This adds tests for clone3() with different values and sizes
of struct clone_args.
This selftest was initially part of of the clone3() with PID selftest.
After that patch was almost merged Eugene sent out a couple of patches
to fix problems with these test.
This commit now only contains the clone3() selftest after the LPC
decision to rework clone3() with PID to allow setting the PID in
multiple PID namespaces including all of Eugene's patches.
Signed-off-by: Eugene Syromiatnikov <[email protected]>
Signed-off-by: Adrian Reber <[email protected]>
---
v2:
- Applied Christian's suggestions
- Skip root-only tests when running as non-root
---
MAINTAINERS | 1 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/clone3/.gitignore | 1 +
tools/testing/selftests/clone3/Makefile | 7 +
tools/testing/selftests/clone3/clone3.c | 225 ++++++++++++++++++++++
5 files changed, 235 insertions(+)
create mode 100644 tools/testing/selftests/clone3/.gitignore
create mode 100644 tools/testing/selftests/clone3/Makefile
create mode 100644 tools/testing/selftests/clone3/clone3.c
diff --git a/MAINTAINERS b/MAINTAINERS
index cba1095547fd..0040b7a6410b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12829,6 +12829,7 @@ S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git
F: samples/pidfd/
F: tools/testing/selftests/pidfd/
+F: tools/testing/selftests/clone3/
K: (?i)pidfd
K: (?i)clone3
K: \b(clone_args|kernel_clone_args)\b
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 4cdbae6f4e61..ad442364218a 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -4,6 +4,7 @@ TARGETS += bpf
TARGETS += breakpoints
TARGETS += capabilities
TARGETS += cgroup
+TARGETS += clone3
TARGETS += cpufreq
TARGETS += cpu-hotplug
TARGETS += drivers/dma-buf
diff --git a/tools/testing/selftests/clone3/.gitignore b/tools/testing/selftests/clone3/.gitignore
new file mode 100644
index 000000000000..85d9d3ba2524
--- /dev/null
+++ b/tools/testing/selftests/clone3/.gitignore
@@ -0,0 +1 @@
+clone3
diff --git a/tools/testing/selftests/clone3/Makefile b/tools/testing/selftests/clone3/Makefile
new file mode 100644
index 000000000000..ea922c014ae4
--- /dev/null
+++ b/tools/testing/selftests/clone3/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+
+CFLAGS += -I../../../../usr/include/
+
+TEST_GEN_PROGS := clone3
+
+include ../lib.mk
diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
new file mode 100644
index 000000000000..a982d95189bf
--- /dev/null
+++ b/tools/testing/selftests/clone3/clone3.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Based on Christian Brauner's clone3() example */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <inttypes.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <sched.h>
+
+#include "../kselftest.h"
+
+/*
+ * Different sizes of struct clone_args
+ */
+#ifndef CLONE3_ARGS_SIZE_V0
+#define CLONE3_ARGS_SIZE_V0 64
+#endif
+
+enum test_mode {
+ CLONE3_ARGS_NO_TEST,
+ CLONE3_ARGS_ALL_0,
+ CLONE3_ARGS_ALL_1,
+ CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG,
+ CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG,
+ CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG,
+ CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
+};
+
+static pid_t raw_clone(struct clone_args *args, size_t size)
+{
+ return syscall(__NR_clone3, args, size);
+}
+
+static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
+{
+ struct clone_args args = {
+ .flags = flags,
+ .exit_signal = SIGCHLD,
+ };
+
+ struct clone_args_extended {
+ struct clone_args args;
+ __aligned_u64 excess_space[2];
+ } args_ext;
+
+ pid_t pid = -1;
+ int status;
+
+ memset(&args_ext, 0, sizeof(args_ext));
+ if (size > sizeof(struct clone_args))
+ args_ext.excess_space[1] = 1;
+
+ if (size == 0)
+ size = sizeof(struct clone_args);
+
+ switch (test_mode) {
+ case CLONE3_ARGS_ALL_0:
+ args.flags = 0;
+ args.exit_signal = 0;
+ break;
+ case CLONE3_ARGS_ALL_1:
+ args.flags = 1;
+ args.pidfd = 1;
+ args.child_tid = 1;
+ args.parent_tid = 1;
+ args.exit_signal = 1;
+ args.stack = 1;
+ args. stack_size = 1;
+ args.tls = 1;
+ break;
+ case CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG:
+ args.exit_signal = 0xbadc0ded00000000ULL;
+ break;
+ case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG:
+ args.exit_signal = 0x0000000080000000ULL;
+ break;
+ case CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG:
+ args.exit_signal = 0x0000000000000100ULL;
