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Message-ID: <20240905055233.70203-1-shung-hsi.yu@suse.com>
Date: Thu, 5 Sep 2024 13:52:32 +0800
From: Shung-Hsi Yu <shung-hsi.yu@...e.com>
To: Eduard Zingerman <eddyz87@...il.com>,
bpf@...r.kernel.org
Cc: Shung-Hsi Yu <shung-hsi.yu@...e.com>,
Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Andrii Nakryiko <andrii@...nel.org>,
Martin KaFai Lau <martin.lau@...ux.dev>,
Song Liu <song@...nel.org>,
Yonghong Song <yonghong.song@...ux.dev>,
John Fastabend <john.fastabend@...il.com>,
KP Singh <kpsingh@...nel.org>,
Stanislav Fomichev <sdf@...ichev.me>,
Hao Luo <haoluo@...gle.com>,
Jiri Olsa <jolsa@...nel.org>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
David Vernet <void@...ifault.com>,
netdev@...r.kernel.org,
linux-kernel@...r.kernel.org,
kernel test robot <lkp@...el.com>
Subject: [PATCH bpf-next] 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 <lkp@...el.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202404241956.HEiRYwWq-lkp@intel.com/
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@...e.com>
---
Due to kernel test bot not setting the correct email header
(reported[1]) Eduard probably never saw the report about the warning
(nor did it show up on Patchwork).
1: https://github.com/intel/lkp-tests/issues/383
---
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;
--
2.46.0
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