diff options
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 460e5790a95f..6602eb479596 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -8591,7 +8591,7 @@ static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, struct perf_buffer_params *p) { const char *online_cpus_file = "/sys/devices/system/cpu/online"; - struct bpf_map_info map = {}; + struct bpf_map_info map; char msg[STRERR_BUFSIZE]; struct perf_buffer *pb; bool *online = NULL; @@ -8604,19 +8604,28 @@ static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, return ERR_PTR(-EINVAL); } + /* best-effort sanity checks */ + memset(&map, 0, sizeof(map)); map_info_len = sizeof(map); err = bpf_obj_get_info_by_fd(map_fd, &map, &map_info_len); if (err) { err = -errno; - pr_warn("failed to get map info for map FD %d: %s\n", - map_fd, libbpf_strerror_r(err, msg, sizeof(msg))); - return ERR_PTR(err); - } - - if (map.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) { - pr_warn("map '%s' should be BPF_MAP_TYPE_PERF_EVENT_ARRAY\n", - map.name); - return ERR_PTR(-EINVAL); + /* if BPF_OBJ_GET_INFO_BY_FD is supported, will return + * -EBADFD, -EFAULT, or -E2BIG on real error + */ + if (err != -EINVAL) { + pr_warn("failed to get map info for map FD %d: %s\n", + map_fd, libbpf_strerror_r(err, msg, sizeof(msg))); + return ERR_PTR(err); + } + pr_debug("failed to get map info for FD %d; API not supported? Ignoring...\n", + map_fd); + } else { + if (map.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) { + pr_warn("map '%s' should be BPF_MAP_TYPE_PERF_EVENT_ARRAY\n", + map.name); + return ERR_PTR(-EINVAL); + } } pb = calloc(1, sizeof(*pb)); @@ -8648,7 +8657,7 @@ static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, err = pb->cpu_cnt; goto error; } - if (map.max_entries < pb->cpu_cnt) + if (map.max_entries && map.max_entries < pb->cpu_cnt) pb->cpu_cnt = map.max_entries; } |