tests/gem_fd_exhaustion: Make it work

- We need to drop root to actually hit the limits. This requires us to
  fork the actual test since otherwise the exit handlers (which
  require root) fail the entire test.
- Don't assert that the gem create ioctl succeeds, it won't on the
  final run of the loop.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/tests/gem_fd_exhaustion.c b/tests/gem_fd_exhaustion.c
index 77faff2..afaa100 100644 (file)
--- a/tests/gem_fd_exhaustion.c
+++ b/tests/gem_fd_exhaustion.c
@@ -57,27 +57,35 @@ igt_simple_main
 
        igt_assert(open("/dev/null", O_RDONLY) >= 0);
 
-       for (i = 0; ; i++) {
-               int tmp_fd = open("/dev/null", O_RDONLY);
-               uint32_t handle;
+       igt_fork(n, 1) {
+               igt_drop_root();
 
-               if (tmp_fd >= 0 && i < FD_ARR_SZ)
-                       fd_arr[i] = tmp_fd;
+               for (i = 0; ; i++) {
+                       int tmp_fd = open("/dev/null", O_RDONLY);
+                       uint32_t handle;
 
-               handle = gem_create(fd, 4096);
-               if (handle)
-                       gem_close(fd, handle);
+                       if (tmp_fd >= 0 && i < FD_ARR_SZ)
+                               fd_arr[i] = tmp_fd;
 
+                       handle = __gem_create(fd, 4096);
+                       if (handle)
+                               gem_close(fd, handle);
 
-               if (!handle || tmp_fd < 0) {
-                       printf("fd exhaustion after %i rounds.\n", i);
-                       break;
+
+                       if (tmp_fd < 0) {
+                               /* Ensure we actually hit the failure path ... */
+                               igt_assert(handle == 0);
+                               printf("fd exhaustion after %i rounds.\n", i);
+                               break;
+                       }
                }
+
+               /* The child will free all the fds when exiting, so no need to
+                * clean up to mess to ensure that the parent can at least run
+                * the exit handlers. */
        }
 
-       /* free a few fd so that the exit handlers can at least run. */
-       for (i = 0; i < FD_ARR_SZ; i++)
-               close(fd_arr[i]);
+       igt_waitchildren();
 
        close(fd);
 }