[PATCH] cxl/memdev: automate cleanup with __free()

[PATCH] cxl/memdev: automate cleanup with __free()

[Pranav Tyagi]

Use the scope based resource management (defined in linux/cleanup.h) to
automate the lifetime control of struct cxl_mbox_transfer_fw. This
eliminates explicit kfree() calls and makes the code more robust and
maintainable in presence of early returns.

Signed-off-by: Pranav Tyagi <pranav.tyagi03@gmail.com>
---
 drivers/cxl/core/memdev.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index f88a13adf7fa..be73a6099cb6 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -7,6 +7,7 @@
 #include <linux/slab.h>
 #include <linux/idr.h>
 #include <linux/pci.h>
+#include <linux/cleanup.h>
 #include <cxlmem.h>
 #include "trace.h"
 #include "core.h"
@@ -802,11 +803,11 @@ static int cxl_mem_activate_fw(struct cxl_memdev_state *mds, int slot)
 static int cxl_mem_abort_fw_xfer(struct cxl_memdev_state *mds)
 {
 	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
-	struct cxl_mbox_transfer_fw *transfer;
 	struct cxl_mbox_cmd mbox_cmd;
 	int rc;
 
-	transfer = kzalloc(struct_size(transfer, data, 0), GFP_KERNEL);
+	struct cxl_mbox_transfer_fw *transfer __free(kfree) =
+		kzalloc(struct_size(transfer, data, 0), GFP_KERNEL);
 	if (!transfer)
 		return -ENOMEM;
 
@@ -822,7 +823,6 @@ static int cxl_mem_abort_fw_xfer(struct cxl_memdev_state *mds)
 	transfer->action = CXL_FW_TRANSFER_ACTION_ABORT;
 
 	rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
-	kfree(transfer);
 	return rc;
 }
 
@@ -880,7 +880,7 @@ static enum fw_upload_err cxl_fw_write(struct fw_upload *fwl, const u8 *data,
 	struct cxl_dev_state *cxlds = &mds->cxlds;
 	struct cxl_mailbox *cxl_mbox = &cxlds->cxl_mbox;
 	struct cxl_memdev *cxlmd = cxlds->cxlmd;
-	struct cxl_mbox_transfer_fw *transfer;
+	struct cxl_mbox_transfer_fw *transfer __free(kfree);
 	struct cxl_mbox_cmd mbox_cmd;
 	u32 cur_size, remaining;
 	size_t size_in;
@@ -970,7 +970,6 @@ static enum fw_upload_err cxl_fw_write(struct fw_upload *fwl, const u8 *data,
 	rc = FW_UPLOAD_ERR_NONE;
 
 out_free:
-	kfree(transfer);
 	return rc;
 }
 
-- 
2.49.0

Re: [PATCH] cxl/memdev: automate cleanup with __free()

[Li Ming]

On 6/22/2025 8:09 PM, Pranav Tyagi wrote:
> Use the scope based resource management (defined in linux/cleanup.h) to
> automate the lifetime control of struct cxl_mbox_transfer_fw. This
> eliminates explicit kfree() calls and makes the code more robust and
> maintainable in presence of early returns.
>
> Signed-off-by: Pranav Tyagi <pranav.tyagi03@gmail.com>
> ---
>  drivers/cxl/core/memdev.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
> index f88a13adf7fa..be73a6099cb6 100644
> --- a/drivers/cxl/core/memdev.c
> +++ b/drivers/cxl/core/memdev.c
> @@ -7,6 +7,7 @@
>  #include <linux/slab.h>
>  #include <linux/idr.h>
>  #include <linux/pci.h>
> +#include <linux/cleanup.h>
>  #include <cxlmem.h>
>  #include "trace.h"
>  #include "core.h"
> @@ -802,11 +803,11 @@ static int cxl_mem_activate_fw(struct cxl_memdev_state *mds, int slot)
>  static int cxl_mem_abort_fw_xfer(struct cxl_memdev_state *mds)
>  {
>  	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
> -	struct cxl_mbox_transfer_fw *transfer;
>  	struct cxl_mbox_cmd mbox_cmd;
>  	int rc;
>  
> -	transfer = kzalloc(struct_size(transfer, data, 0), GFP_KERNEL);
> +	struct cxl_mbox_transfer_fw *transfer __free(kfree) =
> +		kzalloc(struct_size(transfer, data, 0), GFP_KERNEL);
>  	if (!transfer)
>  		return -ENOMEM;
>  
> @@ -822,7 +823,6 @@ static int cxl_mem_abort_fw_xfer(struct cxl_memdev_state *mds)
>  	transfer->action = CXL_FW_TRANSFER_ACTION_ABORT;
>  
>  	rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
> -	kfree(transfer);
>  	return rc;
the rc can be removed with your change, can be "return cxl_internal_send_cmd(cxl_mbox, &mbox_cmd)".
>  }
>  
> @@ -880,7 +880,7 @@ static enum fw_upload_err cxl_fw_write(struct fw_upload *fwl, const u8 *data,
>  	struct cxl_dev_state *cxlds = &mds->cxlds;
>  	struct cxl_mailbox *cxl_mbox = &cxlds->cxl_mbox;
>  	struct cxl_memdev *cxlmd = cxlds->cxlmd;
> -	struct cxl_mbox_transfer_fw *transfer;
> +	struct cxl_mbox_transfer_fw *transfer __free(kfree);
>  	struct cxl_mbox_cmd mbox_cmd;
>  	u32 cur_size, remaining;
>  	size_t size_in;
> @@ -970,7 +970,6 @@ static enum fw_upload_err cxl_fw_write(struct fw_upload *fwl, const u8 *data,
>  	rc = FW_UPLOAD_ERR_NONE;
>  
>  out_free:
> -	kfree(transfer);
>  	return rc;
>  }
>  

