From: Shuyi Cheng <chengshuyi@linux.alibaba.com>
Date: Fri, 10 Dec 2021 17:39:57 +0800
Subject: libbpf: Add "bool skipped" to struct bpf_map
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Patch-mainline: v5.17-rc1
Git-commit: 229fae38d0fc0d6ff58d57cbeb1432da55e58d4f
References: jsc#PED-1377
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>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/lib/bpf/libbpf.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -431,6 +431,7 @@ struct bpf_map {
char *pin_path;
bool pinned;
bool reused;
+ bool skipped;
__u64 map_extra;
};
@@ -5087,8 +5088,10 @@ bpf_object__create_maps(struct bpf_objec
* 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:
@@ -5717,8 +5720,7 @@ bpf_object__relocate_data(struct bpf_obj
} 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;
@@ -7924,6 +7926,9 @@ int bpf_object__pin_maps(struct bpf_obje
char *pin_path = NULL;
char buf[PATH_MAX];
+ if (map->skipped)
+ continue;
+
if (path) {
int len;