drivers/spi/spi-stm32.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-)
In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
and rx_mdma_desc are passed as pointer-to-pointer arguments.
The goal is to pass back to the caller the value returned
by dmaengine_prep_slave_sg(), when it is not NULL.
However, these variables are wrongly handled as simple pointers
during later assignments and checks.
Fix this behaviour by introducing two pointer variables
which can then be treated accordingly.
Fixes: d17dd2f1d8a1 ("spi: stm32: use STM32 DMA with STM32 MDMA to enhance DDR use")
Addresses-Coverity-ID: 1644715 ("Null pointer dereferences (REVERSE_INULL)")
Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>
---
Changes from v1:
* introduce *_mdma_desc and *_dma_desc for better readability
* fix another instance of rx_dma_desc bogus assignment in case of
failure of sg_alloc_table()
* commit title/message reworded accordingly to the previous point
---
drivers/spi/spi-stm32.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 3d20f09f1ae7..4b7f074fdba9 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -1474,6 +1474,8 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
struct dma_async_tx_descriptor **rx_dma_desc,
struct dma_async_tx_descriptor **rx_mdma_desc)
{
+ struct dma_async_tx_descriptor *_mdma_desc = *rx_mdma_desc;
+ struct dma_async_tx_descriptor *_dma_desc = *rx_dma_desc;
struct dma_slave_config rx_mdma_conf = {0};
u32 sram_period, nents = 0, spi_s_len;
struct sg_table dma_sgt, mdma_sgt;
@@ -1524,18 +1526,18 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
}
}
- *rx_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
- dma_sgt.nents, rx_dma_conf->direction,
- DMA_PREP_INTERRUPT);
+ _dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
+ dma_sgt.nents, rx_dma_conf->direction,
+ DMA_PREP_INTERRUPT);
sg_free_table(&dma_sgt);
- if (!rx_dma_desc)
+ if (!_dma_desc)
return -EINVAL;
/* Prepare MDMA slave_sg transfer MEM_TO_MEM (SRAM>DDR) */
ret = sg_alloc_table(&mdma_sgt, nents, GFP_ATOMIC);
if (ret) {
- rx_dma_desc = NULL;
+ _dma_desc = NULL;
return ret;
}
@@ -1558,13 +1560,13 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
}
}
- *rx_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
- mdma_sgt.nents, rx_mdma_conf.direction,
- DMA_PREP_INTERRUPT);
+ _mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
+ mdma_sgt.nents, rx_mdma_conf.direction,
+ DMA_PREP_INTERRUPT);
sg_free_table(&mdma_sgt);
- if (!rx_mdma_desc) {
- rx_dma_desc = NULL;
+ if (!_mdma_desc) {
+ _dma_desc = NULL;
return -EINVAL;
}
--
2.49.0On Mon, 30 Jun 2025 10:12:53 +0200, Antonio Quartulli wrote:
> In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
> and rx_mdma_desc are passed as pointer-to-pointer arguments.
>
> The goal is to pass back to the caller the value returned
> by dmaengine_prep_slave_sg(), when it is not NULL.
>
> However, these variables are wrongly handled as simple pointers
> during later assignments and checks.
>
> [...]
Applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next
Thanks!
[1/1] spi: stm32: fix pointer-to-pointer variables usage
commit: c4f2c05ab02952c9a56067aeb700ded95b183570
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
Thanks,
Mark
On 6/30/25 10:12, Antonio Quartulli wrote:
> In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
> and rx_mdma_desc are passed as pointer-to-pointer arguments.
>
> The goal is to pass back to the caller the value returned
> by dmaengine_prep_slave_sg(), when it is not NULL.
>
> However, these variables are wrongly handled as simple pointers
> during later assignments and checks.
>
> Fix this behaviour by introducing two pointer variables
> which can then be treated accordingly.
