From ba72a7b4badbf4dd3c49c585c3c662bacc54f46e Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 31 Jan 2019 15:40:12 -0800 Subject: selftests/bpf: test for BPF_F_LOCK Add C based test that runs 4 bpf programs in parallel that update the same hash and array maps. And another 2 threads that read from these two maps via lookup(key, value, BPF_F_LOCK) api to make sure the user space sees consistent value in both hash and array elements while user space races with kernel bpf progs. Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/Makefile | 2 +- tools/testing/selftests/bpf/test_map_lock.c | 66 +++++++++++++++++++++++++ tools/testing/selftests/bpf/test_progs.c | 74 +++++++++++++++++++++++++++++ 3 files changed, 141 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/test_map_lock.c diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 302b8e70dec9..9de0a1ae8d65 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -35,7 +35,7 @@ BPF_OBJ_FILES = \ sendmsg4_prog.o sendmsg6_prog.o test_lirc_mode2_kern.o \ get_cgroup_id_kern.o socket_cookie_prog.o test_select_reuseport_kern.o \ test_skb_cgroup_id_kern.o bpf_flow.o netcnt_prog.o test_xdp_vlan.o \ - xdp_dummy.o test_map_in_map.o test_spin_lock.o + xdp_dummy.o test_map_in_map.o test_spin_lock.o test_map_lock.o # Objects are built with default compilation flags and with sub-register # code-gen enabled. diff --git a/tools/testing/selftests/bpf/test_map_lock.c b/tools/testing/selftests/bpf/test_map_lock.c new file mode 100644 index 000000000000..af8cc68ed2f9 --- /dev/null +++ b/tools/testing/selftests/bpf/test_map_lock.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2019 Facebook +#include +#include +#include "bpf_helpers.h" + +#define VAR_NUM 16 + +struct hmap_elem { + struct bpf_spin_lock lock; + int var[VAR_NUM]; +}; + +struct bpf_map_def SEC("maps") hash_map = { + .type = BPF_MAP_TYPE_HASH, + .key_size = sizeof(int), + .value_size = sizeof(struct hmap_elem), + .max_entries = 1, +}; + +BPF_ANNOTATE_KV_PAIR(hash_map, int, struct hmap_elem); + +struct array_elem { + struct bpf_spin_lock lock; + int var[VAR_NUM]; +}; + +struct bpf_map_def SEC("maps") array_map = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(struct array_elem), + .max_entries = 1, +}; + +BPF_ANNOTATE_KV_PAIR(array_map, int, struct array_elem); + +SEC("map_lock_demo") +int bpf_map_lock_test(struct __sk_buff *skb) +{ + struct hmap_elem zero = {}, *val; + int rnd = bpf_get_prandom_u32(); + int key = 0, err = 1, i; + struct array_elem *q; + + val = bpf_map_lookup_elem(&hash_map, &key); + if (!val) + goto err; + /* spin_lock in hash map */ + bpf_spin_lock(&val->lock); + for (i = 0; i < VAR_NUM; i++) + val->var[i] = rnd; + bpf_spin_unlock(&val->lock); + + /* spin_lock in array */ + q = bpf_map_lookup_elem(&array_map, &key); + if (!q) + goto err; + bpf_spin_lock(&q->lock); + for (i = 0; i < VAR_NUM; i++) + q->var[i] = rnd; + bpf_spin_unlock(&q->lock); + err = 0; +err: + return err; +} +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index d2e71d697340..a08d026ac396 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -2025,6 +2025,79 @@ close_prog_noerr: bpf_object__close(obj); } +static void *parallel_map_access(void *arg) +{ + int err, map_fd = *(u32 *) arg; + int vars[17], i, j, rnd, key = 0; + + for (i = 0; i < 10000; i++) { + err = bpf_map_lookup_elem_flags(map_fd, &key, vars, BPF_F_LOCK); + if (err) { + printf("lookup failed\n"); + error_cnt++; + goto out; + } + if (vars[0] != 0) { + printf("lookup #%d var[0]=%d\n", i, vars[0]); + error_cnt++; + goto out; + } + rnd = vars[1]; + for (j = 2; j < 17; j++) { + if (vars[j] == rnd) + continue; + printf("lookup #%d var[1]=%d var[%d]=%d\n", + i, rnd, j, vars[j]); + error_cnt++; + goto out; + } + } +out: + pthread_exit(arg); +} + +static void test_map_lock(void) +{ + const char *file = "./test_map_lock.o"; + int prog_fd, map_fd[2], vars[17] = {}; + pthread_t thread_id[6]; + struct bpf_object *obj; + int err = 0, key = 0, i; + void *ret; + + err = bpf_prog_load(file, BPF_PROG_TYPE_CGROUP_SKB, &obj, &prog_fd); + if (err) { + printf("test_map_lock:bpf_prog_load errno %d\n", errno); + goto close_prog; + } + map_fd[0] = bpf_find_map(__func__, obj, "hash_map"); + if (map_fd[0] < 0) + goto close_prog; + map_fd[1] = bpf_find_map(__func__, obj, "array_map"); + if (map_fd[1] < 0) + goto close_prog; + + bpf_map_update_elem(map_fd[0], &key, vars, BPF_F_LOCK); + + for (i = 0; i < 4; i++) + assert(pthread_create(&thread_id[i], NULL, + &test_spin_lock, &prog_fd) == 0); + for (i = 4; i < 6; i++) + assert(pthread_create(&thread_id[i], NULL, + ¶llel_map_access, &map_fd[i - 4]) == 0); + for (i = 0; i < 4; i++) + assert(pthread_join(thread_id[i], &ret) == 0 && + ret == (void *)&prog_fd); + for (i = 4; i < 6; i++) + assert(pthread_join(thread_id[i], &ret) == 0 && + ret == (void *)&map_fd[i - 4]); + goto close_prog_noerr; +close_prog: + error_cnt++; +close_prog_noerr: + bpf_object__close(obj); +} + int main(void) { srand(time(NULL)); @@ -2054,6 +2127,7 @@ int main(void) test_queue_stack_map(STACK); test_flow_dissector(); test_spinlock(); + test_map_lock(); printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt); return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS; -- cgit v1.2.3-59-g8ed1b