[PATCH] PCI: hv: Use kfree(hbus) in hv_pci_probe()'s error handling path

[PATCH] PCI: hv: Use kfree(hbus) in hv_pci_probe()'s error handling path

[Dexuan Cui]

Now that we use kzalloc() to allocate the hbus buffer, we should use
kfree() in the error path as well.

Also remove the type casting, since it's unnecessary in C.

Fixes: 877b911a5ba0 ("PCI: hv: Avoid a kmemleak false positive caused by the hbus buffer")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
---

Sorry for missing the error handling path.

 drivers/pci/controller/pci-hyperv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 9977abff92fc..15011a349520 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -2922,7 +2922,7 @@ static int hv_pci_probe(struct hv_device *hdev,
 	 * positive by using kmemleak_alloc() and kmemleak_free() to ask
 	 * kmemleak to track and scan the hbus buffer.
 	 */
-	hbus = (struct hv_pcibus_device *)kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
+	hbus = kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
 	if (!hbus)
 		return -ENOMEM;
 	hbus->state = hv_pcibus_init;
@@ -3058,7 +3058,7 @@ static int hv_pci_probe(struct hv_device *hdev,
 free_dom:
 	hv_put_dom_num(hbus->sysdata.domain);
 free_bus:
-	free_page((unsigned long)hbus);
+	kfree(hbus);
 	return ret;
 }
 
-- 
2.19.1

RE: [PATCH] PCI: hv: Use kfree(hbus) in hv_pci_probe()'s error handling path

[Michael Kelley]

From: Dexuan Cui <decui@microsoft.com> Sent: Monday, January 6, 2020 2:39 PM
> 
> Now that we use kzalloc() to allocate the hbus buffer, we should use
> kfree() in the error path as well.
> 
> Also remove the type casting, since it's unnecessary in C.
> 
> Fixes: 877b911a5ba0 ("PCI: hv: Avoid a kmemleak false positive caused by the hbus buffer")
> Signed-off-by: Dexuan Cui <decui@microsoft.com>
> ---
> 
> Sorry for missing the error handling path.
> 
>  drivers/pci/controller/pci-hyperv.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index 9977abff92fc..15011a349520 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -2922,7 +2922,7 @@ static int hv_pci_probe(struct hv_device *hdev,
>  	 * positive by using kmemleak_alloc() and kmemleak_free() to ask
>  	 * kmemleak to track and scan the hbus buffer.
>  	 */
> -	hbus = (struct hv_pcibus_device *)kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
> +	hbus = kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
>  	if (!hbus)
>  		return -ENOMEM;
>  	hbus->state = hv_pcibus_init;
> @@ -3058,7 +3058,7 @@ static int hv_pci_probe(struct hv_device *hdev,
>  free_dom:
>  	hv_put_dom_num(hbus->sysdata.domain);
>  free_bus:
> -	free_page((unsigned long)hbus);
> +	kfree(hbus);
>  	return ret;
>  }
> 
> --
> 2.19.1

Reviewed-by: Michael Kelley <mikelley@microsoft.com>

Re: [PATCH] PCI: hv: Use kfree(hbus) in hv_pci_probe()'s error handling path

[Lorenzo Pieralisi]

On Mon, Jan 06, 2020 at 02:39:11PM -0800, Dexuan Cui wrote:
> Now that we use kzalloc() to allocate the hbus buffer, we should use
> kfree() in the error path as well.
> 
> Also remove the type casting, since it's unnecessary in C.

Two unrelated logical changes -> two patches please, I know it is
tempting but it is important to split logical changes into separate
patches.

Thanks,
Lorenzo

> Fixes: 877b911a5ba0 ("PCI: hv: Avoid a kmemleak false positive caused by the hbus buffer")
> Signed-off-by: Dexuan Cui <decui@microsoft.com>
> ---
> 
> Sorry for missing the error handling path.
> 
>  drivers/pci/controller/pci-hyperv.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index 9977abff92fc..15011a349520 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -2922,7 +2922,7 @@ static int hv_pci_probe(struct hv_device *hdev,
>  	 * positive by using kmemleak_alloc() and kmemleak_free() to ask
>  	 * kmemleak to track and scan the hbus buffer.
>  	 */
> -	hbus = (struct hv_pcibus_device *)kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
> +	hbus = kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
>  	if (!hbus)
>  		return -ENOMEM;
>  	hbus->state = hv_pcibus_init;
> @@ -3058,7 +3058,7 @@ static int hv_pci_probe(struct hv_device *hdev,
>  free_dom:
>  	hv_put_dom_num(hbus->sysdata.domain);
>  free_bus:
> -	free_page((unsigned long)hbus);
> +	kfree(hbus);
>  	return ret;
>  }
>  
> -- 
> 2.19.1
> 

RE: [PATCH] PCI: hv: Use kfree(hbus) in hv_pci_probe()'s error handling path

[Dexuan Cui]

> From: linux-hyperv-owner@vger.kernel.org
> <linux-hyperv-owner@vger.kernel.org> On Behalf Of Lorenzo Pieralisi
> Sent: Friday, February 21, 2020 6:40 AM
> 
> On Mon, Jan 06, 2020 at 02:39:11PM -0800, Dexuan Cui wrote:
> > Now that we use kzalloc() to allocate the hbus buffer, we should use
> > kfree() in the error path as well.
> >
> > Also remove the type casting, since it's unnecessary in C.
> 
> Two unrelated logical changes -> two patches please, I know it is
> tempting but it is important to split logical changes into separate
> patches.
> 
> Thanks,
> Lorenzo

Ok, will post 2 separate patches shortly.

Thanks,
-- Dexuan