Add wait-for-debugger test harness hooks

If WAIT_FOR_DEBUGGER is set to a non-zero value in the environment,
any test that runs will print some useful gdb information and wait
for gdb to attach to it and clear the "wait_for_debugger" variable.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/support/test-container.c b/support/test-container.c
index 9c42d3ae2f..5d08979df3 100644
--- a/support/test-container.c
+++ b/support/test-container.c
@@ -676,6 +676,9 @@ main (int argc, char **argv)
   char *so_base;
   int do_postclean = 0;
 
+  int pipes[2];
+  char pid_buf[20];
+
   uid_t original_uid;
   gid_t original_gid;
   /* If set, the test runs as root instead of the user running the testsuite.  */
@@ -999,6 +1002,11 @@ main (int argc, char **argv)
   if (chdir (new_cwd_path) < 0)
     FAIL_EXIT1 ("Can't cd to new %s - ", new_cwd_path);
 
+  /* This is to pass the "outside" PID to the child, which will be PID
+     1.  */
+  if (pipe2 (pipes, O_CLOEXEC) < 0)
+    FAIL_EXIT1 ("Can't create pid pipe");
+
   /* To complete the containerization, we need to fork () at least
      once.  We can't exec, nor can we somehow link the new child to
      our parent.  So we run the child and propogate it's exit status
@@ -1010,6 +1018,12 @@ main (int argc, char **argv)
     {
       /* Parent.  */
       int status;
+
+      /* Send the child's "outside" pid to it.  */
+      write (pipes[1], &child, sizeof(child));
+      close (pipes[0]);
+      close (pipes[1]);
+
       waitpid (child, &status, 0);
 
       if (WIFEXITED (status))
@@ -1028,6 +1042,14 @@ main (int argc, char **argv)
   /* The rest is the child process, which is now PID 1 and "in" the
      new root.  */
 
+  /* Get our "outside" pid from our parent.  We use this to help with
+     debugging from outside the container.  */
+  read (pipes[0], &child, sizeof(child));
+  close (pipes[0]);
+  close (pipes[1]);
+  sprintf (pid_buf, "%lu", (long unsigned)child);
+  setenv ("PID_OUTSIDE_CONTAINER", pid_buf, 0);
+
   maybe_xmkdir ("/tmp", 0755);
 
   /* Now that we're pid 1 (effectively "root") we can mount /proc  */