Date:   Thu, 16 Feb 2023 15:26:27 -0500
From:   Peter Xu <peterx@redhat.com>
To:     Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc:     David Hildenbrand <david@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        kernel@collabora.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 2/2] mm/userfaultfd: add VM_WARN_ONCE()
Message-ID: <Y+6Rc8RUiv7xAlKH@x1n>
References: <20230216091656.2045471-1-usama.anjum@collabora.com>
 <20230216091656.2045471-2-usama.anjum@collabora.com>
 <4d29a9ec-027d-06b9-8543-87d386e58c94@redhat.com>
 <c239e126-9b75-9a81-6142-a8e518e769e2@collabora.com>
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On Thu, Feb 16, 2023 at 02:48:51PM +0500, Muhammad Usama Anjum wrote:
> On 2/16/23 2:24 PM, David Hildenbrand wrote:
> > On 16.02.23 10:16, Muhammad Usama Anjum wrote:
> >> Add VM_WARN_ONCE() to uffd_wp_range() to detect range (start, len) abuse.
> >>
> >> Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
> >> ---
> >>   mm/userfaultfd.c | 2 ++
> >>   1 file changed, 2 insertions(+)
> >>
> >> diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
> >> index 77c5839e591c..d89ed44d2668 100644
> >> --- a/mm/userfaultfd.c
> >> +++ b/mm/userfaultfd.c
> >> @@ -717,6 +717,8 @@ long uffd_wp_range(struct mm_struct *dst_mm, struct
> >> vm_area_struct *dst_vma,
> >>       struct mmu_gather tlb;
> >>       long ret;
> >>   +    VM_WARN_ONCE(start < dst_vma->vm_start || start + len >
> >> dst_vma->vm_end,
> >> +             "The address range exceeds VMA boundary.\n");
> > 
> > VM_WARN_ON_ONCE is sufficient (sorry for spelling out the wrong variant
> > earlier).
> Will do in the next version. Thanks.

Shall we just squash the two patches?

-- 
Peter Xu