On Wed, Jan 7, 2026 at 6:26 PM Menglong Dong [off-list ref] wrote:

+u64 *bpf_fsession_cookie(void *ctx)
+{
+       /* This helper call is inlined by verifier. */
+       u64 off = (((u64 *)ctx)[-1] >> BPF_TRAMP_M_COOKIE) & 0xFF;
+
+       return &((u64 *)ctx)[-off];
+}

Same question... this can be a comment.
For some of the helpers earlier we kept C functions to make
things work on architectures where JIT is not available,
but kfuncs require JIT, so for kfuncs there is no fallback necessary.