diff options
| -rw-r--r-- | mm/internal.h | 27 | ||||
| -rw-r--r-- | mm/mmap.c | 6 | ||||
| -rw-r--r-- | mm/nommu.c | 4 |
3 files changed, 32 insertions, 5 deletions
diff --git a/mm/internal.h b/mm/internal.h index 16c1f3cd599e..4eab2961e69c 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -108,6 +108,33 @@ static inline void *folio_raw_mapping(const struct folio *folio) return (void *)(mapping & ~PAGE_MAPPING_FLAGS); } +/* + * This is a file-backed mapping, and is about to be memory mapped - invoke its + * mmap hook and safely handle error conditions. On error, VMA hooks will be + * mutated. + * + * @file: File which backs the mapping. + * @vma: VMA which we are mapping. + * + * Returns: 0 if success, error otherwise. + */ +static inline int mmap_file(struct file *file, struct vm_area_struct *vma) +{ + int err = call_mmap(file, vma); + + if (likely(!err)) + return 0; + + /* + * OK, we tried to call the file hook for mmap(), but an error + * arose. The mapping is in an inconsistent state and we most not invoke + * any further hooks on it. + */ + vma->vm_ops = &vma_dummy_vm_ops; + + return err; +} + #ifdef CONFIG_MMU /* Flags for folio_pte_batch(). */ diff --git a/mm/mmap.c b/mm/mmap.c index 9841b41e3c76..6e3b25f7728f 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1422,7 +1422,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, /* * clear PTEs while the vma is still in the tree so that rmap * cannot race with the freeing later in the truncate scenario. - * This is also needed for call_mmap(), which is why vm_ops + * This is also needed for mmap_file(), which is why vm_ops * close function is called. */ vms_clean_up_area(&vms, &mas_detach); @@ -1447,7 +1447,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, if (file) { vma->vm_file = get_file(file); - error = call_mmap(file, vma); + error = mmap_file(file, vma); if (error) goto unmap_and_free_vma; @@ -1470,7 +1470,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, vma_iter_config(&vmi, addr, end); /* - * If vm_flags changed after call_mmap(), we should try merge + * If vm_flags changed after mmap_file(), we should try merge * vma again as we may succeed this time. */ if (unlikely(vm_flags != vma->vm_flags && vmg.prev)) { diff --git a/mm/nommu.c b/mm/nommu.c index 385b0c15add8..f9ccc02458ec 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -885,7 +885,7 @@ static int do_mmap_shared_file(struct vm_area_struct *vma) { int ret; - ret = call_mmap(vma->vm_file, vma); + ret = mmap_file(vma->vm_file, vma); if (ret == 0) { vma->vm_region->vm_top = vma->vm_region->vm_end; return 0; @@ -918,7 +918,7 @@ static int do_mmap_private(struct vm_area_struct *vma, * happy. */ if (capabilities & NOMMU_MAP_DIRECT) { - ret = call_mmap(vma->vm_file, vma); + ret = mmap_file(vma->vm_file, vma); /* shouldn't return success if we're not sharing */ if (WARN_ON_ONCE(!is_nommu_shared_mapping(vma->vm_flags))) ret = -ENOSYS; |