public inbox for glibc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug nptl/10563] New: supplementary groups are not shared between (p)threads
@ 2009-08-25 22:50 kamil dot 76934 at iskra dot name
2009-08-25 22:52 ` [Bug nptl/10563] " kamil dot 76934 at iskra dot name
0 siblings, 1 reply; 2+ messages in thread
From: kamil dot 76934 at iskra dot name @ 2009-08-25 22:50 UTC (permalink / raw)
To: glibc-bugs
I noticed that supplementary groups (getgroups(2)/setgroups(2)) are not shared
between the threads in a multithreaded program. I would expect that since
[e]uid and [e]gid are, so should the supplementary groups? I checked the source
and I can see that set*id() calls use the setxid API to synchronize the ids
between the threads, but setgroups() does not do that; I guess that's the
problem. I didn't try to compile the latest version, but the source is the same
in that respect...
This is with kernel 2.6.30, gcc 4.3.2, binutils 2.18, but I don't think this
matters all that much, as I first saw it on a completely different platform
(PPC64 SLES 10).
I'll attach a self-contained testcode. It needs to be run as root. I'm getting
the following output:
"Initial groups:
0, 1, 2, 3, 4, 6, 10, 11, 20, 26, 27
Launched a new thread
Changing groups in the main thread...
Main thread groups:
12345
Launched thread groups:
0, 1, 2, 3, 4, 6, 10, 11, 20, 26, 27"
Instead, I would expect the last line to be "12345".
--
Summary: supplementary groups are not shared between (p)threads
Product: glibc
Version: 2.9
Status: NEW
Severity: normal
Priority: P2
Component: nptl
AssignedTo: drepper at redhat dot com
ReportedBy: kamil dot 76934 at iskra dot name
CC: glibc-bugs at sources dot redhat dot com
GCC host triplet: x86_64-pc-linux-gnu
http://sourceware.org/bugzilla/show_bug.cgi?id=10563
------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
^ permalink raw reply [flat|nested] 2+ messages in thread
* [Bug nptl/10563] supplementary groups are not shared between (p)threads
2009-08-25 22:50 [Bug nptl/10563] New: supplementary groups are not shared between (p)threads kamil dot 76934 at iskra dot name
@ 2009-08-25 22:52 ` kamil dot 76934 at iskra dot name
0 siblings, 0 replies; 2+ messages in thread
From: kamil dot 76934 at iskra dot name @ 2009-08-25 22:52 UTC (permalink / raw)
To: glibc-bugs
------- Additional Comments From kamil dot 76934 at iskra dot name 2009-08-25 22:51 -------
Created an attachment (id=4151)
--> (http://sourceware.org/bugzilla/attachment.cgi?id=4151&action=view)
self-contained testcase
--
http://sourceware.org/bugzilla/show_bug.cgi?id=10563
------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2009-08-25 22:52 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-08-25 22:50 [Bug nptl/10563] New: supplementary groups are not shared between (p)threads kamil dot 76934 at iskra dot name
2009-08-25 22:52 ` [Bug nptl/10563] " kamil dot 76934 at iskra dot name
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).