+ break;
+ case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG:
+ args.exit_signal = 0x00000000000000f0ULL;
+ break;
+ }
+
+ memcpy(&args_ext.args, &args, sizeof(struct clone_args));
+
+ pid = raw_clone((struct clone_args *)&args_ext, size);
+ if (pid < 0) {
+ ksft_print_msg("%s - Failed to create new process\n",
+ strerror(errno));
+ return -errno;
+ }
+
+ if (pid == 0) {
+ ksft_print_msg("I am the child, my PID is %d\n", getpid());
+ _exit(EXIT_SUCCESS);
+ }
+
+ ksft_print_msg("I am the parent (%d). My child's pid is %d\n",
+ getpid(), pid);
+
+ if (wait(&status) < 0) {
+ ksft_print_msg("Child returned %s\n", strerror(errno));
+ return -errno;
+ }
+ if (WEXITSTATUS(status))
+ return WEXITSTATUS(status);
+
+ return 0;
+}
+
+static void test_clone3(uint64_t flags, size_t size, int expected,
+ enum test_mode test_mode)
+{
+ int ret;
+
+ ksft_print_msg(
+ "[%d] Trying clone3() with flags %#" PRIx64 " (size %zu)\n",
+ getpid(), flags, size);
+ ret = call_clone3(flags, size, test_mode);
+ ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n",
+ getpid(), ret, expected);
+ if (ret != expected)
+ ksft_test_result_fail(
+ "[%d] Result (%d) is different than expected (%d)\n",
+ getpid(), ret, expected);
+ else
+ ksft_test_result_pass(
+ "[%d] Result (%d) matches expectation (%d)\n",
+ getpid(), ret, expected);
+}
+int main(int argc, char *argv[])
+{
+ pid_t pid;
+
+ uid_t uid = getuid();
+
+ ksft_print_header();
+ ksft_set_plan(17);
+
+ /* Just a simple clone3() should return 0.*/
+ test_clone3(0, 0, 0, CLONE3_ARGS_NO_TEST);
+
+ /* Do a clone3() in a new PID NS.*/
+ if (uid == 0)
+ test_clone3(CLONE_NEWPID, 0, 0, CLONE3_ARGS_NO_TEST);
+ else
+ ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
+
+ /* Do a clone3() with CLONE3_ARGS_SIZE_V0. */
+ test_clone3(0, CLONE3_ARGS_SIZE_V0, 0, CLONE3_ARGS_NO_TEST);
+
+ /* Do a clone3() with CLONE3_ARGS_SIZE_V0 - 8 */
+ test_clone3(0, CLONE3_ARGS_SIZE_V0 - 8, -EINVAL, CLONE3_ARGS_NO_TEST);
+
+ /* Do a clone3() with sizeof(struct clone_args) + 8 */
+ test_clone3(0, sizeof(struct clone_args) + 8, 0, CLONE3_ARGS_NO_TEST);
+
+ /* Do a clone3() with all members set to 1 */
+ test_clone3(0, 0, -EINVAL, CLONE3_ARGS_ALL_1);
+
+ /* Do a clone3() with exit_signal having highest 32 bits non-zero */
+ test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG);
+
+ /* Do a clone3() with negative 32-bit exit_signal */
+ test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG);
+
+ /* Do a clone3() with exit_signal not fitting into CSIGNAL mask */
+ test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG);
+
+ /* Do a clone3() with NSIG < exit_signal < CSIG */
+ test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG);
+
+ /*
+ * Do a clone3() with sizeof(struct clone_args) + 8
+ * and all members set to 0. This resets exit_signal and wait()
+ * will not get a result.
+ */
+ test_clone3(0, sizeof(struct clone_args) + 8, -ECHILD,
+ CLONE3_ARGS_ALL_0);
+
+ /*
+ * Do a clone3() with sizeof(struct clone_args) + 8
+ * and all members set to 0.
+ */
+ test_clone3(0, sizeof(struct clone_args) + 8, -EINVAL,
+ CLONE3_ARGS_ALL_1);
+
+ /* Do a clone3() with > page size */
+ test_clone3(0, getpagesize() + 8, -E2BIG, CLONE3_ARGS_NO_TEST);
+
+ /* Do a clone3() with CLONE3_ARGS_SIZE_V0 in a new PID NS. */
+ if (uid == 0)
+ test_clone3(CLONE_NEWPID, CLONE3_ARGS_SIZE_V0, 0,
+ CLONE3_ARGS_NO_TEST);
+ else
+ ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
+
+ /* Do a clone3() with CLONE3_ARGS_SIZE_V0 - 8 in a new PID NS */
+ test_clone3(CLONE_NEWPID, CLONE3_ARGS_SIZE_V0 - 8, -EINVAL,
+ CLONE3_ARGS_NO_TEST);
+
+ /* Do a clone3() with sizeof(struct clone_args) + 8 in a new PID NS */
+ if (uid == 0)
+ test_clone3(CLONE_NEWPID, sizeof(struct clone_args) + 8, 0,
+ CLONE3_ARGS_NO_TEST);
+ else
+ ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
+
+ /* Do a clone3() with > page size in a new PID NS */
+ test_clone3(CLONE_NEWPID, getpagesize() + 8, -E2BIG,
+ CLONE3_ARGS_NO_TEST);
+
+ return !ksft_get_fail_cnt() ? ksft_exit_pass() : ksft_exit_fail();
+}
--
2.23.0
On Mon, Nov 04, 2019 at 02:18:46PM +0100, Adrian Reber wrote:
> This adds tests for clone3() with different values and sizes
> of struct clone_args.
>
> This selftest was initially part of of the clone3() with PID selftest.
> After that patch was almost merged Eugene sent out a couple of patches
> to fix problems with these test.
