Re: [libvirt] [PATCH] Avoid async signal safety problem in glibc's setxid

On 11/15/2013 09:20 AM, Daniel P. Berrange wrote: > The glibc setxid is supposed to be async signal safe, but > libc developers confirm that it is not. This causes a problem > when libvirt_lxc starts the FUSE thread and then runs clone() > to start the container. If the clone() was done before the > FUSE thread has completely started up, then the container > will hang in setxid after clone(). > > The fix is to avoid creating any threads until after the > container has been clone()'d. By avoiding any threads in > the parent, the child is no longer required to run in an > async signal safe context, and we thus avoid the glibc > bug. > > Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; > --- > src/lxc/lxc_controller.c | 11 +++++++++-- > src/lxc/lxc_fuse.c | 21 +++++++++++++++------ > src/lxc/lxc_fuse.h | 1 + > 3 files changed, 25 insertions(+), 8 deletions(-) I can review the code, but I'd feel better if this also got field testing as resolving the problem before you push it. ACK.