[PATCH bpf-next v2 13/13] tools/bpf: bpftool: add support for jited func types

@@ -249,3 +249,99 @@ int btf_dumper_type(const struct btf_dumper *d, __u32 type_id,
 {
 	return btf_dumper_do_type(d, type_id, 0, data);
 }
+
+#define BTF_PRINT_STRING(str)						\
+	{								\
+		pos += snprintf(func_sig + pos, size - pos, str);	\
+		if (pos >= size)					\
+			return -1;					\
+	}
+#define BTF_PRINT_ONE_ARG(fmt, arg)					\
+	{								\
+		pos += snprintf(func_sig + pos, size - pos, fmt, arg);	\
+		if (pos >= size)					\
+			return -1;					\
+	}
+#define BTF_PRINT_TYPE_ONLY(type)					\
+	{								\
+		pos = __btf_dumper_type_only(btf, type, func_sig,	\
+					     pos, size);		\
+		if (pos == -1)						\
+			return -1;					\
+	}
+
+static int __btf_dumper_type_only(struct btf *btf, __u32 type_id,
+				  char *func_sig, int pos, int size)
+{
+	const struct btf_type *t = btf__type_by_id(btf, type_id);
+	const struct btf_array *array;
+	int i, vlen;
+
+	switch (BTF_INFO_KIND(t->info)) {
+	case BTF_KIND_INT:
+		BTF_PRINT_ONE_ARG("%s ",
+				  btf__name_by_offset(btf, t->name_off));
+		break;
+	case BTF_KIND_STRUCT:
+		BTF_PRINT_ONE_ARG("struct %s ",
+				  btf__name_by_offset(btf, t->name_off));
+		break;
+	case BTF_KIND_UNION:
+		BTF_PRINT_ONE_ARG("union %s ",
+				  btf__name_by_offset(btf, t->name_off));
+		break;
+	case BTF_KIND_ENUM:
+		BTF_PRINT_ONE_ARG("enum %s ",
+				  btf__name_by_offset(btf, t->name_off));
+		break;
+	case BTF_KIND_ARRAY:
+		array = (struct btf_array *)(t + 1);
+		BTF_PRINT_TYPE_ONLY(array->type);
+		BTF_PRINT_ONE_ARG("[%d]", array->nelems);
+		break;
+	case BTF_KIND_PTR:
+		BTF_PRINT_TYPE_ONLY(t->type);
+		BTF_PRINT_STRING("* ");
+		break;
+	case BTF_KIND_UNKN:
+	case BTF_KIND_FWD:
+	case BTF_KIND_TYPEDEF:
+		return -1;
+	case BTF_KIND_VOLATILE:
+		BTF_PRINT_STRING("volatile ");
+		BTF_PRINT_TYPE_ONLY(t->type);
+		break;
+	case BTF_KIND_CONST:
+		BTF_PRINT_STRING("const ");
+		BTF_PRINT_TYPE_ONLY(t->type);
+		break;
+	case BTF_KIND_RESTRICT:
+		BTF_PRINT_STRING("restrict ");
+		BTF_PRINT_TYPE_ONLY(t->type);
+		break;
+	case BTF_KIND_FUNC:
+	case BTF_KIND_FUNC_PROTO:
+		BTF_PRINT_TYPE_ONLY(t->type);
+		BTF_PRINT_ONE_ARG("%s(", btf__name_by_offset(btf, t->name_off));
+		vlen = BTF_INFO_VLEN(t->info);
+		for (i = 0; i < vlen; i++) {
+			__u32 arg_type = ((__u32 *)(t + 1))[i];
+
+			BTF_PRINT_TYPE_ONLY(arg_type);
+			if (i != (vlen - 1))
+				BTF_PRINT_STRING(", ");
+		}
+		BTF_PRINT_STRING(")");
+		break;
+	default:
+		return -1;
+	}
+
+	return pos;
+}
+
+int btf_dumper_type_only(struct btf *btf, __u32 type_id, char *func_sig,
+			 int size)
+{
+	return __btf_dumper_type_only(btf, type_id, func_sig, 0, size);
+}

@@ -168,6 +168,8 @@ struct btf_dumper {
  */
 int btf_dumper_type(const struct btf_dumper *d, __u32 type_id,
 		    const void *data);
+int btf_dumper_type_only(struct btf *btf, __u32 func_type_id, char *func_only,
+			 int size);
 
 struct nlattr;
 struct ifinfomsg;

