Proposal: Add ability to tag file mappings with MTE

[Derrick McKee]

Hello,

Currently, the only user space support for Memory Tag Extensions is
for heap and stack memory allocations, and no planned file-backed mmap
support.  Unfortunately, that prevents tagging global data (defined in
.data and potentially .bss ELF sections), as those are in a file
mapping.  It seems worthy to add file mapping support to allow for
protecting global variables.  Additionally, allowing tagging file
backed mapping would allow users to tag code regions, which
researchers like myself can also use to investigate protecting against
code reuse attacks.  These two reasons to support file mapping support
for MTE are fairly compelling, but I'd be interested in hearing what
other people have to say.  Thanks.

--
Derrick McKee
Phone: (703) 957-9362
Email: derrick.mckee at gmail.com