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From: Joshua Hudson <joshudson@gmail.com>
To: musl <musl@lists.openwall.com>
Subject: Re: Hangup calling setuid() from vfork() child
Date: Mon, 30 Sep 2019 13:45:07 -0700	[thread overview]
Message-ID: <CA+jjjYTQ1cnHeHr2PFMPSvUiAKy3wAQ98fA5JvXsJoPnS_v60w@mail.gmail.com> (raw)

> Basically, the vfork() child is in an invalid state and this cannot be repaired without damaging the parent.

Works on glibc just fine.

setuid() is on the list of signal-safe functions.

http://man7.org/linux/man-pages/man7/signal-safety.7.html

How about you call getpid() and check if you're on the process you
think you're on before calling __synccall? Somebody else might have
done syscall(SYS_fork).

> So you might want to enable memory overcommit.

I'm tired of paying the page fault penalty in the parent. It has a
majority of system RAM, and most of the pages are CoW long after the
vfork child hits execve.


             reply	other threads:[~2019-09-30 20:45 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-30 20:45 Joshua Hudson [this message]
2019-09-30 22:47 ` Rich Felker
2019-10-01  5:54 ` Florian Weimer
2019-10-01  9:29   ` Szabolcs Nagy
2019-10-01 11:44     ` Rich Felker
  -- strict thread matches above, loose matches on Subject: below --
2019-09-30 19:57 Joshua Hudson
2019-09-30 15:29 Joshua Hudson
2019-09-30 17:39 ` Markus Wichmann
2019-09-30 17:43   ` Rich Felker
2019-09-30 17:41 ` Rich Felker

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