Generate preload(), to pin defined objects. For pinning, use the
bpf_obj_do_pin_kernel() function, just exported.
Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
---
kernel/bpf/preload/bpf_preload_kern.c | 24 -------
.../bpf/preload/iterators/iterators.lskel.h | 26 ++++++++
tools/bpf/bpftool/gen.c | 64 +++++++++++++++++++
3 files changed, 90 insertions(+), 24 deletions(-)
diff --git a/kernel/bpf/preload/bpf_preload_kern.c b/kernel/bpf/preload/bpf_preload_kern.c
index 8b49beb2b2d6..0869c889255c 100644
--- a/kernel/bpf/preload/bpf_preload_kern.c
+++ b/kernel/bpf/preload/bpf_preload_kern.c
@@ -5,30 +5,6 @@
#include <linux/bpf_preload.h>
#include "iterators/iterators.lskel.h"
-static int preload(struct dentry *parent)
-{
- int err;
-
- bpf_link_inc(dump_bpf_map_link);
- bpf_link_inc(dump_bpf_prog_link);
-
- err = bpf_obj_do_pin_kernel(parent, "maps.debug", dump_bpf_map_link,
- BPF_TYPE_LINK);
- if (err)
- goto undo;
-
- err = bpf_obj_do_pin_kernel(parent, "progs.debug", dump_bpf_prog_link,
- BPF_TYPE_LINK);
- if (err)
- goto undo;
-
- return 0;
-undo:
- bpf_link_put(dump_bpf_map_link);
- bpf_link_put(dump_bpf_prog_link);
- return err;
-}
-
static struct bpf_preload_ops ops = {
.preload = preload,
.owner = THIS_MODULE,
diff --git a/kernel/bpf/preload/iterators/iterators.lskel.h b/kernel/bpf/preload/iterators/iterators.lskel.h
index 4afd983ad40e..75b2e94b7547 100644
--- a/kernel/bpf/preload/iterators/iterators.lskel.h
+++ b/kernel/bpf/preload/iterators/iterators.lskel.h
@@ -448,4 +448,30 @@ static void free_objs_and_skel(void)
iterators_bpf__destroy(skel);
}
+static int preload(struct dentry *parent)
+{
+ int err;
+
+ bpf_link_inc(dump_bpf_map_link);
+ bpf_link_inc(dump_bpf_prog_link);
+
+ err = bpf_obj_do_pin_kernel(parent, "maps.debug",
+ dump_bpf_map_link,
+ BPF_TYPE_LINK);
+ if (err)
+ goto undo;
+
+ err = bpf_obj_do_pin_kernel(parent, "progs.debug",
+ dump_bpf_prog_link,
+ BPF_TYPE_LINK);
+ if (err)
+ goto undo;
+
+ return 0;
+undo:
+ bpf_link_put(dump_bpf_map_link);
+ bpf_link_put(dump_bpf_prog_link);
+ return err;
+}
+
#endif /* __ITERATORS_BPF_SKEL_H__ */
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index e167aa092b7f..fa2c6022b80d 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -701,6 +701,69 @@ static void codegen_preload_free(struct bpf_object *obj, const char *obj_name)
", obj_name);
}
+static void codegen_preload(struct bpf_object *obj, const char *obj_name)
+{
+ struct bpf_program *prog;
+ const char *link_name;
+
+ codegen("\
+ \n\
+ \n\
+ static int preload(struct dentry *parent) \n\
+ { \n\
+ int err; \n\
+ \n\
+ ");
+
+ bpf_object__for_each_program(prog, obj) {
+ codegen("\
+ \n\
+ bpf_link_inc(%s_link); \n\
+ ", bpf_program__name(prog));
+ }
+
+ bpf_object__for_each_program(prog, obj) {
+ link_name = bpf_program__name(prog);
+ /* These need to be hardcoded for compatibility reasons. */
+ if (!strcmp(obj_name, "iterators_bpf")) {
+ if (!strcmp(link_name, "dump_bpf_map"))
+ link_name = "maps.debug";
+ else if (!strcmp(link_name, "dump_bpf_prog"))
+ link_name = "progs.debug";
+ }
+
+ codegen("\
+ \n\
+ \n\
+ err = bpf_obj_do_pin_kernel(parent, \"%s\", \n\
+ %s_link, \n\
+ BPF_TYPE_LINK); \n\
+ if (err) \n\
+ goto undo; \n\
+ ", link_name, bpf_program__name(prog));
+ }
+
+ codegen("\
+ \n\
+ \n\
+ return 0; \n\
+ undo: \n\
+ ");
+
+ bpf_object__for_each_program(prog, obj) {
+ codegen("\
+ \n\
+ bpf_link_put(%s_link); \n\
+ ", bpf_program__name(prog));
+ }
+
+ codegen("\
+ \n\
+ return err; \n\
+ } \n\
+ ");
+}
+
static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *header_guard)
{
DECLARE_LIBBPF_OPTS(gen_loader_opts, opts);
@@ -852,6 +915,7 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h
if (gen_preload_methods) {
codegen_preload_vars(obj, obj_name);
codegen_preload_free(obj, obj_name);
+ codegen_preload(obj, obj_name);
}
codegen("\
--
2.32.0
