[libvirt] [PATCH] qemu: avoid pass null pointer as an argument

[Eric Blake]

On 08/04/2011 02:07 PM, Eric Blake wrote:
>
> We definitely have a bug here, but this is not the right fix. The bug is
> that the cleanup: label is trying to read from logfd if the vm crashed,
> without having opened logfd in the qemuProcessAttach case.
>
> I think the more appropriate patch is this:
>
> diff --git i/src/qemu/qemu_process.c w/src/qemu/qemu_process.c
> index 8508ff6..1eea45f 100644
> --- i/src/qemu/qemu_process.c
> +++ w/src/qemu/qemu_process.c
> @@ -1214,7 +1214,7 @@ qemuProcessWaitForMonitor(struct qemud_driver*
> driver,
> cleanup:
> virHashFree(paths);
>
> - if (kill(vm->pid, 0) == -1 && errno == ESRCH) {
> + if (pos != -1 && kill(vm->pid, 0) == -1 && errno == ESRCH) {
> /* VM is dead, any other error raised in the interim is probably
> * not as important as the qemu cmdline output */
> qemuProcessReadLogFD(logfd, buf, buf_size, strlen(buf));

Also squash this in - no need to free buf twice.

diff --git i/src/qemu/qemu_process.c w/src/qemu/qemu_process.c
index 1eea45f..a37f709 100644
--- i/src/qemu/qemu_process.c
+++ w/src/qemu/qemu_process.c
@@ -1221,16 +1221,14 @@ cleanup:
          qemuReportError(VIR_ERR_INTERNAL_ERROR,
                          _("process exited while connecting to monitor: 
%s"),
                          buf);
          ret = -1;
      }

  closelog:
-    VIR_FREE(buf);
-
      if (VIR_CLOSE(logfd) < 0) {
          char ebuf[1024];
          VIR_WARN("Unable to close logfile: %s",
                   virStrerror(errno, ebuf, sizeof ebuf));
      }

      VIR_FREE(buf);

-- 
Eric Blake   eblake at redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org