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Subject: Re: [PATCH] binfmt_misc: pass binfmt_misc P flag to the interpreter
To:     Florian Weimer <fw@deneb.enyo.de>
Cc:     YunQiang Su <syq@debian.org>, torvalds@linux-foundation.org,
        gregkh@linuxfoundation.org, akpm@linux-foundation.org,
        viro@zeniv.linux.org.uk, James.Bottomley@hansenpartnership.com,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-arch@vger.kernel.org, linux-api@vger.kernel.org,
        libc-alpha@sourceware.org
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From:   Laurent Vivier <laurent@vivier.eu>
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Message-ID: <40da389d-4e74-2644-2e7c-04d988fcc26f@vivier.eu>
Date:   Fri, 6 Mar 2020 12:13:41 +0100
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Le 06/03/2020 à 09:37, Florian Weimer a écrit :
> * Laurent Vivier:
> 
>> Le 06/03/2020 à 09:13, Florian Weimer a écrit :
>>> * YunQiang Su:
>>>
>>>> +	if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
>>>> +		flags |= AT_FLAGS_PRESERVE_ARGV0;
>>>> +	NEW_AUX_ENT(AT_FLAGS, flags);
>>>
>>> Is it necessary to reuse AT_FLAGS?  I think it's cleaner to define a
>>> separate AT_ tag dedicated to binfmt_misc.
>>
>> Not necessary, but it seemed simpler and cleaner to re-use a flag that
>> is marked as unused and with a name matching the new role. It avoids to
>> patch other packages (like glibc) to add it as it is already defined.
> 
> You still need to define AT_FLAGS_PRESERVE_ARGV0.  At that point, you
> might as well define AT_BINFMT and AT_BINFMT_PRESERVE_ARGV0.
> 

Yes, you're right.

But is there any reason to not reuse AT_FLAGS?

Thanks,
Laurent