[PATCH] S390: Sync ptrace.h with kernel. [BZ #21539]

[Stefan Liebler]

On 07/07/2017 12:45 PM, Florian Weimer wrote:
> On 07/07/2017 12:22 PM, Stefan Liebler wrote:
>> +      /* Ptrace request 12 is done with zero data argument:
>> +	 -If the kernel has support for PTRACE_SINGLEBLOCK (then the kernel
>> +	 header asm/ptrace.h defines this macro), the ptrace call is not allowed
>> +	 to fail and has to continue the tracee until next taken branch.
>> +
>> +	 -If the kernel (<3.15) has no support for PTRACE_SINGLEBLOCK, the
>> +	 ptrace call has to fail with EIO. Then I continue the tracee with
>> +	 PTRACE_CONT.
>> +
>> +	 -If the request 12 is interpreted as PTRACE_GETREGS, it will fail too.
>> +	 It fails with EFAULT on intel / power as data argument is NULL.
>> +	 According to the man-page: "Unfortunately, under Linux, different
>> +	 variations of this fault will return EIO or EFAULT more or less
>> +	 arbitrarily".
>> +	 But if request 12 is interpreted as PTRACE_GETREGS, the first ptrace
>> +	 call will touch the buffer which is detected by this test.  */
> 
> I think the comment is still a bit off.  I think it is only necessary to
> retain the second two lines, the other things is already implied by the
> short comments in the code below.
okay. I removed the other lines.
> 
> (I have not tested whether this actually works.  I assume you have
> checked a couple of userspace/kernel permutations.)
Yes. I've run the test on several machines.
> 
> Thanks,
> Florian
> 


If this is okay, I'll commit it on Monday.

Bye.
Stefan
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