| From | Alexander Potapenko <> | Date | Thu, 9 Feb 2023 15:10:07 +0100 | Subject | Re: [PATCHv15 06/17] x86/uaccess: Provide untagged_addr() and remove tags before address check |
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On Mon, Jan 23, 2023 at 11:05 PM Kirill A. Shutemov <kirill.shutemov@linux.intel.com> wrote: > > untagged_addr() is a helper used by the core-mm to strip tag bits and > get the address to the canonical shape based on rules of the current > thread. It only handles userspace addresses. > > The untagging mask is stored in per-CPU variable and set on context > switching to the task. > > The tags must not be included into check whether it's okay to access the > userspace address. Strip tags in access_ok(). > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Alexander Potapenko <glider@google.com>
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