pds_fwctl: Replace kzalloc + copy_from_user with memdup_user in pdsfc_fw_rpc

[PATCH] pds_fwctl: Replace kzalloc + copy_from_user with memdup_user in pdsfc_fw_rpc

Posted by Thorsten Blum 4 months, 3 weeks ago

Replace kzalloc() followed by copy_from_user() with memdup_user() to
improve and simplify pdsfc_fw_rpc().

Return early if an error occurs and remove the obsolete 'err_out' label.

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 drivers/fwctl/pds/main.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/fwctl/pds/main.c b/drivers/fwctl/pds/main.c
index 9b9d1f6b5556..04d84f892fb8 100644
--- a/drivers/fwctl/pds/main.c
+++ b/drivers/fwctl/pds/main.c
@@ -6,6 +6,7 @@
 #include <linux/pci.h>
 #include <linux/vmalloc.h>
 #include <linux/bitfield.h>
+#include <linux/string.h>
 
 #include <uapi/fwctl/fwctl.h>
 #include <uapi/fwctl/pds.h>
@@ -366,18 +367,10 @@ static void *pdsfc_fw_rpc(struct fwctl_uctx *uctx, enum fwctl_rpc_scope scope,
 		return ERR_PTR(err);
 
 	if (rpc->in.len > 0) {
-		in_payload = kzalloc(rpc->in.len, GFP_KERNEL);
-		if (!in_payload) {
-			dev_err(dev, "Failed to allocate in_payload\n");
-			err = -ENOMEM;
-			goto err_out;
-		}
-
-		if (copy_from_user(in_payload, u64_to_user_ptr(rpc->in.payload),
-				   rpc->in.len)) {
+		in_payload = memdup_user(u64_to_user_ptr(rpc->in.payload), rpc->in.len);
+		if (IS_ERR(in_payload)) {
 			dev_dbg(dev, "Failed to copy in_payload from user\n");
-			err = -EFAULT;
-			goto err_in_payload;
+			return in_payload;
 		}
 
 		in_payload_dma_addr = dma_map_single(dev->parent, in_payload,
@@ -453,7 +446,6 @@ static void *pdsfc_fw_rpc(struct fwctl_uctx *uctx, enum fwctl_rpc_scope scope,
 				 rpc->in.len, DMA_TO_DEVICE);
 err_in_payload:
 	kfree(in_payload);
-err_out:
 	if (err)
 		return ERR_PTR(err);
 
-- 
2.51.0

Re: [PATCH] pds_fwctl: Replace kzalloc + copy_from_user with memdup_user in pdsfc_fw_rpc

Posted by Jason Gunthorpe 4 months, 2 weeks ago

On Wed, Sep 17, 2025 at 05:09:41PM +0200, Thorsten Blum wrote:
> Replace kzalloc() followed by copy_from_user() with memdup_user() to
> improve and simplify pdsfc_fw_rpc().
> 
> Return early if an error occurs and remove the obsolete 'err_out' label.
> 
> No functional changes intended.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
>  drivers/fwctl/pds/main.c | 16 ++++------------
>  1 file changed, 4 insertions(+), 12 deletions(-)

Applied, thanks

Jason

Re: [PATCH] pds_fwctl: Replace kzalloc + copy_from_user with memdup_user in pdsfc_fw_rpc

Posted by Brett Creeley 4 months, 3 weeks ago

On 9/17/2025 8:09 AM, Thorsten Blum wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> 
> 
> Replace kzalloc() followed by copy_from_user() with memdup_user() to
> improve and simplify pdsfc_fw_rpc().
> 
> Return early if an error occurs and remove the obsolete 'err_out' label.
> 
> No functional changes intended.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
>   drivers/fwctl/pds/main.c | 16 ++++------------
>   1 file changed, 4 insertions(+), 12 deletions(-)

Thanks for the patch.

