kern/72922: linux emulation: suid/sgid threaded applications hang

[Maxim Sobolev]

The following reply was made to PR kern/72922; it has been noted by GNATS.

From: Maxim Sobolev <sobomax at portaone.com>
To: Andriy Gapon <avg at icyb.net.ua>
Cc: freebsd-gnats-submit at FreeBSD.org
Subject: Re: kern/72922: linux emulation: suid/sgid threaded applications
 hang
Date: Wed, 09 Mar 2005 11:59:48 +0200

 Andriy Gapon wrote:
 > on 20.02.2005 19:21 Maxim Sobolev said the following:
 > 
 >>Andriy,
 >>
 >>Can you please test the following patch and let me know if it help or not.
 >>
 >>http://www.pbxpress.com/~sobomax/72922.diff
 > 
 > 
 > Maxim,
 > sorry that it took me so long to try this patch, I could do reboot only
 >  on the past weekend and, ufortunately, this patch didn't fix the
 > problem with MQ, strmqm command still hangs if conservative_signals=1. I
 > am not sure if you commited exactly this patch or something different in
 > current (unfortunately I am not able to test current), but this patch
 > apparently does not work in this particular case. I am not sure if I
 > will be able to help you with debugging kernel stuff (linux kld - most
 > probably yes, kernel - most propbably not), but I can definitely provide
 > you information about this particular program, strmqm, if you need it
 > and if you tell me what to check for.
 
 Hmm, that's pretty strange. Can you please fetch the following Linux 
 binary, make it suid root and try to run as ordinary user on your 
 system? I've used it to verify that my patch is in fact works - after 
 the change has been made it stopped hanging at my system.
 
 http://www.pbxpress.com/~sobomax/aqueue_linux
 
 It will make sense to execute that strmqm program under ktrace(8) with 
 -i flag (use ports/devel/linux_kdump to decode resulting trace) and send 
 me the output of linux_kdump. Maybe your version of linuxthreads uses 
 some different set of flags in linux_clone(), so that my heuristics fails.
 
 -Maxim