diff mbox series

pci: fix memory leak when virtio pci hotplug

Message ID c48998b7-5308-e196-66b5-905fc8c4edc4@huawei.com (mailing list archive)
State Changes Requested, archived
Headers show
Series pci: fix memory leak when virtio pci hotplug | expand

Commit Message

Zhiqiang Liu March 21, 2021, 3:29 p.m. UTC
From: Feilong Lin <linfeilong@huawei.com>

Repeated hot-plugging of pci devices for a virtual
machine driven by virtio, we found that there is a
leak in kmalloc-4k, which was confirmed as the memory
of the pci_device structure. Then we found out that
it was missing pci_dev_put() after pci_get_slot() in
enable_slot() of acpiphp_glue.c.

Signed-off-by: Feilong Lin <linfeilong@huawei.com>
Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
---
 drivers/pci/hotplug/acpiphp_glue.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Wu Bo March 22, 2021, 2:43 a.m. UTC | #1
On 2021/3/21 23:29, Zhiqiang Liu wrote:
> From: Feilong Lin <linfeilong@huawei.com>
> 
> Repeated hot-plugging of pci devices for a virtual
> machine driven by virtio, we found that there is a
> leak in kmalloc-4k, which was confirmed as the memory
> of the pci_device structure. Then we found out that
> it was missing pci_dev_put() after pci_get_slot() in
> enable_slot() of acpiphp_glue.c.
> 
> Signed-off-by: Feilong Lin <linfeilong@huawei.com>
> Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
> ---
>   drivers/pci/hotplug/acpiphp_glue.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
> index 3365c93abf0e..f031302ad401 100644
> --- a/drivers/pci/hotplug/acpiphp_glue.c
> +++ b/drivers/pci/hotplug/acpiphp_glue.c
> @@ -533,6 +533,7 @@ static void enable_slot(struct acpiphp_slot *slot, bool bridge)
>   			slot->flags &= ~SLOT_ENABLED;
>   			continue;
>   		}
> +		pci_dev_put(dev);
>   	}
>   }
> 
Reviewed-by: Wu Bo <wubo40@huawei.com>
Zhiqiang Liu March 23, 2021, 8:14 a.m. UTC | #2
friendly ping..

On 2021/3/22 10:43, Wu Bo wrote:
> On 2021/3/21 23:29, Zhiqiang Liu wrote:
>> From: Feilong Lin <linfeilong@huawei.com>
>>
>> Repeated hot-plugging of pci devices for a virtual
>> machine driven by virtio, we found that there is a
>> leak in kmalloc-4k, which was confirmed as the memory
>> of the pci_device structure. Then we found out that
>> it was missing pci_dev_put() after pci_get_slot() in
>> enable_slot() of acpiphp_glue.c.
>>
>> Signed-off-by: Feilong Lin <linfeilong@huawei.com>
>> Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
>> ---
>>   drivers/pci/hotplug/acpiphp_glue.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
>> index 3365c93abf0e..f031302ad401 100644
>> --- a/drivers/pci/hotplug/acpiphp_glue.c
>> +++ b/drivers/pci/hotplug/acpiphp_glue.c
>> @@ -533,6 +533,7 @@ static void enable_slot(struct acpiphp_slot *slot, bool bridge)
>>               slot->flags &= ~SLOT_ENABLED;
>>               continue;
>>           }
>> +        pci_dev_put(dev);
>>       }
>>   }
>>
> Reviewed-by: Wu Bo <wubo40@huawei.com>
>
> .
Bjorn Helgaas March 23, 2021, 6:24 p.m. UTC | #3
On Sun, Mar 21, 2021 at 11:29:30PM +0800, Zhiqiang Liu wrote:
> From: Feilong Lin <linfeilong@huawei.com>
> 
> Repeated hot-plugging of pci devices for a virtual
> machine driven by virtio, we found that there is a
> leak in kmalloc-4k, which was confirmed as the memory
> of the pci_device structure. Then we found out that
> it was missing pci_dev_put() after pci_get_slot() in
> enable_slot() of acpiphp_glue.c.
> 
> Signed-off-by: Feilong Lin <linfeilong@huawei.com>
> Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>