@@ -47,6 +47,7 @@
 #include <linux/err.h>
 
 #include <bpf.h>
+#include <btf.h>
 #include <libbpf.h>
 
 #include "cfg.h"

@@ -447,9 +448,11 @@ static int do_show(int argc, char **argv)
 static int do_dump(int argc, char **argv)
 {
 	unsigned long *func_ksyms = NULL;
+	unsigned int *func_types = NULL;
 	struct bpf_prog_info info = {};
 	unsigned int *func_lens = NULL;
 	unsigned int nr_func_ksyms;
+	unsigned int nr_func_types;
 	unsigned int nr_func_lens;
 	struct dump_data dd = {};
 	__u32 len = sizeof(info);

@@ -546,6 +549,16 @@ static int do_dump(int argc, char **argv)
 		}
 	}
 
+	nr_func_types = info.nr_jited_func_types;
+	if (nr_func_types) {
+		func_types = malloc(nr_func_types * sizeof(__u32));
+		if (!func_types) {
+			p_err("mem alloc failed");
+			close(fd);
+			goto err_free;
+		}
+	}
+
 	memset(&info, 0, sizeof(info));
 
 	*member_ptr = ptr_to_u64(buf);

@@ -554,6 +567,8 @@ static int do_dump(int argc, char **argv)
 	info.nr_jited_ksyms = nr_func_ksyms;
 	info.jited_func_lens = ptr_to_u64(func_lens);
 	info.nr_jited_func_lens = nr_func_lens;
+	info.jited_func_types = ptr_to_u64(func_types);
+	info.nr_jited_func_types = nr_func_types;
 
 	err = bpf_obj_get_info_by_fd(fd, &info, &len);
 	close(fd);

@@ -577,6 +592,11 @@ static int do_dump(int argc, char **argv)
 		goto err_free;
 	}
 
+	if (info.nr_jited_func_types > nr_func_types) {
+		p_err("too many types returned");
+		goto err_free;
+	}
+
 	if ((member_len == &info.jited_prog_len &&
 	     info.jited_prog_insns == 0) ||
 	    (member_len == &info.xlated_prog_len &&

@@ -585,6 +605,12 @@ static int do_dump(int argc, char **argv)
 		goto err_free;
 	}
 
+	if (info.btf_id &&
+	    info.nr_jited_func_lens != info.nr_jited_func_types) {
+		p_err("unequal jited func lens and types");
+		goto err_free;
+	}
+
 	if (filepath) {
 		fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 		if (fd < 0) {

@@ -618,7 +644,9 @@ static int do_dump(int argc, char **argv)
 			struct kernel_sym *sym = NULL;
 			char sym_name[SYM_MAX_NAME];
 			unsigned char *img = buf;
+			struct btf *btf = NULL;
 			__u64 *ksyms = NULL;
+			char func_sig[1024];
 			__u32 *lens;
 			__u32 i;
 

@@ -627,6 +655,14 @@ static int do_dump(int argc, char **argv)
 				ksyms = (__u64 *) info.jited_ksyms;
 			}
 
+			if (info.btf_id) {
+				err = btf_get_from_id(info.btf_id, &btf);
+				if (err) {
+					p_err("failed to get btf");
+					goto err_free;
+				}
+			}
+
 			if (json_output)
 				jsonw_start_array(json_wtr);
 

@@ -642,12 +678,28 @@ static int do_dump(int argc, char **argv)
 					strcpy(sym_name, "unknown");
 				}
 
+				func_sig[0] = '\0';
+				if (btf) {
+					err = btf_dumper_type_only(btf,
+								   func_types[i],
+								   func_sig,
+								   sizeof(func_sig));
+					if (err < 0)
+						func_sig[0] = '\0';
+				}
+
 				if (json_output) {
 					jsonw_start_object(json_wtr);
+					if (func_sig[0] != '\0') {
+						jsonw_name(json_wtr, "proto");
+						jsonw_string(json_wtr, func_sig);
+					}
 					jsonw_name(json_wtr, "name");
 					jsonw_string(json_wtr, sym_name);
 					jsonw_name(json_wtr, "insns");
 				} else {
+					if (func_sig[0] != '\0')
+						printf("%s:\n", func_sig);
 					printf("%s:\n", sym_name);
 				}
 

@@ -685,12 +737,14 @@ static int do_dump(int argc, char **argv)
 	free(buf);
 	free(func_ksyms);
 	free(func_lens);
+	free(func_types);
 	return 0;
 
 err_free:
 	free(buf);
 	free(func_ksyms);
 	free(func_lens);
+	free(func_types);
 	return -1;
 }