From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.3) Gecko/20030314 Description of problem: i am running Redhat 9.0 ( kernel 2.4.20 ) and am-utils (am-utils-6.0.9-2) (because i need the browsing feature that automount doen't support). Unfortunatelly, amd sometimes hangs at boot time during its initialization (/etc/rc.d/init.d/amd ). I can reproduce this bug with /etc/rc.d/init.d/amd start / stop sequences, sometimes the start hangs sometimes it works. This bug occurs on ALL RedHat 9.0 boxes we have (7 PC with totally different hardware). When hanging i can observe the following processes : root 2444 1911 0 17:14 pts/0 00:00:00 /bin/bash /etc/rc.d/init.d/amd start root 2453 2444 0 17:14 pts/0 00:00:00 initlog -q -c /usr/sbin/amd -F /etc/amd.conf root 2454 2453 0 17:14 pts/0 00:00:00 /usr/sbin/amd -F /etc/amd.conf root 2455 2454 0 17:14 ? 00:00:00 /usr/sbin/amd -F /etc/amd.conf with the following traces : [root@redhat-serv root]# strace -p 2453 wait4(2454, 0xbfffd9cc, WNOHANG, NULL) = 0 nanosleep({0, 500000}, NULL) = 0 poll([{fd=3, events=POLLIN|POLLPRI}, {fd=5, events=POLLIN|POLLPRI}], 2, 500) = 0 wait4(2454, 0xbfffd9cc, WNOHANG, NULL) = 0 nanosleep({0, 500000}, NULL) = 0 poll([{fd=3, events=POLLIN|POLLPRI}, {fd=5, events=POLLIN|POLLPRI}], 2, 500) = 0 wait4(2454, 0xbfffd9cc, WNOHANG, NULL) = 0 nanosleep({0, 500000}, NULL) = 0 poll([{fd=3, events=POLLIN|POLLPRI}, {fd=5, events=POLLIN|POLLPRI}], 2, 500) = 0 wait4(2454, 0xbfffd9cc, WNOHANG, NULL) = 0 nanosleep({0, 500000}, NULL) = 0 poll( <unfinished ...> [root@redhat-serv root]# strace -p 2454 futex(0x4212e1c8, FUTEX_WAIT, -2, NULL <unfinished ...> [root@redhat-serv root]# strace -p 2455 select(1024, [4 5 6 7], NULL, NULL, {932, 980000} <unfinished ...> Despite the fact the "father" process hangs, the child amd works and the service amd runs perfectly, BUT at boot time, the boot sequence would block in /etc/rc.d/init.d/amd The SAME configuration worked perfectly with RH 8.0, am-utils-6.0.7-9, kernel 2.4.18 I wasn't able to reproduce the bug with a RH 8.0 kernel (2.4.18-14) on top of my RH 9.0 install. Sounds like a kernel bug or a misusage of futexes ? Version-Release number of selected component (if applicable): am-utils-6.0.9-2 How reproducible: Sometimes Steps to Reproduce: 1.service amd stop 2.service amd start 3.goto 1 until amd hangs Actual Results: amd forks but the father process doesn't die Expected Results: amd should go in the background and the boot process should continue Additional info: Seems to be a futex/kernel/libc bug since reverting to an older kernel fixes it.
Created attachment 91705 [details] Version 9 kernel causes amd to hang on boot.
ksa
We (at SLAC) confirm this problem described by Nicolas.
We at dartmouth college also confirm this problem, happens on every one of our RH9 machines... Any ETA on a fix? Thanks much! Cheers, Tim
The following workaround apparently solves the problem (by disabling futex use). Add to the top of /etc/init.d/amd the line export LD_ASSUME_KERNEL=2.4.1 Could this (temporary) fix be included in an updated version of the am-utils package until the correct fix is found?