Re: [libvirt] [PATCH 4/7] Fix potential deadlock across fork() in QEMU driver

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; https://bugzilla.redhat.com/show_bug.cgi?id=964358 The hook scripts used by virCommand must be careful wrt accessing any mutexes that may have been held by other threads in the parent process. With the recent refactoring there are 2 potential flaws lurking, which will become real deadlock bugs once the global QEMU driver lock is removed. Remove use of the QEMU driver lock from the hook function by passing in the 'virQEMUDriverConfigPtr' instance directly. Add functions to the virSecurityManager to be invoked before and after fork, to ensure the mutex is held by the current thread. This allows it to be safely used in the hook script in the child process. Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; (cherry picked from commit 61b52d2e3813cc8c9ff3ab67f232bd0c65f7318d) Conflicts: src/libvirt_private.syms - context src/qemu/qemu_process.c - no backport of qemud_driver struct rename src/security/security_manager.c - no backport of making the security driver self-locking; just expose the interface