[PATCH 0/2] aarch64: Enable pointer auth in PLT

[Szabolcs Nagy]

Pointer authentication is an armv8.3-a extension and it can be used
to harden PLTGOT entries when that is not read-only protected.

binutils bfd linker now supports creating binaries with -z pac-plt
and then PLT entries authenticate the pointers loaded from PLTGOT.

To support such binaries the glibc dynamic linker has to "sign" the
pointers in the PLTGOT. On cpus without pointer authentication support,
both the sign and authentication operations are nops, so such binaries
may appear to work now, but on a new cpu they will crash without glibc
support.

Szabolcs Nagy (2):
  Add DT_AARCH64_BTI_PLT and DT_AARCH64_PAC_PLT to elf.h.
  aarch64: Support PLT with PAC

 elf/elf.h                    |  2 ++
 sysdeps/aarch64/dl-machine.h | 32 ++++++++++++++++++++++++++------
 2 files changed, 28 insertions(+), 6 deletions(-)

-- 
2.17.1