From 19066e58682ec156aac8d6cf94b79ab2f122a556 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 6 Sep 2022 19:48:56 +0000 Subject: [PATCH] exec: use VMA iterator instead of linked list Remove a use of the vm_next list by doing the initial lookup with the VMA iterator and then using it to find the next entry. Link: https://lkml.kernel.org/r/20220906194824.2110408-42-Liam.Howlett@oracle.com Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Liam R. Howlett Tested-by: Yu Zhao Cc: Catalin Marinas Cc: David Hildenbrand Cc: David Howells Cc: Davidlohr Bueso Cc: SeongJae Park Cc: Sven Schnelle Cc: Vlastimil Babka Cc: Will Deacon Signed-off-by: Andrew Morton --- fs/exec.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 2b919b30dc97..afe55d0c3bcf 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -683,6 +683,8 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) unsigned long length = old_end - old_start; unsigned long new_start = old_start - shift; unsigned long new_end = old_end - shift; + VMA_ITERATOR(vmi, mm, new_start); + struct vm_area_struct *next; struct mmu_gather tlb; BUG_ON(new_start > new_end); @@ -691,7 +693,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) * ensure there are no vmas between where we want to go * and where we are */ - if (vma != find_vma(mm, new_start)) + if (vma != vma_next(&vmi)) return -EFAULT; /* @@ -710,12 +712,13 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) lru_add_drain(); tlb_gather_mmu(&tlb, mm); + next = vma_next(&vmi); if (new_end > old_start) { /* * when the old and new regions overlap clear from new_end. */ free_pgd_range(&tlb, new_end, old_end, new_end, - vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING); + next ? next->vm_start : USER_PGTABLES_CEILING); } else { /* * otherwise, clean from old_start; this is done to not touch @@ -724,7 +727,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) * for the others its just a little faster. */ free_pgd_range(&tlb, old_start, old_end, new_end, - vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING); + next ? next->vm_start : USER_PGTABLES_CEILING); } tlb_finish_mmu(&tlb);