Similar to what we did for bpf_prog_load() in previous patch, wire
returning of log_size_actual value from kernel back to the user through
OPTS out field.
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
tools/lib/bpf/bpf.c | 6 ++++--
tools/lib/bpf/bpf.h | 11 +++++++++--
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index cfe79d441c65..586776315afe 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -1083,9 +1083,9 @@ int bpf_raw_tracepoint_open(const char *name, int prog_fd)
return libbpf_err_errno(fd);
}
-int bpf_btf_load(const void *btf_data, size_t btf_size, const struct bpf_btf_load_opts *opts)
+int bpf_btf_load(const void *btf_data, size_t btf_size, struct bpf_btf_load_opts *opts)
{
- const size_t attr_sz = offsetofend(union bpf_attr, btf_log_level);
+ const size_t attr_sz = offsetofend(union bpf_attr, btf_log_size_actual);
union bpf_attr attr;
char *log_buf;
size_t log_size;
@@ -1128,6 +1128,8 @@ int bpf_btf_load(const void *btf_data, size_t btf_size, const struct bpf_btf_loa
attr.btf_log_level = 1;
fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, attr_sz);
}
+
+ OPTS_SET(opts, log_size_actual, attr.btf_log_size_actual);
return libbpf_err_errno(fd);
}
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 45a967e65165..fd45b70b9ea8 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -124,11 +124,18 @@ struct bpf_btf_load_opts {
char *log_buf;
__u32 log_level;
__u32 log_size;
+ /* output: actual total log contents size (including termintaing zero).
+ * It could be both larger than original log_size (if log was
+ * truncated), or smaller (if log buffer wasn't filled completely).
+ * If kernel doesn't support this feature, log_size is left unchanged.
+ */
+ __u32 log_size_actual;
+ size_t :0;
};
-#define bpf_btf_load_opts__last_field log_size
+#define bpf_btf_load_opts__last_field log_size_actual
LIBBPF_API int bpf_btf_load(const void *btf_data, size_t btf_size,
- const struct bpf_btf_load_opts *opts);
+ struct bpf_btf_load_opts *opts);
LIBBPF_API int bpf_map_update_elem(int fd, const void *key, const void *value,
__u64 flags);
--
2.34.1