>
> This commit now only contains the clone3() selftest after the LPC
> decision to rework clone3() with PID to allow setting the PID in
> multiple PID namespaces including all of Eugene's patches.
>
> Signed-off-by: Eugene Syromiatnikov <[email protected]>
> Signed-off-by: Adrian Reber <[email protected]>
>
> A few more comments below.
>
> Also, would you be open to adding tests here for the newly added .stack
> and .stack_size API (cf. [1])?
>
> [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa729c4df558936b4a1a7b3e2234011f44ede28b
>
> ---
> v2:
> - Applied Christian's suggestions
> - Skip root-only tests when running as non-root
> ---
> MAINTAINERS | 1 +
> tools/testing/selftests/Makefile | 1 +
> tools/testing/selftests/clone3/.gitignore | 1 +
> tools/testing/selftests/clone3/Makefile | 7 +
> tools/testing/selftests/clone3/clone3.c | 225 ++++++++++++++++++++++
> 5 files changed, 235 insertions(+)
> create mode 100644 tools/testing/selftests/clone3/.gitignore
> create mode 100644 tools/testing/selftests/clone3/Makefile
> create mode 100644 tools/testing/selftests/clone3/clone3.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index cba1095547fd..0040b7a6410b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -12829,6 +12829,7 @@ S: Maintained
> T: git git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git
> F: samples/pidfd/
> F: tools/testing/selftests/pidfd/
> +F: tools/testing/selftests/clone3/
> K: (?i)pidfd
> K: (?i)clone3
> K: \b(clone_args|kernel_clone_args)\b
> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
> index 4cdbae6f4e61..ad442364218a 100644
> --- a/tools/testing/selftests/Makefile
> +++ b/tools/testing/selftests/Makefile
> @@ -4,6 +4,7 @@ TARGETS += bpf
> TARGETS += breakpoints
> TARGETS += capabilities
> TARGETS += cgroup
> +TARGETS += clone3
> TARGETS += cpufreq
> TARGETS += cpu-hotplug
> TARGETS += drivers/dma-buf
> diff --git a/tools/testing/selftests/clone3/.gitignore b/tools/testing/selftests/clone3/.gitignore
> new file mode 100644
> index 000000000000..85d9d3ba2524
> --- /dev/null
> +++ b/tools/testing/selftests/clone3/.gitignore
> @@ -0,0 +1 @@
> +clone3
> diff --git a/tools/testing/selftests/clone3/Makefile b/tools/testing/selftests/clone3/Makefile
> new file mode 100644
> index 000000000000..ea922c014ae4
> --- /dev/null
> +++ b/tools/testing/selftests/clone3/Makefile
> @@ -0,0 +1,7 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +CFLAGS += -I../../../../usr/include/
> +
> +TEST_GEN_PROGS := clone3
> +
> +include ../lib.mk
> diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
> new file mode 100644
> index 000000000000..a982d95189bf
> --- /dev/null
> +++ b/tools/testing/selftests/clone3/clone3.c
> @@ -0,0 +1,225 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/* Based on Christian Brauner's clone3() example */
> +
> +#define _GNU_SOURCE
> +#include <errno.h>
> +#include <inttypes.h>
> +#include <linux/types.h>
> +#include <linux/sched.h>
> +#include <stdint.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <sys/syscall.h>
> +#include <sys/types.h>
> +#include <sys/un.h>
> +#include <sys/wait.h>
> +#include <unistd.h>
> +#include <sched.h>
> +
> +#include "../kselftest.h"
> +
> +/*
> + * Different sizes of struct clone_args
> + */
> +#ifndef CLONE3_ARGS_SIZE_V0
> +#define CLONE3_ARGS_SIZE_V0 64
> +#endif
> +
> +enum test_mode {
> + CLONE3_ARGS_NO_TEST,
> + CLONE3_ARGS_ALL_0,
> + CLONE3_ARGS_ALL_1,
> + CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG,
> + CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG,
> + CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG,
> + CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
> +};
> +
> +static pid_t raw_clone(struct clone_args *args, size_t size)
> +{
> + return syscall(__NR_clone3, args, size);
> +}
> +
> +static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
> +{
> + struct clone_args args = {
> + .flags = flags,
> + .exit_signal = SIGCHLD,
> + };
> +
> + struct clone_args_extended {
> + struct clone_args args;
> + __aligned_u64 excess_space[2];
> + } args_ext;
> +
> + pid_t pid = -1;
> + int status;
> +
> + memset(&args_ext, 0, sizeof(args_ext));
> + if (size > sizeof(struct clone_args))
> + args_ext.excess_space[1] = 1;
> +
> + if (size == 0)
> + size = sizeof(struct clone_args);
> +
> + switch (test_mode) {
> + case CLONE3_ARGS_ALL_0:
> + args.flags = 0;
> + args.exit_signal = 0;
> + break;
> + case CLONE3_ARGS_ALL_1:
>
> I don't fully understand this test case. What is this for exactly?
