Options cover existing parsing scenarios (ELF, raw, retrieving
.BTF.ext) and also allow specification of the ELF section name
containing BTF. This will allow consumers to retrieve BTF from
.BTF.base sections (BTF_BASE_ELF_SEC) also.
Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
---
tools/lib/bpf/btf.c | 50 ++++++++++++++++++++++++++++------------
tools/lib/bpf/btf.h | 32 +++++++++++++++++++++++++
tools/lib/bpf/libbpf.map | 1 +
3 files changed, 68 insertions(+), 15 deletions(-)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 419cc4fa2e86..9036c1dc45d0 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -1084,7 +1084,7 @@ struct btf *btf__new_split(const void *data, __u32 size, struct btf *base_btf)
return libbpf_ptr(btf_new(data, size, base_btf));
}
-static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
+static struct btf *btf_parse_elf(const char *path, const char *btf_sec, struct btf *base_btf,
struct btf_ext **btf_ext)
{
Elf_Data *btf_data = NULL, *btf_ext_data = NULL;
@@ -1146,7 +1146,7 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
idx, path);
goto done;
}
- if (strcmp(name, BTF_ELF_SEC) == 0) {
+ if (strcmp(name, btf_sec) == 0) {
btf_data = elf_getdata(scn, 0);
if (!btf_data) {
pr_warn("failed to get section(%d, %s) data from %s\n",
@@ -1166,7 +1166,7 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
}
if (!btf_data) {
- pr_warn("failed to find '%s' ELF section in %s\n", BTF_ELF_SEC, path);
+ pr_warn("failed to find '%s' ELF section in %s\n", btf_sec, path);
err = -ENODATA;
goto done;
}
@@ -1212,12 +1212,12 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext)
{
- return libbpf_ptr(btf_parse_elf(path, NULL, btf_ext));
+ return libbpf_ptr(btf_parse_elf(path, BTF_ELF_SEC, NULL, btf_ext));
}
struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf)
{
- return libbpf_ptr(btf_parse_elf(path, base_btf, NULL));
+ return libbpf_ptr(btf_parse_elf(path, BTF_ELF_SEC, base_btf, NULL));
}
static struct btf *btf_parse_raw(const char *path, struct btf *base_btf)
@@ -1293,7 +1293,8 @@ struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf)
return libbpf_ptr(btf_parse_raw(path, base_btf));
}
-static struct btf *btf_parse(const char *path, struct btf *base_btf, struct btf_ext **btf_ext)
+static struct btf *btf_parse(const char *path, const char *btf_elf_sec, struct btf *base_btf,
+ struct btf_ext **btf_ext)
{
struct btf *btf;
int err;
@@ -1301,23 +1302,42 @@ static struct btf *btf_parse(const char *path, struct btf *base_btf, struct btf_
if (btf_ext)
*btf_ext = NULL;
- btf = btf_parse_raw(path, base_btf);
- err = libbpf_get_error(btf);
- if (!err)
- return btf;
- if (err != -EPROTO)
- return ERR_PTR(err);
- return btf_parse_elf(path, base_btf, btf_ext);
+ if (!btf_elf_sec) {
+ btf = btf_parse_raw(path, base_btf);
+ err = libbpf_get_error(btf);
+ if (!err)
+ return btf;
+ if (err != -EPROTO)
+ return ERR_PTR(err);
+ }
+ if (!btf_elf_sec)
+ btf_elf_sec = BTF_ELF_SEC;
+
+ return btf_parse_elf(path, btf_elf_sec, base_btf, btf_ext);
+}
+
+struct btf *btf__parse_opts(const char *path, struct btf_parse_opts *opts)
+{
+ struct btf *base_btf;
+ const char *btf_sec;
+ struct btf_ext **btf_ext;
+
+ if (!OPTS_VALID(opts, btf_parse_opts))
+ return libbpf_err_ptr(-EINVAL);
+ base_btf = OPTS_GET(opts, base_btf, NULL);
+ btf_sec = OPTS_GET(opts, btf_sec, NULL);
+ btf_ext = OPTS_GET(opts, btf_ext, NULL);
+ return libbpf_ptr(btf_parse(path, btf_sec, base_btf, btf_ext));
}
struct btf *btf__parse(const char *path, struct btf_ext **btf_ext)
{
- return libbpf_ptr(btf_parse(path, NULL, btf_ext));
+ return libbpf_ptr(btf_parse(path, NULL, NULL, btf_ext));
}
struct btf *btf__parse_split(const char *path, struct btf *base_btf)
{
- return libbpf_ptr(btf_parse(path, base_btf, NULL));
+ return libbpf_ptr(btf_parse(path, NULL, base_btf, NULL));
}
static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endian);
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 025ed28b7fe8..94dfdfdef617 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -18,6 +18,7 @@ extern "C" {
#define BTF_ELF_SEC ".BTF"
#define BTF_EXT_ELF_SEC ".BTF.ext"
+#define BTF_BASE_ELF_SEC ".BTF.base"
#define MAPS_ELF_SEC ".maps"
struct btf;
@@ -134,6 +135,37 @@ LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_b
LIBBPF_API struct btf *btf__parse_raw(const char *path);
LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf);
+struct btf_parse_opts {
+ size_t sz;
+ /* use base BTF to parse split BTF */
+ struct btf *base_btf;
+ /* retrieve optional .BTF.ext info */
+ struct btf_ext **btf_ext;
+ /* BTF section name */
+ const char *btf_sec;
+ size_t:0;
+};
+
+#define btf_parse_opts__last_field btf_sec
+
+/* @brief **btf__parse_opts()** parses BTF information from either a
+ * raw BTF file (*btf_sec* is NULL) or from the specified BTF section,
+ * also retrieving .BTF.ext info if *btf_ext* is non-NULL. If
+ * *base_btf* is specified, use it to parse split BTF from the
+ * specified location.
+ *
+ * @return new BTF object instance which has to be eventually freed with
+ * **btf__free()**
+ *
+ * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
+ * error code from such a pointer `libbpf_get_error()` should be used. If
+ * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
+ * returned on error instead. In both cases thread-local `errno` variable is
+ * always set to error code as well.
+ */
+
+LIBBPF_API struct btf *btf__parse_opts(const char *path, struct btf_parse_opts *opts);
+
LIBBPF_API struct btf *btf__load_vmlinux_btf(void);
LIBBPF_API struct btf *btf__load_module_btf(const char *module_name, struct btf *vmlinux_btf);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index c4d9bd7d3220..a9151e31dfa9 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -421,6 +421,7 @@ LIBBPF_1.5.0 {
global:
bpf_program__attach_sockmap;
btf__distill_base;
+ btf__parse_opts;
ring__consume_n;
ring_buffer__consume_n;
} LIBBPF_1.4.0;
--
2.31.1
