From: "Ludovic Courtès" <ludo@gnu.org>
To: Omar Polo <op@omarpolo.com>
Cc: Josselin Poiret <dev@jpoiret.xyz>,
Andrew Whatson <whatson@tailcall.au>,
61095-done@debbugs.gnu.org
Subject: bug#61095: possible misuse of posix_spawn API on non-linux OSes
Date: Sun, 02 Apr 2023 15:44:01 +0200 [thread overview]
Message-ID: <87zg7qtn4u.fsf@gnu.org> (raw)
In-Reply-To: <2KFIQJHFVA0GP.2GKMWUIGIVCMU@venera> (Omar Polo's message of "Fri, 31 Mar 2023 19:45:55 +0200")
Hi!
Omar Polo <op@omarpolo.com> skribis:
> On 2023/03/30 22:21:28 +0200, Josselin Poiret <dev@jpoiret.xyz> wrote:
>> Hi Ludo,
>>
>> Ludovic Courtès <ludo@gnu.org> writes:
>>
>> > Coming next is an updated patch series addressing this as proposed
>> > above. Let me know what y’all think!
>> >
>> > I tested the ‘posix_spawn_file_actions_addclosefrom_np’ path by building in:
>> >
>> > guix time-machine --branch=core-updates -- shell -CP -D -f guix.scm
>>
>> I didn't test, but this LGTM! Maybe someone on OpenBSD could test this
>> patchset?
>
> % gmake check
> <snip />
> gmake[5]: Entering directory '/home/op/w/guile/test-suite/standalone'
> PASS: test-system-cmds
>
> it seems to work on OpenBSD 7.3 :)
Awesome! Pushed as 9cc85a4f52147fcdaa4c52a62bcc87bdb267d0a9.
> but note that our libc doesn't have posix_spawn_file_actions_addclosefrom_np,
> so this is using the "racy" code path.
Yeah, not great. :-/ I hope that function will be adopted by other
libcs, especially since ‘closefrom’ is already available.
> Just for curiosity, as it's outside the scope of the bug, what's the
> reason posix_spawn was used instead of a more classic fork() +
> closefrom()?
There’s a long discussion at:
https://issues.guix.gnu.org/52835
Essentially, ‘fork’ is unusable in multi-threaded context, in addition
to being inefficient.
Thanks,
Ludo’.
prev parent reply other threads:[~2023-04-02 13:44 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-27 11:51 bug#61095: possible misuse of posix_spawn API on non-linux OSes Omar Polo
2023-01-27 12:25 ` Omar Polo
2023-03-28 9:34 ` Ludovic Courtès
2023-03-28 16:10 ` Josselin Poiret via Bug reports for GUILE, GNU's Ubiquitous Extension Language
2023-03-29 22:30 ` Ludovic Courtès
2023-03-29 22:30 ` bug#61095: [PATCH 1/3] 'spawn' closes only open file descriptors on non-GNU/Linux systems Ludovic Courtès
2023-03-29 22:30 ` bug#61095: [PATCH 2/3] Remove racy optimized file descriptor closing loop in 'spawn' Ludovic Courtès
2023-03-29 22:30 ` bug#61095: [PATCH 3/3] Use 'posix_spawn_file_actions_addclosefrom_np' where available Ludovic Courtès
2023-03-30 20:21 ` bug#61095: possible misuse of posix_spawn API on non-linux OSes Josselin Poiret via Bug reports for GUILE, GNU's Ubiquitous Extension Language
2023-03-31 17:45 ` Omar Polo
2023-04-02 13:44 ` Ludovic Courtès [this message]
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