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Date: Sat, 11 Nov 2023 23:52:17 -0500
From: "Theodore Ts'o" <tytso@mit.edu>
To: Willy Tarreau <w@1wt.eu>
Cc: York Jasper Niebuhr <yjnworkstation@gmail.com>, akpm@linux-foundation.org,
        linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
        linux-security-module@vger.kernel.org, torvalds@linux-foundation.org
Subject: Re: [PATCH] exitz syscall
Message-ID: <20231112045217.GA39417@mit.edu>
References: <20231111125126.11665-1-yjnworkstation@gmail.com>
 <20231111132431.GA3717@1wt.eu>
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In-Reply-To: <20231111132431.GA3717@1wt.eu>

On Sat, Nov 11, 2023 at 02:24:31PM +0100, Willy Tarreau wrote:
> Hello,
> 
> On Sat, Nov 11, 2023 at 01:51:26PM +0100, York Jasper Niebuhr wrote:
> > Adds a system call to flag a process' resources to be cleared on
> > exit (or, in the case of memory, on free). Currently, only zeroing
> > memory is implemented.
> (...)
> 
> IMHO it does not make sense to add a syscall for this, please have a
> look at prctl(2) instead, which is already used for similar settings.

Another reason to use prctl() is there are other cases when you'd want
to zero a process's memory.  For example, if the process gets killed
to some kind of signal, or when it gets OOM killed (where there is no
system call which forces the process to exit).  Also, if you want to
zero memory when the process exits, you'd want to zero the process
memory on an exec(2).

Cheers,

						- Ted