>
> + args.flags = 1;
> + args.pidfd = 1;
> + args.child_tid = 1;
> + args.parent_tid = 1;
> + args.exit_signal = 1;
> + args.stack = 1;
> + args.tls = 1;
> + break;
> + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG:
> + args.exit_signal = 0xbadc0ded00000000ULL;
> + break;
> + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG:
> + args.exit_signal = 0x0000000080000000ULL;
> + break;
> + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG:
> + args.exit_signal = 0x0000000000000100ULL;
> + break;
> + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG:
> + args.exit_signal = 0x00000000000000f0ULL;
> + break;
> + }
> +
> + memcpy(&args_ext.args, &args, sizeof(struct clone_args));
> +
> + pid = raw_clone((struct clone_args *)&args_ext, size);
> + if (pid < 0) {
> + ksft_print_msg("%s - Failed to create new process\n",
> + strerror(errno));
> + return -errno;
> + }
> +
> + if (pid == 0) {
> + ksft_print_msg("I am the child, my PID is %d\n", getpid());
> + _exit(EXIT_SUCCESS);
> + }
> +
> + ksft_print_msg("I am the parent (%d). My child's pid is %d\n",
> + getpid(), pid);
> +
> + if (wait(&status) < 0) {
> + ksft_print_msg("Child returned %s\n", strerror(errno));
> + return -errno;
> + }
> + if (WEXITSTATUS(status))
> + return WEXITSTATUS(status);
> +
> + return 0;
> +}
> +
> +static void test_clone3(uint64_t flags, size_t size, int expected,
> + enum test_mode test_mode)
> +{
> + int ret;
> +
> + ksft_print_msg(
> + "[%d] Trying clone3() with flags %#" PRIx64 " (size %zu)\n",
> + getpid(), flags, size);
> + ret = call_clone3(flags, size, test_mode);
> + ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n",
> + getpid(), ret, expected);
> + if (ret != expected)
> + ksft_test_result_fail(
> + "[%d] Result (%d) is different than expected (%d)\n",
> + getpid(), ret, expected);
> + else
> + ksft_test_result_pass(
> + "[%d] Result (%d) matches expectation (%d)\n",
> + getpid(), ret, expected);
> +}
> +int main(int argc, char *argv[])
> +{
> + pid_t pid;
> +
> + uid_t uid = getuid();
> +
> + ksft_print_header();
> + ksft_set_plan(17);
> +
> + /* Just a simple clone3() should return 0.*/
> + test_clone3(0, 0, 0, CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() in a new PID NS.*/
> + if (uid == 0)
> + test_clone3(CLONE_NEWPID, 0, 0, CLONE3_ARGS_NO_TEST);
> + else
> + ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
> +
> + /* Do a clone3() with CLONE3_ARGS_SIZE_V0. */
> + test_clone3(0, CLONE3_ARGS_SIZE_V0, 0, CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() with CLONE3_ARGS_SIZE_V0 - 8 */
> + test_clone3(0, CLONE3_ARGS_SIZE_V0 - 8, -EINVAL, CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() with sizeof(struct clone_args) + 8 */
> + test_clone3(0, sizeof(struct clone_args) + 8, 0, CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() with all members set to 1 */
> + test_clone3(0, 0, -EINVAL, CLONE3_ARGS_ALL_1);
> +
> + /* Do a clone3() with exit_signal having highest 32 bits non-zero */
> + test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG);
> +
> + /* Do a clone3() with negative 32-bit exit_signal */
> + test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG);
> +
> + /* Do a clone3() with exit_signal not fitting into CSIGNAL mask */
> + test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG);
> +
> + /* Do a clone3() with NSIG < exit_signal < CSIG */
> + test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG);
> +
> + /*
> + * Do a clone3() with sizeof(struct clone_args) + 8
> + * and all members set to 0. This resets exit_signal and wait()
> + * will not get a result.
> + */
> + test_clone3(0, sizeof(struct clone_args) + 8, -ECHILD,
> + CLONE3_ARGS_ALL_0);
>
> Ah, I haven't caught this during the first review. No, that's not
> correct. You don't get a signal since exit_signal is 0, that's correct
> _but_ you still need to wait on the child. You don't see the child
> because the kernel will by default not wait on clone()-children aka
> processes created with exit_signal != SIGCHLD. To wait on
> clone()-children as well, you need to set __WCLONE or __WALL in the
> options argument for wait{p}id(2).
>
> +
> + /*
> + * Do a clone3() with sizeof(struct clone_args) + 8
> + * and all members set to 0.
> + */
> + test_clone3(0, sizeof(struct clone_args) + 8, -EINVAL,
> + CLONE3_ARGS_ALL_1);
>
> The comment and the test don't line up. :)
>
> +
> + /* Do a clone3() with > page size */
> + test_clone3(0, getpagesize() + 8, -E2BIG, CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() with CLONE3_ARGS_SIZE_V0 in a new PID NS. */
> + if (uid == 0)
> + test_clone3(CLONE_NEWPID, CLONE3_ARGS_SIZE_V0, 0,
> + CLONE3_ARGS_NO_TEST);
> + else
> + ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
> +
> + /* Do a clone3() with CLONE3_ARGS_SIZE_V0 - 8 in a new PID NS */
> + test_clone3(CLONE_NEWPID, CLONE3_ARGS_SIZE_V0 - 8, -EINVAL,
> + CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() with sizeof(struct clone_args) + 8 in a new PID NS */
> + if (uid == 0)
> + test_clone3(CLONE_NEWPID, sizeof(struct clone_args) + 8, 0,
> + CLONE3_ARGS_NO_TEST);
> + else
> + ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
> +
> + /* Do a clone3() with > page size in a new PID NS */
> + test_clone3(CLONE_NEWPID, getpagesize() + 8, -E2BIG,
> + CLONE3_ARGS_NO_TEST);
> +
> + return !ksft_get_fail_cnt() ? ksft_exit_pass() : ksft_exit_fail();
> +}
> --
> 2.23.0
>
On Mon, Nov 04, 2019 at 02:18:46PM +0100, Adrian Reber wrote:
> This adds tests for clone3() with different values and sizes
> of struct clone_args.
