fix dma-buf/udmabuf selftest

This patch fixes the udmabuf selftest. Currently the selftest is broken.
I fixed the selftest by setting the F_SEAL_SHRINK seal on the memfd
file descriptor which is required by udmabuf and added the test to
the selftest Makefile.
Signed-off-by: Tom Murphy <murphyt7@tcd.ie>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Shuah Khan <shuah@kernel.org>

tools/testing/selftests/Makefile

@@ -6,6 +6,7 @@ TARGETS += capabilities
 TARGETS += cgroup
 TARGETS += cpufreq
 TARGETS += cpu-hotplug
+TARGETS += drivers/dma-buf
 TARGETS += efivarfs
 TARGETS += exec
 TARGETS += filesystems

tools/testing/selftests/drivers/dma-buf/Makefile

@@ -2,4 +2,6 @@ CFLAGS += -I../../../../../usr/include/
 
 TEST_GEN_PROGS := udmabuf
 
+top_srcdir ?=../../../../..
+
 include ../../lib.mk

tools/testing/selftests/drivers/dma-buf/udmabuf.c

@@ -4,7 +4,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
-#include <fcntl.h>
+#include <linux/fcntl.h>
 #include <malloc.h>
 
 #include <sys/ioctl.h>
@@ -33,12 +33,19 @@ int main(int argc, char *argv[])
 		exit(77);
 	}
 
-	memfd = memfd_create("udmabuf-test", MFD_CLOEXEC);
+	memfd = memfd_create("udmabuf-test", MFD_ALLOW_SEALING);
 	if (memfd < 0) {
 		printf("%s: [skip,no-memfd]\n", TEST_PREFIX);
 		exit(77);
 	}
 
+	ret = fcntl(memfd, F_ADD_SEALS, F_SEAL_SHRINK);
+	if (ret < 0) {
+		printf("%s: [skip,fcntl-add-seals]\n", TEST_PREFIX);
+		exit(77);
+	}
+
+
 	size = getpagesize() * NUM_PAGES;
 	ret = ftruncate(memfd, size);
 	if (ret == -1) {