Firefox/Thunderbird and SSL not working with libthread_xu

Jordan Gordeev jgordeev at
Sat Apr 12 10:30:53 PDT 2008

Matthew Dillon wrote:
:Simon "corecode" Schubert reported XXX some months ago an issue with 
:Firefox/Thunderbird and SSL when using libthread_xu as the threading 
:I started looking into the issue and found something that seems like a 
:bug to me.
:I traced an execution of firefox with ktrace and observed something 
:strange. Below is a commented extract from the 'kdump -T' output.
:// thread #4 calls umtx_sleep on 0x2a92f664
:// thread #4 never returns from this syscall, according to the kdump output
:75875:4    firefox-bin 1207996217.713757 CALL  umtx_sleep(0x2a92f664,0,0)
:// thread #1 attempts to wake up thread #4
:75875:1    firefox-bin 1207996244.646643 CALL  
:// I terminate the process
:75875:5    firefox-bin 1207996413.782573 PSIG  SIGQUIT SIG_DFL
:The expected behaviour is for thread #4 to wake up when thread #1 calls 
:I'd appreciate any feedback on the issue.
:If you need information about my environment, I'd be happy to provide it.

    Could you paste all the ofktrace output between those two points?  It
    definitely should have woken up thread 4.
					Matthew Dillon 
					<dillon at>
There are about 2 million lines of kdump output between these two 
points, which include the output of some debugging printfs and likely 
information read from/written to my personal profile. The only mentions 
of 0x2a92f664 in the kdump output are the lines pasted above. And, as I 
said, no return from umtx_sleep for thread 4 is noticed by ktrace. 
Before I terminated the process I ran 'ps -axHl' which resulted in the 
following line, among others:
1001 75875     4 74331  79 200   0 54880 43764 umtxsl IL+   p6    
0:00.00 /usr/pkg/lib/firefox/firefox-bin
Notice the 'I' in 'IL+'.
The issue is very easy to reproduce - just run 'ktrace -i firefox' and 
try to open an SSL site. If opening the site fails, then close the 
window, wait for some time, then terminate the process. If opening the 
SSL site succeeds, just try again.
I've reproduced the issue with thunderbird too, where the thread than 
never woke up happened to be thread #5. I'm running DragonFly 1.12.1 
with UP kernel.
I ask anybody who doesn't trust my results to try and reproduce the issue.

More information about the Bugs mailing list