1 files changed, 518 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/task_local_storage.c b/tools/testing/selftests/bpf/prog_tests/task_local_storage.c
new file mode 100644
index 000000000000..42e822ea352f
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/task_local_storage.c
@@ -0,0 +1,518 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+
+#define _GNU_SOURCE         /* See feature_test_macros(7) */
+#include <unistd.h>
+#include <sched.h>
+#include <pthread.h>
+#include <sys/syscall.h>   /* For SYS_xxx definitions */
+#include <sys/types.h>
+#include <sys/eventfd.h>
+#include <sys/mman.h>
+#include <test_progs.h>
+#include <bpf/btf.h>
+#include "task_local_storage_helpers.h"
+#include "task_local_storage.skel.h"
+#include "task_local_storage_exit_creds.skel.h"
+#include "task_ls_recursion.skel.h"
+#include "task_storage_nodeadlock.skel.h"
+#include "uptr_test_common.h"
+#include "task_ls_uptr.skel.h"
+#include "uptr_update_failure.skel.h"
+#include "uptr_failure.skel.h"
+#include "uptr_map_failure.skel.h"
+
+static void test_sys_enter_exit(void)
+{
+	struct task_local_storage *skel;
+	int err;
+
+	skel = task_local_storage__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
+		return;
+
+	skel->bss->target_pid = sys_gettid();
+
+	err = task_local_storage__attach(skel);
+	if (!ASSERT_OK(err, "skel_attach"))
+		goto out;
+
+	sys_gettid();
+	sys_gettid();
+
+	/* 3x syscalls: 1x attach and 2x gettid */
+	ASSERT_EQ(skel->bss->enter_cnt, 3, "enter_cnt");
+	ASSERT_EQ(skel->bss->exit_cnt, 3, "exit_cnt");
+	ASSERT_EQ(skel->bss->mismatch_cnt, 0, "mismatch_cnt");
+out:
+	task_local_storage__destroy(skel);
+}
+
+static void test_exit_creds(void)
+{
+	struct task_local_storage_exit_creds *skel;
+	int err, run_count, sync_rcu_calls = 0;
+	const int MAX_SYNC_RCU_CALLS = 1000;
+
+	skel = task_local_storage_exit_creds__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
+		return;
+
+	err = task_local_storage_exit_creds__attach(skel);
+	if (!ASSERT_OK(err, "skel_attach"))
+		goto out;
+
+	/* trigger at least one exit_creds() */
+	if (CHECK_FAIL(system("ls > /dev/null")))
+		goto out;
+
+	/* kern_sync_rcu is not enough on its own as the read section we want
+	 * to wait for may start after we enter synchronize_rcu, so our call
+	 * won't wait for the section to finish. Loop on the run counter
+	 * as well to ensure the program has run.
+	 */
+	do {
+		kern_sync_rcu();
+		run_count = __atomic_load_n(&skel->bss->run_count, __ATOMIC_SEQ_CST);
+	} while (run_count == 0 && ++sync_rcu_calls < MAX_SYNC_RCU_CALLS);
+
+	ASSERT_NEQ(sync_rcu_calls, MAX_SYNC_RCU_CALLS,
+		   "sync_rcu count too high");
+	ASSERT_NEQ(run_count, 0, "run_count");
+	ASSERT_EQ(skel->bss->valid_ptr_count, 0, "valid_ptr_count");
+	ASSERT_NEQ(skel->bss->null_ptr_count, 0, "null_ptr_count");
+out:
+	task_local_storage_exit_creds__destroy(skel);
+}
+
+static void test_recursion(void)
+{
+	int err, map_fd, prog_fd, task_fd;
+	struct task_ls_recursion *skel;
+	struct bpf_prog_info info;
+	__u32 info_len = sizeof(info);
+	long value;
+
+	task_fd = sys_pidfd_open(getpid(), 0);
+	if (!ASSERT_NEQ(task_fd, -1, "sys_pidfd_open"))
+		return;
+
+	skel = task_ls_recursion__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
+		goto out;
+
+	err = task_ls_recursion__attach(skel);
+	if (!ASSERT_OK(err, "skel_attach"))
+		goto out;
+
+	/* trigger sys_enter, make sure it does not cause deadlock */
+	skel->bss->test_pid = getpid();
+	sys_gettid();
+	skel->bss->test_pid = 0;
+	task_ls_recursion__detach(skel);
+
+	/* Refer to the comment in BPF_PROG(on_update) for
+	 * the explanation on the value 201 and 100.