>
> This selftest was initially part of of the clone3() with PID selftest.
> After that patch was almost merged Eugene sent out a couple of patches
> to fix problems with these test.
>
> This commit now only contains the clone3() selftest after the LPC
> decision to rework clone3() with PID to allow setting the PID in
> multiple PID namespaces including all of Eugene's patches.
>
> Signed-off-by: Eugene Syromiatnikov <[email protected]>
> Signed-off-by: Adrian Reber <[email protected]>
Resending, since mutt messed-up the quoting due to a new configuration I
was testing.
A few more comments below.
Also, would you be open to adding tests here for the newly added .stack
and .stack_size API (cf. [1])?
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa729c4df558936b4a1a7b3e2234011f44ede28b
> ---
> v2:
> - Applied Christian's suggestions
> - Skip root-only tests when running as non-root
> ---
> MAINTAINERS | 1 +
> tools/testing/selftests/Makefile | 1 +
> tools/testing/selftests/clone3/.gitignore | 1 +
> tools/testing/selftests/clone3/Makefile | 7 +
> tools/testing/selftests/clone3/clone3.c | 225 ++++++++++++++++++++++
> 5 files changed, 235 insertions(+)
> create mode 100644 tools/testing/selftests/clone3/.gitignore
> create mode 100644 tools/testing/selftests/clone3/Makefile
> create mode 100644 tools/testing/selftests/clone3/clone3.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index cba1095547fd..0040b7a6410b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -12829,6 +12829,7 @@ S: Maintained
> T: git git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git
> F: samples/pidfd/
> F: tools/testing/selftests/pidfd/
> +F: tools/testing/selftests/clone3/
> K: (?i)pidfd
> K: (?i)clone3
> K: \b(clone_args|kernel_clone_args)\b
> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
> index 4cdbae6f4e61..ad442364218a 100644
> --- a/tools/testing/selftests/Makefile
> +++ b/tools/testing/selftests/Makefile
> @@ -4,6 +4,7 @@ TARGETS += bpf
> TARGETS += breakpoints
> TARGETS += capabilities
> TARGETS += cgroup
> +TARGETS += clone3
> TARGETS += cpufreq
> TARGETS += cpu-hotplug
> TARGETS += drivers/dma-buf
> diff --git a/tools/testing/selftests/clone3/.gitignore b/tools/testing/selftests/clone3/.gitignore
> new file mode 100644
> index 000000000000..85d9d3ba2524
> --- /dev/null
> +++ b/tools/testing/selftests/clone3/.gitignore
> @@ -0,0 +1 @@
> +clone3
> diff --git a/tools/testing/selftests/clone3/Makefile b/tools/testing/selftests/clone3/Makefile
> new file mode 100644
> index 000000000000..ea922c014ae4
> --- /dev/null
> +++ b/tools/testing/selftests/clone3/Makefile
> @@ -0,0 +1,7 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +CFLAGS += -I../../../../usr/include/
> +
> +TEST_GEN_PROGS := clone3
> +
> +include ../lib.mk
> diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
> new file mode 100644
> index 000000000000..a982d95189bf
> --- /dev/null
> +++ b/tools/testing/selftests/clone3/clone3.c
> @@ -0,0 +1,225 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/* Based on Christian Brauner's clone3() example */
> +
> +#define _GNU_SOURCE
> +#include <errno.h>
> +#include <inttypes.h>
> +#include <linux/types.h>
> +#include <linux/sched.h>
> +#include <stdint.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <sys/syscall.h>
> +#include <sys/types.h>
> +#include <sys/un.h>
> +#include <sys/wait.h>
> +#include <unistd.h>
> +#include <sched.h>
> +
> +#include "../kselftest.h"
> +
> +/*
> + * Different sizes of struct clone_args
> + */
> +#ifndef CLONE3_ARGS_SIZE_V0
> +#define CLONE3_ARGS_SIZE_V0 64
> +#endif
> +
> +enum test_mode {
> + CLONE3_ARGS_NO_TEST,
> + CLONE3_ARGS_ALL_0,
> + CLONE3_ARGS_ALL_1,
> + CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG,
> + CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG,
> + CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG,
> + CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
> +};
> +
> +static pid_t raw_clone(struct clone_args *args, size_t size)
> +{
> + return syscall(__NR_clone3, args, size);
> +}
> +
> +static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
> +{
> + struct clone_args args = {
> + .flags = flags,
> + .exit_signal = SIGCHLD,
> + };
> +
> + struct clone_args_extended {
> + struct clone_args args;
> + __aligned_u64 excess_space[2];
> + } args_ext;
> +
> + pid_t pid = -1;
> + int status;
> +
> + memset(&args_ext, 0, sizeof(args_ext));
> + if (size > sizeof(struct clone_args))
> + args_ext.excess_space[1] = 1;
> +
> + if (size == 0)
> + size = sizeof(struct clone_args);
> +
> + switch (test_mode) {
> + case CLONE3_ARGS_ALL_0:
> + args.flags = 0;
> + args.exit_signal = 0;
> + break;
> + case CLONE3_ARGS_ALL_1:
I don't fully understand this test case. What is this for exactly?
