um: Fix wait_stub_done() error handling

If we die within a stub handler we only way to reliable
kill the (obviously) dying uml guest process is killing
it's host twin on the host side.

Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 7 insertions, 2 deletions

diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 4625949bf1e4..441e4ba074f4 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -54,7 +54,7 @@ static int ptrace_dump_regs(int pid)
 
 void wait_stub_done(int pid)
 {
-        int n, status, err;
+        int n, status, err, bad_stop = 0;
 
         while (1) {
                 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL));
@@ -74,6 +74,8 @@ void wait_stub_done(int pid)
 
         if (((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0)
                 return;
+        else
+                bad_stop = 1;
 
 bad_wait:
         err = ptrace_dump_regs(pid);
@@ -83,7 +85,10 @@ bad_wait:
         printk(UM_KERN_ERR "wait_stub_done : failed to wait for SIGTRAP, "
                "pid = %d, n = %d, errno = %d, status = 0x%x\n", pid, n, errno,
                status);
-        fatal_sigsegv();
+        if (bad_stop)
+                kill(pid, SIGKILL);
+        else
+                fatal_sigsegv();
 }
 
 extern unsigned long current_stub_stack(void);