+	 */
+	map_fd = bpf_map__fd(skel->maps.map_a);
+	err = bpf_map_lookup_elem(map_fd, &task_fd, &value);
+	ASSERT_OK(err, "lookup map_a");
+	ASSERT_EQ(value, 201, "map_a value");
+	ASSERT_EQ(skel->bss->nr_del_errs, 1, "bpf_task_storage_delete busy");
+
+	map_fd = bpf_map__fd(skel->maps.map_b);
+	err = bpf_map_lookup_elem(map_fd, &task_fd, &value);
+	ASSERT_OK(err, "lookup map_b");
+	ASSERT_EQ(value, 100, "map_b value");
+
+	prog_fd = bpf_program__fd(skel->progs.on_update);
+	memset(&info, 0, sizeof(info));
+	err = bpf_prog_get_info_by_fd(prog_fd, &info, &info_len);
+	ASSERT_OK(err, "get prog info");
+	ASSERT_EQ(info.recursion_misses, 0, "on_update prog recursion");
+
+	prog_fd = bpf_program__fd(skel->progs.on_enter);
+	memset(&info, 0, sizeof(info));
+	err = bpf_prog_get_info_by_fd(prog_fd, &info, &info_len);
+	ASSERT_OK(err, "get prog info");
+	ASSERT_EQ(info.recursion_misses, 0, "on_enter prog recursion");
+
+out:
+	close(task_fd);
+	task_ls_recursion__destroy(skel);
+}
+
+static bool stop;
+
+static void waitall(const pthread_t *tids, int nr)
+{
+	int i;
+
+	stop = true;
+	for (i = 0; i < nr; i++)
+		pthread_join(tids[i], NULL);
+}
+
+static void *sock_create_loop(void *arg)
+{
+	struct task_storage_nodeadlock *skel = arg;
+	int fd;
+
+	while (!stop) {
+		fd = socket(AF_INET, SOCK_STREAM, 0);
+		close(fd);
+		if (skel->bss->nr_get_errs || skel->bss->nr_del_errs)
+			stop = true;
+	}
+
+	return NULL;
+}
+
+static void test_nodeadlock(void)
+{
+	struct task_storage_nodeadlock *skel;
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	const int nr_threads = 32;
+	pthread_t tids[nr_threads];
+	int i, prog_fd, err;
+	cpu_set_t old, new;
+
+	/* Pin all threads to one cpu to increase the chance of preemption
+	 * in a sleepable bpf prog.
+	 */
+	CPU_ZERO(&new);
+	CPU_SET(0, &new);
+	err = sched_getaffinity(getpid(), sizeof(old), &old);
+	if (!ASSERT_OK(err, "getaffinity"))
+		return;
+	err = sched_setaffinity(getpid(), sizeof(new), &new);
+	if (!ASSERT_OK(err, "setaffinity"))
+		return;
+
+	skel = task_storage_nodeadlock__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "open_and_load"))
+		goto done;
+
+	/* Unnecessary recursion and deadlock detection are reproducible
+	 * in the preemptible kernel.
+	 */
+	if (!skel->kconfig->CONFIG_PREEMPTION) {
+		test__skip();
+		goto done;
+	}
+
+	err = task_storage_nodeadlock__attach(skel);
+	ASSERT_OK(err, "attach prog");
+
+	for (i = 0; i < nr_threads; i++) {
+		err = pthread_create(&tids[i], NULL, sock_create_loop, skel);
+		if (err) {
+			/* Only assert once here to avoid excessive
+			 * PASS printing during test failure.