> + args.flags = 1;
> + args.pidfd = 1;
> + args.child_tid = 1;
> + args.parent_tid = 1;
> + args.exit_signal = 1;
> + args.stack = 1;
> + args. stack_size = 1;
> + args.tls = 1;
> + break;
> + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG:
> + args.exit_signal = 0xbadc0ded00000000ULL;
> + break;
> + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG:
> + args.exit_signal = 0x0000000080000000ULL;
> + break;
> + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG:
> + args.exit_signal = 0x0000000000000100ULL;
> + break;
> + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG:
> + args.exit_signal = 0x00000000000000f0ULL;
> + break;
> + }
> +
> + memcpy(&args_ext.args, &args, sizeof(struct clone_args));
> +
> + pid = raw_clone((struct clone_args *)&args_ext, size);
> + if (pid < 0) {
> + ksft_print_msg("%s - Failed to create new process\n",
> + strerror(errno));
> + return -errno;
> + }
> +
> + if (pid == 0) {
> + ksft_print_msg("I am the child, my PID is %d\n", getpid());
> + _exit(EXIT_SUCCESS);
> + }
> +
> + ksft_print_msg("I am the parent (%d). My child's pid is %d\n",
> + getpid(), pid);
> +
> + if (wait(&status) < 0) {
> + ksft_print_msg("Child returned %s\n", strerror(errno));
> + return -errno;
> + }
> + if (WEXITSTATUS(status))
> + return WEXITSTATUS(status);
> +
> + return 0;
> +}
> +
> +static void test_clone3(uint64_t flags, size_t size, int expected,
> + enum test_mode test_mode)
> +{
> + int ret;
> +
> + ksft_print_msg(
> + "[%d] Trying clone3() with flags %#" PRIx64 " (size %zu)\n",
> + getpid(), flags, size);
> + ret = call_clone3(flags, size, test_mode);
> + ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n",
> + getpid(), ret, expected);
> + if (ret != expected)
> + ksft_test_result_fail(
> + "[%d] Result (%d) is different than expected (%d)\n",
> + getpid(), ret, expected);
> + else
> + ksft_test_result_pass(
> + "[%d] Result (%d) matches expectation (%d)\n",
> + getpid(), ret, expected);
> +}
> +int main(int argc, char *argv[])
> +{
> + pid_t pid;
> +
> + uid_t uid = getuid();
> +
> + ksft_print_header();
> + ksft_set_plan(17);
> +
> + /* Just a simple clone3() should return 0.*/
> + test_clone3(0, 0, 0, CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() in a new PID NS.*/
> + if (uid == 0)
> + test_clone3(CLONE_NEWPID, 0, 0, CLONE3_ARGS_NO_TEST);
> + else
> + ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
> +
> + /* Do a clone3() with CLONE3_ARGS_SIZE_V0. */
> + test_clone3(0, CLONE3_ARGS_SIZE_V0, 0, CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() with CLONE3_ARGS_SIZE_V0 - 8 */
> + test_clone3(0, CLONE3_ARGS_SIZE_V0 - 8, -EINVAL, CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() with sizeof(struct clone_args) + 8 */
> + test_clone3(0, sizeof(struct clone_args) + 8, 0, CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() with all members set to 1 */
> + test_clone3(0, 0, -EINVAL, CLONE3_ARGS_ALL_1);
> +
> + /* Do a clone3() with exit_signal having highest 32 bits non-zero */
> + test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG);
> +
> + /* Do a clone3() with negative 32-bit exit_signal */
> + test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG);
> +
> + /* Do a clone3() with exit_signal not fitting into CSIGNAL mask */
> + test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG);
> +
> + /* Do a clone3() with NSIG < exit_signal < CSIG */
> + test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG);
> +
> + /*
> + * Do a clone3() with sizeof(struct clone_args) + 8
> + * and all members set to 0. This resets exit_signal and wait()
> + * will not get a result.
> + */
> + test_clone3(0, sizeof(struct clone_args) + 8, -ECHILD,
> + CLONE3_ARGS_ALL_0);
Ah, I haven't caught this during the first review. No, that's not
correct. You don't get a signal since exit_signal is 0, that's correct
_but_ you still need to wait on the child. You don't see the child
because the kernel will by default not wait on clone()-children aka
processes created with exit_signal != SIGCHLD. To wait on
clone()-children as well, you need to set __WCLONE or __WALL in the
options argument for wait{p}id(2).
> +
> + /*
> + * Do a clone3() with sizeof(struct clone_args) + 8
> + * and all members set to 0.
