Add non-sleepable and sleepable tests with percpu kptr. For
non-sleepable test, four programs are executed in the order of:
1. allocate percpu data.
2. assign values to percpu data.
3. retrieve percpu data.
4. de-allocate percpu data.
The sleepable prog tried to exercise all above 4 steps in a
single prog. Also for sleepable prog, rcu_read_lock is needed
to protect direct percpu ptr access (from map value) and
following bpf_this_cpu_ptr() and bpf_per_cpu_ptr() helpers.
Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/percpu_alloc.c | 78 ++++++++
.../selftests/bpf/progs/percpu_alloc_array.c | 187 ++++++++++++++++++
2 files changed, 265 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/percpu_alloc.c
create mode 100644 tools/testing/selftests/bpf/progs/percpu_alloc_array.c
diff --git a/tools/testing/selftests/bpf/prog_tests/percpu_alloc.c b/tools/testing/selftests/bpf/prog_tests/percpu_alloc.c
new file mode 100644
index 000000000000..0fb536822f14
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/percpu_alloc.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include "percpu_alloc_array.skel.h"
+
+static void test_array(void)
+{
+ struct percpu_alloc_array *skel;
+ int err, prog_fd;
+ LIBBPF_OPTS(bpf_test_run_opts, topts);
+
+ skel = percpu_alloc_array__open();
+ if (!ASSERT_OK_PTR(skel, "percpu_alloc_array__open"))
+ return;
+
+ bpf_program__set_autoload(skel->progs.test_array_map_1, true);
+ bpf_program__set_autoload(skel->progs.test_array_map_2, true);
+ bpf_program__set_autoload(skel->progs.test_array_map_3, true);
+ bpf_program__set_autoload(skel->progs.test_array_map_4, true);
+
+ skel->rodata->nr_cpus = libbpf_num_possible_cpus();
+
+ err = percpu_alloc_array__load(skel);
+ if (!ASSERT_OK(err, "percpu_alloc_array__load"))
+ goto out;
+
+ err = percpu_alloc_array__attach(skel);
+ if (!ASSERT_OK(err, "percpu_alloc_array__attach"))
+ goto out;
+
+ prog_fd = bpf_program__fd(skel->progs.test_array_map_1);
+ err = bpf_prog_test_run_opts(prog_fd, &topts);
+ ASSERT_OK(err, "test_run array_map 1-4");
+ ASSERT_EQ(topts.retval, 0, "test_run array_map 1-4");
+ ASSERT_EQ(skel->bss->cpu0_field_d, 2, "cpu0_field_d");
+ ASSERT_EQ(skel->bss->sum_field_c, 1, "sum_field_c");
+out:
+ percpu_alloc_array__destroy(skel);
+}
+
+static void test_array_sleepable(void)
+{
+ struct percpu_alloc_array *skel;
+ int err, prog_fd;
+ LIBBPF_OPTS(bpf_test_run_opts, topts);
+
+ skel = percpu_alloc_array__open();
+ if (!ASSERT_OK_PTR(skel, "percpu_alloc__open"))
+ return;
+
+ bpf_program__set_autoload(skel->progs.test_array_map_10, true);
+
+ skel->rodata->nr_cpus = libbpf_num_possible_cpus();
+
+ err = percpu_alloc_array__load(skel);
+ if (!ASSERT_OK(err, "percpu_alloc_array__load"))
+ goto out;
+
+ err = percpu_alloc_array__attach(skel);
+ if (!ASSERT_OK(err, "percpu_alloc_array__attach"))
+ goto out;
+
+ prog_fd = bpf_program__fd(skel->progs.test_array_map_10);
+ err = bpf_prog_test_run_opts(prog_fd, &topts);
+ ASSERT_OK(err, "test_run array_map_10");
+ ASSERT_EQ(topts.retval, 0, "test_run array_map_10");
+ ASSERT_EQ(skel->bss->cpu0_field_d, 2, "cpu0_field_d");
+ ASSERT_EQ(skel->bss->sum_field_c, 1, "sum_field_c");
+out:
+ percpu_alloc_array__destroy(skel);
+}
+
+void test_percpu_alloc(void)
+{
+ if (test__start_subtest("array"))
+ test_array();
