selftests/bpf: Add C tests for kptr

This uses the __kptr and __kptr_ref macros as well, and tries to test
the stuff that is supposed to work, since we have negative tests in
test_verifier suite. Also include some code to test map-in-map support,
such that the inner_map_meta matches the kptr_off_tab of map added as
element.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-12-memxor@gmail.com
This commit is contained in:
Kumar Kartikeya Dwivedi 2022-04-25 03:18:59 +05:30 committed by Alexei Starovoitov
parent ef89654f2b
commit 2cbc469a6f
2 changed files with 227 additions and 0 deletions

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// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#include "map_kptr.skel.h"
void test_map_kptr(void)
{
struct map_kptr *skel;
int key = 0, ret;
char buf[24];
skel = map_kptr__open_and_load();
if (!ASSERT_OK_PTR(skel, "map_kptr__open_and_load"))
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);
ASSERT_OK(ret, "array_map update2");
ret = bpf_map_update_elem(bpf_map__fd(skel->maps.hash_map), &key, buf, 0);
ASSERT_OK(ret, "hash_map update");
ret = bpf_map_delete_elem(bpf_map__fd(skel->maps.hash_map), &key);
ASSERT_OK(ret, "hash_map delete");
ret = bpf_map_update_elem(bpf_map__fd(skel->maps.hash_malloc_map), &key, buf, 0);
ASSERT_OK(ret, "hash_malloc_map update");
ret = bpf_map_delete_elem(bpf_map__fd(skel->maps.hash_malloc_map), &key);
ASSERT_OK(ret, "hash_malloc_map delete");
ret = bpf_map_update_elem(bpf_map__fd(skel->maps.lru_hash_map), &key, buf, 0);
ASSERT_OK(ret, "lru_hash_map update");
ret = bpf_map_delete_elem(bpf_map__fd(skel->maps.lru_hash_map), &key);
ASSERT_OK(ret, "lru_hash_map delete");
map_kptr__destroy(skel);
}

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// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_helpers.h>
struct map_value {
struct prog_test_ref_kfunc __kptr *unref_ptr;
struct prog_test_ref_kfunc __kptr_ref *ref_ptr;
};
struct array_map {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, int);
__type(value, struct map_value);
__uint(max_entries, 1);
} array_map SEC(".maps");
struct hash_map {
__uint(type, BPF_MAP_TYPE_HASH);
__type(key, int);
__type(value, struct map_value);
__uint(max_entries, 1);
} hash_map SEC(".maps");
struct hash_malloc_map {
__uint(type, BPF_MAP_TYPE_HASH);
__type(key, int);
__type(value, struct map_value);
__uint(max_entries, 1);
__uint(map_flags, BPF_F_NO_PREALLOC);
} hash_malloc_map SEC(".maps");
struct lru_hash_map {
__uint(type, BPF_MAP_TYPE_LRU_HASH);
__type(key, int);
__type(value, struct map_value);
__uint(max_entries, 1);
} lru_hash_map SEC(".maps");
#define DEFINE_MAP_OF_MAP(map_type, inner_map_type, name) \
struct { \
__uint(type, map_type); \
__uint(max_entries, 1); \
__uint(key_size, sizeof(int)); \
__uint(value_size, sizeof(int)); \
__array(values, struct inner_map_type); \
} name SEC(".maps") = { \
.values = { [0] = &inner_map_type }, \
}
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_ARRAY_OF_MAPS, array_map, array_of_array_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_ARRAY_OF_MAPS, hash_map, array_of_hash_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_ARRAY_OF_MAPS, hash_malloc_map, array_of_hash_malloc_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_ARRAY_OF_MAPS, lru_hash_map, array_of_lru_hash_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_HASH_OF_MAPS, array_map, hash_of_array_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_HASH_OF_MAPS, hash_map, hash_of_hash_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_HASH_OF_MAPS, hash_malloc_map, hash_of_hash_malloc_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_HASH_OF_MAPS, lru_hash_map, hash_of_lru_hash_maps);
extern struct prog_test_ref_kfunc *bpf_kfunc_call_test_acquire(unsigned long *sp) __ksym;
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;
static void test_kptr_unref(struct map_value *v)
{
struct prog_test_ref_kfunc *p;
p = v->unref_ptr;
/* store untrusted_ptr_or_null_ */
v->unref_ptr = p;
if (!p)
return;
if (p->a + p->b > 100)
return;
/* store untrusted_ptr_ */
v->unref_ptr = p;
/* store NULL */
v->unref_ptr = NULL;
}
static void test_kptr_ref(struct map_value *v)
{
struct prog_test_ref_kfunc *p;
p = v->ref_ptr;
/* store ptr_or_null_ */
v->unref_ptr = p;
if (!p)
return;
if (p->a + p->b > 100)
return;
/* store NULL */
p = bpf_kptr_xchg(&v->ref_ptr, NULL);
if (!p)
return;
if (p->a + p->b > 100) {
bpf_kfunc_call_test_release(p);
return;
}
/* store ptr_ */
v->unref_ptr = p;
bpf_kfunc_call_test_release(p);
p = bpf_kfunc_call_test_acquire(&(unsigned long){0});
if (!p)
return;
/* store ptr_ */
p = bpf_kptr_xchg(&v->ref_ptr, p);
if (!p)
return;
if (p->a + p->b > 100) {
bpf_kfunc_call_test_release(p);
return;
}
bpf_kfunc_call_test_release(p);
}
static void test_kptr_get(struct map_value *v)
{
struct prog_test_ref_kfunc *p;
p = bpf_kfunc_call_test_kptr_get(&v->ref_ptr, 0, 0);
if (!p)
return;
if (p->a + p->b > 100) {
bpf_kfunc_call_test_release(p);
return;
}
bpf_kfunc_call_test_release(p);
}
static void test_kptr(struct map_value *v)
{
test_kptr_unref(v);
test_kptr_ref(v);
test_kptr_get(v);
}
SEC("tc")
int test_map_kptr(struct __sk_buff *ctx)
{
struct map_value *v;
int i, key = 0;
#define TEST(map) \
v = bpf_map_lookup_elem(&map, &key); \
if (!v) \
return 0; \
test_kptr(v)
TEST(array_map);
TEST(hash_map);
TEST(hash_malloc_map);
TEST(lru_hash_map);
#undef TEST
return 0;
}
SEC("tc")
int test_map_in_map_kptr(struct __sk_buff *ctx)
{
struct map_value *v;
int i, key = 0;
void *map;
#define TEST(map_in_map) \
map = bpf_map_lookup_elem(&map_in_map, &key); \
if (!map) \
return 0; \
v = bpf_map_lookup_elem(map, &key); \
if (!v) \
return 0; \
test_kptr(v)
TEST(array_of_array_maps);
TEST(array_of_hash_maps);
TEST(array_of_hash_malloc_maps);
TEST(array_of_lru_hash_maps);
TEST(hash_of_array_maps);
TEST(hash_of_hash_maps);
TEST(hash_of_hash_malloc_maps);
TEST(hash_of_lru_hash_maps);
#undef TEST
return 0;
}
char _license[] SEC("license") = "GPL";