libbpf: Support BTF_KIND_FLOAT during type compatibility checks in CO-RE

Add BTF_KIND_FLOAT support when doing CO-RE field type compatibility check. Without this, relocations against float/double fields will fail. Also adjust one error message to emit instruction index instead of less convenient instruction byte offset. Fixes: 22541a9 ("libbpf: Add BTF_KIND_FLOAT support") Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Lorenz Bauer <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
Kaz205 · Apr 27, 2021 · 6709a91 · 6709a91
1 parent 7a2fa70
commit 6709a91
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
@@ -5115,6 +5115,7 @@ bpf_core_find_cands(struct bpf_object *obj, const struct btf *local_btf, __u32 l
  *     least one of enums should be anonymous;
  *   - for ENUMs, check sizes, names are ignored;
  *   - for INT, size and signedness are ignored;
+ *   - any two FLOATs are always compatible;
  *   - for ARRAY, dimensionality is ignored, element types are checked for
  *     compatibility recursively;
  *   - everything else shouldn't be ever a target of relocation.
@@ -5141,6 +5142,7 @@ static int bpf_core_fields_are_compat(const struct btf *local_btf,
 
 	switch (btf_kind(local_type)) {
 	case BTF_KIND_PTR:
+	case BTF_KIND_FLOAT:
 		return 1;
 	case BTF_KIND_FWD:
 	case BTF_KIND_ENUM: {
@@ -6245,8 +6247,8 @@ static int bpf_core_apply_relo(struct bpf_program *prog,
 	/* bpf_core_patch_insn() should know how to handle missing targ_spec */
 	err = bpf_core_patch_insn(prog, relo, relo_idx, &targ_res);
 	if (err) {
-		pr_warn("prog '%s': relo #%d: failed to patch insn at offset %d: %d\n",
-			prog->name, relo_idx, relo->insn_off, err);
+		pr_warn("prog '%s': relo #%d: failed to patch insn #%zu: %d\n",
+			prog->name, relo_idx, relo->insn_off / BPF_INSN_SZ, err);
 		return -EINVAL;
 	}