Re: [PATCH v2 4/6] [gdb/aarch64] sme2: Core file support for ZT register set

[Thiago Jung Bauermann <thiago.bauermann@linaro.org>]

Luis Machado <luis.machado@arm.com> writes:

> This patch adds support for ZT register dumps/reads for core files.  The
> ZT register is available when the SME2 feature is advertised as available
> by the Linux Kernel.
>
> Unlike the enablement for SME1 and the ZA register, support for SME2 is rather
> simple given the fixed size of the ZT0 register.
>
> Validated on the Fast Models.
> ---
>  gdb/aarch64-linux-tdep.c | 81 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 81 insertions(+)
>
> diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
> index 8b0b4d32971..a4d1fb87cbf 100644
> --- a/gdb/aarch64-linux-tdep.c
> +++ b/gdb/aarch64-linux-tdep.c
> @@ -1374,6 +1374,50 @@ aarch64_linux_collect_za_regset (const struct regset *regset,
>  			    size - SVE_HEADER_SIZE);
>  }
>  
> +/* Supply register REGNUM from BUF to REGCACHE, using the register map
> +   in REGSET.  If REGNUM is -1, do this for all registers in REGSET.
> +   If BUF is NULL, set the registers to "unavailable" status.  */
> +
> +static void
> +aarch64_linux_supply_zt_regset (const struct regset *regset,
> +				struct regcache *regcache,
> +				int regnum, const void *buf, size_t size)
> +{
> +  /* Read the ZT register note from a core file into the register buffer.  */
> +
> +  /* Handle an empty buffer.  */
> +  if (buf == nullptr)
> +    return regcache->supply_regset (regset, regnum, nullptr, size);
> +
> +  aarch64_gdbarch_tdep *tdep
> +    = gdbarch_tdep<aarch64_gdbarch_tdep> (regcache->arch ());

Is it worth adding here a "gdb_assert (size >= AARCH64_SME2_ZT0_SIZE)"?

> +
> +  /* Supply the ZT0 register contents.  */
> +  regcache->raw_supply (tdep->sme2_zt0_regnum, buf);
> +}
> +
> +/* Collect register REGNUM from REGCACHE to BUF, using the register
> +   map in REGSET.  If REGNUM is -1, do this for all registers in
> +   REGSET.  */
> +
> +static void
> +aarch64_linux_collect_zt_regset (const struct regset *regset,
> +				 const struct regcache *regcache,
> +				 int regnum, void *buf, size_t size)
> +{
> +  /* Read the ZT register contents from the register buffer into the core
> +     file section.  */
> +
> +  gdb_assert (buf != nullptr);

Also here, is it worth adding a
"gdb_assert (size >= AARCH64_SME2_ZT0_SIZE)"?

> +
> +  aarch64_gdbarch_tdep *tdep
> +    = gdbarch_tdep<aarch64_gdbarch_tdep> (regcache->arch ());
> +
> +  /* Dump the register cache contents for the ZT register to the buffer.  */
> +  regcache->collect_regset (regset, tdep->sme2_zt0_regnum, buf,
> +			    AARCH64_SME2_ZT0_SIZE);
> +}
> +

Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>

-- 
Thiago