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Diffstat (limited to 'tools/lib/bpf/bpf_core_read.h')
-rw-r--r--tools/lib/bpf/bpf_core_read.h37
1 files changed, 33 insertions, 4 deletions
diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h
index e4aa9996a550..fd48b1ff59ca 100644
--- a/tools/lib/bpf/bpf_core_read.h
+++ b/tools/lib/bpf/bpf_core_read.h
@@ -110,21 +110,50 @@ enum bpf_enum_value_kind {
val; \
})
+#define ___bpf_field_ref1(field) (field)
+#define ___bpf_field_ref2(type, field) (((typeof(type) *)0)->field)
+#define ___bpf_field_ref(args...) \
+ ___bpf_apply(___bpf_field_ref, ___bpf_narg(args))(args)
+
/*
* Convenience macro to check that field actually exists in target kernel's.
* Returns:
* 1, if matching field is present in target kernel;
* 0, if no matching field found.
+ *
+ * Supports two forms:
+ * - field reference through variable access:
+ * bpf_core_field_exists(p->my_field);
+ * - field reference through type and field names:
+ * bpf_core_field_exists(struct my_type, my_field).
*/
-#define bpf_core_field_exists(field) \
- __builtin_preserve_field_info(field, BPF_FIELD_EXISTS)
+#define bpf_core_field_exists(field...) \
+ __builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_EXISTS)
/*
* Convenience macro to get the byte size of a field. Works for integers,
* struct/unions, pointers, arrays, and enums.
+ *
+ * Supports two forms:
+ * - field reference through variable access:
+ * bpf_core_field_size(p->my_field);
+ * - field reference through type and field names:
+ * bpf_core_field_size(struct my_type, my_field).
+ */
+#define bpf_core_field_size(field...) \
+ __builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_BYTE_SIZE)
+
+/*
+ * Convenience macro to get field's byte offset.
+ *
+ * Supports two forms:
+ * - field reference through variable access:
+ * bpf_core_field_offset(p->my_field);
+ * - field reference through type and field names:
+ * bpf_core_field_offset(struct my_type, my_field).
*/
-#define bpf_core_field_size(field) \
- __builtin_preserve_field_info(field, BPF_FIELD_BYTE_SIZE)
+#define bpf_core_field_offset(field...) \
+ __builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_BYTE_OFFSET)
/*
* Convenience macro to get BTF type ID of a specified type, using a local BTF