um: Cleanup SIGTERM handling

Richard reported that some UML processes survive if the UML
main process receives a SIGTERM.
This issue was caused by a wrongly placed signal(SIGTERM, SIG_DFL)
in init_new_thread_signals().
It disabled the UML exit handler accidently for some processes.
The correct solution is to disable the fatal handler for all
UML helper threads/processes.
Such that last_ditch_exit() does not get called multiple times
and all processes can exit due to SIGTERM.

Reported-and-tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 1812bc81715b..3716e6952554 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -1476,7 +1476,8 @@ int io_thread(void *arg)
         struct io_thread_req *req;
         int n;
 
-        ignore_sigwinch_sig();
+        os_fix_helper_signals();
+
         while(1){
                 n = os_read_file(kernel_fd, &req,
                                  sizeof(struct io_thread_req *));