diff options
| -rw-r--r-- | drivers/vfio/vfio_iommu_spapr_tce.c | 160 |
1 files changed, 100 insertions, 60 deletions
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index 88622be0d6b5..4c03c8525c26 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -31,49 +31,49 @@ static void tce_iommu_detach_group(void *iommu_data, struct iommu_group *iommu_group); -static long try_increment_locked_vm(long npages) +static long try_increment_locked_vm(struct mm_struct *mm, long npages) { long ret = 0, locked, lock_limit; - if (!current || !current->mm) - return -ESRCH; /* process exited */ + if (WARN_ON_ONCE(!mm)) + return -EPERM; if (!npages) return 0; - down_write(¤t->mm->mmap_sem); - locked = current->mm->locked_vm + npages; + down_write(&mm->mmap_sem); + locked = mm->locked_vm + npages; lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; if (locked > lock_limit && !capable(CAP_IPC_LOCK)) ret = -ENOMEM; else - current->mm->locked_vm += npages; + mm->locked_vm += npages; pr_debug("[%d] RLIMIT_MEMLOCK +%ld %ld/%ld%s\n", current->pid, npages << PAGE_SHIFT, - current->mm->locked_vm << PAGE_SHIFT, + mm->locked_vm << PAGE_SHIFT, rlimit(RLIMIT_MEMLOCK), ret ? " - exceeded" : ""); - up_write(¤t->mm->mmap_sem); + up_write(&mm->mmap_sem); return ret; } -static void decrement_locked_vm(long npages) +static void decrement_locked_vm(struct mm_struct *mm, long npages) { - if (!current || !current->mm || !npages) - return; /* process exited */ + if (!mm || !npages) + return; - down_write(¤t->mm->mmap_sem); - if (WARN_ON_ONCE(npages > current->mm->locked_vm)) - npages = current->mm->locked_vm; - current->mm->locked_vm -= npages; + down_write(&mm->mmap_sem); + if (WARN_ON_ONCE(npages > mm->locked_vm)) + npages = mm->locked_vm; + mm->locked_vm -= npages; pr_debug("[%d] RLIMIT_MEMLOCK -%ld %ld/%ld\n", current->pid, npages << PAGE_SHIFT, - current->mm->locked_vm << PAGE_SHIFT, + mm->locked_vm << PAGE_SHIFT, rlimit(RLIMIT_MEMLOCK)); - up_write(¤t->mm->mmap_sem); + up_write(&mm->mmap_sem); } /* @@ -99,26 +99,38 @@ struct tce_container { bool v2; bool def_window_pending; unsigned long locked_pages; + struct mm_struct *mm; struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES]; struct list_head group_list; }; +static long tce_iommu_mm_set(struct tce_container *container) +{ + if (container->mm) { + if (container->mm == current->mm) + return 0; + return -EPERM; + } + BUG_ON(!current->mm); + container->mm = current->mm; + atomic_inc(&container->mm->mm_count); + + return 0; +} + static long tce_iommu_unregister_pages(struct tce_container *container, __u64 vaddr, __u64 size) { struct mm_iommu_table_group_mem_t *mem; - if (!current || !current->mm) - return -ESRCH; /* process exited */ - if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK)) return -EINVAL; - mem = mm_iommu_find(current->mm, vaddr, size >> PAGE_SHIFT); + mem = mm_iommu_find(container->mm, vaddr, size >> PAGE_SHIFT); if (!mem) return -ENOENT; - return mm_iommu_put(current->mm, mem); + return mm_iommu_put(container->mm, mem); } static long tce_iommu_register_pages(struct tce_container *container, @@ -128,14 +140,11 @@ static long tce_iommu_register_pages(struct tce_container *container, struct mm_iommu_table_group_mem_t *mem = NULL; unsigned long entries = size >> PAGE_SHIFT; - if (!current || !current->mm) - return -ESRCH; /* process exited */ - if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) || ((vaddr + size) < vaddr)) return -EINVAL; - ret = mm_iommu_get(current->mm, vaddr, entries, &mem); + ret = mm_iommu_get(container->mm, vaddr, entries, &mem); if (ret) return ret; @@ -144,7 +153,8 @@ static long tce_iommu_register_pages(struct tce_container *container, return 0; } -static long tce_iommu_userspace_view_alloc(struct iommu_table *tbl) +static long tce_iommu_userspace_view_alloc(struct iommu_table *tbl, + struct mm_struct *mm) { unsigned long cb = _ALIGN_UP(sizeof(tbl->it_userspace[0]) * tbl->it_size, PAGE_SIZE); @@ -153,13 +163,13 @@ static long tce_iommu_userspace_view_alloc(struct iommu_table *tbl) BUG_ON(tbl->it_userspace); - ret = try_increment_locked_vm(cb >> PAGE_SHIFT); + ret = try_increment_locked_vm(mm, cb >> PAGE_SHIFT); if (ret) return ret; uas = vzalloc(cb); if (!uas) { - decrement_locked_vm(cb >> PAGE_SHIFT); + decrement_locked_vm(mm, cb >> PAGE_SHIFT); return -ENOMEM; } tbl->it_userspace = uas; @@ -167,7 +177,8 @@ static long tce_iommu_userspace_view_alloc(struct iommu_table *tbl) return 0; } -static void tce_iommu_userspace_view_free(struct iommu_table *tbl) +static void tce_iommu_userspace_view_free(struct iommu_table *tbl, + struct mm_struct *mm) { unsigned long cb = _ALIGN_UP(sizeof(tbl->it_userspace[0]) * tbl->it_size, PAGE_SIZE); @@ -177,7 +188,7 @@ static void tce_iommu_userspace_view_free(struct iommu_table *tbl) vfree(tbl->it_userspace); tbl->it_userspace = NULL; - decrement_locked_vm(cb >> PAGE_SHIFT); + decrement_locked_vm(mm, cb >> PAGE_SHIFT); } static bool tce_page_is_contained(struct page *page, unsigned page_shift) @@ -237,9 +248,6 @@ static int tce_iommu_enable(struct tce_container *container) struct iommu_table_group *table_group; struct tce_iommu_group *tcegrp; - if (!current->mm) - return -ESRCH; /* process exited */ - if (container->enabled) return -EBUSY; @@ -284,8 +292,12 @@ static int tce_iommu_enable(struct tce_container *container) if (!table_group->tce32_size) return -EPERM; + ret = tce_iommu_mm_set(container); + if (ret) + return ret; + locked = table_group->tce32_size >> PAGE_SHIFT; - ret = try_increment_locked_vm(locked); + ret = try_increment_locked_vm(container->mm, locked); if (ret) return ret; @@ -303,10 +315,8 @@ static void tce_iommu_disable(struct tce_container *container) container->enabled = false; - if (!current->mm) - return; - - decrement_locked_vm(container->locked_pages); + BUG_ON(!container->mm); + decrement_locked_vm(container->mm, container->locked_pages); } static void *tce_iommu_open(unsigned long arg) @@ -333,7 +343,8 @@ static void *tce_iommu_open(unsigned long arg) static int tce_iommu_clear(struct tce_container *container, struct iommu_table *tbl, unsigned long entry, unsigned long pages); -static void tce_iommu_free_table(struct iommu_table *tbl); +static void tce_iommu_free_table(struct tce_container *container, + struct iommu_table *tbl); static void tce_iommu_release(void *iommu_data) { @@ -358,10 +369,12 @@ static void tce_iommu_release(void *iommu_data) continue; tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size); - tce_iommu_free_table(tbl); + tce_iommu_free_table(container, tbl); } tce_iommu_disable(container); + if (container->mm) + mmdrop(container->mm); mutex_destroy(&container->lock); kfree(container); @@ -376,13 +389,14 @@ static void tce_iommu_unuse_page(struct tce_container *container, put_page(page); } -static int tce_iommu_prereg_ua_to_hpa(unsigned long tce, unsigned long size, +static int tce_iommu_prereg_ua_to_hpa(struct tce_container *container, + unsigned long tce, unsigned long size, unsigned long *phpa, struct mm_iommu_table_group_mem_t **pmem) { long ret = 0; struct mm_iommu_table_group_mem_t *mem; - mem = mm_iommu_lookup(current->mm, tce, size); + mem = mm_iommu_lookup(container->mm, tce, size); if (!mem) return -EINVAL; @@ -395,18 +409,18 @@ static int tce_iommu_prereg_ua_to_hpa(unsigned long tce, unsigned long size, return 0; } -static void tce_iommu_unuse_page_v2(struct iommu_table *tbl, - unsigned long entry) +static void tce_iommu_unuse_page_v2(struct tce_container *container, + struct iommu_table *tbl, unsigned long entry) { struct mm_iommu_table_group_mem_t *mem = NULL; int ret; unsigned long hpa = 0; unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry); - if (!pua || !current || !current->mm) + if (!pua) return; - ret = tce_iommu_prereg_ua_to_hpa(*pua, IOMMU_PAGE_SIZE(tbl), + ret = tce_iommu_prereg_ua_to_hpa(container, *pua, IOMMU_PAGE_SIZE(tbl), &hpa, &mem); if (ret) pr_debug("%s: tce %lx at #%lx was not cached, ret=%d\n", @@ -436,7 +450,7 @@ static int tce_iommu_clear(struct tce_container *container, continue; if (container->v2) { - tce_iommu_unuse_page_v2(tbl, entry); + tce_iommu_unuse_page_v2(container, tbl, entry); continue; } @@ -517,7 +531,7 @@ static long tce_iommu_build_v2(struct