Fwd: why are init's arguments wiped ?

[Nicolas CARRIER]

I used prctl from time to time to change a child's name, but I didn't
think of using argv directly, to pass more information. In fact I
discovered it was possible, when I asked this very question.
Thank you all for all the really interesting information.

2016-02-02 0:14 GMT+01:00 Mike Frysinger <vapier at gentoo.org>:
> On 02 Feb 2016 00:09, Didier Kryn wrote:
>> Le 01/02/2016 23:34, Mike Frysinger a écrit :
>> > On 01 Feb 2016 22:33, Didier Kryn wrote:
>> >> Le 01/02/2016 18:10, Mike Frysinger a écrit :
>> >>> it makes a lot of sense when you fork children that have specific purposes.
>> >>> rather than just seeing the program's name 4 times, it's more helpful for
>> >>> them to be broken up.
>> >>       prctl() can be used for that, with the operation code PR_SET_NAME.
>> >> It does not change the command line.
>> > right, but that has its own limitations:
>> > - it's new to linux-2.6.9
>> > - can only set the name
>> > - is limited to 16 bytes
>> > - can't change command line args
>> >
>> > so we're still stuck with this behavior of modifying the argv mem directly :(
>>
>>      IIUC your argument was there's a need to give sensible names to
>> children. prctl() allows this *without* resorting to modifying the
>> command line args. I don't find 16 chars (in reality 15) is short for
>> the purpose.
>
> if you look at the examples i already posted, 16 is too small for every
> one there.  when i've munged the `ps` listing in the past, i've also
> easily run past 16 bytes.  your cases might be short, but that doesn't
> mean every scenario is that way.
> -mike
>
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