On Tue, Nov 19, 2024 at 2:13 AM Anton Protopopov <aspsk@xxxxxxxxxxxxx> wrote:
>
> Add a new set of tests to test the new field in PROG_LOAD-related
> part of bpf_attr: fd_array_cnt.
>
> Add the following test cases:
>
> * fd_array_cnt/no-fd-array: program is loaded in a normal
> way, without any fd_array present
>
> * fd_array_cnt/fd-array-ok: pass two extra non-used maps,
> check that they're bound to the program
>
> * fd_array_cnt/fd-array-dup-input: pass a few extra maps,
> only two of which are unique
>
> * fd_array_cnt/fd-array-ref-maps-in-array: pass a map in
> fd_array which is also referenced from within the program
>
> * fd_array_cnt/fd-array-trash-input: pass array with some trash
>
> * fd_array_cnt/fd-array-with-holes: pass an array with holes (fd=0)
>
> * fd_array_cnt/fd-array-2big: pass too large array
>
> All the tests above are using the bpf(2) syscall directly,
> no libbpf involved.
>
> Signed-off-by: Anton Protopopov <aspsk@xxxxxxxxxxxxx>
> ---
> .../selftests/bpf/prog_tests/fd_array.c | 381 ++++++++++++++++++
> 1 file changed, 381 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/fd_array.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/fd_array.c b/tools/testing/selftests/bpf/prog_tests/fd_array.c
> new file mode 100644
> index 000000000000..1b47386e66c3
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/fd_array.c
> @@ -0,0 +1,381 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <test_progs.h>
> +
> +#include <linux/btf.h>
> +#include <sys/syscall.h>
> +#include <bpf/bpf.h>
> +
> +#include "../test_btf.h"
> +
> +static inline int _bpf_map_create(void)
> +{
> + static union bpf_attr attr = {
> + .map_type = BPF_MAP_TYPE_ARRAY,
> + .key_size = 4,
> + .value_size = 8,
> + .max_entries = 1,
> + };
> +
> + return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
> +}
libbpf provides bpf_map_create() API. Please use that (and make sure
it supports the new field as well), don't re-define your own wrappers.
> +
> +static int _btf_create(void)
> +{
> + struct btf_blob {
> + struct btf_header btf_hdr;
> + __u32 types[8];
> + __u32 str;
> + } raw_btf = {
> + .btf_hdr = {
> + .magic = BTF_MAGIC,
> + .version = BTF_VERSION,
> + .hdr_len = sizeof(struct btf_header),
> + .type_len = sizeof(raw_btf.types),
> + .str_off = offsetof(struct btf_blob, str) - offsetof(struct btf_blob, types),
> + .str_len = sizeof(raw_btf.str),
> + },
> + .types = {
> + /* long */
> + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 64, 8), /* [1] */
> + /* unsigned long */
> + BTF_TYPE_INT_ENC(0, 0, 0, 64, 8), /* [2] */
> + },
> + };
> + static union bpf_attr attr = {
> + .btf_size = sizeof(raw_btf),
> + };
> +
> + attr.btf = (long)&raw_btf;
> +
> + return syscall(__NR_bpf, BPF_BTF_LOAD, &attr, sizeof(attr));
ditto, libbpf provides low-level API wrappers for a reason, let's tick to them
> +}
> +
> +static bool map_exists(__u32 id)
> +{
> + int fd;
> +
> + fd = bpf_map_get_fd_by_id(id);
> + if (fd >= 0) {
> + close(fd);
> + return true;
> + }
> + return false;
> +}
> +
> +static inline int bpf_prog_get_map_ids(int prog_fd, __u32 *nr_map_ids, __u32 *map_ids)
> +{
> + __u32 len = sizeof(struct bpf_prog_info);
> + struct bpf_prog_info info = {
> + .nr_map_ids = *nr_map_ids,
> + .map_ids = ptr_to_u64(map_ids),
> + };
> + int err;
> +
> + err = bpf_prog_get_info_by_fd(prog_fd, &info, &len);
> + if (!ASSERT_OK(err, "bpf_prog_get_info_by_fd"))
> + return -1;
> +
> + *nr_map_ids = info.nr_map_ids;
> +
> + return 0;
> +}
> +
> +static int __load_test_prog(int map_fd, int *fd_array, int fd_array_cnt)
> +{
> + /* A trivial program which uses one map */
> + struct bpf_insn insns[] = {
> + BPF_LD_MAP_FD(BPF_REG_1, map_fd),
> + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
> + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
> + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
> + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
> + BPF_MOV64_IMM(BPF_REG_0, 0),
> + BPF_EXIT_INSN(),
> + };
> + union bpf_attr attr = {
> + .prog_type = BPF_PROG_TYPE_XDP, /* we don't care */
> + .insns = ptr_to_u64(insns),
> + .insn_cnt = ARRAY_SIZE(insns),
> + .license = ptr_to_u64("GPL"),
> + .fd_array = ptr_to_u64(fd_array),
> + .fd_array_cnt = fd_array_cnt,
> + };
> +
> + return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
bpf_prog_load() API
> +}
> +
> +static int load_test_prog(int *fd_array, int fd_array_cnt)
> +{
> + int map_fd;
> + int ret;
> +
> + map_fd = _bpf_map_create();
> + if (!ASSERT_GE(map_fd, 0, "_bpf_map_create"))
> + return map_fd;
> +
> + ret = __load_test_prog(map_fd, fd_array, fd_array_cnt);
> + close(map_fd);
> +
> + /* switch back to returning the actual value */
> + if (ret < 0)
> + return -errno;
> + return ret;
> +}
> +
[...]
