diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/syscall.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/syscall.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/syscall.c b/tools/testing/selftests/bpf/progs/syscall.c new file mode 100644 index 000000000000..3d3cafdebe72 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/syscall.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ +#include <linux/stddef.h> +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include <../../../tools/include/linux/filter.h> +#include <linux/btf.h> +#include <string.h> +#include <errno.h> + +char _license[] SEC("license") = "GPL"; + +struct bpf_map { + int id; +} __attribute__((preserve_access_index)); + +struct args { + __u64 log_buf; + __u32 log_size; + int max_entries; + int map_fd; + int prog_fd; + int btf_fd; +}; + +#define BTF_INFO_ENC(kind, kind_flag, vlen) \ + ((!!(kind_flag) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN)) +#define BTF_TYPE_ENC(name, info, size_or_type) (name), (info), (size_or_type) +#define BTF_INT_ENC(encoding, bits_offset, nr_bits) \ + ((encoding) << 24 | (bits_offset) << 16 | (nr_bits)) +#define BTF_TYPE_INT_ENC(name, encoding, bits_offset, bits, sz) \ + BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_INT, 0, 0), sz), \ + BTF_INT_ENC(encoding, bits_offset, bits) + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, int); + __type(value, union bpf_attr); + __uint(max_entries, 1); +} bpf_attr_array SEC(".maps"); + +struct inner_map_type { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(key_size, 4); + __uint(value_size, 4); + __uint(max_entries, 1); +} inner_map SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS); + __type(key, int); + __type(value, int); + __uint(max_entries, 1); + __array(values, struct inner_map_type); +} outer_array_map SEC(".maps") = { + .values = { + [0] = &inner_map, + }, +}; + +static inline __u64 ptr_to_u64(const void *ptr) +{ + return (__u64) (unsigned long) ptr; +} + +static int btf_load(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(__u32) * 8, + .str_off = sizeof(__u32) * 8, + .str_len = sizeof(__u32), + }, + .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 btf_load_attr = { + .btf_size = sizeof(raw_btf), + }; + + btf_load_attr.btf = (long)&raw_btf; + return bpf_sys_bpf(BPF_BTF_LOAD, &btf_load_attr, sizeof(btf_load_attr)); +} + +SEC("syscall") +int load_prog(struct args *ctx) +{ + static char license[] = "GPL"; + static struct bpf_insn insns[] = { + 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_LD_MAP_FD(BPF_REG_1, 0), + 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(), + }; + static union bpf_attr map_create_attr = { + .map_type = BPF_MAP_TYPE_HASH, + .key_size = 8, + .value_size = 8, + .btf_key_type_id = 1, + .btf_value_type_id = 2, + }; + static union bpf_attr map_update_attr = { .map_fd = 1, }; + static __u64 key = 12; + static __u64 value = 34; + static union bpf_attr prog_load_attr = { + .prog_type = BPF_PROG_TYPE_XDP, + .insn_cnt = sizeof(insns) / sizeof(insns[0]), + }; + int ret; + + ret = btf_load(); + if (ret <= 0) + return ret; + + ctx->btf_fd = ret; + map_create_attr.max_entries = ctx->max_entries; + map_create_attr.btf_fd = ret; + + prog_load_attr.license = ptr_to_u64(license); + prog_load_attr.insns = ptr_to_u64(insns); + prog_load_attr.log_buf = ctx->log_buf; + prog_load_attr.log_size = ctx->log_size; + prog_load_attr.log_level = 1; + + ret = bpf_sys_bpf(BPF_MAP_CREATE, &map_create_attr, sizeof(map_create_attr)); + if (ret <= 0) + return ret; + ctx->map_fd = ret; + insns[3].imm = ret; + + map_update_attr.map_fd = ret; + map_update_attr.key = ptr_to_u64(&key); + map_update_attr.value = ptr_to_u64(&value); + ret = bpf_sys_bpf(BPF_MAP_UPDATE_ELEM, &map_update_attr, sizeof(map_update_attr)); + if (ret < 0) + return ret; + + ret = bpf_sys_bpf(BPF_PROG_LOAD, &prog_load_attr, sizeof(prog_load_attr)); + if (ret <= 0) + return ret; + ctx->prog_fd = ret; + return 1; +} + +SEC("syscall") +int update_outer_map(void *ctx) +{ + int zero = 0, ret = 0, outer_fd = -1, inner_fd = -1, err; + const int attr_sz = sizeof(union bpf_attr); + union bpf_attr *attr; + + attr = bpf_map_lookup_elem((struct bpf_map *)&bpf_attr_array, &zero); + if (!attr) + goto out; + + memset(attr, 0, attr_sz); + attr->map_id = ((struct bpf_map *)&outer_array_map)->id; + outer_fd = bpf_sys_bpf(BPF_MAP_GET_FD_BY_ID, attr, attr_sz); + if (outer_fd < 0) + goto out; + + memset(attr, 0, attr_sz); + attr->map_type = BPF_MAP_TYPE_ARRAY; + attr->key_size = 4; + attr->value_size = 4; + attr->max_entries = 1; + inner_fd = bpf_sys_bpf(BPF_MAP_CREATE, attr, attr_sz); + if (inner_fd < 0) + goto out; + + memset(attr, 0, attr_sz); + attr->map_fd = outer_fd; + attr->key = ptr_to_u64(&zero); + attr->value = ptr_to_u64(&inner_fd); + err = bpf_sys_bpf(BPF_MAP_UPDATE_ELEM, attr, attr_sz); + if (err) + goto out; + + memset(attr, 0, attr_sz); + attr->map_fd = outer_fd; + attr->key = ptr_to_u64(&zero); + err = bpf_sys_bpf(BPF_MAP_DELETE_ELEM, attr, attr_sz); + if (err) + goto out; + ret = 1; +out: + if (inner_fd >= 0) + bpf_sys_close(inner_fd); + if (outer_fd >= 0) + bpf_sys_close(outer_fd); + return ret; +} |