[PATCH] gdb-script: updated lx_current for riscv

[Conor Dooley]

On Fri, Nov 11, 2022 at 11:59:38AM -0800, debug at rivosinc.com wrote:
> From: Deepak Gupta <debug at rivosinc.com>
> 
> lx_current python gdb command defined in scripts/gdb/cpus.py updated
> to support riscv architecture.

The commit which added support for arm64 gave an explanation of why
SP_EL0 needed to be checked. Would be nice if you could do the same here
for RISC-V. See 526940e39626 ("scripts/gdb: add lx_current support for
arm64") for what I mean.

While you're at it, "scripts/gdb: add support for RISC-V" would appear
to be a more standard $subject for this file.

Thanks,
Conor.

> 
> Signed-off-by: Deepak Gupta <debug at rivosinc.com>
> ---
>  scripts/gdb/linux/cpus.py | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py
> index 15fc4626d236..ce6703f1e35a 100644
> --- a/scripts/gdb/linux/cpus.py
> +++ b/scripts/gdb/linux/cpus.py
> @@ -173,6 +173,14 @@ def get_current_task(cpu):
>           else:
>               raise gdb.GdbError("Sorry, obtaining the current task is not allowed "
>                                  "while running in userspace(EL0)")
> +    elif utils.is_target_arch("riscv"):
> +         current_task_addr = gdb.parse_and_eval("$tp")
> +         if((current_task_addr.cast(utils.get_long_type()) >> 63) != 0):
> +             current_task = current_task_addr.cast(task_ptr_type)
> +             return current_task.dereference()
> +         else:
> +             raise gdb.GdbError("Sorry, obtaining the current task is not allowed "
> +                                "while running in userspace")
>      else:
>          raise gdb.GdbError("Sorry, obtaining the current task is not yet "
>                             "supported with this arch")
> -- 
> 2.25.1
>