Re: [PATCH 00/23] Memory Tagging Support + AArch64 Linux implementation

[Luis Machado <luis.machado@linaro.org>]

Ping?

On 7/15/20 4:44 PM, Luis Machado wrote:
> This patch series implements general memory tagging support for GDB, as well
> as an implementation for AArch64 Linux.
> 
> 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 (23):
>    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
>    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                | 121 ++++++-
>   gdb/aarch64-linux-tdep.c               | 330 ++++++++++++++++-
>   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                    | 174 ++++++++-
>   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                       | 356 ++++++++++++-------
>   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                           | 230 ++++++++++++
>   gdb/target-delegates.c                 |  84 +++++
>   gdb/target.h                           |  25 ++
>   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         |  89 ++++-
>   gdbserver/linux-aarch64-tdesc.cc       |  10 +-
>   gdbserver/linux-aarch64-tdesc.h        |   3 +-
>   gdbserver/remote-utils.cc              |  40 +--
>   gdbserver/remote-utils.h               |   2 +
>   gdbserver/server.cc                    | 214 +++++++++++
>   gdbserver/server.h                     |   3 +
>   gdbserver/target.cc                    |  20 ++
>   gdbserver/target.h                     |  17 +
>   gdbsupport/rsp-low.cc                  |   2 +-
>   include/elf/common.h                   |   3 +
>   49 files changed, 3421 insertions(+), 182 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
>