From 1ae497c78f01855f3695b58481311ffdd429b028 Mon Sep 17 00:00:00 2001 From: Shung-Hsi Yu Date: Thu, 5 Sep 2024 13:52:32 +0800 Subject: [PATCH] bpf: use type_may_be_null() helper for nullable-param check Commit 980ca8ceeae6 ("bpf: check bpf_dummy_struct_ops program params for test runs") does bitwise AND between reg_type and PTR_MAYBE_NULL, which is correct, but due to type difference the compiler complains: net/bpf/bpf_dummy_struct_ops.c:118:31: warning: bitwise operation between different enumeration types ('const enum bpf_reg_type' and 'enum bpf_type_flag') [-Wenum-enum-conversion] 118 | if (info && (info->reg_type & PTR_MAYBE_NULL)) | ~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~ Workaround the warning by moving the type_may_be_null() helper from verifier.c into bpf_verifier.h, and reuse it here to check whether param is nullable. Fixes: 980ca8ceeae6 ("bpf: check bpf_dummy_struct_ops program params for test runs") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202404241956.HEiRYwWq-lkp@intel.com/ Signed-off-by: Shung-Hsi Yu Acked-by: Eduard Zingerman Link: https://lore.kernel.org/r/20240905055233.70203-1-shung-hsi.yu@suse.com Signed-off-by: Alexei Starovoitov --- include/linux/bpf_verifier.h | 5 +++++ kernel/bpf/verifier.c | 5 ----- net/bpf/bpf_dummy_struct_ops.c | 2 +- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 8458632824a4..4513372c5bc8 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -927,6 +927,11 @@ static inline bool type_is_sk_pointer(enum bpf_reg_type type) type == PTR_TO_XDP_SOCK; } +static inline bool type_may_be_null(u32 type) +{ + return type & PTR_MAYBE_NULL; +} + static inline void mark_reg_scratched(struct bpf_verifier_env *env, u32 regno) { env->scratched_regs |= 1U << regno; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index b806afeba212..53d0556fbbf3 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -383,11 +383,6 @@ static void verbose_invalid_scalar(struct bpf_verifier_env *env, verbose(env, " should have been in [%d, %d]\n", range.minval, range.maxval); } -static bool type_may_be_null(u32 type) -{ - return type & PTR_MAYBE_NULL; -} - static bool reg_not_null(const struct bpf_reg_state *reg) { enum bpf_reg_type type; diff --git a/net/bpf/bpf_dummy_struct_ops.c b/net/bpf/bpf_dummy_struct_ops.c index 3ea52b05adfb..f71f67c6896b 100644 --- a/net/bpf/bpf_dummy_struct_ops.c +++ b/net/bpf/bpf_dummy_struct_ops.c @@ -115,7 +115,7 @@ static int check_test_run_args(struct bpf_prog *prog, struct bpf_dummy_ops_test_ offset = btf_ctx_arg_offset(bpf_dummy_ops_btf, func_proto, arg_no); info = find_ctx_arg_info(prog->aux, offset); - if (info && (info->reg_type & PTR_MAYBE_NULL)) + if (info && type_may_be_null(info->reg_type)) continue; return -EINVAL;