Bug#533360: libc6: signalfd creation with SFD_* flags breaks under 2.9-15

[Nick Black <dank@qemfd.net>]

Package: libc6
Version: 2.9-13
Severity: important


Howdy!

This morning, I upgraded libc6 et al from 2.9-13 to 2.9-15. Immediately,
one of my unit tests began failing with a -1 return from signalfd():

14|***** Error (Invalid argument) in Signalfd(): Couldn't generate signalfd from -1/526336

with libc2.9-13, signalfd() returns a new file descriptor as expected.

I'm passing SFD_CLOEXEC|SFD_NONBLOCK (0x2004000), but the same behavior
is seen with either SFD_CLOEXEC or SFD_NONBLOCK (these are the only two
signalfd() flags described in the man page, last updated 2009-01-13).
With no flags passed, 2.9-15 works and creates the new signalfd.

-- System Information:
Debian Release: squeeze/sid
  APT prefers unstable
  APT policy: (990, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.30 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages libc6 depends on:
ii  libgcc1                       1:4.4.0-6  GCC support library

libc6 recommends no packages.

Versions of packages libc6 suggests:
ii  glibc-doc                     2.9-15     GNU C Library: Documentation
ii  locales                       2.9-15     GNU C Library: National Language (

-- debconf information:
  glibc/upgrade: true
* glibc/disable-screensaver:
  glibc/restart-failed:
* glibc/restart-services: spamassassin snmpd rsync postfix cups cron