bpftool: Print function linkage in BTF dump

[platform/kernel/linux-rpi.git] / tools / bpf / bpftool / btf.c

diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index e5bc97b..b3745ed 100644 (file)
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -8,15 +8,15 @@
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
-#include <bpf.h>
-#include <libbpf.h>
+#include <bpf/bpf.h>
+#include <bpf/btf.h>
+#include <bpf/libbpf.h>
 #include <linux/btf.h>
 #include <linux/hashtable.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
-#include "btf.h"
 #include "json_writer.h"
 #include "main.h"
 
@@ -77,6 +77,20 @@ static const char *btf_var_linkage_str(__u32 linkage)
        }
 }
 
+static const char *btf_func_linkage_str(const struct btf_type *t)
+{
+       switch (btf_vlen(t)) {
+       case BTF_FUNC_STATIC:
+               return "static";
+       case BTF_FUNC_GLOBAL:
+               return "global";
+       case BTF_FUNC_EXTERN:
+               return "extern";
+       default:
+               return "(unknown)";
+       }
+}
+
 static const char *btf_str(const struct btf *btf, __u32 off)
 {
        if (!off)
@@ -231,12 +245,17 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
                        printf(" fwd_kind=%s", fwd_kind);
                break;
        }
-       case BTF_KIND_FUNC:
-               if (json_output)
+       case BTF_KIND_FUNC: {
+               const char *linkage = btf_func_linkage_str(t);
+
+               if (json_output) {
                        jsonw_uint_field(w, "type_id", t->type);
-               else
-                       printf(" type_id=%u", t->type);
+                       jsonw_string_field(w, "linkage", linkage);
+               } else {
+                       printf(" type_id=%u linkage=%s", t->type, linkage);
+               }
                break;
+       }
        case BTF_KIND_FUNC_PROTO: {
                const struct btf_param *p = (const void *)(t + 1);
                __u16 vlen = BTF_INFO_VLEN(t->info);
@@ -370,6 +389,10 @@ static int dump_btf_c(const struct btf *btf,
        if (IS_ERR(d))
                return PTR_ERR(d);
 
+       printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
+       printf("#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)\n");
+       printf("#endif\n\n");
+
        if (root_type_cnt) {
                for (i = 0; i < root_type_cnt; i++) {
                        err = btf_dump__dump_type(d, root_type_ids[i]);
@@ -386,6 +409,10 @@ static int dump_btf_c(const struct btf *btf,
                }
        }
 
+       printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
+       printf("#pragma clang attribute pop\n");
+       printf("#endif\n");
+
 done:
        btf_dump__free(d);
        return err;
@@ -524,7 +551,7 @@ static int do_dump(int argc, char **argv)
                if (IS_ERR(btf)) {
                        err = PTR_ERR(btf);
                        btf = NULL;
-                       p_err("failed to load BTF from %s: %s", 
+                       p_err("failed to load BTF from %s: %s",
                              *argv, strerror(err));
                        goto done;
                }