+			 */
+			ASSERT_OK(err, "pthread_create");
+			waitall(tids, i);
+			goto done;
+		}
+	}
+
+	/* With 32 threads, 1s is enough to reproduce the issue */
+	sleep(1);
+	waitall(tids, nr_threads);
+
+	info_len = sizeof(info);
+	prog_fd = bpf_program__fd(skel->progs.socket_post_create);
+	err = bpf_prog_get_info_by_fd(prog_fd, &info, &info_len);
+	ASSERT_OK(err, "get prog info");
+	ASSERT_EQ(info.recursion_misses, 0, "prog recursion");
+
+	ASSERT_EQ(skel->bss->nr_get_errs, 0, "bpf_task_storage_get busy");
+	ASSERT_EQ(skel->bss->nr_del_errs, 0, "bpf_task_storage_delete busy");
+
+done:
+	task_storage_nodeadlock__destroy(skel);
+	sched_setaffinity(getpid(), sizeof(old), &old);
+}
+
+static struct user_data udata __attribute__((aligned(16))) = {
+	.a = 1,
+	.b = 2,
+};
+
+static struct user_data udata2 __attribute__((aligned(16))) = {
+	.a = 3,
+	.b = 4,
+};
+
+static void check_udata2(int expected)
+{
+	udata2.result = udata2.nested_result = 0;
+	usleep(1);
+	ASSERT_EQ(udata2.result, expected, "udata2.result");
+	ASSERT_EQ(udata2.nested_result, expected, "udata2.nested_result");
+}
+
+static void test_uptr_basic(void)
+{
+	int map_fd, parent_task_fd, ev_fd;
+	struct value_type value = {};
+	struct task_ls_uptr *skel;
+	pid_t child_pid, my_tid;
+	__u64 ev_dummy_data = 1;
+	int err;
+
+	my_tid = sys_gettid();
+	parent_task_fd = sys_pidfd_open(my_tid, 0);
+	if (!ASSERT_OK_FD(parent_task_fd, "parent_task_fd"))
+		return;
+
+	ev_fd = eventfd(0, 0);
+	if (!ASSERT_OK_FD(ev_fd, "ev_fd")) {
+		close(parent_task_fd);
+		return;
+	}
+
+	skel = task_ls_uptr__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
+		goto out;
+
+	map_fd = bpf_map__fd(skel->maps.datamap);
+	value.udata = &udata;
+	value.nested.udata = &udata;
+	err = bpf_map_update_elem(map_fd, &parent_task_fd, &value, BPF_NOEXIST);
+	if (!ASSERT_OK(err, "update_elem(udata)"))
+		goto out;
+
+	err = task_ls_uptr__attach(skel);
+	if (!ASSERT_OK(err, "skel_attach"))
+		goto out;
+
+	child_pid = fork();
+	if (!ASSERT_NEQ(child_pid, -1, "fork"))
+		goto out;
+
+	/* Call syscall in the child process, but access the map value of
+	 * the parent process in the BPF program to check if the user kptr
+	 * is translated/mapped correctly.
+	 */
+	if (child_pid == 0) {
+		/* child */
+
+		/* Overwrite the user_data in the child process to check if
+		 * the BPF program accesses the user_data of the parent.