Since this came from you, Zhiqiang, it needs a signed-off-by (not just
a reviewed-by) from you.  See
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=v5.11#n361

Also see
https://lore.kernel.org/r/20171026223701.GA25649@bhelgaas-glaptop.roam.corp.google.com
and

  - Wrap commit log to fill 80 columns
  - s/pci/PCI/ (subject and commit log)
  - Run "git log --oneline drivers/pci/hotplug/acpiphp_glue.c".  It's
    not completely consistent, but at least match the style of one of
    them.

There is no "pci_device" structure.  I think you mean the "struct
pci_dev".

The commit log doesn't actually say what the patch does.  It's obvious
from the patch, but it should say in the commit log.  Look at previous
commit logs to see how they do it.

> ---
>  drivers/pci/hotplug/acpiphp_glue.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
> index 3365c93abf0e..f031302ad401 100644
> --- a/drivers/pci/hotplug/acpiphp_glue.c
> +++ b/drivers/pci/hotplug/acpiphp_glue.c
> @@ -533,6 +533,7 @@ static void enable_slot(struct acpiphp_slot *slot, bool bridge)
>  			slot->flags &= ~SLOT_ENABLED;
>  			continue;
>  		}
> +		pci_dev_put(dev);
>  	}
>  }
> 
> -- 
> 2.19.1
> 
>
Zhiqiang Liu March 25, 2021, 12:52 a.m. UTC | #4
Thanks for your suggestion.

I will rewrite the commit log and send the v2 patch.


On 2021/3/24 2:24, Bjorn Helgaas wrote:
> On Sun, Mar 21, 2021 at 11:29:30PM +0800, Zhiqiang Liu wrote:
>> From: Feilong Lin <linfeilong@huawei.com>
>>
>> Repeated hot-plugging of pci devices for a virtual
>> machine driven by virtio, we found that there is a
>> leak in kmalloc-4k, which was confirmed as the memory
>> of the pci_device structure. Then we found out that
>> it was missing pci_dev_put() after pci_get_slot() in
>> enable_slot() of acpiphp_glue.c.
>>
>> Signed-off-by: Feilong Lin <linfeilong@huawei.com>
>> Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
> Since this came from you, Zhiqiang, it needs a signed-off-by (not just
> a reviewed-by) from you.  See
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=v5.11#n361
>
> Also see
> https://lore.kernel.org/r/20171026223701.GA25649@bhelgaas-glaptop.roam.corp.google.com
> and
>
>   - Wrap commit log to fill 80 columns
>   - s/pci/PCI/ (subject and commit log)
>   - Run "git log --oneline drivers/pci/hotplug/acpiphp_glue.c".  It's
>     not completely consistent, but at least match the style of one of
>     them.
>
> There is no "pci_device" structure.  I think you mean the "struct
> pci_dev".
>
> The commit log doesn't actually say what the patch does.  It's obvious
> from the patch, but it should say in the commit log.  Look at previous
> commit logs to see how they do it.
>
>> ---
>>  drivers/pci/hotplug/acpiphp_glue.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
>> index 3365c93abf0e..f031302ad401 100644
>> --- a/drivers/pci/hotplug/acpiphp_glue.c
>> +++ b/drivers/pci/hotplug/acpiphp_glue.c
>> @@ -533,6 +533,7 @@ static void enable_slot(struct acpiphp_slot *slot, bool bridge)
>>  			slot->flags &= ~SLOT_ENABLED;
>>  			continue;
>>  		}
>> +		pci_dev_put(dev);
>>  	}
>>  }
>>
>> -- 
>> 2.19.1
>>
>>
> .
diff mbox series

Patch

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 3365c93abf0e..f031302ad401 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -533,6 +533,7 @@  static void enable_slot(struct acpiphp_slot *slot, bool bridge)
 			slot->flags &= ~SLOT_ENABLED;
 			continue;
 		}
+		pci_dev_put(dev);
 	}
 }