Re: [PATCH v3] Add support for "info auxv" on NetBSD

[Kamil Rytarowski <n54@gmx.com>]

On 27.03.2020 20:22, John Baldwin wrote:
> On 3/27/20 10:04 AM, Kamil Rytarowski wrote:
>> On 27.03.2020 17:31, John Baldwin wrote:
>>> On 3/26/20 4:26 PM, Kamil Rytarowski wrote:
>>>> Ping?
>>>>
>>>> On 20.03.2020 18:27, Kamil Rytarowski wrote:
>>>>> Register nbsd_auxv_parse() that overloads the default (Linux-style)
>>>>> AUXV parsing. On NetBSD the type parameter is defined as int32_t
>>>>> for all architectures.
>>>
>>> I would tone down some of the rhetoric.  FreeBSD uses the default AUXV
>>> parsing, and I think Solaris does as well, so describing it as Linux-only
>>> isn't very accurate.
>>>
>>
>> It is phrases as Linux-style, not Linux-only.
>
> I would still perhaps drop the paranthetical part as it reads that way
> I think even with -style vs -only.
>
>>> (Similarly, I think the earlier reviews I saw around ptrace() claimed that
>>> NetBSD was the only OS to use LWPs with ptrace() in the log messages in
>>> effect which isn't really true as both Solaris and FreeBSD use LWPs
>>> happily with ptrace(), just using a different convention.)
>>>
>>
>> The pair of (PID+LWP) for getters and setters of registers (among
>> certain other ptrace operations) is NetBSD style ptrace(2) API design.
>> This leads to the point that NetBSD is currently the only OS where
>> get_ptrace_pid() is not compatible (at leat in the current form).
>
> It might be a bit of how it was said, the actual text:
>
> <quote>
>     Unlike most other Operating Systems, NetBSD tracks both pid and lwp.
>     The process id on NetBSD is stored always in the pid field of ptid.
> </quote>
>
> If by "track" you mean "the kernel keeps track of LWPs as distinct
> from processes" (which is how I read "track"), then I think it is
> inaccurate.
>
>
>>> I would also tone this down a bit, and at least reference the correct
>>> specification.  The ELF spec doesn't define the layout of auxv_t.  The
>>> per-architecture psABI documents do.  Also, just saying that you follow
>>> the spec doesn't help.  I would suggest something like:
>>>
>>> /* NetBSD-specific parser for AUXV entries.  NetBSD always uses an int
>>>    to store the type as defined in the SVR4 psABI specifications rather
>>>    than long as assumed by the default parser.  */
>>>
>>
>> This is toned down compared to obsd-tdet.c, that says:
>>
>> /* Unlike Linux, OpenBSD actually follows the ELF standard.  */
>
> That may be, but that probably isn't who I would choose as a model to
> follow.
>
>> OK, is this patch fine after rephrasing the above texts?
>
> It looks fine to me, but it probably needs an approver such as Tom to ok it.
> (I can approve FreeBSD-related things, but not really other bits.)
>

OK. I will rephrase the texts as I understand that the wording is sensitive.