Andrii reported a bug with the following information:
2859 if (enum64_placeholder_id == 0) {
2860 enum64_placeholder_id = btf__add_int(btf, "enum64_placeholder", 1, 0);
>>> CID 394804: Control flow issues (NO_EFFECT)
>>> This less-than-zero comparison of an unsigned value is never true. "enum64_placeholder_id < 0U".
2861 if (enum64_placeholder_id < 0)
2862 return enum64_placeholder_id;
2863 ...
Here enum64_placeholder_id declared as '__u32' so enum64_placeholder_id < 0
is always false.
Declare enum64_placeholder_id as 'int' in order to capture the potential
error properly.
Fixes: f2a625889bb8("libbpf: Add enum64 sanitization")
Reported-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
tools/lib/bpf/libbpf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 0781fae58a06..d989b0a17a89 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2786,7 +2786,7 @@ static int bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG);
bool has_enum64 = kernel_supports(obj, FEAT_BTF_ENUM64);
- __u32 enum64_placeholder_id = 0;
+ int enum64_placeholder_id = 0;
struct btf_type *t;
int i, j, vlen;
--
2.30.2
