Re: [PATCH] Let gcore use ptrace interface rather than the procfs

On 19 Nov 2009, at 13:45, Attilio Rao wrote:

>> If you add the missing include of sys/wait.h, elfcore.c generates an error
>> instead of a warning on this non-traditional use of wait(2):
>> 
>> +       wait();
>> 
>> Something like this may be preferred:
>> 
>>       if (waitpid(pid, NULL, 0) < 0)
>>               err(1, "waitpid");
> 
> I didn't get a warning neither an error but yes, the waitpid() is
> preferred and should be used.

This warning was on i386 9.x, FYI, and was a property of failing to call wait(2) with an argument.

>> I think that kills the last of the procfs dependencies, in which case
>> perhaps we can remove the procfs.h include from elfcore.c, which requires
>> defining a local version of a summary data structure borrowed from procfs.
>> It's worth trying with procfs unmounted, however, to make sure they're
>> really all gone (which is how I ran into the above problem).
> 
> I don't like the idea to replicate the structures because of code
> maintence. IMHO is ok to have procfs header.


I'm not sure I agree; looking at the elfcore code, it looks like it goes to some amount of inconvenience to stuff things into the structure in the first place, primarily because that was how procfs exported it. With your excellent change, there's no need for gcore(1) to depend on procfs-specific data structures that may change, or more ideally, be removed in the future.

Robert