From: kernel test robot <lkp@intel.com>
To: Paul Chaignon <paul.chaignon@gmail.com>, bpf@vger.kernel.org
Cc: llvm@lists.linux.dev, oe-kbuild-all@lists.linux.dev,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Eduard Zingerman <eddyz87@gmail.com>
Subject: Re: [PATCH bpf-next 1/4] bpf: Refactor cleanup of bpf_prog_test_run_skb
Date: Fri, 5 Sep 2025 20:57:29 +0800 [thread overview]
Message-ID: <202509052000.sL96WwEb-lkp@intel.com> (raw)
In-Reply-To: <6fda7c7fd57e6134ff70d12b622c9c7c3cf0b226.1756983952.git.paul.chaignon@gmail.com>
Hi Paul,
kernel test robot noticed the following build warnings:
[auto build test WARNING on bpf-next/master]
url: https://github.com/intel-lab-lkp/linux/commits/Paul-Chaignon/bpf-Refactor-cleanup-of-bpf_prog_test_run_skb/20250904-201515
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link: https://lore.kernel.org/r/6fda7c7fd57e6134ff70d12b622c9c7c3cf0b226.1756983952.git.paul.chaignon%40gmail.com
patch subject: [PATCH bpf-next 1/4] bpf: Refactor cleanup of bpf_prog_test_run_skb
config: i386-buildonly-randconfig-006-20250905 (https://download.01.org/0day-ci/archive/20250905/202509052000.sL96WwEb-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250905/202509052000.sL96WwEb-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202509052000.sL96WwEb-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> net/bpf/test_run.c:1011:6: warning: variable 'sk' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
1011 | if (IS_ERR(ctx)) {
| ^~~~~~~~~~~
net/bpf/test_run.c:1142:6: note: uninitialized use occurs here
1142 | if (sk)
| ^~
net/bpf/test_run.c:1011:2: note: remove the 'if' if its condition is always false
1011 | if (IS_ERR(ctx)) {
| ^~~~~~~~~~~~~~~~~~
1012 | ret = PTR_ERR(ctx);
| ~~~~~~~~~~~~~~~~~~~
1013 | goto out;
| ~~~~~~~~~
1014 | }
| ~
net/bpf/test_run.c:996:17: note: initialize the variable 'sk' to silence this warning
996 | struct sock *sk;
| ^
| = NULL
>> net/bpf/test_run.c:1032:6: warning: variable 'skb' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
1032 | if (!sk) {
| ^~~
net/bpf/test_run.c:1140:12: note: uninitialized use occurs here
1140 | kfree_skb(skb);
| ^~~
net/bpf/test_run.c:1032:2: note: remove the 'if' if its condition is always false
1032 | if (!sk) {
| ^~~~~~~~~~
1033 | ret = -ENOMEM;
| ~~~~~~~~~~~~~~
1034 | goto out;
| ~~~~~~~~~
1035 | }
| ~
net/bpf/test_run.c:1011:6: warning: variable 'skb' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
1011 | if (IS_ERR(ctx)) {
| ^~~~~~~~~~~
net/bpf/test_run.c:1140:12: note: uninitialized use occurs here
1140 | kfree_skb(skb);
| ^~~
net/bpf/test_run.c:1011:2: note: remove the 'if' if its condition is always false
1011 | if (IS_ERR(ctx)) {
| ^~~~~~~~~~~~~~~~~~
1012 | ret = PTR_ERR(ctx);
| ~~~~~~~~~~~~~~~~~~~
1013 | goto out;
| ~~~~~~~~~
1014 | }
| ~
net/bpf/test_run.c:995:21: note: initialize the variable 'skb' to silence this warning
995 | struct sk_buff *skb;
| ^
| = NULL
3 warnings generated.
