proc: pid/status: show all supplementary groups
authorArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Tue, 18 Dec 2012 00:03:17 +0000 (16:03 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 18 Dec 2012 01:15:23 +0000 (17:15 -0800)
commit8d238027b87e654be552eabdf492042a34c5c300
tree8bf20551d778f2bf8e76c5f03cb1359e5ed9461c
parent2f4b3bf6b2318cfaa177ec5a802f4d8d6afbd816
proc: pid/status: show all supplementary groups

We display a list of supplementary group for each process in
/proc/<pid>/status.  However, we show only the first 32 groups, not all of
them.

Although this is rare, but sometimes processes do have more than 32
supplementary groups, and this kernel limitation breaks user-space apps
that rely on the group list in /proc/<pid>/status.

Number 32 comes from the internal NGROUPS_SMALL macro which defines the
length for the internal kernel "small" groups buffer.  There is no
apparent reason to limit to this value.

This patch removes the 32 groups printing limit.

The Linux kernel limits the amount of supplementary groups by NGROUPS_MAX,
which is currently set to 65536.  And this is the maximum count of groups
we may possibly print.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/proc/array.c