>
> Fixes: d17dd2f1d8a1 ("spi: stm32: use STM32 DMA with STM32 MDMA to enhance DDR use")
> Addresses-Coverity-ID: 1644715 ("Null pointer dereferences (REVERSE_INULL)")
> Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>
>
> ---
> Changes from v1:
> * introduce *_mdma_desc and *_dma_desc for better readability
> * fix another instance of rx_dma_desc bogus assignment in case of
> failure of sg_alloc_table()
> * commit title/message reworded accordingly to the previous point
> ---
> drivers/spi/spi-stm32.c | 22 ++++++++++++----------
> 1 file changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
> index 3d20f09f1ae7..4b7f074fdba9 100644
> --- a/drivers/spi/spi-stm32.c
> +++ b/drivers/spi/spi-stm32.c
> @@ -1474,6 +1474,8 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
> struct dma_async_tx_descriptor **rx_dma_desc,
> struct dma_async_tx_descriptor **rx_mdma_desc)
> {
> + struct dma_async_tx_descriptor *_mdma_desc = *rx_mdma_desc;
> + struct dma_async_tx_descriptor *_dma_desc = *rx_dma_desc;
> struct dma_slave_config rx_mdma_conf = {0};
> u32 sram_period, nents = 0, spi_s_len;
> struct sg_table dma_sgt, mdma_sgt;
> @@ -1524,18 +1526,18 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
> }
> }
>
> - *rx_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> - dma_sgt.nents, rx_dma_conf->direction,
> - DMA_PREP_INTERRUPT);
> + _dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> + dma_sgt.nents, rx_dma_conf->direction,
> + DMA_PREP_INTERRUPT);
> sg_free_table(&dma_sgt);
>
> - if (!rx_dma_desc)
> + if (!_dma_desc)
> return -EINVAL;
>
> /* Prepare MDMA slave_sg transfer MEM_TO_MEM (SRAM>DDR) */
> ret = sg_alloc_table(&mdma_sgt, nents, GFP_ATOMIC);
> if (ret) {
> - rx_dma_desc = NULL;
> + _dma_desc = NULL;
> return ret;
> }
>
> @@ -1558,13 +1560,13 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
> }
> }
>
> - *rx_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> - mdma_sgt.nents, rx_mdma_conf.direction,
> - DMA_PREP_INTERRUPT);
> + _mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> + mdma_sgt.nents, rx_mdma_conf.direction,
> + DMA_PREP_INTERRUPT);
> sg_free_table(&mdma_sgt);
>
> - if (!rx_mdma_desc) {
> - rx_dma_desc = NULL;
> + if (!_mdma_desc) {
> + _dma_desc = NULL;
> return -EINVAL;
> }
>
Reviewed-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Hi Antonio,
Thank you for the patch.
On Mon, Jun 30, 2025 at 10:12:53AM +0200, Antonio Quartulli wrote:
> In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
> and rx_mdma_desc are passed as pointer-to-pointer arguments.
>
> The goal is to pass back to the caller the value returned
> by dmaengine_prep_slave_sg(), when it is not NULL.
>
> However, these variables are wrongly handled as simple pointers
> during later assignments and checks.
>
> Fix this behaviour by introducing two pointer variables
> which can then be treated accordingly.
>
> Fixes: d17dd2f1d8a1 ("spi: stm32: use STM32 DMA with STM32 MDMA to enhance DDR use")
> Addresses-Coverity-ID: 1644715 ("Null pointer dereferences (REVERSE_INULL)")
> Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>
>
> ---
> Changes from v1:
> * introduce *_mdma_desc and *_dma_desc for better readability
> * fix another instance of rx_dma_desc bogus assignment in case of
> failure of sg_alloc_table()
> * commit title/message reworded accordingly to the previous point
> ---
> drivers/spi/spi-stm32.c | 22 ++++++++++++----------
> 1 file changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
> index 3d20f09f1ae7..4b7f074fdba9 100644
> --- a/drivers/spi/spi-stm32.c
> +++ b/drivers/spi/spi-stm32.c
> @@ -1474,6 +1474,8 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
> struct dma_async_tx_descriptor **rx_dma_desc,
> struct dma_async_tx_descriptor **rx_mdma_desc)
> {
> + struct dma_async_tx_descriptor *_mdma_desc = *rx_mdma_desc;
> + struct dma_async_tx_descriptor *_dma_desc = *rx_dma_desc;
> struct dma_slave_config rx_mdma_conf = {0};
> u32 sram_period, nents = 0, spi_s_len;
> struct sg_table dma_sgt, mdma_sgt;
> @@ -1524,18 +1526,18 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
> }
> }
>
> - *rx_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> - dma_sgt.nents, rx_dma_conf->direction,
> - DMA_PREP_INTERRUPT);
> + _dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> + dma_sgt.nents, rx_dma_conf->direction,
> + DMA_PREP_INTERRUPT);
> sg_free_table(&dma_sgt);
>
> - if (!rx_dma_desc)
> + if (!_dma_desc)
> return -EINVAL;
>
> /* Prepare MDMA slave_sg transfer MEM_TO_MEM (SRAM>DDR) */
> ret = sg_alloc_table(&mdma_sgt, nents, GFP_ATOMIC);
> if (ret) {
> - rx_dma_desc = NULL;
> + _dma_desc = NULL;
> return ret;
> }
>
> @@ -1558,13 +1560,13 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
> }
> }
>
> - *rx_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> - mdma_sgt.nents, rx_mdma_conf.direction,
> - DMA_PREP_INTERRUPT);
> + _mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> + mdma_sgt.nents, rx_mdma_conf.direction,
> + DMA_PREP_INTERRUPT);
> sg_free_table(&mdma_sgt);
>
> - if (!rx_mdma_desc) {
> - rx_dma_desc = NULL;
> + if (!_mdma_desc) {
> + _dma_desc = NULL;
> return -EINVAL;
> }
>
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Regards,
Alain
> --
> 2.49.0
>
On 6/30/25 10:12, Antonio Quartulli wrote:
> In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
> and rx_mdma_desc are passed as pointer-to-pointer arguments.
