diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/internal.h | 27 | ||||
| -rw-r--r-- | mm/mmap.c | 4 | ||||
| -rw-r--r-- | mm/nommu.c | 4 |
3 files changed, 31 insertions, 4 deletions
diff --git a/mm/internal.h b/mm/internal.h index b30907537801..841f22f99ad7 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -83,6 +83,33 @@ static inline void *folio_raw_mapping(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; +} + void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio, int nr_throttled); static inline void acct_reclaim_writeback(struct folio *folio) diff --git a/mm/mmap.c b/mm/mmap.c index 6530e9cac458..8a055bae6bdb 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2779,7 +2779,7 @@ cannot_expand: } vma->vm_file = get_file(file); - error = call_mmap(file, vma); + error = mmap_file(file, vma); if (error) goto unmap_and_free_vma; @@ -2793,7 +2793,7 @@ cannot_expand: 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 && prev)) { diff --git a/mm/nommu.c b/mm/nommu.c index 5816b15eeb2b..2cd7277a6ef5 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -896,7 +896,7 @@ 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; @@ -929,7 +929,7 @@ 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; |