I believe all "goto out_free" in the function are not needed with your change.


Ming

Re: [PATCH] cxl/memdev: automate cleanup with __free()

[Pranav Tyagi]

On Sun, Jun 22, 2025 at 5:53 PM Li Ming <ming.li@zohomail.com> wrote:
>
> On 6/22/2025 8:09 PM, Pranav Tyagi wrote:
> > Use the scope based resource management (defined in linux/cleanup.h) to
> > automate the lifetime control of struct cxl_mbox_transfer_fw. This
> > eliminates explicit kfree() calls and makes the code more robust and
> > maintainable in presence of early returns.
> >
> > Signed-off-by: Pranav Tyagi <pranav.tyagi03@gmail.com>
> > ---
> >  drivers/cxl/core/memdev.c | 9 ++++-----
> >  1 file changed, 4 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
> > index f88a13adf7fa..be73a6099cb6 100644
> > --- a/drivers/cxl/core/memdev.c
> > +++ b/drivers/cxl/core/memdev.c
> > @@ -7,6 +7,7 @@
> >  #include <linux/slab.h>
> >  #include <linux/idr.h>
> >  #include <linux/pci.h>
> > +#include <linux/cleanup.h>
> >  #include <cxlmem.h>
> >  #include "trace.h"
> >  #include "core.h"
> > @@ -802,11 +803,11 @@ static int cxl_mem_activate_fw(struct cxl_memdev_state *mds, int slot)
> >  static int cxl_mem_abort_fw_xfer(struct cxl_memdev_state *mds)
> >  {
> >       struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
> > -     struct cxl_mbox_transfer_fw *transfer;
> >       struct cxl_mbox_cmd mbox_cmd;
> >       int rc;
> >
> > -     transfer = kzalloc(struct_size(transfer, data, 0), GFP_KERNEL);
> > +     struct cxl_mbox_transfer_fw *transfer __free(kfree) =
> > +             kzalloc(struct_size(transfer, data, 0), GFP_KERNEL);
> >       if (!transfer)
> >               return -ENOMEM;
> >
> > @@ -822,7 +823,6 @@ static int cxl_mem_abort_fw_xfer(struct cxl_memdev_state *mds)
> >       transfer->action = CXL_FW_TRANSFER_ACTION_ABORT;
> >
> >       rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
> > -     kfree(transfer);
> >       return rc;
> the rc can be removed with your change, can be "return cxl_internal_send_cmd(cxl_mbox, &mbox_cmd)".
> >  }
> >
> > @@ -880,7 +880,7 @@ static enum fw_upload_err cxl_fw_write(struct fw_upload *fwl, const u8 *data,
> >       struct cxl_dev_state *cxlds = &mds->cxlds;
> >       struct cxl_mailbox *cxl_mbox = &cxlds->cxl_mbox;
> >       struct cxl_memdev *cxlmd = cxlds->cxlmd;
> > -     struct cxl_mbox_transfer_fw *transfer;
> > +     struct cxl_mbox_transfer_fw *transfer __free(kfree);
> >       struct cxl_mbox_cmd mbox_cmd;
> >       u32 cur_size, remaining;
> >       size_t size_in;
> > @@ -970,7 +970,6 @@ static enum fw_upload_err cxl_fw_write(struct fw_upload *fwl, const u8 *data,
> >       rc = FW_UPLOAD_ERR_NONE;
> >
> >  out_free:
> > -     kfree(transfer);
> >       return rc;
> >  }
> >
>
> I believe all "goto out_free" in the function are not needed with your change.
>
>
> Ming
>

Hi,

Thanks for the feedback.

You're absolutely right - with __free() handling cleanup, the
explicit rc variable and the goto out_free blocks can now be
eliminated.

I'll send a v2 shortly incorporating these cleanups.

Regards
Pranav Tyagi