+ if (test__start_subtest("array_sleepable"))
+ test_array_sleepable();
+}
diff --git a/tools/testing/selftests/bpf/progs/percpu_alloc_array.c b/tools/testing/selftests/bpf/progs/percpu_alloc_array.c
new file mode 100644
index 000000000000..24903ea565a0
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/percpu_alloc_array.c
@@ -0,0 +1,187 @@
+#include "bpf_experimental.h"
+
+struct val_t {
+ long b, c, d;
+};
+
+struct elem {
+ long sum;
+ struct val_t __percpu *pc;
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, 1);
+ __type(key, int);
+ __type(value, struct elem);
+} array SEC(".maps");
+
+void bpf_rcu_read_lock(void) __ksym;
+void bpf_rcu_read_unlock(void) __ksym;
+
+const volatile int nr_cpus;
+
+/* Initialize the percpu object */
+SEC("?fentry/bpf_fentry_test1")
+int BPF_PROG(test_array_map_1)
+{
+ struct val_t __percpu *p;
+ struct elem *e;
+ int index = 0;
+
+ e = bpf_map_lookup_elem(&array, &index);
+ if (!e)
+ return 0;
+
+ p = bpf_percpu_obj_new(struct val_t);
+ if (!p)
+ return 0;
+
+ p = bpf_kptr_xchg(&e->pc, p);
+ if (p)
+ bpf_percpu_obj_drop(p);
+
+ return 0;
+}
+
+/* Update percpu data */
+SEC("?fentry/bpf_fentry_test2")
+int BPF_PROG(test_array_map_2)
+{
+ struct val_t __percpu *p;
+ struct val_t *v;
+ struct elem *e;
+ int index = 0;
+
+ e = bpf_map_lookup_elem(&array, &index);
+ if (!e)
+ return 0;
+
+ p = e->pc;
+ if (!p)
+ return 0;
+
+ v = bpf_per_cpu_ptr(p, 0);
+ if (!v)
+ return 0;
+ v->c = 1;
+ v->d = 2;
+
+ return 0;
+}
+
+int cpu0_field_d, sum_field_c;
+
+/* Summarize percpu data */
+SEC("?fentry/bpf_fentry_test3")
+int BPF_PROG(test_array_map_3)
+{
+ struct val_t __percpu *p;
+ int i, index = 0;
+ struct val_t *v;
+ struct elem *e;
+
+ e = bpf_map_lookup_elem(&array, &index);
+ if (!e)
+ return 0;
+
+ p = e->pc;
+ if (!p)
+ return 0;
+
+ bpf_for(i, 0, nr_cpus) {
+ v = bpf_per_cpu_ptr(p, i);
+ if (v) {
+ if (i == 0)
+ cpu0_field_d = v->d;
+ sum_field_c += v->c;
+ }
+ }
+
+ return 0;
+}
+
+/* Explicitly free allocated percpu data */
+SEC("?fentry/bpf_fentry_test4")
+int BPF_PROG(test_array_map_4)
+{
+ struct val_t __percpu *p;
+ struct elem *e;
+ int index = 0;
+
+ e = bpf_map_lookup_elem(&array, &index);
+ if (!e)
+ return 0;
+
+ /* delete */
+ p = bpf_kptr_xchg(&e->pc, NULL);
+ if (p) {
+ bpf_percpu_obj_drop(p);
+ }
+
+ return 0;
+}
+
+SEC("?fentry.s/bpf_fentry_test1")
+int BPF_PROG(test_array_map_10)
+{
+ struct val_t __percpu *p, *p1;
+ int i, index = 0;
+ struct val_t *v;
+ struct elem *e;
+
+ e = bpf_map_lookup_elem(&array, &index);
+ if (!e)
+ return 0;
+
+ bpf_rcu_read_lock();
+ p = e->pc;
+ if (!p) {
+ p = bpf_percpu_obj_new(struct val_t);
+ if (!p)
+ goto out;
+
+ p1 = bpf_kptr_xchg(&e->pc, p);
+ if (p1) {
+ /* race condition */
+ bpf_percpu_obj_drop(p1);
+ }
+
+ p = e->pc;
+ if (!p)
+ goto out;
+ }
+
+ v = bpf_this_cpu_ptr(p);
+ v->c = 3;
+ v = bpf_this_cpu_ptr(p);
+ v->c = 0;
+
+ v = bpf_per_cpu_ptr(p, 0);
+ if (!v)
+ goto out;
+ v->c = 1;
+ v->d = 2;
+
+ /* delete */
+ p1 = bpf_kptr_xchg(&e->pc, NULL);
+ if (!p1)
+ goto out;
+
+ bpf_for(i, 0, nr_cpus) {
+ v = bpf_per_cpu_ptr(p, i);
+ if (v) {
+ if (i == 0)
+ cpu0_field_d = v->d;
+ sum_field_c += v->c;
+ }
+ }
+
+ /* finally release p */
+ bpf_percpu_obj_drop(p1);
+out:
+ bpf_rcu_read_unlock();
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
--
2.34.1