vim +1011 net/bpf/test_run.c
435b08ec0094ac Daniel Borkmann 2021-09-27 983
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 984 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 985 union bpf_attr __user *uattr)
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 986 {
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 987 bool is_l2 = false, is_direct_pkt_access = false;
21594c44083c37 Dmitry Yakunin 2020-08-03 988 struct net *net = current->nsproxy->net_ns;
21594c44083c37 Dmitry Yakunin 2020-08-03 989 struct net_device *dev = net->loopback_dev;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 990 u32 size = kattr->test.data_size_in;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 991 u32 repeat = kattr->test.repeat;
b0b9395d865e30 Stanislav Fomichev 2019-04-09 992 struct __sk_buff *ctx = NULL;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 993 u32 retval, duration;
6e6fddc7832353 Daniel Borkmann 2018-07-11 994 int hh_len = ETH_HLEN;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 995 struct sk_buff *skb;
2cb494a36c9827 Song Liu 2018-10-19 996 struct sock *sk;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 997 void *data;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 998 int ret;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 999
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1000 if ((kattr->test.flags & ~BPF_F_TEST_SKB_CHECKSUM_COMPLETE) ||
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1001 kattr->test.cpu || kattr->test.batch_size)
1b4d60ec162f82 Song Liu 2020-09-25 1002 return -EINVAL;
1b4d60ec162f82 Song Liu 2020-09-25 1003
be3d72a2896cb2 Lorenzo Bianconi 2022-01-21 1004 data = bpf_test_init(kattr, kattr->test.data_size_in,
be3d72a2896cb2 Lorenzo Bianconi 2022-01-21 1005 size, NET_SKB_PAD + NET_IP_ALIGN,
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1006 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1007 if (IS_ERR(data))
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1008 return PTR_ERR(data);
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1009
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1010 ctx = bpf_ctx_init(kattr, sizeof(struct __sk_buff));
b0b9395d865e30 Stanislav Fomichev 2019-04-09 @1011 if (IS_ERR(ctx)) {
ed22fb43432aaa Paul Chaignon 2025-09-04 1012 ret = PTR_ERR(ctx);
ed22fb43432aaa Paul Chaignon 2025-09-04 1013 goto out;
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1014 }
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1015
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1016 switch (prog->type) {
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1017 case BPF_PROG_TYPE_SCHED_CLS:
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1018 case BPF_PROG_TYPE_SCHED_ACT:
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1019 is_l2 = true;
df561f6688fef7 Gustavo A. R. Silva 2020-08-23 1020 fallthrough;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1021 case BPF_PROG_TYPE_LWT_IN:
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1022 case BPF_PROG_TYPE_LWT_OUT:
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1023 case BPF_PROG_TYPE_LWT_XMIT:
ed3e469d021cba Mahe Tardy 2024-11-25 1024 case BPF_PROG_TYPE_CGROUP_SKB:
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1025 is_direct_pkt_access = true;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1026 break;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1027 default:
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1028 break;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1029 }
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1030
435b08ec0094ac Daniel Borkmann 2021-09-27 1031 sk = sk_alloc(net, AF_UNSPEC, GFP_USER, &bpf_dummy_proto, 1);
2cb494a36c9827 Song Liu 2018-10-19 @1032 if (!sk) {
ed22fb43432aaa Paul Chaignon 2025-09-04 1033 ret = -ENOMEM;
ed22fb43432aaa Paul Chaignon 2025-09-04 1034 goto out;
2cb494a36c9827 Song Liu 2018-10-19 1035 }
2cb494a36c9827 Song Liu 2018-10-19 1036 sock_init_data(NULL, sk);
2cb494a36c9827 Song Liu 2018-10-19 1037
ce098da1497c6d Kees Cook 2022-12-07 1038 skb = slab_build_skb(data);
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1039 if (!skb) {
ed22fb43432aaa Paul Chaignon 2025-09-04 1040 ret = -ENOMEM;
ed22fb43432aaa Paul Chaignon 2025-09-04 1041 goto out;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1042 }
2cb494a36c9827 Song Liu 2018-10-19 1043 skb->sk = sk;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1044
586f8525979ad9 David Miller 2017-05-02 1045 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1046 __skb_put(skb, size);
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1047
