diff options
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ac54ebc0629f..d2828a26b011 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4999,12 +4999,17 @@ enum kern_feature_result { FEAT_MISSING = 2, }; +struct kern_feature_cache { + enum kern_feature_result res[__FEAT_CNT]; +}; + typedef int (*feature_probe_fn)(void); +static struct kern_feature_cache feature_cache; + static struct kern_feature_desc { const char *desc; feature_probe_fn probe; - enum kern_feature_result res; } feature_probes[__FEAT_CNT] = { [FEAT_PROG_NAME] = { "BPF program name", probe_kern_prog_name, @@ -5072,6 +5077,7 @@ static struct kern_feature_desc { bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id) { struct kern_feature_desc *feat = &feature_probes[feat_id]; + struct kern_feature_cache *cache = &feature_cache; int ret; if (obj && obj->gen_loader) @@ -5080,19 +5086,19 @@ bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id) */ return true; - if (READ_ONCE(feat->res) == FEAT_UNKNOWN) { + if (READ_ONCE(cache->res[feat_id]) == FEAT_UNKNOWN) { ret = feat->probe(); if (ret > 0) { - WRITE_ONCE(feat->res, FEAT_SUPPORTED); + WRITE_ONCE(cache->res[feat_id], FEAT_SUPPORTED); } else if (ret == 0) { - WRITE_ONCE(feat->res, FEAT_MISSING); + WRITE_ONCE(cache->res[feat_id], FEAT_MISSING); } else { pr_warn("Detection of kernel %s support failed: %d\n", feat->desc, ret); - WRITE_ONCE(feat->res, FEAT_MISSING); + WRITE_ONCE(cache->res[feat_id], FEAT_MISSING); } } - return READ_ONCE(feat->res) == FEAT_SUPPORTED; + return READ_ONCE(cache->res[feat_id]) == FEAT_SUPPORTED; } static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd) |