The unmap_region code uses a number of arguments that could use better documentation. With the addition of a descriptor for unmap (called unmap_desc), the arguments can be more self-documenting and increase the descriptions within the declaration. No functional change intended Signed-off-by: Liam R. Howlett --- mm/mmap.c | 12 ++++++++---- mm/vma.c | 27 ++++++++++++--------------- mm/vma.h | 35 ++++++++++++++++++++++++++++++++--- 3 files changed, 52 insertions(+), 22 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index aa4770b8d7f1e..5c9bd3f20e53f 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1883,11 +1883,15 @@ __latent_entropy int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) if (max) { vma_iter_set(&vmi, 0); tmp = vma_next(&vmi); + UNMAP_REGION(unmap, &vmi, /* first vma = */ tmp, + /* min vma addr = */ 0, + /* max vma addr = */ max, + /* prev = */ NULL, /* next = */ NULL); + + /* Don't free the pgtables higher than the failure */ + unmap.tree_max = max; flush_cache_mm(mm); - unmap_region(&vmi.mas, /* vma = */ tmp, - /*vma_min = */ 0, /* vma_max = */ max, - /* pg_max = */ max, /* prev = */ NULL, - /* next = */ NULL); + unmap_region(&unmap); charge = tear_down_vmas(mm, &vmi, tmp, max); vm_unacct_memory(charge); } diff --git a/mm/vma.c b/mm/vma.c index 4c850ffd83a4b..c92384975cbb2 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -473,22 +473,20 @@ void remove_vma(struct vm_area_struct *vma) * * Called with the mm semaphore held. */ -void unmap_region(struct ma_state *mas, struct vm_area_struct *vma, - unsigned long vma_min, unsigned long vma_max, unsigned long pg_max, - struct vm_area_struct *prev, struct vm_area_struct *next) +void unmap_region(struct unmap_desc *desc) { - struct mm_struct *mm = vma->vm_mm; + struct mm_struct *mm = desc->first->vm_mm; + struct ma_state *mas = desc->mas; struct mmu_gather tlb; tlb_gather_mmu(&tlb, mm); update_hiwater_rss(mm); - unmap_vmas(&tlb, mas, vma, vma_min, vma_max, vma_max, - /* mm_wr_locked = */ true); - mas_set(mas, vma->vm_end); - free_pgtables(&tlb, mas, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS, - next ? next->vm_start : USER_PGTABLES_CEILING, - pg_max, - /* mm_wr_locked = */ true); + unmap_vmas(&tlb, mas, desc->first, desc->vma_min, desc->vma_max, + desc->vma_max, desc->mm_wr_locked); + mas_set(mas, desc->tree_reset); + free_pgtables(&tlb, mas, desc->first, desc->first_pgaddr, + desc->last_pgaddr, desc->tree_max, + desc->mm_wr_locked); tlb_finish_mmu(&tlb); } @@ -2414,15 +2412,14 @@ static int __mmap_new_file_vma(struct mmap_state *map, error = mmap_file(vma->vm_file, vma); if (error) { + UNMAP_REGION(unmap, vmi, vma, vma->vm_start, vma->vm_end, + map->prev, map->next); fput(vma->vm_file); vma->vm_file = NULL; vma_iter_set(vmi, vma->vm_end); /* Undo any partial mapping done by a device driver. */ - unmap_region(&vmi->mas, vma, vma->vm_start, vma->vm_end, - map->next ? map->next->vm_start : USER_PGTABLES_CEILING, - map->prev, map->next); - + unmap_region(&unmap); return error; } diff --git a/mm/vma.h b/mm/vma.h index b0ebc81d5862e..4edd5d26ffcfc 100644 --- a/mm/vma.h +++ b/mm/vma.h @@ -152,6 +152,37 @@ struct vma_merge_struct { }; +struct unmap_desc { + struct ma_state *mas; /* the maple state point to the first vma */ + struct vm_area_struct *first; /* The first vma */ + unsigned long first_pgaddr; /* The first pagetable address to free */ + unsigned long last_pgaddr; /* The last pagetable address to free */ + unsigned long vma_min; /* The min vma address */ + unsigned long vma_max; /* The max vma address */ + unsigned long tree_max; /* Maximum for the vma tree search */ + unsigned long tree_reset; /* Where to reset the vma tree walk */ + bool mm_wr_locked; /* If the mmap write lock is held */ +}; + +#define UNMAP_REGION(name, _vmi, _vma, _vma_min, _vma_max, _prev, _next) \ + struct unmap_desc name = { \ + .mas = &(_vmi)->mas, \ + .first = _vma, \ + .first_pgaddr = _prev ? \ + ((struct vm_area_struct *)_prev)->vm_end : \ + FIRST_USER_ADDRESS, \ + .last_pgaddr = _next ? \ + ((struct vm_area_struct *)_next)->vm_start : \ + USER_PGTABLES_CEILING, \ + .vma_min = _vma_min, \ + .vma_max = _vma_max, \ + .tree_max = _next ? \ + ((struct vm_area_struct *)_next)->vm_start : \ + USER_PGTABLES_CEILING, \ + .tree_reset = _vma->vm_end, \ + .mm_wr_locked = true, \ + } + static inline bool vmg_nomem(struct vma_merge_struct *vmg) { return vmg->state == VMA_MERGE_ERROR_NOMEM; @@ -260,9 +291,7 @@ int do_vmi_munmap(struct vma_iterator *vmi, struct mm_struct *mm, void remove_vma(struct vm_area_struct *vma); -void unmap_region(struct ma_state *mas, struct vm_area_struct *vma, - unsigned long min, unsigned long max, unsigned long pg_max, - struct vm_area_struct *prev, struct vm_area_struct *next); +void unmap_region(struct unmap_desc *desc); /* We are about to modify the VMA's flags. */ __must_check struct vm_area_struct -- 2.47.2