tests: add close_range() tests

This adds basic tests for the new close_range() syscall.
- test that no invalid flags can be passed
- test that a range of file descriptors is correctly closed
- test that a range of file descriptors is correctly closed if there there
  are already closed file descriptors in the range
- test that max_fd is correctly capped to the current fdtable maximum

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jann Horn <jannh@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Dmitry V. Levin <ldv@altlinux.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-api@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 1195bd85af386d9384f9fb72813566df2b12eaa2..5c042b58413d91f17ba2dc043b4f250d007fe861 100644 (file)
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -6,6 +6,7 @@ TARGETS += breakpoints
 TARGETS += capabilities
 TARGETS += cgroup
 TARGETS += clone3
+TARGETS += core
 TARGETS += cpufreq
 TARGETS += cpu-hotplug
 TARGETS += drivers/dma-buf

diff --git a/tools/testing/selftests/core/.gitignore b/tools/testing/selftests/core/.gitignore
new file mode 100644 (file)
index 0000000..6e6712c
--- /dev/null
+++ b/tools/testing/selftests/core/.gitignore
@@ -0,0 +1 @@
+close_range_test

diff --git a/tools/testing/selftests/core/Makefile b/tools/testing/selftests/core/Makefile
new file mode 100644 (file)
index 0000000..f6f2d6f
--- /dev/null
+++ b/tools/testing/selftests/core/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+CFLAGS += -g -I../../../../usr/include/
+
+TEST_GEN_PROGS := close_range_test
+
+include ../lib.mk
+

diff --git a/tools/testing/selftests/core/close_range_test.c b/tools/testing/selftests/core/close_range_test.c
new file mode 100644 (file)
index 0000000..9d92f2d
--- /dev/null
+++ b/tools/testing/selftests/core/close_range_test.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/kernel.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <unistd.h>
+
+#include "../kselftest_harness.h"
+
+#ifndef __NR_close_range
+#define __NR_close_range -1
+#endif
+
+static inline int sys_close_range(unsigned int fd, unsigned int max_fd,
+                                 unsigned int flags)
+{
+       return syscall(__NR_close_range, fd, max_fd, flags);
+}
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#endif
+
+TEST(close_range)
+{
+       int i, ret;
+       int open_fds[101];
+
+       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;
+       }
+
+       EXPECT_EQ(-1, sys_close_range(open_fds[0], open_fds[100], -1)) {
+               if (errno == ENOSYS)
+                       XFAIL(return, "close_range() syscall not supported");
+       }
+
+       EXPECT_EQ(0, sys_close_range(open_fds[0], open_fds[50], 0));
+
+       for (i = 0; i <= 50; i++)
+               EXPECT_EQ(-1, fcntl(open_fds[i], F_GETFL));
+
+       for (i = 51; i <= 100; i++)
+               EXPECT_GT(fcntl(open_fds[i], F_GETFL), -1);
+
+       /* create a couple of gaps */
+       close(57);
+       close(78);
+       close(81);
+       close(82);
+       close(84);
+       close(90);
+
+       EXPECT_EQ(0, sys_close_range(open_fds[51], open_fds[92], 0));
+
+       for (i = 51; i <= 92; i++)
+               EXPECT_EQ(-1, fcntl(open_fds[i], F_GETFL));
+
+       for (i = 93; i <= 100; i++)
+               EXPECT_GT(fcntl(open_fds[i], F_GETFL), -1);
+
+       /* test that the kernel caps and still closes all fds */
+       EXPECT_EQ(0, sys_close_range(open_fds[93], open_fds[99], 0));
+
+       for (i = 93; i <= 99; i++)
+               EXPECT_EQ(-1, fcntl(open_fds[i], F_GETFL));
+
+       EXPECT_GT(fcntl(open_fds[i], F_GETFL), -1);
+
+       EXPECT_EQ(0, sys_close_range(open_fds[100], open_fds[100], 0));
+
+       EXPECT_EQ(-1, fcntl(open_fds[100], F_GETFL));
+}
+
+TEST_HARNESS_MAIN