struct btf is an efficient and convenient data structure to be used as a set
of deduplicated strings. This patch adds libbpf-internal btf_raw_str() helper
that gives access to strings section raw data (regardless of whether BTF
object is read-only or writeable) and its size in bytes. This is going to be
used by bpf_linker to implement ELF string table section.
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
tools/lib/bpf/btf.c | 11 +++++++++++
tools/lib/bpf/libbpf_internal.h | 1 +
2 files changed, 12 insertions(+)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index e0b0a78b04fe..6ee82ffcf3ff 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -1296,6 +1296,17 @@ static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endi
return NULL;
}
+/*
+ * Internal helper to get the size and direct pointer to strings section.
+ * This is used in cases where struct btf is used as an efficient and
+ * convenient strings container (e.g., bpf_linker).
+ */
+const void *btf_raw_strs(const struct btf *btf, size_t *size)
+{
+ *size = btf->hdr->str_len;
+ return btf->strs_data;
+}
+
const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size)
{
struct btf *btf = (struct btf *)btf_ro;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index d09860e435c8..069250e8e871 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -115,6 +115,7 @@ struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id);
void *btf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz,
size_t cur_cnt, size_t max_cnt, size_t add_cnt);
int btf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt);
+const void *btf_raw_strs(const struct btf *btf, size_t *size);
static inline bool libbpf_validate_opts(const char *opts,
size_t opts_sz, size_t user_sz,
--
2.24.1
