Commit 7419fcad authored by Alan Maguire's avatar Alan Maguire Committed by Alexei Starovoitov
Browse files

libbpf: Allow use of feature cache for non-token cases 



Allow bpf object feat_cache assignment in BPF selftests
to simulate missing features via inclusion of libbpf_internal.h
and use of bpf_object_set_feat_cache() and bpf_object__sanitize_btf() to
test BTF sanitization for cases where missing features are simulated.

Signed-off-by: default avatarAlan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/r/20260408165735.843763-2-alan.maguire@oracle.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent aacee214

tools/lib/bpf/libbpf.c

+10 −2
Original line number Diff line number Diff line
@@ -3145,7 +3145,7 @@ static bool btf_needs_sanitization(struct bpf_object *obj) 
	       !has_layout;

}



static struct btf *bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *orig_btf)

struct btf *bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *orig_btf)

{

	bool has_func_global = kernel_supports(obj, FEAT_BTF_GLOBAL_FUNC);

	bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
@@ -5203,12 +5203,20 @@ bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id) 
		 */

		return true;



	if (obj->token_fd)

	if (obj->feat_cache)

		return feat_supported(obj->feat_cache, feat_id);



	return feat_supported(NULL, feat_id);

}



/* Used in testing to simulate missing features. */

void bpf_object_set_feat_cache(struct bpf_object *obj, struct kern_feature_cache *cache)

{

	if (obj->feat_cache)

		free(obj->feat_cache);

	obj->feat_cache = cache;

}



static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)

{

	struct bpf_map_info map_info;

tools/lib/bpf/libbpf_internal.h

+2 −1
Original line number Diff line number Diff line
@@ -414,6 +414,7 @@ struct kern_feature_cache { 


bool feat_supported(struct kern_feature_cache *cache, enum kern_feature_id feat_id);

bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id);

void bpf_object_set_feat_cache(struct bpf_object *obj, struct kern_feature_cache *cache);



int probe_kern_syscall_wrapper(int token_fd);

int probe_memcg_account(int token_fd);
@@ -427,7 +428,7 @@ int libbpf__load_raw_btf(const char *raw_types, size_t types_len, 
int libbpf__load_raw_btf_hdr(const struct btf_header *hdr,

			     const char *raw_types, const char *str_sec,

			     const char *layout_sec, int token_fd);



struct btf *bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *orig_btf);

int btf_load_into_kernel(struct btf *btf,

			 char *log_buf, size_t log_sz, __u32 log_level,

			 int token_fd);