tests: add CLOSE_RANGE_UNSHARE tests

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

tools/testing/selftests/core/close_range_test.c

@@ -13,11 +13,16 @@
 #include <unistd.h>
 
 #include "../kselftest_harness.h"
+#include "../clone3/clone3_selftests.h"
 
 #ifndef __NR_close_range
 #define __NR_close_range -1
 #endif
 
+#ifndef CLOSE_RANGE_UNSHARE
+#define CLOSE_RANGE_UNSHARE	(1U << 1)
+#endif
+
 static inline int sys_close_range(unsigned int fd, unsigned int max_fd,
 				  unsigned int flags)
 {
@@ -87,4 +92,136 @@ TEST(close_range)
 	EXPECT_EQ(-1, fcntl(open_fds[100], F_GETFL));
 }
 
+TEST(close_range_unshare)
+{
+	int i, ret, status;
+	pid_t pid;
+	int open_fds[101];
+	struct clone_args args = {
+		.flags = CLONE_FILES,
+		.exit_signal = SIGCHLD,
+	};
+
+	for (i = 0; i < ARRAY_SIZE(open_fds); i++) {
+		int fd;
+
+		fd = open("/dev/null", O_RDONLY | O_CLOEXEC);
+		ASSERT_GE(fd, 0) {
+			if (errno == ENOENT)
+				XFAIL(return, "Skipping test since /dev/null does not exist");
+		}
+
+		open_fds[i] = fd;
+	}
+
+	pid = sys_clone3(&args, sizeof(args));
+	ASSERT_GE(pid, 0);
+
+	if (pid == 0) {
+		ret = sys_close_range(open_fds[0], open_fds[50],
+				      CLOSE_RANGE_UNSHARE);
+		if (ret)
+			exit(EXIT_FAILURE);
+
+		for (i = 0; i <= 50; i++)
+			if (fcntl(open_fds[i], F_GETFL) != -1)
+				exit(EXIT_FAILURE);
+
+		for (i = 51; i <= 100; i++)
+			if (fcntl(open_fds[i], F_GETFL) == -1)
+				exit(EXIT_FAILURE);
+
+		/* create a couple of gaps */
+		close(57);
+		close(78);
+		close(81);
+		close(82);
+		close(84);
+		close(90);
+
+		ret = sys_close_range(open_fds[51], open_fds[92],
+				      CLOSE_RANGE_UNSHARE);
+		if (ret)
+			exit(EXIT_FAILURE);
+
+		for (i = 51; i <= 92; i++)
+			if (fcntl(open_fds[i], F_GETFL) != -1)
+				exit(EXIT_FAILURE);
+
+		for (i = 93; i <= 100; i++)
+			if (fcntl(open_fds[i], F_GETFL) == -1)
+				exit(EXIT_FAILURE);
+
+		/* test that the kernel caps and still closes all fds */
+		ret = sys_close_range(open_fds[93], open_fds[99],
+				      CLOSE_RANGE_UNSHARE);
+		if (ret)
+			exit(EXIT_FAILURE);
+
+		for (i = 93; i <= 99; i++)
+			if (fcntl(open_fds[i], F_GETFL) != -1)
+				exit(EXIT_FAILURE);
+
+		if (fcntl(open_fds[100], F_GETFL) == -1)
+			exit(EXIT_FAILURE);
+
+		ret = sys_close_range(open_fds[100], open_fds[100],
+				      CLOSE_RANGE_UNSHARE);
+		if (ret)
+			exit(EXIT_FAILURE);
+
+		if (fcntl(open_fds[100], F_GETFL) != -1)
+			exit(EXIT_FAILURE);
+
+		exit(EXIT_SUCCESS);
+	}
+
+	EXPECT_EQ(waitpid(pid, &status, 0), pid);
+	EXPECT_EQ(true, WIFEXITED(status));
+	EXPECT_EQ(0, WEXITSTATUS(status));
+}
+
+TEST(close_range_unshare_capped)
+{
+	int i, ret, status;
+	pid_t pid;
+	int open_fds[101];
+	struct clone_args args = {
+		.flags = CLONE_FILES,
+		.exit_signal = SIGCHLD,
+	};
+
+	for (i = 0; i < ARRAY_SIZE(open_fds); i++) {
+		int fd;
+
+		fd = open("/dev/null", O_RDONLY | O_CLOEXEC);
+		ASSERT_GE(fd, 0) {
+			if (errno == ENOENT)
+				XFAIL(return, "Skipping test since /dev/null does not exist");
+		}
+
+		open_fds[i] = fd;
+	}
+
+	pid = sys_clone3(&args, sizeof(args));
+	ASSERT_GE(pid, 0);
+
+	if (pid == 0) {
+		ret = sys_close_range(open_fds[0], UINT_MAX,
+				      CLOSE_RANGE_UNSHARE);
+		if (ret)
+			exit(EXIT_FAILURE);
+
+		for (i = 0; i <= 100; i++)
+			if (fcntl(open_fds[i], F_GETFL) != -1)
+				exit(EXIT_FAILURE);
+
+		exit(EXIT_SUCCESS);
+	}
+
+	EXPECT_EQ(waitpid(pid, &status, 0), pid);
+	EXPECT_EQ(true, WIFEXITED(status));
+	EXPECT_EQ(0, WEXITSTATUS(status));
+}
+
 TEST_HARNESS_MAIN