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

From: Jike Song
Date: Wed Dec 21 2016 - 03:19:10 EST


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@xxxxxxxxxx>
Cc: Kirti Wankhede <kwankhede@xxxxxxxxxx>
Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx>
Signed-off-by: Jike Song <jike.song@xxxxxxxxx>
---
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);
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;
--
2.4.4.488.gdf97e5d