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From: Szabolcs Nagy <szabolcs.nagy@arm.com>
To: Rain <glibc@sunshowers.io>
Cc: "Florian Weimer" <fweimer@redhat.com>,
	"Adhemerval Zanella Netto" <adhemerval.zanella@linaro.org>,
	Adhemerval Zanella Netto via Libc-help <libc-help@sourceware.org>,
	Christian Brauner <brauner@kernel.org>
Subject: Re: posix_spawn: parent can get stuck in uninterruptible sleep if child receives SIGTSTP early enough
Date: Fri, 21 Oct 2022 15:18:30 +0100	[thread overview]
Message-ID: <Y1KqNmduF1tTlxMp@arm.com> (raw)
In-Reply-To: <1ccd76de-6d37-4e77-9142-c5c330bde8ca@app.fastmail.com>

The 10/20/2022 18:40, Rain wrote:
> On Thu, Oct 20, 2022, at 04:55, Florian Weimer wrote:
> > * Adhemerval Zanella Netto:
> >
> >>> I don't think switching back to fork by default is really an option.
> >>> The impact on latency is much worse than with vfork.
> >>
> >> I agree and I have been chatting with Christian if we can improve this
> >> with some kernel support.  My idea would to add a new clone3 argument
> >> to define a signal mask and another options (either through clone3
> >> itself or with a new execve variant) to setup the desired signal mask
> >> after execve call.
> >>
> >> The first features is more an optimization to avoid the sigprocmask
> >> (although I think we will need it anyway to proper reap the child if
> >> the spawni fails), while the second feature should fix the issue
> >> raised in this thread.
> >
> > But I think it would only work for SIGTSTP, not for SIGSTOP, right?
> > But maybe SIGSTOP is sufficiently unusual that fixing SIGTSP on its own
> > is already a welcome improvement.
> 
> From my perspective, fixing SIGTSTP is enough.
> 
> However, I do care about older versions of the Linux kernel and glibc,
> as well as other operating systems, so I'll probably have to maintain
> the double-process-spawn workaround indefinitely, sadly.

either way i think you should open a ticket on bugzilla about this
(so you and others can follow related discussions)

  reply	other threads:[~2022-10-21 14:19 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-14  3:30 Rain
2022-08-14  3:38 ` Rain
2022-08-22 16:51 ` Adhemerval Zanella Netto
2022-08-22 17:00   ` Rain
2022-08-22 17:48     ` Adhemerval Zanella Netto
2022-08-22 18:21       ` Florian Weimer
2022-08-22 18:32         ` Adhemerval Zanella Netto
2022-08-22 22:28           ` Adhemerval Zanella Netto
2022-09-13 10:04           ` Florian Weimer
2022-09-21 15:24             ` Adhemerval Zanella Netto
2022-09-22 12:18               ` Florian Weimer
2022-09-22 16:56                 ` Adhemerval Zanella Netto
2022-09-22 17:38                   ` Florian Weimer
2022-09-22 19:14                     ` Adhemerval Zanella Netto
2022-10-10 13:45                       ` Florian Weimer
2022-10-18 20:04                         ` Adhemerval Zanella Netto
2022-10-20 11:55                           ` Florian Weimer
2022-10-21  1:40                             ` Rain
2022-10-21 14:18                               ` Szabolcs Nagy [this message]
2022-08-22 22:30       ` Adhemerval Zanella Netto

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