From: Natanael Copa <ncopa@alpinelinux.org>
To: musl@lists.openwall.com
Subject: bug with sysconf(_SC_CHILD_MAX) with user process ulimit set to unlimited
Date: Thu, 7 Dec 2017 16:26:09 +0100 [thread overview]
Message-ID: <20171207162609.45e02f83@ncopa-desktop.copa.dup.pw> (raw)
Hi,
While trying to debug why `bash -c 'sleep 1 & wait $!'` hangs with
alpine in docker[1] I made an interesting discovery.
Set user process ulimit to "unlimited" and run the following program on
an x86_64 machine:
#include <stdio.h>
#include <unistd.h>
int main() {
long maxchild = sysconf(_SC_CHILD_MAX);
printf("maxchild: %ld\n", maxchild);
return 0;
}
With musl libc it prints:
maxchild: 9223372036854775807
With glibc it prints:
maxchild: -1
Setting the process ulimit to something like 64k makes bash work again.
Shouldn't sysconf(_SC_CHILD_MAX) return -1 if ulimit is set to
"unlimited"?
Thanks!
-nc
[1]: https://github.com/tianon/docker-bash/issues/4
next reply other threads:[~2017-12-07 15:26 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-07 15:26 Natanael Copa [this message]
2017-12-07 17:05 ` Rich Felker
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