>
> The goal is to pass back to the caller the value returned
> by dmaengine_prep_slave_sg(), when it is not NULL.
>
> However, these variables are wrongly handled as simple pointers
> during later assignments and checks.
>
> Fix this behaviour by introducing two pointer variables
> which can then be treated accordingly.
>
> Fixes: d17dd2f1d8a1 ("spi: stm32: use STM32 DMA with STM32 MDMA to enhance DDR use")
> Addresses-Coverity-ID: 1644715 ("Null pointer dereferences (REVERSE_INULL)")
> Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>
>
> ---
> Changes from v1:
> * introduce *_mdma_desc and *_dma_desc for better readability
> * fix another instance of rx_dma_desc bogus assignment in case of
> failure of sg_alloc_table()
> * commit title/message reworded accordingly to the previous point
> ---
> drivers/spi/spi-stm32.c | 22 ++++++++++++----------
> 1 file changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
> index 3d20f09f1ae7..4b7f074fdba9 100644
> --- a/drivers/spi/spi-stm32.c
> +++ b/drivers/spi/spi-stm32.c
> @@ -1474,6 +1474,8 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
> struct dma_async_tx_descriptor **rx_dma_desc,
> struct dma_async_tx_descriptor **rx_mdma_desc)
> {
> + struct dma_async_tx_descriptor *_mdma_desc = *rx_mdma_desc;
> + struct dma_async_tx_descriptor *_dma_desc = *rx_dma_desc;
> struct dma_slave_config rx_mdma_conf = {0};
> u32 sram_period, nents = 0, spi_s_len;
> struct sg_table dma_sgt, mdma_sgt;
> @@ -1524,18 +1526,18 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
> }
> }
>
> - *rx_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> - dma_sgt.nents, rx_dma_conf->direction,
> - DMA_PREP_INTERRUPT);
> + _dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> + dma_sgt.nents, rx_dma_conf->direction,
> + DMA_PREP_INTERRUPT);
> sg_free_table(&dma_sgt);
>
> - if (!rx_dma_desc)
> + if (!_dma_desc)
> return -EINVAL;
>
> /* Prepare MDMA slave_sg transfer MEM_TO_MEM (SRAM>DDR) */
> ret = sg_alloc_table(&mdma_sgt, nents, GFP_ATOMIC);
> if (ret) {
> - rx_dma_desc = NULL;
> + _dma_desc = NULL;
> return ret;
> }
>
> @@ -1558,13 +1560,13 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
> }
> }
>
> - *rx_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> - mdma_sgt.nents, rx_mdma_conf.direction,
> - DMA_PREP_INTERRUPT);
> + _mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> + mdma_sgt.nents, rx_mdma_conf.direction,
> + DMA_PREP_INTERRUPT);
> sg_free_table(&mdma_sgt);
>
> - if (!rx_mdma_desc) {
> - rx_dma_desc = NULL;
> + if (!_mdma_desc) {
> + _dma_desc = NULL;
> return -EINVAL;
> }
>
Thank you, LGTM
You can add my Reviewed-by
Best regards,
Clément
On Mon, Jun 30, 2025 at 10:28:50AM +0200, Clement LE GOFFIC wrote: > Thank you, LGTM > You can add my Reviewed-by If you want to add a Reviewed-by you should actually write it out in the mail, people rely on tooling like b4 to pick them up.
On 6/30/25 13:20, Mark Brown wrote: > On Mon, Jun 30, 2025 at 10:28:50AM +0200, Clement LE GOFFIC wrote: > >> Thank you, LGTM >> You can add my Reviewed-by > > If you want to add a Reviewed-by you should actually write it out in the > mail, people rely on tooling like b4 to pick them up. Yes, sorry. Fixed it. Best regards, Clément
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