diff options
Diffstat (limited to 'tools/lib/bpf/features.c')
| -rw-r--r-- | tools/lib/bpf/features.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/tools/lib/bpf/features.c b/tools/lib/bpf/features.c index b842b83e2480..2fa434f09cce 100644 --- a/tools/lib/bpf/features.c +++ b/tools/lib/bpf/features.c @@ -506,6 +506,68 @@ static int probe_kern_arg_ctx_tag(int token_fd) return probe_fd(prog_fd); } +static int probe_ldimm64_full_range_off(int token_fd) +{ + char log_buf[1024]; + int prog_fd, map_fd; + int ret; + LIBBPF_OPTS(bpf_map_create_opts, map_opts, + .token_fd = token_fd, + .map_flags = token_fd ? BPF_F_TOKEN_FD : 0, + ); + LIBBPF_OPTS(bpf_prog_load_opts, prog_opts, + .token_fd = token_fd, + .prog_flags = token_fd ? BPF_F_TOKEN_FD : 0, + .log_buf = log_buf, + .log_size = sizeof(log_buf), + ); + struct bpf_insn insns[] = { + BPF_LD_MAP_VALUE(BPF_REG_1, 0, 1UL << 30), + BPF_EXIT_INSN(), + }; + int insn_cnt = ARRAY_SIZE(insns); + + map_fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, "arr", sizeof(int), 1, 1, &map_opts); + if (map_fd < 0) { + ret = -errno; + pr_warn("Error in %s(): %s. Couldn't create simple array map.\n", + __func__, errstr(ret)); + return ret; + } + insns[0].imm = map_fd; + + log_buf[0] = '\0'; + prog_fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, "global_reloc", "GPL", insns, insn_cnt, &prog_opts); + ret = -errno; + + close(map_fd); + + if (prog_fd >= 0) { + pr_warn("Error in %s(): Program loading unexpectedly succeeded.\n", __func__); + close(prog_fd); + return -EINVAL; + } + + /* + * Feature is allowed if we're not failing with the error message + * "direct value offset of %u is not allowed" removed in + * 12a1fe6e12db ("bpf/verifier: Do not limit maximum direct offset into arena map"). + * We should instead fail with "invalid access to map value pointer". + * Ensure we match with one of the two and we're not failing with a + * different, unexpected message. + */ + if (strstr(log_buf, "direct value offset of")) + return 0; + + if (!strstr(log_buf, "invalid access to map value pointer")) { + pr_warn("Error in %s(): Program unexpectedly failed with message: %s.\n", + __func__, log_buf); + return ret; + } + + return 1; +} + typedef int (*feature_probe_fn)(int /* token_fd */); static struct kern_feature_cache feature_cache; @@ -581,6 +643,9 @@ static struct kern_feature_desc { [FEAT_BTF_QMARK_DATASEC] = { "BTF DATASEC names starting from '?'", probe_kern_btf_qmark_datasec, }, + [FEAT_LDIMM64_FULL_RANGE_OFF] = { + "full range LDIMM64 support", probe_ldimm64_full_range_off, + }, }; bool feat_supported(struct kern_feature_cache *cache, enum kern_feature_id feat_id) |