> + */
> + test_clone3(0, sizeof(struct clone_args) + 8, -EINVAL,
> + CLONE3_ARGS_ALL_1);
The comment and the test don't line up. :)
> +
> + /* Do a clone3() with > page size */
> + test_clone3(0, getpagesize() + 8, -E2BIG, CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() with CLONE3_ARGS_SIZE_V0 in a new PID NS. */
> + if (uid == 0)
> + test_clone3(CLONE_NEWPID, CLONE3_ARGS_SIZE_V0, 0,
> + CLONE3_ARGS_NO_TEST);
> + else
> + ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
> +
> + /* Do a clone3() with CLONE3_ARGS_SIZE_V0 - 8 in a new PID NS */
> + test_clone3(CLONE_NEWPID, CLONE3_ARGS_SIZE_V0 - 8, -EINVAL,
> + CLONE3_ARGS_NO_TEST);
> +
> + /* Do a clone3() with sizeof(struct clone_args) + 8 in a new PID NS */
> + if (uid == 0)
> + test_clone3(CLONE_NEWPID, sizeof(struct clone_args) + 8, 0,
> + CLONE3_ARGS_NO_TEST);
> + else
> + ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
> +
> + /* Do a clone3() with > page size in a new PID NS */
> + test_clone3(CLONE_NEWPID, getpagesize() + 8, -E2BIG,
> + CLONE3_ARGS_NO_TEST);
> +
> + return !ksft_get_fail_cnt() ? ksft_exit_pass() : ksft_exit_fail();
> +}
> --
> 2.23.0
>
On Wed, Nov 06, 2019 at 04:59:14PM +0100, Christian Brauner wrote:
> On Mon, Nov 04, 2019 at 02:18:46PM +0100, Adrian Reber wrote:
> > This adds tests for clone3() with different values and sizes
> > of struct clone_args.
> >
> > This selftest was initially part of of the clone3() with PID selftest.
> > After that patch was almost merged Eugene sent out a couple of patches
> > to fix problems with these test.
> >
> > This commit now only contains the clone3() selftest after the LPC
> > decision to rework clone3() with PID to allow setting the PID in
> > multiple PID namespaces including all of Eugene's patches.
> >
> > Signed-off-by: Eugene Syromiatnikov <[email protected]>
> > Signed-off-by: Adrian Reber <[email protected]>
>
> Resending, since mutt messed-up the quoting due to a new configuration I
> was testing.
>
> A few more comments below.
>
> Also, would you be open to adding tests here for the newly added .stack
> and .stack_size API (cf. [1])?
Actually, forget that part for now. We can do this later in a separate
patchset.
Christian
On Wed, Nov 06, 2019 at 04:59:15PM +0100, Christian Brauner wrote:
> On Mon, Nov 04, 2019 at 02:18:46PM +0100, Adrian Reber wrote:
> > This adds tests for clone3() with different values and sizes
> > of struct clone_args.
> >
> > This selftest was initially part of of the clone3() with PID selftest.
> > After that patch was almost merged Eugene sent out a couple of patches
> > to fix problems with these test.
> >
> > This commit now only contains the clone3() selftest after the LPC
> > decision to rework clone3() with PID to allow setting the PID in
> > multiple PID namespaces including all of Eugene's patches.
> >
> > Signed-off-by: Eugene Syromiatnikov <[email protected]>
> > Signed-off-by: Adrian Reber <[email protected]>
>
> Resending, since mutt messed-up the quoting due to a new configuration I
> was testing.
>
> A few more comments below.
>
> Also, would you be open to adding tests here for the newly added .stack
> and .stack_size API (cf. [1])?
>
> [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa729c4df558936b4a1a7b3e2234011f44ede28b
As mentioned in your follow-up email. Let's do that in a later patch.
