_per when calling axi_chan_config_write. [show details]
418        axi_chan_config_write(chan, &config);

Fix this by initializing the structure to 0 which should at least be benign in axi_chan_config_write(). Also fix
what looks like a cut-n-paste error when initializing config.hs_sel_dst.

Fixes: 824351668a413 ("dmaengine: dw-axi-dmac: support DMAX_NUM_CHANNELS > 8")
Cc: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---

v2 - Use static initializer for 'config'. Drop the memset() call.

---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index 79572ec532ef..9a9194da0dcb 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -373,7 +373,7 @@ static void axi_chan_block_xfer_start(struct axi_dma_chan *chan,
 				      struct axi_dma_desc *first)
 {
 	u32 priority = chan->chip->dw->hdata->priority[chan->id];
-	struct axi_dma_chan_config config;
+	struct axi_dma_chan_config config = {};
 	u32 irq_mask;
 	u8 lms = 0; /* Select AXI0 master for LLI fetching */
 
@@ -391,7 +391,7 @@ static void axi_chan_block_xfer_start(struct axi_dma_chan *chan,
 	config.tt_fc = DWAXIDMAC_TT_FC_MEM_TO_MEM_DMAC;
 	config.prior = priority;
 	config.hs_sel_dst = DWAXIDMAC_HS_SEL_HW;
-	config.hs_sel_dst = DWAXIDMAC_HS_SEL_HW;
+	config.hs_sel_src = DWAXIDMAC_HS_SEL_HW;
 	switch (chan->direction) {
 	case DMA_MEM_TO_DEV:
 		dw_axi_dma_set_byte_halfword(chan, true);
-- 
2.33.1

Re: [PATCH v2][linux-next] dmaengine: dw-axi-dmac: Fix uninitialized variable in axi_chan_block_xfer_start()

[Vinod Koul]

On 25-10-21, 12:16, Tim Gardner wrote:
> Coverity complains of an uninitialized variable:
> 
> 5. uninit_use_in_call: Using uninitialized value config.dst_per when calling axi_chan_config_write. [show details]
> 6. uninit_use_in_call: Using uninitialized value config.hs_sel_src when calling axi_chan_config_write. [show details]
> CID 121164 (#1-3 of 3): Uninitialized scalar variable (UNINIT)
> 7. uninit_use_in_call: Using uninitialized value config.src_per when calling axi_chan_config_write. [show details]
> 418        axi_chan_config_write(chan, &config);
> 
> Fix this by initializing the structure to 0 which should at least be benign in axi_chan_config_write(). Also fix
> what looks like a cut-n-paste error when initializing config.hs_sel_dst.

Applied, thanks

-- 
~Vinod