From: Shuyi Cheng chengshuyi@linux.alibaba.com
[ Upstream commit 229fae38d0fc0d6ff58d57cbeb1432da55e58d4f ]
Fix error: "failed to pin map: Bad file descriptor, path: /sys/fs/bpf/_rodata_str1_1."
In the old kernel, the global data map will not be created, see [0]. So we should skip the pinning of the global data map to avoid bpf_object__pin_maps returning error. Therefore, when the map is not created, we mark “map->skipped" as true and then check during relocation and during pinning.
Fixes: 16e0c35c6f7a ("libbpf: Load global data maps lazily on legacy kernels") Signed-off-by: Shuyi Cheng chengshuyi@linux.alibaba.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/bpf/libbpf.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 4050a0f8dad66..fd25e30e70cc2 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -400,6 +400,7 @@ struct bpf_map { char *pin_path; bool pinned; bool reused; + bool skipped; __u64 map_extra; };
@@ -5003,8 +5004,10 @@ bpf_object__create_maps(struct bpf_object *obj) * kernels. */ if (bpf_map__is_internal(map) && - !kernel_supports(obj, FEAT_GLOBAL_DATA)) + !kernel_supports(obj, FEAT_GLOBAL_DATA)) { + map->skipped = true; continue; + }
retried = false; retry: @@ -5607,8 +5610,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog) } else { const struct bpf_map *map = &obj->maps[relo->map_idx];
- if (bpf_map__is_internal(map) && - !kernel_supports(obj, FEAT_GLOBAL_DATA)) { + if (map->skipped) { pr_warn("prog '%s': relo #%d: kernel doesn't support global data\n", prog->name, i); return -ENOTSUP; @@ -7733,6 +7735,9 @@ int bpf_object__pin_maps(struct bpf_object *obj, const char *path) char *pin_path = NULL; char buf[PATH_MAX];
+ if (map->skipped) + continue; + if (path) { int len;