+		 */
+		udata.a = 0;
+		udata.b = 0;
+
+		/* Wait for the parent to set child_pid */
+		read(ev_fd, &ev_dummy_data, sizeof(ev_dummy_data));
+		exit(0);
+	}
+
+	skel->bss->parent_pid = my_tid;
+	skel->bss->target_pid = child_pid;
+
+	write(ev_fd, &ev_dummy_data, sizeof(ev_dummy_data));
+
+	err = waitpid(child_pid, NULL, 0);
+	ASSERT_EQ(err, child_pid, "waitpid");
+	ASSERT_EQ(udata.result, MAGIC_VALUE + udata.a + udata.b, "udata.result");
+	ASSERT_EQ(udata.nested_result, MAGIC_VALUE + udata.a + udata.b, "udata.nested_result");
+
+	skel->bss->target_pid = my_tid;
+
+	/* update_elem: uptr changes from udata1 to udata2 */
+	value.udata = &udata2;
+	value.nested.udata = &udata2;
+	err = bpf_map_update_elem(map_fd, &parent_task_fd, &value, BPF_EXIST);
+	if (!ASSERT_OK(err, "update_elem(udata2)"))
+		goto out;
+	check_udata2(MAGIC_VALUE + udata2.a + udata2.b);
+
+	/* update_elem: uptr changes from udata2 uptr to NULL */
+	memset(&value, 0, sizeof(value));
+	err = bpf_map_update_elem(map_fd, &parent_task_fd, &value, BPF_EXIST);
+	if (!ASSERT_OK(err, "update_elem(udata2)"))
+		goto out;
+	check_udata2(0);
+
+	/* update_elem: uptr changes from NULL to udata2 */
+	value.udata = &udata2;
+	value.nested.udata = &udata2;
+	err = bpf_map_update_elem(map_fd, &parent_task_fd, &value, BPF_EXIST);
+	if (!ASSERT_OK(err, "update_elem(udata2)"))
+		goto out;
+	check_udata2(MAGIC_VALUE + udata2.a + udata2.b);
+
+	/* Check if user programs can access the value of user kptrs
+	 * through bpf_map_lookup_elem(). Make sure the kernel value is not
+	 * leaked.
+	 */
+	err = bpf_map_lookup_elem(map_fd, &parent_task_fd, &value);
+	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
+		goto out;
+	ASSERT_EQ(value.udata, NULL, "value.udata");
+	ASSERT_EQ(value.nested.udata, NULL, "value.nested.udata");
+
+	/* delete_elem */
+	err = bpf_map_delete_elem(map_fd, &parent_task_fd);
+	ASSERT_OK(err, "delete_elem(udata2)");
+	check_udata2(0);
+
+	/* update_elem: add uptr back to test map_free */
+	value.udata = &udata2;
+	value.nested.udata = &udata2;
+	err = bpf_map_update_elem(map_fd, &parent_task_fd, &value, BPF_NOEXIST);
+	ASSERT_OK(err, "update_elem(udata2)");
+
+out:
+	task_ls_uptr__destroy(skel);
+	close(ev_fd);
+	close(parent_task_fd);
+}
+
+static void test_uptr_across_pages(void)
+{
+	int page_size = getpagesize();
+	struct value_type value = {};
+	struct task_ls_uptr *skel;
+	int err, task_fd, map_fd;
+	void *mem;
+
+	task_fd = sys_pidfd_open(getpid(), 0);
+	if (!ASSERT_OK_FD(task_fd, "task_fd"))
+		return;
+
+	mem = mmap(NULL, page_size * 2, PROT_READ | PROT_WRITE,
+		   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	if (!ASSERT_OK_PTR(mem, "mmap(page_size * 2)")) {
+		close(task_fd);
+		return;
+	}
+
+	skel = task_ls_uptr__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
+		goto out;
+
+	map_fd = bpf_map__fd(skel->maps.datamap);
+	value.udata = mem + page_size - offsetof(struct user_data, b);
+	err = bpf_map_update_elem(map_fd, &task_fd, &value, 0);
+	if (!ASSERT_ERR(err, "update_elem(udata)"))
+		goto out;
+	ASSERT_EQ(errno, EOPNOTSUPP, "errno");
+
+	value.udata = mem + page_size - sizeof(struct user_data);
+	err = bpf_map_update_elem(map_fd, &task_fd, &value, 0);
+	ASSERT_OK(err, "update_elem(udata)");
