Re: [PATCH v2 2/2] Propagate NT_RISCV_VECTOR from Linux kernel headers to binutils. The value is identical to pre-existing NT_RISCV_CSR but the note names different (NT_RISCV_CSR is "GDB" and NT_RISCV_VECTOR is "CORE")

John Baldwin
2023-08-12T00:47:50Z

On 8/11/23 9:43 AM, Palmer Dabbelt wrote:
> On Fri, 11 Aug 2023 05:51:45 PDT (-0700), Andrew Burgess wrote:
>> Greg Savin via Gdb-patches <gdb-patches@sourceware.org> writes:
>>
>>> ---
>>> include/elf/common.h | 2 ++
>>> 1 file changed, 2 insertions(+)
>>>
>>> diff --git a/include/elf/common.h b/include/elf/common.h
>>> index e7eede23a07..d28f5c6ccf5 100644
>>> --- a/include/elf/common.h
>>> +++ b/include/elf/common.h
>>> @@ -715,6 +715,8 @@
>>> /* note name must be "CORE". */
>>> #define NT_RISCV_CSR 0x900 /* RISC-V Control and Status Registers */
>>> /* note name must be "GDB". */
>>> +#define NT_RISCV_VECTOR 0x900 /* RISC-V Vector Registers */
>>> + /* note name must be "CORE". */
>>
>> I'm not a binutils maintainer, but do have an interest from the
>> RISC-V/GDB side.
>>
>> Given the comments you made in an earlier mail, I guess we're going to
>> have to restructure some of the core file support in order to handle
>> NT_RISCV_CSR and NT_RISCV_VECTOR having the same values. But that
>> should be doable.
>>
>> No objections to this patch from me.
>
> NT_RISCV_VECTOR isn't in a releasted kernel, so it's not a stable uABI
> yet. So there's still time to change it. 0I've got a revert on the
> kernel lists, it'd mean we miss 6.5 but we'd just end up in 6.6 which
> isn't so bad.

While it is possible to handle colliding NT_RISCV_* values, it will probably
be simpler all-around if you are able to make NT_RISCV_VECTOR be 0x901 since
you are going to revert and redo.

--
John Baldwin