gdb: xtensa: handle privileged registers

  gdb/
2018-04-25  Max Filippov  <jcmvbkbc@gmail.com>

	* xtensa-linux-tdep.c (xtensa-tdep.h): New include.
	(xtensa_linux_init_abi): Limit tdep->num_regs by
	tdep->num_nopriv_regs.
	* xtensa-tdep.c (xtensa_derive_tdep): Calculate
	tdep->num_nopriv_regs and only copy it to tdep->num_regs if it's
	not initialized.
---
 gdb/xtensa-linux-tdep.c |  6 ++++++
 gdb/xtensa-tdep.c       | 12 ++++--------
 2 files changed, 10 insertions(+), 8 deletions(-)
  

On Wed, Apr 25, 2018 at 7:41 PM, Max Filippov <jcmvbkbc@gmail.com> wrote:
> gdb/
> 2018-04-25  Max Filippov  <jcmvbkbc@gmail.com>
>
>         * xtensa-linux-tdep.c (xtensa-tdep.h): New include.
>         (xtensa_linux_init_abi): Limit tdep->num_regs by
>         tdep->num_nopriv_regs.
>         * xtensa-tdep.c (xtensa_derive_tdep): Calculate
>         tdep->num_nopriv_regs and only copy it to tdep->num_regs if it's
>         not initialized.
> ---
>  gdb/xtensa-linux-tdep.c |  6 ++++++
>  gdb/xtensa-tdep.c       | 12 ++++--------
>  2 files changed, 10 insertions(+), 8 deletions(-)

Ping?
The fix was verified by the reporting party
( https://github.com/zephyrproject-rtos/zephyr/issues/4309#issuecomment-387017968
)
If there are no objections I'd like to commit it.

> diff --git a/gdb/xtensa-linux-tdep.c b/gdb/xtensa-linux-tdep.c
> index a9b30c73f7bf..b62085de2fcb 100644
> --- a/gdb/xtensa-linux-tdep.c
> +++ b/gdb/xtensa-linux-tdep.c
> @@ -18,6 +18,7 @@
>     along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
>
>  #include "defs.h"
> +#include "xtensa-tdep.h"
>  #include "osabi.h"
>  #include "linux-tdep.h"
>  #include "solib-svr4.h"
> @@ -97,6 +98,11 @@ xtensa_linux_gdb_signal_to_target (struct gdbarch *gdbarch,
>  static void
>  xtensa_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
>  {
> +  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
> +
> +  if (tdep->num_nopriv_regs < tdep->num_regs)
> +    tdep->num_regs = tdep->num_nopriv_regs;
> +
>    linux_init_abi (info, gdbarch);
>
>    set_solib_svr4_fetch_link_map_offsets
> diff --git a/gdb/xtensa-tdep.c b/gdb/xtensa-tdep.c
> index a1ecf5f56a42..01f96165dc8d 100644
> --- a/gdb/xtensa-tdep.c
> +++ b/gdb/xtensa-tdep.c
> @@ -3145,16 +3145,12 @@ xtensa_derive_tdep (struct gdbarch_tdep *tdep)
>         max_size = rmap->byte_size;
>        if (rmap->mask != 0 && tdep->num_regs == 0)
>         tdep->num_regs = n;
> -      /* Find out out how to deal with priveleged registers.
> -
> -         if ((rmap->flags & XTENSA_REGISTER_FLAGS_PRIVILEGED) != 0
> -              && tdep->num_nopriv_regs == 0)
> -           tdep->num_nopriv_regs = n;
> -      */
>        if ((rmap->flags & XTENSA_REGISTER_FLAGS_PRIVILEGED) != 0
> -         && tdep->num_regs == 0)
> -       tdep->num_regs = n;
> +         && tdep->num_nopriv_regs == 0)
> +       tdep->num_nopriv_regs = n;
>      }
> +  if (tdep->num_regs == 0)
> +    tdep->num_regs = tdep->num_nopriv_regs;
>
>    /* Number of pseudo registers.  */
>    tdep->num_pseudo_regs = n - tdep->num_regs;
> --
> 2.11.0
>
  

Hi Max,

On 05/07/2018 05:23 PM, Max Filippov wrote:

> Ping?
> The fix was verified by the reporting party
> ( https://github.com/zephyrproject-rtos/zephyr/issues/4309#issuecomment-387017968
> )
> If there are no objections I'd like to commit it.

It would help if the the patch included some rationale/explanation.
Like:

 - what is wrong or broken currently,
 - what does the patch fix,
 - and how.

Could you please resend the patch with that info included in
the proposed git commit log?

Thanks,
Pedro Alves