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Diffstat (limited to 'tools/lib/bpf/bpf_core_read.h')
-rw-r--r--tools/lib/bpf/bpf_core_read.h52
1 files changed, 51 insertions, 1 deletions
diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h
index 03152cb143b7..684bfb86361a 100644
--- a/tools/lib/bpf/bpf_core_read.h
+++ b/tools/lib/bpf/bpf_core_read.h
@@ -19,6 +19,18 @@ enum bpf_field_info_kind {
BPF_FIELD_RSHIFT_U64 = 5,
};
+/* second argument to __builtin_btf_type_id() built-in */
+enum bpf_type_id_kind {
+ BPF_TYPE_ID_LOCAL = 0, /* BTF type ID in local program */
+ BPF_TYPE_ID_TARGET = 1, /* BTF type ID in target kernel */
+};
+
+/* second argument to __builtin_preserve_type_info() built-in */
+enum bpf_type_info_kind {
+ BPF_TYPE_EXISTS = 0, /* type existence in target kernel */
+ BPF_TYPE_SIZE = 1, /* type size in target kernel */
+};
+
#define __CORE_RELO(src, field, info) \
__builtin_preserve_field_info((src)->field, BPF_FIELD_##info)
@@ -94,13 +106,51 @@ enum bpf_field_info_kind {
__builtin_preserve_field_info(field, BPF_FIELD_EXISTS)
/*
- * Convenience macro to get byte size of a field. Works for integers,
+ * Convenience macro to get the byte size of a field. Works for integers,
* struct/unions, pointers, arrays, and enums.
*/
#define bpf_core_field_size(field) \
__builtin_preserve_field_info(field, BPF_FIELD_BYTE_SIZE)
/*
+ * Convenience macro to get BTF type ID of a specified type, using a local BTF
+ * information. Return 32-bit unsigned integer with type ID from program's own
+ * BTF. Always succeeds.
+ */
+#define bpf_core_type_id_local(type) \
+ __builtin_btf_type_id(*(typeof(type) *)0, BPF_TYPE_ID_LOCAL)
+
+/*
+ * Convenience macro to get BTF type ID of a target kernel's type that matches
+ * specified local type.
+ * Returns:
+ * - valid 32-bit unsigned type ID in kernel BTF;
+ * - 0, if no matching type was found in a target kernel BTF.
+ */
+#define bpf_core_type_id_kernel(type) \
+ __builtin_btf_type_id(*(typeof(type) *)0, BPF_TYPE_ID_TARGET)
+
+/*
+ * Convenience macro to check that provided named type
+ * (struct/union/enum/typedef) exists in a target kernel.
+ * Returns:
+ * 1, if such type is present in target kernel's BTF;
+ * 0, if no matching type is found.
+ */
+#define bpf_core_type_exists(type) \
+ __builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_EXISTS)
+
+/*
+ * Convenience macro to get the byte size of a provided named type
+ * (struct/union/enum/typedef) in a target kernel.
+ * Returns:
+ * >= 0 size (in bytes), if type is present in target kernel's BTF;
+ * 0, if no matching type is found.
+ */
+#define bpf_core_type_size(type) \
+ __builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_SIZE)
+
+/*
* bpf_core_read() abstracts away bpf_probe_read_kernel() call and captures
* offset relocation for source address using __builtin_preserve_access_index()
* built-in, provided by Clang.