diff options
Diffstat (limited to 'mm/vma.c')
| -rw-r--r-- | mm/vma.c | 95 |
1 files changed, 62 insertions, 33 deletions
@@ -737,32 +737,30 @@ vmi_complete_munmap_vmas(struct vma_iterator *vmi, struct vm_area_struct *vma, } /* - * do_vmi_align_munmap() - munmap the aligned region from @start to @end. + * vmi_gather_munmap_vmas() - Put all VMAs within a range into a maple tree + * for removal at a later date. Handles splitting first and last if necessary + * and marking the vmas as isolated. + * * @vmi: The vma iterator * @vma: The starting vm_area_struct * @mm: The mm_struct * @start: The aligned start address to munmap. * @end: The aligned end address to munmap. * @uf: The userfaultfd list_head - * @unlock: Set to true to drop the mmap_lock. unlocking only happens on - * success. + * @mas_detach: The maple state tracking the detached tree + * @locked_vm: a pointer to store the VM_LOCKED pages count. * - * Return: 0 on success and drops the lock if so directed, error and leaves the - * lock held otherwise. + * Return: 0 on success, -EPERM on mseal vmas, -ENOMEM otherwise */ -int -do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, +static int +vmi_gather_munmap_vmas(struct vma_iterator *vmi, struct vm_area_struct *vma, struct mm_struct *mm, unsigned long start, - unsigned long end, struct list_head *uf, bool unlock) + unsigned long end, struct list_head *uf, + struct ma_state *mas_detach, unsigned long *locked_vm) { struct vm_area_struct *next = NULL; - struct maple_tree mt_detach; int count = 0; int error = -ENOMEM; - unsigned long locked_vm = 0; - MA_STATE(mas_detach, &mt_detach, 0, 0); - mt_init_flags(&mt_detach, vmi->mas.tree->ma_flags & MT_FLAGS_LOCK_MASK); - mt_on_stack(mt_detach); /* * If we need to split any vma, do it now to save pain later. @@ -789,8 +787,7 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, goto start_split_failed; } - error = __split_vma(vmi, vma, start, 1); - if (error) + if (__split_vma(vmi, vma, start, 1)) goto start_split_failed; } @@ -807,20 +804,18 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, /* Does it split the end? */ if (next->vm_end > end) { - error = __split_vma(vmi, next, end, 0); - if (error) + if (__split_vma(vmi, next, end, 0)) goto end_split_failed; } vma_start_write(next); - mas_set(&mas_detach, count); - error = mas_store_gfp(&mas_detach, next, GFP_KERNEL); - if (error) + mas_set(mas_detach, count++); + if (mas_store_gfp(mas_detach, next, GFP_KERNEL)) goto munmap_gather_failed; + vma_mark_detached(next, true); if (next->vm_flags & VM_LOCKED) - locked_vm += vma_pages(next); + *locked_vm += vma_pages(next); - count++; if (unlikely(uf)) { /* * If userfaultfd_unmap_prep returns an error the vmas @@ -831,9 +826,7 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, * split, despite we could. This is unlikely enough * failure that it's not worth optimizing it for. */ - error = userfaultfd_unmap_prep(next, start, end, uf); - - if (error) + if (userfaultfd_unmap_prep(next, start, end, uf)) goto userfaultfd_error; } #ifdef CONFIG_DEBUG_VM_MAPLE_TREE @@ -845,7 +838,7 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, #if defined(CONFIG_DEBUG_VM_MAPLE_TREE) /* Make sure no VMAs are about to be lost. */ { - MA_STATE(test, &mt_detach, 0, 0); + MA_STATE(test, mas_detach->tree, 0, 0); struct vm_area_struct *vma_mas, *vma_test; int test_count = 0; @@ -865,6 +858,48 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, while (vma_iter_addr(vmi) > start) vma_iter_prev_range(vmi); + return 0; + +userfaultfd_error: +munmap_gather_failed: +end_split_failed: +modify_vma_failed: + abort_munmap_vmas(mas_detach); +start_split_failed: +map_count_exceeded: + return error; +} + +/* + * do_vmi_align_munmap() - munmap the aligned region from @start to @end. + * @vmi: The vma iterator + * @vma: The starting vm_area_struct + * @mm: The mm_struct + * @start: The aligned start address to munmap. + * @end: The aligned end address to munmap. + * @uf: The userfaultfd list_head + * @unlock: Set to true to drop the mmap_lock. unlocking only happens on + * success. + * + * Return: 0 on success and drops the lock if so directed, error and leaves the + * lock held otherwise. + */ +int do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, + struct mm_struct *mm, unsigned long start, unsigned long end, + struct list_head *uf, bool unlock) +{ + struct maple_tree mt_detach; + MA_STATE(mas_detach, &mt_detach, 0, 0); + mt_init_flags(&mt_detach, vmi->mas.tree->ma_flags & MT_FLAGS_LOCK_MASK); + mt_on_stack(mt_detach); + int error; + unsigned long locked_vm = 0; + + error = vmi_gather_munmap_vmas(vmi, vma, mm, start, end, uf, + &mas_detach, &locked_vm); + if (error) + goto gather_failed; + error = vma_iter_clear_gfp(vmi, start, end, GFP_KERNEL); if (error) goto clear_tree_failed; @@ -872,17 +907,11 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, /* Point of no return */ vmi_complete_munmap_vmas(vmi, vma, mm, start, end, unlock, &mas_detach, locked_vm); - return 0; -modify_vma_failed: clear_tree_failed: -userfaultfd_error: -munmap_gather_failed: -end_split_failed: abort_munmap_vmas(&mas_detach); -start_split_failed: -map_count_exceeded: +gather_failed: validate_mm(mm); return error; } |