Merge branch 'bpf-ctx-narrow'

Yonghong Song says:

====================
bpf: permit bpf program narrower loads for ctx fields

Today, if users try to access a ctx field through a narrower load, e.g.,
__be16 prot = __sk_buff->protocol, verifier will fail.
This set contains the verifier change to permit such loads for
certain ctx fields as well as the new test cases in selftests/bpf.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 2 insertions, 1 deletions

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index c32bace66d3d..1bcbf0a71f75 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -157,7 +157,7 @@ struct bpf_verifier_ops {
 	 * with 'type' (read or write) is allowed
 	 */
 	bool (*is_valid_access)(int off, int size, enum bpf_access_type type,
-				enum bpf_reg_type *reg_type);
+				enum bpf_reg_type *reg_type, int *ctx_field_size);
 	int (*gen_prologue)(struct bpf_insn *insn, bool direct_write,
 			    const struct bpf_prog *prog);
 	u32 (*convert_ctx_access)(enum bpf_access_type type,
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index d5093b52b485..189741c0da85 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -73,6 +73,7 @@ struct bpf_insn_aux_data {
 		enum bpf_reg_type ptr_type;	/* pointer type for load/store insns */
 		struct bpf_map *map_ptr;	/* pointer for call insn into lookup_elem */
 	};
+	int ctx_field_size; /* the ctx field size for load/store insns, maybe 0 */
 };
 
 #define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */