On 02/24/2010 02:06 PM, Richard W.M. Jones wrote:
The correct solution is to mask out SIGWINCH for the duration of the poll(2) system call. The per-thread mask is changed and restored immediately after the call. Since we are using pthread_sigmask, this should not affect other threads, and since we restore the signal mask immediately afterwards it should not affect the current thread visibly either.
This is interesting. No signal handler will necessarily do things like longjmp-ing out of the remote driver, so every signal could give rise to a similar bug.
In particular, SIGCHLD would be an obvious candidate for being handled the same way, since both SIGWINCH and SIGCHLD are default-ignored signals. On the other hand, while for SIGWINCH it would be mostly harmless(*), for SIGCHLD it would leave a zombie until the remote libvirtd answers. Any ideas?
(*) Unless you have more than one thread using curses, and a thread other than the one calling libvirt has blocked SIGWINCH. Paolo -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list