bpf: widen dynptr size/offset to 64 bit

Dynptr currently caps size and offset at 24 bits, which isn’t sufficient
for file-backed use cases; even 32 bits can be limiting. Refactor dynptr
helpers/kfuncs to use 64-bit size and offset, ensuring consistency
across the APIs.

This change does not affect internals of xdp, skb or other dynptrs,
which continue to behave as before. Also it does not break binary
compatibility.

The widening enables large-file access support via dynptr, implemented
in the next patches.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-3-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 10 insertions, 10 deletions

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index e53cda0aabb6..907c69295293 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1387,19 +1387,19 @@ enum bpf_dynptr_type {
 	BPF_DYNPTR_TYPE_SKB_META,
 };
 
-int bpf_dynptr_check_size(u32 size);
-u32 __bpf_dynptr_size(const struct bpf_dynptr_kern *ptr);
-const void *__bpf_dynptr_data(const struct bpf_dynptr_kern *ptr, u32 len);
-void *__bpf_dynptr_data_rw(const struct bpf_dynptr_kern *ptr, u32 len);
+int bpf_dynptr_check_size(u64 size);
+u64 __bpf_dynptr_size(const struct bpf_dynptr_kern *ptr);
+const void *__bpf_dynptr_data(const struct bpf_dynptr_kern *ptr, u64 len);
+void *__bpf_dynptr_data_rw(const struct bpf_dynptr_kern *ptr, u64 len);
 bool __bpf_dynptr_is_rdonly(const struct bpf_dynptr_kern *ptr);
-int __bpf_dynptr_write(const struct bpf_dynptr_kern *dst, u32 offset,
-		       void *src, u32 len, u64 flags);
-void *bpf_dynptr_slice_rdwr(const struct bpf_dynptr *p, u32 offset,
-			    void *buffer__opt, u32 buffer__szk);
+int __bpf_dynptr_write(const struct bpf_dynptr_kern *dst, u64 offset,
+		       void *src, u64 len, u64 flags);
+void *bpf_dynptr_slice_rdwr(const struct bpf_dynptr *p, u64 offset,
+			    void *buffer__opt, u64 buffer__szk);
 
-static inline int bpf_dynptr_check_off_len(const struct bpf_dynptr_kern *ptr, u32 offset, u32 len)
+static inline int bpf_dynptr_check_off_len(const struct bpf_dynptr_kern *ptr, u64 offset, u64 len)
 {
-	u32 size = __bpf_dynptr_size(ptr);
+	u64 size = __bpf_dynptr_size(ptr);
 
 	if (len > size || offset > size - len)
 		return -E2BIG;