libbpf: Assume unsigned values for BTF_KIND_ENUM

Currently, BTF_KIND_ENUM type doesn't record whether enum values should be
interpreted as signed or unsigned. In Linux, most enums are unsigned, though,
so interpreting them as unsigned matches real world better.

Change btf_dump test case to test maximum 32-bit value, instead of negative
value.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200303003233.3496043-3-andriin@fb.com

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index dc451e4..0c28ee8 100644 (file)
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -916,13 +916,13 @@ static void btf_dump_emit_enum_def(struct btf_dump *d, __u32 id,
                        /* enumerators share namespace with typedef idents */
                        dup_cnt = btf_dump_name_dups(d, d->ident_names, name);
                        if (dup_cnt > 1) {
-                               btf_dump_printf(d, "\n%s%s___%zu = %d,",
+                               btf_dump_printf(d, "\n%s%s___%zu = %u,",
                                                pfx(lvl + 1), name, dup_cnt,
-                                               (__s32)v->val);
+                                               (__u32)v->val);
                        } else {
-                               btf_dump_printf(d, "\n%s%s = %d,",
+                               btf_dump_printf(d, "\n%s%s = %u,",
                                                pfx(lvl + 1), name,
-                                               (__s32)v->val);
+                                               (__u32)v->val);
                        }
                }
                btf_dump_printf(d, "\n%s}", pfx(lvl));

diff --git a/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c b/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c
index d4a02fe..31975c9 100644 (file)
--- a/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c
+++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c
@@ -13,7 +13,7 @@ enum e1 {
 
 enum e2 {
        C = 100,
-       D = -100,
+       D = 4294967295,
        E = 0,
 };