Tested-by: Brett Creeley <brett.creeley@amd.com>

> 
> diff --git a/drivers/fwctl/pds/main.c b/drivers/fwctl/pds/main.c
> index 9b9d1f6b5556..04d84f892fb8 100644
> --- a/drivers/fwctl/pds/main.c
> +++ b/drivers/fwctl/pds/main.c
> @@ -6,6 +6,7 @@
>   #include <linux/pci.h>
>   #include <linux/vmalloc.h>
>   #include <linux/bitfield.h>
> +#include <linux/string.h>
> 
>   #include <uapi/fwctl/fwctl.h>
>   #include <uapi/fwctl/pds.h>
> @@ -366,18 +367,10 @@ static void *pdsfc_fw_rpc(struct fwctl_uctx *uctx, enum fwctl_rpc_scope scope,
>                  return ERR_PTR(err);
> 
>          if (rpc->in.len > 0) {
> -               in_payload = kzalloc(rpc->in.len, GFP_KERNEL);
> -               if (!in_payload) {
> -                       dev_err(dev, "Failed to allocate in_payload\n");
> -                       err = -ENOMEM;
> -                       goto err_out;
> -               }
> -
> -               if (copy_from_user(in_payload, u64_to_user_ptr(rpc->in.payload),
> -                                  rpc->in.len)) {
> +               in_payload = memdup_user(u64_to_user_ptr(rpc->in.payload), rpc->in.len);
> +               if (IS_ERR(in_payload)) {
>                          dev_dbg(dev, "Failed to copy in_payload from user\n");
> -                       err = -EFAULT;
> -                       goto err_in_payload;
> +                       return in_payload;
>                  }
> 
>                  in_payload_dma_addr = dma_map_single(dev->parent, in_payload,
> @@ -453,7 +446,6 @@ static void *pdsfc_fw_rpc(struct fwctl_uctx *uctx, enum fwctl_rpc_scope scope,
>                                   rpc->in.len, DMA_TO_DEVICE);
>   err_in_payload:
>          kfree(in_payload);
> -err_out:
>          if (err)
>                  return ERR_PTR(err);
> 
> --
> 2.51.0
>

Re: [PATCH] pds_fwctl: Replace kzalloc + copy_from_user with memdup_user in pdsfc_fw_rpc

Posted by Dave Jiang 4 months, 3 weeks ago


On 9/17/25 8:09 AM, Thorsten Blum wrote:
> Replace kzalloc() followed by copy_from_user() with memdup_user() to
> improve and simplify pdsfc_fw_rpc().
> 
> Return early if an error occurs and remove the obsolete 'err_out' label.
> 
> No functional changes intended.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/fwctl/pds/main.c | 16 ++++------------
>  1 file changed, 4 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/fwctl/pds/main.c b/drivers/fwctl/pds/main.c
> index 9b9d1f6b5556..04d84f892fb8 100644
> --- a/drivers/fwctl/pds/main.c
> +++ b/drivers/fwctl/pds/main.c
> @@ -6,6 +6,7 @@
>  #include <linux/pci.h>
>  #include <linux/vmalloc.h>
>  #include <linux/bitfield.h>
> +#include <linux/string.h>
>  
>  #include <uapi/fwctl/fwctl.h>
>  #include <uapi/fwctl/pds.h>
> @@ -366,18 +367,10 @@ static void *pdsfc_fw_rpc(struct fwctl_uctx *uctx, enum fwctl_rpc_scope scope,
>  		return ERR_PTR(err);
>  
>  	if (rpc->in.len > 0) {
> -		in_payload = kzalloc(rpc->in.len, GFP_KERNEL);
> -		if (!in_payload) {
> -			dev_err(dev, "Failed to allocate in_payload\n");
> -			err = -ENOMEM;
> -			goto err_out;
> -		}
> -
> -		if (copy_from_user(in_payload, u64_to_user_ptr(rpc->in.payload),
> -				   rpc->in.len)) {
> +		in_payload = memdup_user(u64_to_user_ptr(rpc->in.payload), rpc->in.len);
> +		if (IS_ERR(in_payload)) {
>  			dev_dbg(dev, "Failed to copy in_payload from user\n");
> -			err = -EFAULT;
> -			goto err_in_payload;
> +			return in_payload;
>  		}
>  
>  		in_payload_dma_addr = dma_map_single(dev->parent, in_payload,
> @@ -453,7 +446,6 @@ static void *pdsfc_fw_rpc(struct fwctl_uctx *uctx, enum fwctl_rpc_scope scope,
>  				 rpc->in.len, DMA_TO_DEVICE);
>  err_in_payload:
>  	kfree(in_payload);
> -err_out:
>  	if (err)
>  		return ERR_PTR(err);
>

Re: [PATCH] pds_fwctl: Replace kzalloc + copy_from_user with memdup_user in pdsfc_fw_rpc

Posted by Jason Gunthorpe 4 months, 3 weeks ago

On Wed, Sep 17, 2025 at 05:09:41PM +0200, Thorsten Blum wrote:
> Replace kzalloc() followed by copy_from_user() with memdup_user() to
> improve and simplify pdsfc_fw_rpc().
> 
> Return early if an error occurs and remove the obsolete 'err_out' label.
> 
> No functional changes intended.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
>  drivers/fwctl/pds/main.c | 16 ++++------------
>  1 file changed, 4 insertions(+), 12 deletions(-)

Looks OK to me

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason