[2/2] gdbserver: xtensa: support THREADPTR register

Message ID 1484783816-13856-3-git-send-email-jcmvbkbc@gmail.com
State New, archived
Headers

Commit Message

Max Filippov Jan. 18, 2017, 11:56 p.m. UTC
  Provide aceess to the THREADPTR register to remote gdb.

2017-01-18  Max Filippov  <jcmvbkbc@gmail.com>
gdb/gdbserver/
	* linux-xtensa-low.c (regnum::R_THREADPTR): New enum member.
	(xtensa_fill_gregset): Call collect_register_by_name for
	threadptr register.
	(xtensa_store_gregset): Call supply_register_by_name for
	threadptr register.
---
 gdb/gdbserver/linux-xtensa-low.c | 9 +++++++++
 1 file changed, 9 insertions(+)
  

Comments

Luis Machado Feb. 13, 2017, 6:26 p.m. UTC | #1
On 01/18/2017 05:56 PM, Max Filippov wrote:
> Provide aceess to the THREADPTR register to remote gdb.
>
> 2017-01-18  Max Filippov  <jcmvbkbc@gmail.com>
> gdb/gdbserver/


Similarly, drop the gdb/gdbserver/

> 	* linux-xtensa-low.c (regnum::R_THREADPTR): New enum member.
> 	(xtensa_fill_gregset): Call collect_register_by_name for
> 	threadptr register.
> 	(xtensa_store_gregset): Call supply_register_by_name for
> 	threadptr register.
> ---
>  gdb/gdbserver/linux-xtensa-low.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/gdb/gdbserver/linux-xtensa-low.c b/gdb/gdbserver/linux-xtensa-low.c
> index 73fbfe2..eca0289 100644
> --- a/gdb/gdbserver/linux-xtensa-low.c
> +++ b/gdb/gdbserver/linux-xtensa-low.c
> @@ -36,6 +36,7 @@ enum regnum {
>  	R_LBEG,	R_LEND,	R_LCOUNT,
>  	R_SAR,
>  	R_WS, R_WB,
> +	R_THREADPTR,
>  	R_A0 = 64
>  };

Does xtensa have xml register description support? It would be nice to 
have those described instead of hardcoding the entries like this.

>
> @@ -86,6 +87,10 @@ xtensa_fill_gregset (struct regcache *regcache, void *buf)
>        collect_register (regcache, i, ptr);
>        ptr += register_size (tdesc, i);
>      }
> +
> +#if XCHAL_HAVE_THREADPTR
> +  collect_register_by_name (regcache, "threadptr", (char*)&rset[R_THREADPTR]);

Missing spaces in the cast. "(char *) &rset[R_THREADPTR]"

How is XCHAL_HAVE_THREADPTR set? Is it a reliable way of confirming the 
presence of this register? Can a runtime check be used instead?

> +#endif
>  }
>
>  static void
> @@ -133,6 +138,10 @@ xtensa_store_gregset (struct regcache *regcache, const void *buf)
>    supply_register_by_name (regcache, "ps", (char*)&rset[R_PS]);
>    supply_register_by_name (regcache, "windowbase", (char*)&rset[R_WB]);
>    supply_register_by_name (regcache, "windowstart", (char*)&rset[R_WS]);
> +
> +#if XCHAL_HAVE_THREADPTR
> +  supply_register_by_name (regcache, "threadptr", (char*)&rset[R_THREADPTR]);

Same as above regarding spaces and the cast construct and the 
XCHAL_HAVE_THREADPTR check.
  
Max Filippov Feb. 14, 2017, 9:37 a.m. UTC | #2
On Mon, Feb 13, 2017 at 10:26 AM, Luis Machado
<lgustavo@codesourcery.com> wrote:
> On 01/18/2017 05:56 PM, Max Filippov wrote:
>>
>> Provide aceess to the THREADPTR register to remote gdb.
>>
>> 2017-01-18  Max Filippov  <jcmvbkbc@gmail.com>
>> gdb/gdbserver/
>
>
>
> Similarly, drop the gdb/gdbserver/
>
>>         * linux-xtensa-low.c (regnum::R_THREADPTR): New enum member.
>>         (xtensa_fill_gregset): Call collect_register_by_name for
>>         threadptr register.
>>         (xtensa_store_gregset): Call supply_register_by_name for
>>         threadptr register.
>> ---
>>  gdb/gdbserver/linux-xtensa-low.c | 9 +++++++++
>>  1 file changed, 9 insertions(+)
>>
>> diff --git a/gdb/gdbserver/linux-xtensa-low.c
>> b/gdb/gdbserver/linux-xtensa-low.c
>> index 73fbfe2..eca0289 100644
>> --- a/gdb/gdbserver/linux-xtensa-low.c
>> +++ b/gdb/gdbserver/linux-xtensa-low.c
>> @@ -36,6 +36,7 @@ enum regnum {
>>         R_LBEG, R_LEND, R_LCOUNT,
>>         R_SAR,
>>         R_WS, R_WB,
>> +       R_THREADPTR,
>>         R_A0 = 64
>>  };
>
>
> Does xtensa have xml register description support?

AFAIK no.

> It would be nice to have
> those described instead of hardcoding the entries like this.
>>
>> @@ -86,6 +87,10 @@ xtensa_fill_gregset (struct regcache *regcache, void
>> *buf)
>>        collect_register (regcache, i, ptr);
>>        ptr += register_size (tdesc, i);
>>      }
>> +
>> +#if XCHAL_HAVE_THREADPTR
>> +  collect_register_by_name (regcache, "threadptr",
>> (char*)&rset[R_THREADPTR]);
>
>
> Missing spaces in the cast. "(char *) &rset[R_THREADPTR]"

Will add.

> How is XCHAL_HAVE_THREADPTR set?

It is defined in the core configuration overlay, include/xtensa-config.h
This file is generated for each Xtensa core and is copied over to the
source tree before building gdb for that specific core.

> Is it a reliable way of confirming the presence of this register?

This is the primary source of configuration-specific information.

> Can a runtime check be used instead?

AFAIK this information is not provided anywhere else.

>> +#endif
>>  }
>>
>>  static void
>> @@ -133,6 +138,10 @@ xtensa_store_gregset (struct regcache *regcache,
>> const void *buf)
>>    supply_register_by_name (regcache, "ps", (char*)&rset[R_PS]);
>>    supply_register_by_name (regcache, "windowbase", (char*)&rset[R_WB]);
>>    supply_register_by_name (regcache, "windowstart", (char*)&rset[R_WS]);
>> +
>> +#if XCHAL_HAVE_THREADPTR
>> +  supply_register_by_name (regcache, "threadptr",
>> (char*)&rset[R_THREADPTR]);
>
>
> Same as above regarding spaces and the cast construct and the
> XCHAL_HAVE_THREADPTR check.

Will fix.
  

Patch

diff --git a/gdb/gdbserver/linux-xtensa-low.c b/gdb/gdbserver/linux-xtensa-low.c
index 73fbfe2..eca0289 100644
--- a/gdb/gdbserver/linux-xtensa-low.c
+++ b/gdb/gdbserver/linux-xtensa-low.c
@@ -36,6 +36,7 @@  enum regnum {
 	R_LBEG,	R_LEND,	R_LCOUNT,
 	R_SAR,
 	R_WS, R_WB,
+	R_THREADPTR,
 	R_A0 = 64
 };
 
@@ -86,6 +87,10 @@  xtensa_fill_gregset (struct regcache *regcache, void *buf)
       collect_register (regcache, i, ptr);
       ptr += register_size (tdesc, i);
     }
+
+#if XCHAL_HAVE_THREADPTR
+  collect_register_by_name (regcache, "threadptr", (char*)&rset[R_THREADPTR]);
+#endif
 }
 
 static void
@@ -133,6 +138,10 @@  xtensa_store_gregset (struct regcache *regcache, const void *buf)
   supply_register_by_name (regcache, "ps", (char*)&rset[R_PS]);
   supply_register_by_name (regcache, "windowbase", (char*)&rset[R_WB]);
   supply_register_by_name (regcache, "windowstart", (char*)&rset[R_WS]);
+
+#if XCHAL_HAVE_THREADPTR
+  supply_register_by_name (regcache, "threadptr", (char*)&rset[R_THREADPTR]);
+#endif
 }
 
 /* Xtensa GNU/Linux PTRACE interface includes extended register set.  */