From 33108b05f39b78137c38c677b7a2d0fb7defed14 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 6 Sep 2022 19:49:02 +0000 Subject: mm/mlock: use vma iterator and maple state instead of vma linked list Handle overflow checking in count_mm_mlocked_page_nr() differently. Link: https://lkml.kernel.org/r/20220906194824.2110408-58-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 --- mm/mlock.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) (limited to 'mm/mlock.c') diff --git a/mm/mlock.c b/mm/mlock.c index b14e929084cc..43d19a1f28eb 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -471,6 +471,7 @@ static int apply_vma_lock_flags(unsigned long start, size_t len, unsigned long nstart, end, tmp; struct vm_area_struct *vma, *prev; int error; + MA_STATE(mas, ¤t->mm->mm_mt, start, start); VM_BUG_ON(offset_in_page(start)); VM_BUG_ON(len != PAGE_ALIGN(len)); @@ -479,13 +480,14 @@ static int apply_vma_lock_flags(unsigned long start, size_t len, return -EINVAL; if (end == start) return 0; - vma = find_vma(current->mm, start); - if (!vma || vma->vm_start > start) + vma = mas_walk(&mas); + if (!vma) return -ENOMEM; - prev = vma->vm_prev; if (start > vma->vm_start) prev = vma; + else + prev = mas_prev(&mas, 0); for (nstart = start ; ; ) { vm_flags_t newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; @@ -505,7 +507,7 @@ static int apply_vma_lock_flags(unsigned long start, size_t len, if (nstart >= end) break; - vma = prev->vm_next; + vma = find_vma(prev->vm_mm, prev->vm_end); if (!vma || vma->vm_start != nstart) { error = -ENOMEM; break; @@ -526,24 +528,23 @@ static unsigned long count_mm_mlocked_page_nr(struct mm_struct *mm, { struct vm_area_struct *vma; unsigned long count = 0; + unsigned long end; + VMA_ITERATOR(vmi, mm, start); if (mm == NULL) mm = current->mm; - vma = find_vma(mm, start); - if (vma == NULL) - return 0; - - for (; vma ; vma = vma->vm_next) { - if (start >= vma->vm_end) - continue; - if (start + len <= vma->vm_start) - break; + /* Don't overflow past ULONG_MAX */ + if (unlikely(ULONG_MAX - len < start)) + end = ULONG_MAX; + else + end = start + len; + for_each_vma_range(vmi, vma, end) { if (vma->vm_flags & VM_LOCKED) { if (start > vma->vm_start) count -= (start - vma->vm_start); - if (start + len < vma->vm_end) { - count += start + len - vma->vm_start; + if (end < vma->vm_end) { + count += end - vma->vm_start; break; } count += vma->vm_end - vma->vm_start; @@ -659,6 +660,7 @@ SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len) */ static int apply_mlockall_flags(int flags) { + MA_STATE(mas, ¤t->mm->mm_mt, 0, 0); struct vm_area_struct *vma, *prev = NULL; vm_flags_t to_add = 0; @@ -679,7 +681,7 @@ static int apply_mlockall_flags(int flags) to_add |= VM_LOCKONFAULT; } - for (vma = current->mm->mmap; vma ; vma = prev->vm_next) { + mas_for_each(&mas, vma, ULONG_MAX) { vm_flags_t newflags; newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; @@ -687,6 +689,7 @@ static int apply_mlockall_flags(int flags) /* Ignore errors */ mlock_fixup(vma, &prev, vma->vm_start, vma->vm_end, newflags); + mas_pause(&mas); cond_resched(); } out: -- cgit v1.2.3