[PATCH 0/3 v3] [AArch64] Support tagged pointer

[Yao Qi <qiyaoltc at gmail dot com>]

ARMv8 supports tagged address, that is, the top one byte in address
is ignored.  It is always enabled on aarch64-linux.  See
https://www.kernel.org/doc/Documentation/arm64/tagged-pointers.txt

Some parts of GDB related to address are updated in this patch series,

 - Memory access, like command 'x',
 - Setting hw breakpoint on some address,
 - Setting watchpoint on some address,

Address tag is treated as non-significant bits of address, so this patch
series add a new gdbarch significant_addr_bit, and use it in gdbarch to
get rid of non-significant bits.  This was the suggestion in the v2 review.
(https://sourceware.org/ml/gdb-patches/2017-10/msg00792.html)

When I test this patch series, and I find a regression in linespec.  I
posted the fix https://sourceware.org/ml/gdb-patches/2017-12/msg00158.html
Without this fix, this series causes a regression.

*** BLURB HERE ***

Yao Qi (3):
  Clear non-significant bits of address on memory access
  Adjust breakpoint address by clearing non-significant bits
  Clear non-significant bits of address in watchpoint

 gdb/aarch64-linux-tdep.c                          |   2 +
 gdb/breakpoint.c                                  |  22 ++---
 gdb/gdbarch.c                                     |  22 +++++
 gdb/gdbarch.h                                     |   8 ++
 gdb/gdbarch.sh                                    |   6 ++
 gdb/target.c                                      |   2 +
 gdb/testsuite/gdb.arch/aarch64-tagged-pointer.c   |  57 ++++++++++++
 gdb/testsuite/gdb.arch/aarch64-tagged-pointer.exp | 105 ++++++++++++++++++++++
 gdb/utils.c                                       |  17 ++++
 gdb/utils.h                                       |   3 +
 10 files changed, 233 insertions(+), 11 deletions(-)
 create mode 100644 gdb/testsuite/gdb.arch/aarch64-tagged-pointer.c
 create mode 100644 gdb/testsuite/gdb.arch/aarch64-tagged-pointer.exp

-- 
1.9.1