From mboxrd@z Thu Jan  1 00:00:00 1970
From: Florian Weimer <fweimer@redhat.com>
Subject: Re: [PATCH v2 0/5] pid: add pidfd_open()
Date: Tue, 02 Apr 2019 13:03:24 +0200
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        (Daniel Colascione's message of "Mon, 1 Apr 2019 09:45:22 -0700")
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To: Daniel Colascione <dancol@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>, Jonathan Kowalski <bl0pbl33p@gmail.com>, Aleksa Sarai <cyphar@cyphar.com>, Andy Lutomirski <luto@amacapital.net>, Christian Brauner <christian@brauner.io>, Jann Horn <jannh@google.com>, Andrew Lutomirski <luto@kernel.org>, David Howells <dhowells@redhat.com>, "Serge E. Hallyn" <serge@hallyn.com>, Linux API <linux-api@vger.kernel.org>, Linux List Kernel Mailing <linux-kernel@vger.kernel.org>, Arnd Bergmann <arnd@arndb.de>, "Eric W. Biederman" <ebiederm@xmission.com>, Konstantin Khlebnikov <khlebnikov@yandex-team.ru>, Kees Cook <keescook@chromium.org>, Alexey Dobriyan <adobriyan@gmail.com>, Thomas Gleixner <tglx@linutronix.de>, Michael Kerrisk-manpages <mtk.manpages@gmail.com>
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* Daniel Colascione:

> But doesn't the CSIGNAL approach still require that libraries somehow
> coordinate which non-SIGCHLD signal they use? (Signal coordination a
> separate problem, unfortunately.)

There's already an allocation mechanism for realtime signals in glibc,
via __libc_allocate_rtsig.  I don't know what it is about: It's clearly
intended as an external interface, yet there isn't a declaration in any
installed header file.  ALSA has some optional code to use it, but I
don't think distributions compile ALSA in that way; it always uses SIGIO.

Thanks,
Florian