[v1] EDAC: altera: Delete an inappropriate dma_free_coherent() call in altr_sdr_mc_err_inject_write()

[PATCH] EDAC: altera: Delete an inappropriate dma_free_coherent() call in altr_sdr_mc_err_inject_write()

Posted by Salah Triki 2 months ago

`dma_free_coherent()` must only be called if the corresponding
`dma_alloc_coherent()` call has succeeded. Calling it when the allocation
fails leads to undefined behavior.

Add a check to ensure that the memory is only freed when the allocation
was successful.

Signed-off-by: Salah Triki <salah.triki@gmail.com>
Fixes: 71bcada88b0f3 ("edac: altera: Add Altera SDRAM EDAC support")
Cc: Markus Elfring <Markus.Elfring@web.de>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rric@kernel.org>
Cc: linux-edac@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
---
 drivers/edac/altera_edac.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
index cae52c654a15..7685a8550d4b 100644
--- a/drivers/edac/altera_edac.c
+++ b/drivers/edac/altera_edac.c
@@ -128,7 +128,6 @@ static ssize_t altr_sdr_mc_err_inject_write(struct file *file,
 
 	ptemp = dma_alloc_coherent(mci->pdev, 16, &dma_handle, GFP_KERNEL);
 	if (!ptemp) {
-		dma_free_coherent(mci->pdev, 16, ptemp, dma_handle);
 		edac_printk(KERN_ERR, EDAC_MC,
 			    "Inject: Buffer Allocation error\n");
 		return -ENOMEM;
-- 
2.43.0

Re: [PATCH] EDAC: altera: Delete an inappropriate dma_free_coherent() call in altr_sdr_mc_err_inject_write()

Posted by Borislav Petkov 1 month, 1 week ago

On Thu, Jul 31, 2025 at 04:15:27AM +0100, Salah Triki wrote:
> `dma_free_coherent()` must only be called if the corresponding
> `dma_alloc_coherent()` call has succeeded. Calling it when the allocation
> fails leads to undefined behavior.
> 
> Add a check to ensure that the memory is only freed when the allocation
> was successful.
> 
> Signed-off-by: Salah Triki <salah.triki@gmail.com>
> Fixes: 71bcada88b0f3 ("edac: altera: Add Altera SDRAM EDAC support")
> Cc: Markus Elfring <Markus.Elfring@web.de>
> Cc: Dinh Nguyen <dinguyen@kernel.org>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: James Morse <james.morse@arm.com>
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: Robert Richter <rric@kernel.org>
> Cc: linux-edac@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: stable@vger.kernel.org
> ---
>  drivers/edac/altera_edac.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
> index cae52c654a15..7685a8550d4b 100644
> --- a/drivers/edac/altera_edac.c
> +++ b/drivers/edac/altera_edac.c
> @@ -128,7 +128,6 @@ static ssize_t altr_sdr_mc_err_inject_write(struct file *file,
>  
>  	ptemp = dma_alloc_coherent(mci->pdev, 16, &dma_handle, GFP_KERNEL);
>  	if (!ptemp) {
> -		dma_free_coherent(mci->pdev, 16, ptemp, dma_handle);
>  		edac_printk(KERN_ERR, EDAC_MC,
>  			    "Inject: Buffer Allocation error\n");
>  		return -ENOMEM;
> -- 


Applied, thanks.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

Re: [PATCH] EDAC: altera: Delete an inappropriate dma_free_coherent() call in altr_sdr_mc_err_inject_write()

Posted by Markus Elfring 1 month, 1 week ago

…> Add a check to ensure that the memory is only freed when the allocation
> was successful.

How good does such a wording fit to the proposed function call deletion?

Regards,
Markus

Re: [PATCH] EDAC: altera: Delete an inappropriate dma_free_coherent() call in altr_sdr_mc_err_inject_write()

Posted by Dinh Nguyen 1 month, 1 week ago

On 7/30/25 22:15, Salah Triki wrote:
> `dma_free_coherent()` must only be called if the corresponding
> `dma_alloc_coherent()` call has succeeded. Calling it when the allocation
> fails leads to undefined behavior.
> 
> Add a check to ensure that the memory is only freed when the allocation
> was successful.
> 
> Signed-off-by: Salah Triki <salah.triki@gmail.com>
> Fixes: 71bcada88b0f3 ("edac: altera: Add Altera SDRAM EDAC support")
> Cc: Markus Elfring <Markus.Elfring@web.de>
> Cc: Dinh Nguyen <dinguyen@kernel.org>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: James Morse <james.morse@arm.com>
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: Robert Richter <rric@kernel.org>
> Cc: linux-edac@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: stable@vger.kernel.org
> ---
>   drivers/edac/altera_edac.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
> index cae52c654a15..7685a8550d4b 100644
> --- a/drivers/edac/altera_edac.c
> +++ b/drivers/edac/altera_edac.c
> @@ -128,7 +128,6 @@ static ssize_t altr_sdr_mc_err_inject_write(struct file *file,
>   
>   	ptemp = dma_alloc_coherent(mci->pdev, 16, &dma_handle, GFP_KERNEL);
>   	if (!ptemp) {
> -		dma_free_coherent(mci->pdev, 16, ptemp, dma_handle);
>   		edac_printk(KERN_ERR, EDAC_MC,
>   			    "Inject: Buffer Allocation error\n");
>   		return -ENOMEM;


Acked-by: Dinh Nguyen <dinguyen@kernel.org>