1 files changed, 28 insertions, 16 deletions

diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
index de6365b53c9c..73409e27be01 100644
--- a/tools/bpf/resolve_btfids/main.c
+++ b/tools/bpf/resolve_btfids/main.c
@@ -60,8 +60,8 @@
 #include <linux/rbtree.h>
 #include <linux/zalloc.h>
 #include <linux/err.h>
-#include <btf.h>
-#include <libbpf.h>
+#include <bpf/btf.h>
+#include <bpf/libbpf.h>
 #include <parse-options.h>
 
 #define BTF_IDS_SECTION	".BTF_ids"
@@ -83,12 +83,14 @@ struct btf_id {
 		int	 cnt;
 	};
 	int		 addr_cnt;
+	bool		 is_set;
 	Elf64_Addr	 addr[ADDR_CNT];
 };
 
 struct object {
 	const char *path;
 	const char *btf;
+	const char *base_btf_path;
 
 	struct {
 		int		 fd;
@@ -450,8 +452,10 @@ static int symbols_collect(struct object *obj)
 			 * in symbol's size, together with 'cnt' field hence
 			 * that - 1.
 			 */
-			if (id)
+			if (id) {
 				id->cnt = sym.st_size / sizeof(int) - 1;
+				id->is_set = true;
+			}
 		} else {
 			pr_err("FAILED unsupported prefix %s\n", prefix);
 			return -1;
@@ -477,25 +481,36 @@ static int symbols_resolve(struct object *obj)
 	int nr_structs  = obj->nr_structs;
 	int nr_unions   = obj->nr_unions;
 	int nr_funcs    = obj->nr_funcs;
+	struct btf *base_btf = NULL;
 	int err, type_id;
 	struct btf *btf;
 	__u32 nr_types;
 
-	btf = btf__parse(obj->btf ?: obj->path, NULL);
+	if (obj->base_btf_path) {
+		base_btf = btf__parse(obj->base_btf_path, NULL);
+		err = libbpf_get_error(base_btf);
+		if (err) {
+			pr_err("FAILED: load base BTF from %s: %s\n",
+			       obj->base_btf_path, strerror(-err));
+			return -1;
+		}
+	}
+
+	btf = btf__parse_split(obj->btf ?: obj->path, base_btf);
 	err = libbpf_get_error(btf);
 	if (err) {
 		pr_err("FAILED: load BTF from %s: %s\n",
 			obj->btf ?: obj->path, strerror(-err));
-		return -1;
+		goto out;
 	}
 
 	err = -1;
-	nr_types = btf__get_nr_types(btf);
+	nr_types = btf__type_cnt(btf);
 
 	/*
 	 * Iterate all the BTF types and search for collected symbol IDs.
 	 */
-	for (type_id = 1; type_id <= nr_types; type_id++) {
+	for (type_id = 1; type_id < nr_types; type_id++) {
 		const struct btf_type *type;
 		struct rb_root *root;
 		struct btf_id *id;
@@ -545,6 +560,7 @@ static int symbols_resolve(struct object *obj)
 
 	err = 0;
 out:
+	btf__free(base_btf);
 	btf__free(btf);
 	return err;
 }
@@ -555,9 +571,8 @@ static int id_patch(struct object *obj, struct btf_id *id)
 	int *ptr = data->d_buf;
 	int i;
 
-	if (!id->id) {
+	if (!id->id && !id->is_set)
 		pr_err("WARN: resolve_btfids: unresolved symbol %s\n", id->name);
-	}
 
 	for (i = 0; i < id->addr_cnt; i++) {
 		unsigned long addr = id->addr[i];
@@ -678,7 +693,6 @@ static const char * const resolve_btfids_usage[] = {
 
 int main(int argc, const char **argv)
 {
-	bool no_fail = false;
 	struct object obj = {
 		.efile = {
 			.idlist_shndx  = -1,
@@ -695,8 +709,8 @@ int main(int argc, const char **argv)
 			 "be more verbose (show errors, etc)"),
 		OPT_STRING(0, "btf", &obj.btf, "BTF data",
 			   "BTF data"),
-		OPT_BOOLEAN(0, "no-fail", &no_fail,
-			   "do not fail if " BTF_IDS_SECTION " section is not found"),
+		OPT_STRING('b', "btf_base", &obj.base_btf_path, "file",
+			   "path of file providing base BTF"),
 		OPT_END()
 	};
 	int err = -1;
@@ -717,10 +731,8 @@ int main(int argc, const char **argv)
 	 */
 	if (obj.efile.idlist_shndx == -1 ||
 	    obj.efile.symbols_shndx == -1) {
-		if (no_fail)
-			return 0;
-		pr_err("FAILED to find needed sections\n");
-		return -1;
+		pr_debug("Cannot find .BTF_ids or symbols sections, nothing to do\n");
+		return 0;
 	}
 
 	if (symbols_collect(&obj))