Check at runtime how various operations for kptr_ref affect its refcount
and verify against the actual count. We use the per-CPU prog_test_struct
to get an isolated object to inspect the refcount of.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/map_kptr.c | 28 ++++-
tools/testing/selftests/bpf/progs/map_kptr.c | 109 +++++++++++++++++-
2 files changed, 132 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/map_kptr.c b/tools/testing/selftests/bpf/prog_tests/map_kptr.c
index ffef3a319bac..bcee3e54e3ed 100644
--- a/tools/testing/selftests/bpf/prog_tests/map_kptr.c
+++ b/tools/testing/selftests/bpf/prog_tests/map_kptr.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
+#include <network_helpers.h>
#include "map_kptr.skel.h"
#include "map_kptr_fail.skel.h"
@@ -81,8 +82,14 @@ static void test_map_kptr_fail(void)
}
}
-static void test_map_kptr_success(void)
+static void test_map_kptr_success(bool test_run)
{
+ LIBBPF_OPTS(bpf_test_run_opts, opts,
+ .data_in = &pkt_v4,
+ .data_size_in = sizeof(pkt_v4),
+ .repeat = 1,
+ .cpu = 0,
+ );
struct map_kptr *skel;
int key = 0, ret;
char buf[24];
@@ -91,6 +98,16 @@ static void test_map_kptr_success(void)
if (!ASSERT_OK_PTR(skel, "map_kptr__open_and_load"))
return;
+ ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.test_map_kptr_ref), &opts);
+ ASSERT_OK(ret, "test_map_kptr_ref refcount");
+ ASSERT_OK(opts.retval, "test_map_kptr_ref retval");
+ ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.test_map_kptr_ref2), &opts);
+ ASSERT_OK(ret, "test_map_kptr_ref2 refcount");
+ ASSERT_OK(opts.retval, "test_map_kptr_ref2 retval");
+
+ if (test_run)
+ return;
+
ret = bpf_map_update_elem(bpf_map__fd(skel->maps.array_map), &key, buf, 0);
ASSERT_OK(ret, "array_map update");
ret = bpf_map_update_elem(bpf_map__fd(skel->maps.array_map), &key, buf, 0);
@@ -116,7 +133,12 @@ static void test_map_kptr_success(void)
void test_map_kptr(void)
{
- if (test__start_subtest("success"))
- test_map_kptr_success();
+ if (test__start_subtest("success")) {
+ test_map_kptr_success(false);
+ /* Do test_run twice, so that we see refcount going back to 1
+ * after we leave it in map from first iteration.
+ */
+ test_map_kptr_success(true);
+ }
test_map_kptr_fail();
}
diff --git a/tools/testing/selftests/bpf/progs/map_kptr.c b/tools/testing/selftests/bpf/progs/map_kptr.c
index 1b0e0409eaa5..569d7522bb9f 100644
--- a/tools/testing/selftests/bpf/progs/map_kptr.c
+++ b/tools/testing/selftests/bpf/progs/map_kptr.c
@@ -61,6 +61,7 @@ extern struct prog_test_ref_kfunc *bpf_kfunc_call_test_acquire(unsigned long *sp
extern struct prog_test_ref_kfunc *
bpf_kfunc_call_test_kptr_get(struct prog_test_ref_kfunc **p, int a, int b) __ksym;
extern void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym;
+extern struct prog_test_ref_kfunc prog_test_struct __ksym;
static void test_kptr_unref(struct map_value *v)
{
@@ -141,7 +142,7 @@ SEC("tc")
int test_map_kptr(struct __sk_buff *ctx)
{
struct map_value *v;
- int i, key = 0;
+ int key = 0;
#define TEST(map) \
v = bpf_map_lookup_elem(&map, &key); \
@@ -162,7 +163,7 @@ SEC("tc")
int test_map_in_map_kptr(struct __sk_buff *ctx)
{
struct map_value *v;
- int i, key = 0;
+ int key = 0;
void *map;
#define TEST(map_in_map) \
@@ -187,4 +188,108 @@ int test_map_in_map_kptr(struct __sk_buff *ctx)
return 0;
}
+SEC("tc")
+int test_map_kptr_ref(struct __sk_buff *ctx)
+{
+ struct prog_test_ref_kfunc *volatile p, *p_cpu;
+ unsigned long arg = 0;
+ struct map_value *v;
+ int key = 0, ret;
+
+ p_cpu = bpf_this_cpu_ptr(&prog_test_struct);
+ if (p_cpu->cnt.refs.counter != 1)
+ return 1;
+
+ p = bpf_kfunc_call_test_acquire(&arg);
+ if (!p)
+ return 2;
+ if (p != p_cpu || p_cpu->cnt.refs.counter != 2) {
+ ret = 3;
+ goto end;
+ }
+
+ v = bpf_map_lookup_elem(&array_map, &key);
+ if (!v) {
+ ret = 4;
+ goto end;
+ }
+
+ p = bpf_kptr_xchg(&v->ref_ptr, p);
+ if (p) {
+ ret = 5;
+ goto end;
+ }
+ if (p_cpu->cnt.refs.counter != 2)
+ return 6;
+
+ p = bpf_kfunc_call_test_kptr_get(&v->ref_ptr, 0, 0);
+ if (!p)
+ return 7;
+ if (p_cpu->cnt.refs.counter != 3) {
+ ret = 8;
+ goto end;
+ }
+ bpf_kfunc_call_test_release(p);
+ if (p_cpu->cnt.refs.counter != 2)
+ return 9;
+
+ p = bpf_kptr_xchg(&v->ref_ptr, NULL);
+ if (!p)
+ return 10;
+ bpf_kfunc_call_test_release(p);
+ if (p_cpu->cnt.refs.counter != 1)
+ return 11;
+
+ p = bpf_kfunc_call_test_acquire(&arg);
+ if (!p)
+ return 12;
+ p = bpf_kptr_xchg(&v->ref_ptr, p);
+ if (p) {
+ ret = 13;
+ goto end;
+ }
+ if (p_cpu->cnt.refs.counter != 2)
+ return 14;
+ /* Leave in map */
+
+ return 0;
+end:
+ bpf_kfunc_call_test_release(p);
+ return ret;
+}
+
+SEC("tc")
+int test_map_kptr_ref2(struct __sk_buff *ctx)
+{
+ struct prog_test_ref_kfunc *volatile p, *p_cpu;
+ struct map_value *v;
+ int key = 0;
+
+ p_cpu = bpf_this_cpu_ptr(&prog_test_struct);
+ if (p_cpu->cnt.refs.counter != 2)
+ return 1;
+
+ v = bpf_map_lookup_elem(&array_map, &key);
+ if (!v)
+ return 2;
+
+ p = bpf_kptr_xchg(&v->ref_ptr, NULL);
+ if (!p)
+ return 3;
+ if (p != p_cpu || p_cpu->cnt.refs.counter != 2) {
+ bpf_kfunc_call_test_release(p);
+ return 4;
+ }
+
+ p = bpf_kptr_xchg(&v->ref_ptr, p);
+ if (p) {
+ bpf_kfunc_call_test_release(p);
+ return 5;
+ }
+ if (p_cpu->cnt.refs.counter != 2)
+ return 6;
+
+ return 0;
+}
+
char _license[] SEC("license") = "GPL";
--
2.35.1
