On Fri, 2022-06-17 at 02:43 +0300, Kirill A. Shutemov wrote: > On Thu, Jun 16, 2022 at 10:52:14PM +0000, Edgecombe, Rick P wrote: > > On Fri, 2022-06-10 at 17:35 +0300, Kirill A. Shutemov wrote: > > > Linear Address Masking[1] (LAM) modifies the checking that is > > > applied > > > to > > > 64-bit linear addresses, allowing software to use of the > > > untranslated > > > address bits for metadata. > > > > > > The patchset brings support for LAM for userspace addresses. > > > > Arm has this documentation about which memory operations support > > being > > passed tagged pointers, and which do not: > > Documentation/arm64/tagged-address-abi.rst > > > > Is the idea that LAM would have something similar, or exactly > > mirror > > the arm ABI? It seems like it is the same right now. Should the > > docs be > > generalized? > > It is somewhat similar, but not exact. ARM TBI interface implies tag > size > and placement. ARM TBI is per-thread and LAM is per-process. Ah right. I was thinking more the part about which syscalls support tagged addresses: https://www.kernel.org/doc/html/latest/arm64/tagged-address-abi.html#id1 Some mention kernel versions where they changed. Just thinking it could get complex to track which HW features support which syscalls for which kernel versions.
