Re: [PATCH] x86: make PTRACE_GETREGSET return 32-bit regs if 64-bit process entered kernel with int 80

H. Peter Anvin
2013-02-14T19:21:26Z

On 02/14/2013 11:18 AM, Oleg Nesterov wrote:
> On 02/14, H. Peter Anvin wrote:
>>
>> On 02/14/2013 07:00 AM, Oleg Nesterov wrote:
>>> On 02/14, Denys Vlasenko wrote:
>>>>
>>>> Determining personality of a ptraced process is a murky area.
>>>> On x86, for years strace was looking at segment selectors,
>>>> which is conceptually wrong: see, for example,
>>>> https://lkml.org/lkml/2012/1/18/320
>>>>
>>
>> One proposal that keeps being on the table is to export a regset with
>> metadatam, including process mode at launch (i386, x86-64, x32).
>
> Yes... but if this metadata includes TS_COMPAT-is-set, then strace should
> do PTRACE_GETREGSET(REGSET_META) + PTRACE_GETREGSET(REGSET_GENERAL) every
> time. Or REGSET_META should include META+GENERAL.
>
> IOW, it is not clear to me what this "meta" should actually report.
>

That is one of the things that needs to be nailed down. In particular,
what are the things people need.

-hpa