* [PATCH] iommu/amd: Convert from atomic_t to refcount_t on pasid_state->count
@ 2021-07-19 8:32 Xiyu Yang via iommu
2021-07-22 19:34 ` Suthikulpanit, Suravee via iommu
2021-07-26 11:47 ` Joerg Roedel
0 siblings, 2 replies; 3+ messages in thread
From: Xiyu Yang via iommu @ 2021-07-19 8:32 UTC (permalink / raw)
To: Joerg Roedel, Suravee Suthikulpanit, Will Deacon, iommu, linux-kernel
Cc: Xin Tan, yuanxzhang, Xiyu Yang
refcount_t type and corresponding API can protect refcounters from
accidental underflow and overflow and further use-after-free situations.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
---
drivers/iommu/amd/iommu_v2.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/iommu/amd/iommu_v2.c b/drivers/iommu/amd/iommu_v2.c
index f8d4ad421e07..a9e568276c99 100644
--- a/drivers/iommu/amd/iommu_v2.c
+++ b/drivers/iommu/amd/iommu_v2.c
@@ -6,6 +6,7 @@
#define pr_fmt(fmt) "AMD-Vi: " fmt
+#include <linux/refcount.h>
#include <linux/mmu_notifier.h>
#include <linux/amd-iommu.h>
#include <linux/mm_types.h>
@@ -33,7 +34,7 @@ struct pri_queue {
struct pasid_state {
struct list_head list; /* For global state-list */
- atomic_t count; /* Reference count */
+ refcount_t count; /* Reference count */
unsigned mmu_notifier_count; /* Counting nested mmu_notifier
calls */
struct mm_struct *mm; /* mm_struct for the faults */
@@ -242,7 +243,7 @@ static struct pasid_state *get_pasid_state(struct device_state *dev_state,
ret = *ptr;
if (ret)
- atomic_inc(&ret->count);
+ refcount_inc(&ret->count);
out_unlock:
spin_unlock_irqrestore(&dev_state->lock, flags);
@@ -257,14 +258,14 @@ static void free_pasid_state(struct pasid_state *pasid_state)
static void put_pasid_state(struct pasid_state *pasid_state)
{
- if (atomic_dec_and_test(&pasid_state->count))
+ if (refcount_dec_and_test(&pasid_state->count))
wake_up(&pasid_state->wq);
}
static void put_pasid_state_wait(struct pasid_state *pasid_state)
{
- atomic_dec(&pasid_state->count);
- wait_event(pasid_state->wq, !atomic_read(&pasid_state->count));
+ refcount_dec(&pasid_state->count);
+ wait_event(pasid_state->wq, !refcount_read(&pasid_state->count));
free_pasid_state(pasid_state);
}
@@ -624,7 +625,7 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, u32 pasid,
goto out;
- atomic_set(&pasid_state->count, 1);
+ refcount_set(&pasid_state->count, 1);
init_waitqueue_head(&pasid_state->wq);
spin_lock_init(&pasid_state->lock);
--
2.7.4
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^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] iommu/amd: Convert from atomic_t to refcount_t on pasid_state->count
2021-07-19 8:32 [PATCH] iommu/amd: Convert from atomic_t to refcount_t on pasid_state->count Xiyu Yang via iommu
@ 2021-07-22 19:34 ` Suthikulpanit, Suravee via iommu
2021-07-26 11:47 ` Joerg Roedel
1 sibling, 0 replies; 3+ messages in thread
From: Suthikulpanit, Suravee via iommu @ 2021-07-22 19:34 UTC (permalink / raw)
To: Xiyu Yang, Joerg Roedel, Will Deacon, iommu, linux-kernel
Cc: Xin Tan, yuanxzhang
On 7/19/2021 3:32 AM, Xiyu Yang wrote:
> refcount_t type and corresponding API can protect refcounters from
> accidental underflow and overflow and further use-after-free situations.
>
> Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Thanks,
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] iommu/amd: Convert from atomic_t to refcount_t on pasid_state->count
2021-07-19 8:32 [PATCH] iommu/amd: Convert from atomic_t to refcount_t on pasid_state->count Xiyu Yang via iommu
2021-07-22 19:34 ` Suthikulpanit, Suravee via iommu
@ 2021-07-26 11:47 ` Joerg Roedel
1 sibling, 0 replies; 3+ messages in thread
From: Joerg Roedel @ 2021-07-26 11:47 UTC (permalink / raw)
To: Xiyu Yang; +Cc: Xin Tan, yuanxzhang, linux-kernel, iommu, Will Deacon
On Mon, Jul 19, 2021 at 04:32:58PM +0800, Xiyu Yang wrote:
> drivers/iommu/amd/iommu_v2.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
Applied, thanks.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-07-22 19:34 ` Suthikulpanit, Suravee via iommu
2021-07-26 11:47 ` Joerg Roedel
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