Bug 456914 – glibc's _get_nprocs reads /sys/devices/system/cpu/online

• Status: VERIFIED FIXED
• Product: Gentoo Linux

[Description Mira Ressel 2013-02-12 11:17:56 UTC]

glibc's linux-specific implementation of get_nprocs (__get_nprocs in sysdeps/unix/sysv/linux/getsysstats.c" tries to read /sys/devices/system/cpu/online, which has a type of sysfs_t and is therefore not readable for many processes. As a fallback, it uses /proc/stat or /proc/cpuinfo, but they aren't accessible by everyone either.

A solution would be to flag /sys/devices/system/cpu/online as another type, e.g. "cpu_online_t", and allow everyone access to that. But this approach would require an init script for reflagging the file on each boot.

[Comment 1 Sven Vermeulen (RETIRED) 2013-02-12 18:50:27 UTC]

Indeed; this is also the approach that fedora takes in this matter

[Comment 2 Sven Vermeulen (RETIRED) 2013-03-10 15:29:48 UTC]

Is in the repository, will be in rev 13. Am contemplating where/how to push out the init script.

[Comment 3 Sven Vermeulen (RETIRED) 2013-03-10 15:53:32 UTC]

policycoreutils-2.1.13-r8 will provide a "selinux_gentoo" init script that includes a restorecon against the cpu/online file.

[Comment 4 Sven Vermeulen (RETIRED) 2013-05-06 18:27:18 UTC]

In main tree,  ~arch'ed (20130424-r1 release)

[Comment 5 Sven Vermeulen (RETIRED) 2013-06-16 18:00:23 UTC]

Now stable in repo