> > ---
> > v2:
> > - Applied Christian's suggestions
> > - Skip root-only tests when running as non-root
> > ---
> > MAINTAINERS | 1 +
> > tools/testing/selftests/Makefile | 1 +
> > tools/testing/selftests/clone3/.gitignore | 1 +
> > tools/testing/selftests/clone3/Makefile | 7 +
> > tools/testing/selftests/clone3/clone3.c | 225 ++++++++++++++++++++++
> > 5 files changed, 235 insertions(+)
> > create mode 100644 tools/testing/selftests/clone3/.gitignore
> > create mode 100644 tools/testing/selftests/clone3/Makefile
> > create mode 100644 tools/testing/selftests/clone3/clone3.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index cba1095547fd..0040b7a6410b 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -12829,6 +12829,7 @@ S: Maintained
> > T: git git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git
> > F: samples/pidfd/
> > F: tools/testing/selftests/pidfd/
> > +F: tools/testing/selftests/clone3/
> > K: (?i)pidfd
> > K: (?i)clone3
> > K: \b(clone_args|kernel_clone_args)\b
> > diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
> > index 4cdbae6f4e61..ad442364218a 100644
> > --- a/tools/testing/selftests/Makefile
> > +++ b/tools/testing/selftests/Makefile
> > @@ -4,6 +4,7 @@ TARGETS += bpf
> > TARGETS += breakpoints
> > TARGETS += capabilities
> > TARGETS += cgroup
> > +TARGETS += clone3
> > TARGETS += cpufreq
> > TARGETS += cpu-hotplug
> > TARGETS += drivers/dma-buf
> > diff --git a/tools/testing/selftests/clone3/.gitignore b/tools/testing/selftests/clone3/.gitignore
> > new file mode 100644
> > index 000000000000..85d9d3ba2524
> > --- /dev/null
> > +++ b/tools/testing/selftests/clone3/.gitignore
> > @@ -0,0 +1 @@
> > +clone3
> > diff --git a/tools/testing/selftests/clone3/Makefile b/tools/testing/selftests/clone3/Makefile
> > new file mode 100644
> > index 000000000000..ea922c014ae4
> > --- /dev/null
> > +++ b/tools/testing/selftests/clone3/Makefile
> > @@ -0,0 +1,7 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +
> > +CFLAGS += -I../../../../usr/include/
> > +
> > +TEST_GEN_PROGS := clone3
> > +
> > +include ../lib.mk
> > diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
> > new file mode 100644
> > index 000000000000..a982d95189bf
> > --- /dev/null
> > +++ b/tools/testing/selftests/clone3/clone3.c
> > @@ -0,0 +1,225 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +/* Based on Christian Brauner's clone3() example */
> > +
> > +#define _GNU_SOURCE
> > +#include <errno.h>
> > +#include <inttypes.h>
> > +#include <linux/types.h>
> > +#include <linux/sched.h>
> > +#include <stdint.h>
> > +#include <stdio.h>
> > +#include <stdlib.h>
> > +#include <sys/syscall.h>
> > +#include <sys/types.h>
> > +#include <sys/un.h>
> > +#include <sys/wait.h>
> > +#include <unistd.h>
> > +#include <sched.h>
> > +
> > +#include "../kselftest.h"
> > +
> > +/*
> > + * Different sizes of struct clone_args
> > + */
> > +#ifndef CLONE3_ARGS_SIZE_V0
> > +#define CLONE3_ARGS_SIZE_V0 64
> > +#endif
> > +
> > +enum test_mode {
> > + CLONE3_ARGS_NO_TEST,
> > + CLONE3_ARGS_ALL_0,
> > + CLONE3_ARGS_ALL_1,
> > + CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG,
> > + CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG,
> > + CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG,
> > + CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
> > +};
> > +
> > +static pid_t raw_clone(struct clone_args *args, size_t size)
> > +{
> > + return syscall(__NR_clone3, args, size);
> > +}
> > +
> > +static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
> > +{
> > + struct clone_args args = {
> > + .flags = flags,
> > + .exit_signal = SIGCHLD,
> > + };
> > +
> > + struct clone_args_extended {
> > + struct clone_args args;
> > + __aligned_u64 excess_space[2];
> > + } args_ext;
> > +
> > + pid_t pid = -1;
> > + int status;
> > +
> > + memset(&args_ext, 0, sizeof(args_ext));
> > + if (size > sizeof(struct clone_args))
> > + args_ext.excess_space[1] = 1;
> > +
> > + if (size == 0)
> > + size = sizeof(struct clone_args);
> > +
> > + switch (test_mode) {
> > + case CLONE3_ARGS_ALL_0:
> > + args.flags = 0;
> > + args.exit_signal = 0;
> > + break;
> > + case CLONE3_ARGS_ALL_1:
>
> I don't fully understand this test case. What is this for exactly?
Not sure myself. It was just to make sure clone3() does not something
unexpected when given wrong and unexpected input. It is the opposite to
setting everything to zero. Not sure how much sense it makes, but as it
already exists I would say to just keep it.
> > + args.flags = 1;
> > + args.pidfd = 1;
> > + args.child_tid = 1;
> > + args.parent_tid = 1;
> > + args.exit_signal = 1;
> > + args.stack = 1;
> > + args.stack_size = 1;
> > + args.tls = 1;
> > + break;
> > + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG:
[...]
Let me know if you think that the CLONE3_ARGS_ALL_1 should really be
removed. I will fix the other two things you mentioned and resend a new
version.
Adrian
On Fri, Nov 08, 2019 at 07:44:16AM +0100, Adrian Reber wrote:
> On Wed, Nov 06, 2019 at 04:59:15PM +0100, Christian Brauner wrote:
> > On Mon, Nov 04, 2019 at 02:18:46PM +0100, Adrian Reber wrote:
> Not sure myself. It was just to make sure clone3() does not something
> unexpected when given wrong and unexpected input. It is the opposite to
> setting everything to zero. Not sure how much sense it makes, but as it
> already exists I would say to just keep it.
If it serves no real purpose then please remove it. It's not clear from
thist test _why_ it it expected to fail. Is it because of invalid stack
and stack_size or invalid tls etc.
>
> > > + args.flags = 1;
> > > + args.pidfd = 1;
> > > + args.child_tid = 1;
> > > + args.parent_tid = 1;
> > > + args.exit_signal = 1;
> > > + args.stack = 1;
> > > + args.stack_size = 1;
> > > + args.tls = 1;
> > > + break;
> > > + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG:
> [...]
>
> Let me know if you think that the CLONE3_ARGS_ALL_1 should really be
> removed. I will fix the other two things you mentioned and resend a new
> version.
Yes, please.
Christian