tce_container *container, enum dma_data_direction dirtmp; if (!tbl->it_userspace) { - ret = tce_iommu_userspace_view_alloc(tbl); + ret = tce_iommu_userspace_view_alloc(tbl, container->mm); if (ret) return ret; } @@ -527,8 +541,8 @@ static long tce_iommu_build_v2(struct tce_container *container, unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry + i); - ret = tce_iommu_prereg_ua_to_hpa(tce, IOMMU_PAGE_SIZE(tbl), - &hpa, &mem); + ret = tce_iommu_prereg_ua_to_hpa(container, + tce, IOMMU_PAGE_SIZE(tbl), &hpa, &mem); if (ret) break; @@ -549,7 +563,7 @@ static long tce_iommu_build_v2(struct tce_container *container, ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp); if (ret) { /* dirtmp cannot be DMA_NONE here */ - tce_iommu_unuse_page_v2(tbl, entry + i); + tce_iommu_unuse_page_v2(container, tbl, entry + i); pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n", __func__, entry << tbl->it_page_shift, tce, ret); @@ -557,7 +571,7 @@ static long tce_iommu_build_v2(struct tce_container *container, } if (dirtmp != DMA_NONE) - tce_iommu_unuse_page_v2(tbl, entry + i); + tce_iommu_unuse_page_v2(container, tbl, entry + i); *pua = tce; @@ -585,7 +599,7 @@ static long tce_iommu_create_table(struct tce_container *container, if (!table_size) return -EINVAL; - ret = try_increment_locked_vm(table_size >> PAGE_SHIFT); + ret = try_increment_locked_vm(container->mm, table_size >> PAGE_SHIFT); if (ret) return ret; @@ -598,13 +612,14 @@ static long tce_iommu_create_table(struct tce_container *container, return ret; } -static void tce_iommu_free_table(struct iommu_table *tbl) +static void tce_iommu_free_table(struct tce_container *container, + struct iommu_table *tbl) { unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT; - tce_iommu_userspace_view_free(tbl); + tce_iommu_userspace_view_free(tbl, container->mm); tbl->it_ops->free(tbl); - decrement_locked_vm(pages); + decrement_locked_vm(container->mm, pages); } static long tce_iommu_create_window(struct tce_container *container, @@ -667,7 +682,7 @@ unset_exit: table_group = iommu_group_get_iommudata(tcegrp->grp); table_group->ops->unset_window(table_group, num); } - tce_iommu_free_table(tbl); + tce_iommu_free_table(container, tbl); return ret; } @@ -705,7 +720,7 @@ static long tce_iommu_remove_window(struct tce_container *container, /* Free table */ tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size); - tce_iommu_free_table(tbl); + tce_iommu_free_table(container, tbl); container->tables[num] = NULL; return 0; @@ -760,7 +775,17 @@ static long tce_iommu_ioctl(void *iommu_data, } return (ret < 0) ? 0 : ret; + } + + /* + * Sanity check to prevent one userspace from manipulating + * another userspace mm. + */ + BUG_ON(!container); + if (container->mm && container->mm != current->mm) + return -EPERM; + switch (cmd) { case VFIO_IOMMU_SPAPR_TCE_GET_INFO: { struct vfio_iommu_spapr_tce_info info; struct tce_iommu_group *tcegrp; @@ -929,6 +954,10 @@ static long tce_iommu_ioctl(void *iommu_data, minsz = offsetofend(struct vfio_iommu_spapr_register_memory, size); + ret = tce_iommu_mm_set(container); + if (ret) + return ret; + if (copy_from_user(¶m, (void __user *)arg, minsz)) return -EFAULT; @@ -952,6 +981,9 @@ static long tce_iommu_ioctl(void *iommu_data, if (!container->v2) break; + if (!container->mm) + return -EPERM; + minsz = offsetofend(struct vfio_iommu_spapr_register_memory, size); @@ -1010,6 +1042,10 @@ static long tce_iommu_ioctl(void *iommu_data, if (!container->v2) break; + ret = tce_iommu_mm_set(container); + if (ret) + return ret; + if (!tce_groups_attached(container)) return -ENXIO; @@ -1048,6 +1084,10 @@ static long tce_iommu_ioctl(void *iommu_data, if (!container->v2) break; + ret = tce_iommu_mm_set(container); + if (ret) + return ret; + if (!tce_groups_attached(container)) return -ENXIO; @@ -1093,7 +1133,7 @@ static void tce_iommu_release_ownership(struct tce_container *container, continue; tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size); - tce_iommu_userspace_view_free(tbl); + tce_iommu_userspace_view_free(tbl, container->mm); if (tbl->it_map) iommu_release_ownership(tbl); |