Re: [PATCH 0/8] Add SVE support for Aarch64 GDB

Alan Hayward
2018-05-22T08:34:32Z

Ping.

Thanks,
Alan.

> On 11 May 2018, at 11:52, Alan Hayward <Alan.Hayward@arm.com> wrote:
>
> This set of patches adds gdb support for SVE on AArch64.
>
> SVE is the new vector extension for Aarch64. SVE is different in that the
> length of a vector register is not fixed - it is can vary for different
> hardware implementors. All code compiled for SVE is vector length agnostic.
> The Linux kernel can then further restrict the vector length up to the
> supported maximum for the hardware. Potentially different process and
> threads can have different vector lengths, and they could change at any
> time. However, in practice, we expect the vector length to remain constant
> across the lifetime of a process.
> This set of patches assumes the vector length will not change and either
> warns once (when reading registers) or errors (when writing registers) if the
> vector length has changed. A future set of patches will offer full support.
>
> This series does not support gdbserver. However, where it makes sense I have
> commonised as much code as possible and have added the groundwork in
> gdbserver. Enabling gdbserver should be a small set of additional patches.
>
> Core files and watchpoints are not yet supported.
>
> The vector length is read from ptrace and is required to create the target
> description for the running process. There is no hardcoded SVE XML.
>
> The patches require recent linux header files for all the SVE ptrace macros.
> To allow builds for older headers, I've added all required macros and
> structures within ifdef checks. I'm not sure if this is the ideal solution.
> When including kernel header code, I've not performed any reformatting (ie
> they are not in GNU style).
>
> One of the later patches adds functions to gdbserver regcache so that I can
> add common functionality that works on gdb and gdbserver.
>
> Given there are no working SVE systems available today, this was manually
> tested on an Aarch64 SVE emulator running Ubuntu. In addition I've run make
> check on X86 and Aarch64 builds for both unix and native-gdbserver.
>
>
> Alan.
>
> Alan Hayward (8):
> Add Aarch64 SVE target description
> Function for reading the Aarch64 SVE vector length.
> Add SVE register defines
> Enable SVE for GDB
> Add aarch64 psuedo help functions
> Aarch64 SVE pseudo register support
> Add methods to gdbserver regcache and raw_compare
> Ptrace support for Aarch64 SVE
>
> gdb/Makefile.in | 1 +
> gdb/aarch64-linux-nat.c | 60 +++++-
> gdb/aarch64-linux-tdep.c | 5 +-
> gdb/aarch64-tdep.c | 402 +++++++++++++++++++++++-------------
> gdb/aarch64-tdep.h | 12 +-
> gdb/arch/aarch64.c | 12 +-
> gdb/arch/aarch64.h | 37 +++-
> gdb/configure.nat | 2 +-
> gdb/doc/gdb.texinfo | 4 +
> gdb/features/aarch64-sve.c | 158 ++++++++++++++
> gdb/gdbserver/Makefile.in | 1 +
> gdb/gdbserver/configure.srv | 1 +
> gdb/gdbserver/linux-aarch64-tdesc.c | 3 +-
> gdb/gdbserver/regcache.c | 55 ++++-
> gdb/gdbserver/regcache.h | 8 +
> gdb/nat/aarch64-sve-linux-ptrace.c | 315 ++++++++++++++++++++++++++++
> gdb/nat/aarch64-sve-linux-ptrace.h | 193 +++++++++++++++++
> gdb/regcache.c | 17 ++
> gdb/regcache.h | 2 +
> 19 files changed, 1122 insertions(+), 166 deletions(-)
> create mode 100644 gdb/features/aarch64-sve.c
> create mode 100644 gdb/nat/aarch64-sve-linux-ptrace.c
> create mode 100644 gdb/nat/aarch64-sve-linux-ptrace.h
>
> --
> 2.15.1 (Apple Git-101)
>