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From: Florian Weimer <fweimer@redhat.com>
To: Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org>
Cc: Jonathon Anderson <janderson@rice.edu>,
	 Adhemerval Zanella <adhemerval.zanella@linaro.org>,
	 John Mellor-Crummey <johnmc@rice.edu>
Subject: Re: [PATCH v6 4/5] io: Add closefrom [BZ #10353]
Date: Tue, 06 Jul 2021 13:37:08 +0200	[thread overview]
Message-ID: <874kd7hdwb.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <f58c689d-2b33-3e1a-5357-24d0c08105e3@linaro.org> (Adhemerval Zanella via Libc-alpha's message of "Mon, 5 Jul 2021 17:26:37 -0300")

* Adhemerval Zanella via Libc-alpha:

> Valgrind can overwrite it because it make is invisible to user program and 
> libc, and for your tool I think the best course of action would be to 
> interpose closefrom() and clone_range() and exclude the file descriptors 
> you want to keep it opened.

I agree.

Just to be clear: glibc will not clean up descriptors behind the
application's back.  The application has to request that, so interposing
the call should be sufficient for your purposes.

(We even have a policy of not opening long-term file descriptors for
internal use because we know that extra file descriptors confuse many
applications.)

Thanks,
Florian


  reply	other threads:[~2021-07-06 11:37 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-23 18:51 [PATCH v6 0/5] Add close_range, closefrom, and posix_spawn_file_actions_closefrom_np Adhemerval Zanella
2021-06-23 18:51 ` [PATCH v6 1/5] support: Add support_stack_alloc Adhemerval Zanella
2021-06-24  9:15   ` Florian Weimer
2021-06-24 11:33     ` Adhemerval Zanella
2021-06-23 18:51 ` [PATCH v6 2/5] support: Add xclone Adhemerval Zanella
2021-06-24  9:15   ` Florian Weimer
2021-06-23 18:51 ` [PATCH v6 3/5] linux: Add close_range Adhemerval Zanella
2021-06-27 17:23   ` Florian Weimer
2021-06-23 18:51 ` [PATCH v6 4/5] io: Add closefrom [BZ #10353] Adhemerval Zanella
2021-07-03 14:45   ` Jonathon Anderson
2021-07-05 20:26     ` Adhemerval Zanella
2021-07-06 11:37       ` Florian Weimer [this message]
2021-06-23 18:51 ` [PATCH v6 5/5] posix: Add posix_spawn_file_actions_closefrom_np Adhemerval Zanella

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