From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx> Use the vma iterator so that the iterator can be invalidated or updated to avoid each caller doing so. Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> --- fs/exec.c | 5 ++++- include/linux/mm.h | 6 +++--- mm/mprotect.c | 47 ++++++++++++++++++++++------------------------ 3 files changed, 29 insertions(+), 29 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index ab913243a367..b98647eeae9f 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -758,6 +758,7 @@ int setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_expand; unsigned long rlim_stack; struct mmu_gather tlb; + struct vma_iterator vmi; #ifdef CONFIG_STACK_GROWSUP /* Limit stack size */ @@ -812,8 +813,10 @@ int setup_arg_pages(struct linux_binprm *bprm, vm_flags |= mm->def_flags; vm_flags |= VM_STACK_INCOMPLETE_SETUP; + vma_iter_init(&vmi, mm, vma->vm_start); + tlb_gather_mmu(&tlb, mm); - ret = mprotect_fixup(&tlb, vma, &prev, vma->vm_start, vma->vm_end, + ret = mprotect_fixup(&vmi, &tlb, vma, &prev, vma->vm_start, vma->vm_end, vm_flags); tlb_finish_mmu(&tlb); diff --git a/include/linux/mm.h b/include/linux/mm.h index 956025940053..bd0017ab13f3 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2197,9 +2197,9 @@ bool can_change_pte_writable(struct vm_area_struct *vma, unsigned long addr, extern long change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long start, unsigned long end, unsigned long cp_flags); -extern int mprotect_fixup(struct mmu_gather *tlb, struct vm_area_struct *vma, - struct vm_area_struct **pprev, unsigned long start, - unsigned long end, unsigned long newflags); +extern int mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb, + struct vm_area_struct *vma, struct vm_area_struct **pprev, + unsigned long start, unsigned long end, unsigned long newflags); /* * doesn't attempt to fault and will return short. diff --git a/mm/mprotect.c b/mm/mprotect.c index 6ecdf0671b81..42ceb0548754 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -585,9 +585,9 @@ static const struct mm_walk_ops prot_none_walk_ops = { }; int -mprotect_fixup(struct mmu_gather *tlb, struct vm_area_struct *vma, - struct vm_area_struct **pprev, unsigned long start, - unsigned long end, unsigned long newflags) +mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb, + struct vm_area_struct *vma, struct vm_area_struct **pprev, + unsigned long start, unsigned long end, unsigned long newflags) { struct mm_struct *mm = vma->vm_mm; unsigned long oldflags = vma->vm_flags; @@ -642,7 +642,7 @@ mprotect_fixup(struct mmu_gather *tlb, struct vm_area_struct *vma, * First try to merge with previous and/or next vma. */ pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); - *pprev = vma_merge(mm, *pprev, start, end, newflags, + *pprev = vmi_vma_merge(vmi, mm, *pprev, start, end, newflags, vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma), vma->vm_userfaultfd_ctx, anon_vma_name(vma)); if (*pprev) { @@ -654,13 +654,13 @@ mprotect_fixup(struct mmu_gather *tlb, struct vm_area_struct *vma, *pprev = vma; if (start != vma->vm_start) { - error = split_vma(mm, vma, start, 1); + error = vmi_split_vma(vmi, mm, vma, start, 1); if (error) goto fail; } if (end != vma->vm_end) { - error = split_vma(mm, vma, end, 0); + error = vmi_split_vma(vmi, mm, vma, end, 0); if (error) goto fail; } @@ -709,7 +709,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len, const bool rier = (current->personality & READ_IMPLIES_EXEC) && (prot & PROT_READ); struct mmu_gather tlb; - MA_STATE(mas, ¤t->mm->mm_mt, 0, 0); + struct vma_iterator vmi; start = untagged_addr(start); @@ -741,8 +741,8 @@ static int do_mprotect_pkey(unsigned long start, size_t len, if ((pkey != -1) && !mm_pkey_is_allocated(current->mm, pkey)) goto out; - mas_set(&mas, start); - vma = mas_find(&mas, ULONG_MAX); + vma_iter_init(&vmi, current->mm, start); + vma = vma_find(&vmi, end); error = -ENOMEM; if (!vma) goto out; @@ -765,18 +765,22 @@ static int do_mprotect_pkey(unsigned long start, size_t len, } } + prev = vma_prev(&vmi); if (start > vma->vm_start) prev = vma; - else - prev = mas_prev(&mas, 0); tlb_gather_mmu(&tlb, current->mm); - for (nstart = start ; ; ) { + nstart = start; + tmp = vma->vm_start; + for_each_vma_range(vmi, vma, end) { unsigned long mask_off_old_flags; unsigned long newflags; int new_vma_pkey; - /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ + if (vma->vm_start != tmp) { + error = -ENOMEM; + break; + } /* Does the application expect PROT_READ to imply PROT_EXEC */ if (rier && (vma->vm_flags & VM_MAYEXEC)) @@ -819,25 +823,18 @@ static int do_mprotect_pkey(unsigned long start, size_t len, break; } - error = mprotect_fixup(&tlb, vma, &prev, nstart, tmp, newflags); + error = mprotect_fixup(&vmi, &tlb, vma, &prev, nstart, tmp, newflags); if (error) break; nstart = tmp; - - if (nstart < prev->vm_end) - nstart = prev->vm_end; - if (nstart >= end) - break; - - vma = find_vma(current->mm, prev->vm_end); - if (!vma || vma->vm_start != nstart) { - error = -ENOMEM; - break; - } prot = reqprot; } tlb_finish_mmu(&tlb); + + if (vma_iter_end(&vmi) < end) + error = -ENOMEM; + out: mmap_write_unlock(current->mm); return error; -- 2.35.1