[2/2] vfio iommu type1: fix the testing of capability for remote task
diff mbox

Message ID 1482336616-19252-3-git-send-email-jike.song@intel.com
State New
Headers show

Commit Message

Jike Song Dec. 21, 2016, 4:10 p.m. UTC
Before the mdev enhancement type1 iommu used capable() to test the
capability of current task; in the course of mdev development a
new requirement, testing for another task other than current, was
raised.  ns_capable() was used for this purpose, however it still
tests current, the only difference is, in a specified namespace.

Fix it by using has_capability() instead, which tests the cap for
specified task in init_user_ns, the same namespace as capable().

Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Kirti Wankhede <kwankhede@nvidia.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Jike Song <jike.song@intel.com>
---
 drivers/vfio/vfio_iommu_type1.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

Comments

Kirti Wankhede Dec. 22, 2016, 12:20 p.m. UTC | #1
On 12/21/2016 9:40 PM, Jike Song wrote:
> Before the mdev enhancement type1 iommu used capable() to test the
> capability of current task; in the course of mdev development a
> new requirement, testing for another task other than current, was
> raised.  ns_capable() was used for this purpose, however it still
> tests current, the only difference is, in a specified namespace.
> 
> Fix it by using has_capability() instead, which tests the cap for
> specified task in init_user_ns, the same namespace as capable().
> 
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Cc: Kirti Wankhede <kwankhede@nvidia.com>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Signed-off-by: Jike Song <jike.song@intel.com>
> ---
>  drivers/vfio/vfio_iommu_type1.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index f3726ba..b54aedf 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -394,8 +394,7 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
>  				  long npage, unsigned long *pfn_base)
>  {
>  	unsigned long limit;
> -	bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns,
> -				   CAP_IPC_LOCK);
> +	bool lock_cap = has_capability(dma->task, CAP_IPC_LOCK);


Hi Jike,

Alex's patch already changes this to capable(), you need to resolve.
https://lkml.org/lkml/2016/12/20/490

You need to do only below change, which looks fine to me.

>  	struct mm_struct *mm;
>  	long ret, i = 0, lock_acct = 0;
>  	bool rsvd;
> @@ -491,8 +490,7 @@ static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
>  				  unsigned long *pfn_base, bool do_accounting)
>  {
>  	unsigned long limit;
> -	bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns,
> -				   CAP_IPC_LOCK);
> +	bool lock_cap = has_capability(dma->task, CAP_IPC_LOCK);
>  	struct mm_struct *mm;
>  	int ret;
>  	bool rsvd;
> 


Thanks,
Kirti

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Jike Song Dec. 23, 2016, 2:36 a.m. UTC | #2
On 12/22/2016 08:20 PM, Kirti Wankhede wrote:
> On 12/21/2016 9:40 PM, Jike Song wrote:
>> Before the mdev enhancement type1 iommu used capable() to test the
>> capability of current task; in the course of mdev development a
>> new requirement, testing for another task other than current, was
>> raised.  ns_capable() was used for this purpose, however it still
>> tests current, the only difference is, in a specified namespace.
>>
>> Fix it by using has_capability() instead, which tests the cap for
>> specified task in init_user_ns, the same namespace as capable().
>>
>> Cc: Alex Williamson <alex.williamson@redhat.com>
>> Cc: Kirti Wankhede <kwankhede@nvidia.com>
>> Cc: Gerd Hoffmann <kraxel@redhat.com>
>> Signed-off-by: Jike Song <jike.song@intel.com>
>> ---
>>  drivers/vfio/vfio_iommu_type1.c | 6 ++----
>>  1 file changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
>> index f3726ba..b54aedf 100644
>> --- a/drivers/vfio/vfio_iommu_type1.c
>> +++ b/drivers/vfio/vfio_iommu_type1.c
>> @@ -394,8 +394,7 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
>>  				  long npage, unsigned long *pfn_base)
>>  {
>>  	unsigned long limit;
>> -	bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns,
>> -				   CAP_IPC_LOCK);
>> +	bool lock_cap = has_capability(dma->task, CAP_IPC_LOCK);
> 
> 
> Hi Jike,
> 
> Alex's patch already changes this to capable(), you need to resolve.
> https://lkml.org/lkml/2016/12/20/490
> 
> You need to do only below change, which looks fine to me.
> 

Thanks for the point, will change it in v2.  However, that will probably be
after patch 1/2 accepted, otherwise we get undefined symbols.

--
Thanks,
Jike

>>  	struct mm_struct *mm;
>>  	long ret, i = 0, lock_acct = 0;
>>  	bool rsvd;
>> @@ -491,8 +490,7 @@ static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
>>  				  unsigned long *pfn_base, bool do_accounting)
>>  {
>>  	unsigned long limit;
>> -	bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns,
>> -				   CAP_IPC_LOCK);
>> +	bool lock_cap = has_capability(dma->task, CAP_IPC_LOCK);
>>  	struct mm_struct *mm;
>>  	int ret;
>>  	bool rsvd;
>>
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Patch
diff mbox

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index f3726ba..b54aedf 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -394,8 +394,7 @@  static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
 				  long npage, unsigned long *pfn_base)
 {
 	unsigned long limit;
-	bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns,
-				   CAP_IPC_LOCK);
+	bool lock_cap = has_capability(dma->task, CAP_IPC_LOCK);
 	struct mm_struct *mm;
 	long ret, i = 0, lock_acct = 0;
 	bool rsvd;
@@ -491,8 +490,7 @@  static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
 				  unsigned long *pfn_base, bool do_accounting)
 {
 	unsigned long limit;
-	bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns,
-				   CAP_IPC_LOCK);
+	bool lock_cap = has_capability(dma->task, CAP_IPC_LOCK);
 	struct mm_struct *mm;
 	int ret;
 	bool rsvd;