diff options
| author | Xiyu Yang via iommu <iommu@lists.linux-foundation.org> | 2021-07-19 16:32:58 +0800 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2021-07-26 13:46:57 +0200 |
| commit | 8bc54824da4e8fcf0ed679cf09ac32f23d83254a (patch) | |
| tree | 1184c4ce24a49aee108dda9ebd2f3d55ba216c63 /drivers/iommu/amd | |
| parent | ff1176468d368232b684f75e82563369208bc371 (diff) | |
iommu/amd: Convert from atomic_t to refcount_t on pasid_state->count
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>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/1626683578-64214-1-git-send-email-xiyuyang19@fudan.edu.cn
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/amd')
| -rw-r--r-- | drivers/iommu/amd/iommu_v2.c | 13 |
1 files 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); |