+
+out:
+	task_ls_uptr__destroy(skel);
+	close(task_fd);
+	munmap(mem, page_size * 2);
+}
+
+static void test_uptr_update_failure(void)
+{
+	struct value_lock_type value = {};
+	struct uptr_update_failure *skel;
+	int err, task_fd, map_fd;
+
+	task_fd = sys_pidfd_open(getpid(), 0);
+	if (!ASSERT_OK_FD(task_fd, "task_fd"))
+		return;
+
+	skel = uptr_update_failure__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
+		goto out;
+
+	map_fd = bpf_map__fd(skel->maps.datamap);
+
+	value.udata = &udata;
+	err = bpf_map_update_elem(map_fd, &task_fd, &value, BPF_F_LOCK);
+	if (!ASSERT_ERR(err, "update_elem(udata, BPF_F_LOCK)"))
+		goto out;
+	ASSERT_EQ(errno, EOPNOTSUPP, "errno");
+
+	err = bpf_map_update_elem(map_fd, &task_fd, &value, BPF_EXIST);
+	if (!ASSERT_ERR(err, "update_elem(udata, BPF_EXIST)"))
+		goto out;
+	ASSERT_EQ(errno, ENOENT, "errno");
+
+	err = bpf_map_update_elem(map_fd, &task_fd, &value, BPF_NOEXIST);
+	if (!ASSERT_OK(err, "update_elem(udata, BPF_NOEXIST)"))
+		goto out;
+
+	value.udata = &udata2;
+	err = bpf_map_update_elem(map_fd, &task_fd, &value, BPF_NOEXIST);
+	if (!ASSERT_ERR(err, "update_elem(udata2, BPF_NOEXIST)"))
+		goto out;
+	ASSERT_EQ(errno, EEXIST, "errno");
+
+out:
+	uptr_update_failure__destroy(skel);
+	close(task_fd);
+}
+
+static void test_uptr_map_failure(const char *map_name, int expected_errno)
+{
+	LIBBPF_OPTS(bpf_map_create_opts, create_attr);
+	struct uptr_map_failure *skel;
+	struct bpf_map *map;
+	struct btf *btf;
+	int map_fd, err;
+
+	skel = uptr_map_failure__open();
+	if (!ASSERT_OK_PTR(skel, "uptr_map_failure__open"))
+		return;
+
+	map = bpf_object__find_map_by_name(skel->obj, map_name);
+	btf = bpf_object__btf(skel->obj);
+	err = btf__load_into_kernel(btf);
+	if (!ASSERT_OK(err, "btf__load_into_kernel"))
+		goto done;
+
+	create_attr.map_flags = bpf_map__map_flags(map);
+	create_attr.btf_fd = btf__fd(btf);
+	create_attr.btf_key_type_id = bpf_map__btf_key_type_id(map);
+	create_attr.btf_value_type_id = bpf_map__btf_value_type_id(map);
+	map_fd = bpf_map_create(bpf_map__type(map), map_name,
+				bpf_map__key_size(map), bpf_map__value_size(map),
+				0, &create_attr);
+	if (ASSERT_ERR_FD(map_fd, "map_create"))
+		ASSERT_EQ(errno, expected_errno, "errno");
+	else
+		close(map_fd);
+
+done:
+	uptr_map_failure__destroy(skel);
+}
+
+void test_task_local_storage(void)
+{
+	if (test__start_subtest("sys_enter_exit"))
+		test_sys_enter_exit();
+	if (test__start_subtest("exit_creds"))
+		test_exit_creds();
+	if (test__start_subtest("recursion"))
+		test_recursion();
+	if (test__start_subtest("nodeadlock"))
+		test_nodeadlock();
+	if (test__start_subtest("uptr_basic"))
+		test_uptr_basic();
+	if (test__start_subtest("uptr_across_pages"))
+		test_uptr_across_pages();
+	if (test__start_subtest("uptr_update_failure"))
+		test_uptr_update_failure();
+	if (test__start_subtest("uptr_map_failure_e2big")) {
+		if (getpagesize() == PAGE_SIZE)
+			test_uptr_map_failure("large_uptr_map", E2BIG);
+		else
+			test__skip();
+	}
+	if (test__start_subtest("uptr_map_failure_size0"))
+		test_uptr_map_failure("empty_uptr_map", EINVAL);
+	if (test__start_subtest("uptr_map_failure_kstruct"))
+		test_uptr_map_failure("kstruct_uptr_map", EINVAL);
+	RUN_TESTS(uptr_failure);
+}