From 88d1d4a7eebea2836859246d91fe9d141789dfc3 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Wed, 6 Mar 2024 19:12:23 -0800 Subject: bpf: Allow kfuncs return 'void *' Recognize return of 'void *' from kfunc as returning unknown scalar. Acked-by: Andrii Nakryiko Acked-by: Kumar Kartikeya Dwivedi Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/r/20240307031228.42896-2-alexei.starovoitov@gmail.com Signed-off-by: Martin KaFai Lau --- kernel/bpf/verifier.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel/bpf') diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index ee86e4d7d5fc..9c2a36b1373b 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -12364,6 +12364,9 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, meta.func_name); return -EFAULT; } + } else if (btf_type_is_void(ptr_type)) { + /* kfunc returning 'void *' is equivalent to returning scalar */ + mark_reg_unknown(env, regs, BPF_REG_0); } else if (!__btf_type_is_struct(ptr_type)) { if (!meta.r0_size) { __u32 sz; -- cgit