tests: Add gem_fd_exhaustion

Exhausts the system limit on open files and then tries to create
a new shmem-backed gem object. Linus Torvalds reported that this
blows up on a null obj->base.filp, but I can't reproduce this here:

http://lists.freedesktop.org/archives/intel-gfx/2014-January/038433.html

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

3 files changed, 85 insertions, 0 deletions

diff --git a/tests/.gitignore b/tests/.gitignore
index 1e52c2f3..7377275c 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -35,6 +35,7 @@ gem_exec_blt
 gem_exec_faulting_reloc
 gem_exec_lut_handle
 gem_exec_nop
+gem_fd_exhaustion
 gem_fenced_exec_thrash
 gem_fence_thrash
 gem_flink
diff --git a/tests/Makefile.sources b/tests/Makefile.sources
index 74ea1b52..a8c0c964 100644
--- a/tests/Makefile.sources
+++ b/tests/Makefile.sources
@@ -85,6 +85,7 @@ TESTS_progs = \
 	gem_exec_big \
 	gem_exec_blt \
 	gem_exec_lut_handle \
+	gem_fd_exhaustion \
 	gem_gtt_cpu_tlb \
 	gem_gtt_hog \
 	gem_gtt_speed \
diff --git a/tests/gem_fd_exhaustion.c b/tests/gem_fd_exhaustion.c
new file mode 100644
index 00000000..77faff2e
--- /dev/null
+++ b/tests/gem_fd_exhaustion.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Daniel Vetter <daniel.vetter@ffwll.ch>
+ *
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/resource.h>
+#include <sys/time.h>
+#include <fcntl.h>
+#include <limits.h>
+#include "drmtest.h"
+
+
+#define FD_ARR_SZ 100
+int fd_arr[FD_ARR_SZ];
+
+igt_simple_main
+{
+	int fd, i;
+	struct rlimit rlim;
+	unsigned nofile_rlim;
+	FILE *file_max = fopen("/proc/sys/fs/file-max", "r");
+	igt_assert(fscanf(file_max, "%u", &nofile_rlim) == 1);
+	fclose(file_max);
+
+	printf("System limit for open files is %u\n", nofile_rlim);
+
+	igt_assert(getrlimit(RLIMIT_NOFILE, &rlim) == 0);
+	rlim.rlim_cur = nofile_rlim;
+	rlim.rlim_max = nofile_rlim;
+	igt_assert(setrlimit(RLIMIT_NOFILE, &rlim) == 0);
+
+	fd = drm_open_any();
+
+	igt_assert(open("/dev/null", O_RDONLY) >= 0);
+
+	for (i = 0; ; i++) {
+		int tmp_fd = open("/dev/null", O_RDONLY);
+		uint32_t 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;
+		}
+	}
+
+	/* 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]);
+
+	close(fd);
+}