Messages in this thread Patch in this message | | | From | Nadav Amit <> | Subject | [RFC PATCH 3/8] mm/madvise: remove unnecessary checks on madvise_free_single_vma() | Date | Sun, 26 Sep 2021 09:12:54 -0700 |
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From: Nadav Amit <namit@vmware.com>
madvise_free_single_vma() currently rechecks that the range fits within the VMA, adapts it accordingly, and returns -EINVAL if the range is entirely outside of the VMA.
The error-code of -EINVAL is incorrect according to the man pages (as it should have been -ENOMEM), but anyhow the range that is provided to madvise_free_single_vma() should always be valid. It is set correctly in do_madvise() and then rechecked in madvise_dontneed_free() is the mmap-lock is dropped.
Remove this check.
Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Colin Cross <ccross@google.com> Cc: Suren Baghdasarya <surenb@google.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Nadav Amit <namit@vmware.com> --- mm/madvise.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/mm/madvise.c b/mm/madvise.c index fe843513a4e8..17e39c70704b 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -716,14 +716,8 @@ static int madvise_free_single_vma(struct vm_area_struct *vma, if (!vma_is_anonymous(vma)) return -EINVAL; - range.start = max(vma->vm_start, start_addr); - if (range.start >= vma->vm_end) - return -EINVAL; - range.end = min(vma->vm_end, end_addr); - if (range.end <= vma->vm_start) - return -EINVAL; mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, - range.start, range.end); + start_addr, end_addr); lru_add_drain(); tlb_gather_mmu(&tlb, mm); -- 2.25.1
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