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Date: Fri, 9 Apr 2021 19:32:04 +0200
From: tomas@tuxteam.de
To: Peng Yu <pengyu.ut@gmail.com>
Cc: libc-help <libc-help@sourceware.org>
Subject: Re: When is it OK to pass NULLs to the 2nd and 3rd args of execve()?
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On Fri, Apr 09, 2021 at 12:20:50PM -0500, Peng Yu wrote:

[man page]

> The above paragraph also reads awkwardly. Why it first mentions `On
> many other ... argv as NULL ... Some other UNIX ... envp==NULL`? It
> seems to be contrasting two cases. But then it should be either argv
> or envp but not mentioning both. So it is confusing.

I don't know. I read it as "anything can happen, so don't do it",
for any of argv and envp or both.

> What systems have glibc been ported to? On all these systems, are
> there specifics on what systems argv=NULL causes EFAULT?

I don't know :-)

> Does the above paragraph mean envp=NULL can also cause EFAULT? I don't
> get what error could envp=NULL cause?

Perhaps. It seems to be the kernel's realm and libc just passes things
around, so you'd have to look into the respective kernel documentation.

Cheers
 - t

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