[PATCH v3 00/24] Memory Tagging Support + AArch64 Linux implementation

[Alan Hayward]

I’m happy with this series now. Specifically, the AArch64 parts are fine.


Alan.

> On 16 Nov 2020, at 13:48, Luis Machado <luis.machado@linaro.org> wrote:
> 
> Ping?
> 
> FTR, I'm aiming at having this ready for GDB 11.
> 
> On 11/9/20 2:04 PM, Luis Machado wrote:
>> Here's v3 of this patch series.
>> Memory tagging improves memory safety by tagging various parts of memory and
>> raising exceptions when the allocation tag (the one associated with a range of
>> memory addresses) does not match the logical tag contained in a pointer that is
>> used to access the memory area.
>> We already have an implementation of such a mechanism for sparc64 (ADI), but
>> it is target-specific and not exposed to the rest of GDB. This series aims to
>> make the infrastructure available to other targets that may wish to support
>> their specific memory tagging approaches. For AArch64 Linux this is called
>> MTE (Memory Tagging Extensions).
>> The series is split into a set that deals with generic changes to GDB's
>> infrastructure (target methods, gdbarch hooks and remote packets), a set that
>> implements support for AArch64 Linux and one last set that implements new
>> commands, updates the documentation and adds tests.
>> The goal is to make it so the architecture independent parts of GDB don't
>> need to interpret tag formats, given the formats are likely different
>> for each architecture.  For this reason, GDB will handle tags as a sequence of
>> bytes and will not assume a particular format.
>> The architecture-specific code can handle the sequence of bytes appropriately.
>> Luis Machado (24):
>>   New target methods for memory tagging support
>>   New gdbarch memory tagging hooks
>>   Add GDB-side remote target support for memory tagging
>>   Unit testing for GDB-side remote memory tagging handling
>>   GDBserver remote packet support for memory tagging
>>   Unit tests for gdbserver memory tagging remote packets
>>   Documentation for memory tagging remote packets
>>   AArch64: Add MTE CPU feature check support
>>   AArch64: Add target description/feature for MTE registers
>>   AArch64: Add MTE register set support for GDB and gdbserver
>>   AArch64: Add MTE ptrace requests
>>   AArch64: Implement memory tagging target methods for AArch64
>>   Refactor parsing of /proc/<pid>/smaps
>>   AArch64: Implement the memory tagging gdbarch hooks
>>   AArch64: Add unit testing for logical tag set/get operations
>>   AArch64: Report tag violation error information
>>   AArch64: Add gdbserver MTE support
>>   AArch64: Add MTE register set support for core files
>>   New mtag commands
>>   Documentation for the new mtag commands
>>   Extend "x" and "print" commands to support memory tagging
>>   Document new "x" and "print" memory tagging extensions
>>   Add NEWS entry.
>>   Add memory tagging testcases
>>  gdb/Makefile.in                        |   3 +
>>  gdb/NEWS                               |  32 ++
>>  gdb/aarch64-linux-nat.c                | 129 ++++++-
>>  gdb/aarch64-linux-tdep.c               | 334 +++++++++++++++++-
>>  gdb/aarch64-linux-tdep.h               |   3 +
>>  gdb/aarch64-tdep.c                     |  40 ++-
>>  gdb/aarch64-tdep.h                     |  12 +-
>>  gdb/arch-utils.c                       |  50 +++
>>  gdb/arch-utils.h                       |  23 ++
>>  gdb/arch/aarch64-mte-linux.c           |  70 ++++
>>  gdb/arch/aarch64-mte-linux.h           |  66 ++++
>>  gdb/arch/aarch64.c                     |   7 +-
>>  gdb/arch/aarch64.h                     |   7 +-
>>  gdb/configure.nat                      |   3 +-
>>  gdb/configure.tgt                      |   1 +
>>  gdb/doc/gdb.texinfo                    | 215 +++++++++++-
>>  gdb/features/Makefile                  |   1 +
>>  gdb/features/aarch64-mte.c             |  14 +
>>  gdb/features/aarch64-mte.xml           |  11 +
>>  gdb/gdbarch.c                          | 137 ++++++++
>>  gdb/gdbarch.h                          |  53 +++
>>  gdb/gdbarch.sh                         |  36 ++
>>  gdb/linux-tdep.c                       | 358 ++++++++++++-------
>>  gdb/linux-tdep.h                       |   4 +
>>  gdb/nat/aarch64-mte-linux-ptrace.c     | 200 +++++++++++
>>  gdb/nat/aarch64-mte-linux-ptrace.h     |  50 +++
>>  gdb/printcmd.c                         | 468 ++++++++++++++++++++++++-
>>  gdb/remote.c                           | 232 ++++++++++++
>>  gdb/target-delegates.c                 |  84 +++++
>>  gdb/target.h                           |  37 ++
>>  gdb/testsuite/gdb.arch/aarch64-mte.c   | 107 ++++++
>>  gdb/testsuite/gdb.arch/aarch64-mte.exp | 371 ++++++++++++++++++++
>>  gdb/testsuite/gdb.base/memtag.c        |  22 ++
>>  gdb/testsuite/gdb.base/memtag.exp      |  64 ++++
>>  gdb/testsuite/lib/gdb.exp              |  16 +
>>  gdb/valprint.h                         |   1 +
>>  gdbserver/Makefile.in                  |   1 +
>>  gdbserver/configure.srv                |   2 +
>>  gdbserver/linux-aarch64-ipa.cc         |   8 +-
>>  gdbserver/linux-aarch64-low.cc         |  97 ++++-
>>  gdbserver/linux-aarch64-tdesc.cc       |  10 +-
>>  gdbserver/linux-aarch64-tdesc.h        |   3 +-
>>  gdbserver/remote-utils.cc              |  43 ++-
>>  gdbserver/remote-utils.h               |   7 +-
>>  gdbserver/server.cc                    | 245 +++++++++++++
>>  gdbserver/server.h                     |   3 +
>>  gdbserver/target.cc                    |  20 ++
>>  gdbserver/target.h                     |  17 +
>>  gdbsupport/rsp-low.cc                  |   2 +-
>>  include/elf/common.h                   |   3 +
>>  50 files changed, 3536 insertions(+), 186 deletions(-)
>>  create mode 100644 gdb/arch/aarch64-mte-linux.c
>>  create mode 100644 gdb/arch/aarch64-mte-linux.h
>>  create mode 100644 gdb/features/aarch64-mte.c
>>  create mode 100644 gdb/features/aarch64-mte.xml
>>  create mode 100644 gdb/nat/aarch64-mte-linux-ptrace.c
>>  create mode 100644 gdb/nat/aarch64-mte-linux-ptrace.h
>>  create mode 100644 gdb/testsuite/gdb.arch/aarch64-mte.c
>>  create mode 100644 gdb/testsuite/gdb.arch/aarch64-mte.exp
>>  create mode 100644 gdb/testsuite/gdb.base/memtag.c
>>  create mode 100644 gdb/testsuite/gdb.base/memtag.exp