diff options
| -rw-r--r-- | drivers/vfio/vfio_iommu_type1.c | 110 |
1 files changed, 51 insertions, 59 deletions
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 32d2633092a3..a8a079ba9477 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -246,69 +246,46 @@ static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn) return ret; } -struct vwork { - struct mm_struct *mm; - long npage; - struct work_struct work; -}; - -/* delayed decrement/increment for locked_vm */ -static void vfio_lock_acct_bg(struct work_struct *work) -{ - struct vwork *vwork = container_of(work, struct vwork, work); - struct mm_struct *mm; - - mm = vwork->mm; - down_write(&mm->mmap_sem); - mm->locked_vm += vwork->npage; - up_write(&mm->mmap_sem); - mmput(mm); - kfree(vwork); -} - -static void vfio_lock_acct(struct task_struct *task, long npage) +static int vfio_lock_acct(struct task_struct *task, long npage, bool *lock_cap) { - struct vwork *vwork; struct mm_struct *mm; bool is_current; + int ret; if (!npage) - return; + return 0; is_current = (task->mm == current->mm); mm = is_current ? task->mm : get_task_mm(task); if (!mm) - return; /* process exited */ + return -ESRCH; /* process exited */ - if (down_write_trylock(&mm->mmap_sem)) { - mm->locked_vm += npage; - up_write(&mm->mmap_sem); - if (!is_current) - mmput(mm); - return; - } + ret = down_write_killable(&mm->mmap_sem); + if (!ret) { + if (npage > 0) { + if (lock_cap ? !*lock_cap : + !has_capability(task, CAP_IPC_LOCK)) { + unsigned long limit; + + limit = task_rlimit(task, + RLIMIT_MEMLOCK) >> PAGE_SHIFT; + + if (mm->locked_vm + npage > limit) + ret = -ENOMEM; + } + } + + if (!ret) + mm->locked_vm += npage; - if (is_current) { - mm = get_task_mm(task); - if (!mm) - return; + up_write(&mm->mmap_sem); } - /* - * Couldn't get mmap_sem lock, so must setup to update - * mm->locked_vm later. If locked_vm were atomic, we - * wouldn't need this silliness - */ - vwork = kmalloc(sizeof(struct vwork), GFP_KERNEL); - if (WARN_ON(!vwork)) { + if (!is_current) mmput(mm); - return; - } - INIT_WORK(&vwork->work, vfio_lock_acct_bg); - vwork->mm = mm; - vwork->npage = npage; - schedule_work(&vwork->work); + + return ret; } /* @@ -405,7 +382,7 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr, long npage, unsigned long *pfn_base) { - unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + unsigned long pfn = 0, limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; bool lock_cap = capable(CAP_IPC_LOCK); long ret, pinned = 0, lock_acct = 0; bool rsvd; @@ -442,8 +419,6 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr, /* Lock all the consecutive pages from pfn_base */ for (vaddr += PAGE_SIZE, iova += PAGE_SIZE; pinned < npage; pinned++, vaddr += PAGE_SIZE, iova += PAGE_SIZE) { - unsigned long pfn = 0; - ret = vaddr_get_pfn(current->mm, vaddr, dma->prot, &pfn); if (ret) break; @@ -460,14 +435,25 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr, put_pfn(pfn, dma->prot); pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__, limit << PAGE_SHIFT); - break; + ret = -ENOMEM; + goto unpin_out; } lock_acct++; } } out: - vfio_lock_acct(current, lock_acct); + ret = vfio_lock_acct(current, lock_acct, &lock_cap); + +unpin_out: + if (ret) { + if (!rsvd) { + for (pfn = *pfn_base ; pinned ; pfn++, pinned--) + put_pfn(pfn, dma->prot); + } + + return ret; + } return pinned; } @@ -488,7 +474,7 @@ static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova, } if (do_accounting) - vfio_lock_acct(dma->task, locked - unlocked); + vfio_lock_acct(dma->task, locked - unlocked, NULL); return unlocked; } @@ -522,8 +508,14 @@ static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr, goto pin_page_exit; } - if (!rsvd && do_accounting) - vfio_lock_acct(dma->task, 1); + if (!rsvd && do_accounting) { + ret = vfio_lock_acct(dma->task, 1, &lock_cap); + if (ret) { + put_pfn(*pfn_base, dma->prot); + goto pin_page_exit; + } + } + ret = 1; pin_page_exit: @@ -543,7 +535,7 @@ static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova, unlocked = vfio_iova_put_vfio_pfn(dma, vpfn); if (do_accounting) - vfio_lock_acct(dma->task, -unlocked); + vfio_lock_acct(dma->task, -unlocked, NULL); return unlocked; } @@ -740,7 +732,7 @@ static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma, dma->iommu_mapped = false; if (do_accounting) { - vfio_lock_acct(dma->task, -unlocked); + vfio_lock_acct(dma->task, -unlocked, NULL); return 0; } return unlocked; @@ -1382,7 +1374,7 @@ static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu) if (!is_invalid_reserved_pfn(vpfn->pfn)) locked++; } - vfio_lock_acct(dma->task, locked - unlocked); + vfio_lock_acct(dma->task, locked - unlocked, NULL); } } |