[bpf-next,3/9] bpf: Allow registration of const struct bpf_struct_ops

Commit Message

Thomas Weißschuh Nov. 27, 2024, 7:15 p.m. UTC

The BPF core does not need to modify instances of struct bpf_struct_ops
anymore. Reflect this in the API so users can move their instances into
read-only memory.

Signed-off-by: Thomas Weißschuh <[e-mail]>
---
 include/linux/bpf.h         | 2 +-
 include/linux/btf.h         | 2 +-
 kernel/bpf/bpf_struct_ops.c | 2 +-
 kernel/bpf/btf.c            | 4 ++--
 4 files changed, 5 insertions(+), 5 deletions(-)

Patch

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index b734543b7a2b48e717d4f1be765e0198114b4f0a..a9267af9671b2bc8961cde24d2f79f473ab227d7 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1814,7 +1814,7 @@  struct bpf_struct_ops_arg_info {
 };
 
 struct bpf_struct_ops_desc {
-	struct bpf_struct_ops *st_ops;
+	const struct bpf_struct_ops *st_ops;
 
 	const struct btf_type *type;
 	const struct btf_type *value_type;
diff --git a/include/linux/btf.h b/include/linux/btf.h
index 4214e76c916861462e45e98690fcf461c05ca737..87a5ddef9fdc4b7f09d375ec5959abd6d07533a9 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -519,7 +519,7 @@  struct bpf_verifier_log;
 
 #if defined(CONFIG_BPF_JIT) && defined(CONFIG_BPF_SYSCALL)
 struct bpf_struct_ops;
-int __register_bpf_struct_ops(struct bpf_struct_ops *st_ops);
+int __register_bpf_struct_ops(const struct bpf_struct_ops *st_ops);
 const struct bpf_struct_ops_desc *bpf_struct_ops_find_value(struct btf *btf, u32 value_id);
 const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *btf, u32 type_id);
 #else
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index 7ee7c25d21d480d46b40b23ff8aec9d12ea81f68..967f0914d473fcde4a6ce3bb6ac976345daf8e88 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -314,7 +314,7 @@  int bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc,
 			     struct btf *btf,
 			     struct bpf_verifier_log *log)
 {
-	struct bpf_struct_ops *st_ops = st_ops_desc->st_ops;
+	const struct bpf_struct_ops *st_ops = st_ops_desc->st_ops;
 	struct bpf_struct_ops_arg_info *arg_info;
 	const struct btf_member *member;
 	const struct btf_type *t;
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index e7a59e6462a9331d0acb17a88a4ebf641509c050..e3be8b7d6cbb268cf389bac9d3f889dbfd664a2e 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -9155,7 +9155,7 @@  bool btf_type_ids_nocast_alias(struct bpf_verifier_log *log,
 
 #ifdef CONFIG_BPF_JIT
 static int
-btf_add_struct_ops(struct btf *btf, struct bpf_struct_ops *st_ops,
+btf_add_struct_ops(struct btf *btf, const struct bpf_struct_ops *st_ops,
 		   struct bpf_verifier_log *log)
 {
 	struct btf_struct_ops_tab *tab, *new_tab;
@@ -9242,7 +9242,7 @@  bpf_struct_ops_find(struct btf *btf, u32 type_id)
 	return NULL;
 }
 
-int __register_bpf_struct_ops(struct bpf_struct_ops *st_ops)
+int __register_bpf_struct_ops(const struct bpf_struct_ops *st_ops)
 {
 	struct bpf_verifier_log *log;
 	struct btf *btf;