ed22fb43432aaa Paul Chaignon 2025-09-04 1048 data = NULL; /* data released via kfree_skb */
ed22fb43432aaa Paul Chaignon 2025-09-04 1049
21594c44083c37 Dmitry Yakunin 2020-08-03 1050 if (ctx && ctx->ifindex > 1) {
21594c44083c37 Dmitry Yakunin 2020-08-03 1051 dev = dev_get_by_index(net, ctx->ifindex);
21594c44083c37 Dmitry Yakunin 2020-08-03 1052 if (!dev) {
21594c44083c37 Dmitry Yakunin 2020-08-03 1053 ret = -ENODEV;
21594c44083c37 Dmitry Yakunin 2020-08-03 1054 goto out;
21594c44083c37 Dmitry Yakunin 2020-08-03 1055 }
21594c44083c37 Dmitry Yakunin 2020-08-03 1056 }
21594c44083c37 Dmitry Yakunin 2020-08-03 1057 skb->protocol = eth_type_trans(skb, dev);
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1058 skb_reset_network_header(skb);
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1059
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1060 switch (skb->protocol) {
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1061 case htons(ETH_P_IP):
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1062 sk->sk_family = AF_INET;
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1063 if (sizeof(struct iphdr) <= skb_headlen(skb)) {
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1064 sk->sk_rcv_saddr = ip_hdr(skb)->saddr;
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1065 sk->sk_daddr = ip_hdr(skb)->daddr;
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1066 }
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1067 break;
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1068 #if IS_ENABLED(CONFIG_IPV6)
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1069 case htons(ETH_P_IPV6):
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1070 sk->sk_family = AF_INET6;
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1071 if (sizeof(struct ipv6hdr) <= skb_headlen(skb)) {
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1072 sk->sk_v6_rcv_saddr = ipv6_hdr(skb)->saddr;
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1073 sk->sk_v6_daddr = ipv6_hdr(skb)->daddr;
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1074 }
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1075 break;
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1076 #endif
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1077 default:
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1078 break;
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1079 }
fa5cb548ced61b Dmitry Yakunin 2020-08-03 1080
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1081 if (is_l2)
6e6fddc7832353 Daniel Borkmann 2018-07-11 1082 __skb_push(skb, hh_len);
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1083 if (is_direct_pkt_access)
6aaae2b6c4330a Daniel Borkmann 2017-09-25 1084 bpf_compute_data_pointers(skb);
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1085
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1086 ret = convert___skb_to_skb(skb, ctx);
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1087 if (ret)
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1088 goto out;
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1089
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1090 if (kattr->test.flags & BPF_F_TEST_SKB_CHECKSUM_COMPLETE) {
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1091 const int off = skb_network_offset(skb);
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1092 int len = skb->len - off;
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1093
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1094 skb->csum = skb_checksum(skb, off, len, 0);
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1095 skb->ip_summed = CHECKSUM_COMPLETE;
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1096 }
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1097
f23c4b3924d2e9 Björn Töpel 2019-12-13 1098 ret = bpf_test_run(prog, skb, repeat, &retval, &duration, false);
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1099 if (ret)
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1100 goto out;
6e6fddc7832353 Daniel Borkmann 2018-07-11 1101 if (!is_l2) {
6e6fddc7832353 Daniel Borkmann 2018-07-11 1102 if (skb_headroom(skb) < hh_len) {
6e6fddc7832353 Daniel Borkmann 2018-07-11 1103 int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
6e6fddc7832353 Daniel Borkmann 2018-07-11 1104
6e6fddc7832353 Daniel Borkmann 2018-07-11 1105 if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1106 ret = -ENOMEM;
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1107 goto out;
6e6fddc7832353 Daniel Borkmann 2018-07-11 1108 }
6e6fddc7832353 Daniel Borkmann 2018-07-11 1109 }
6e6fddc7832353 Daniel Borkmann 2018-07-11 1110 memset(__skb_push(skb, hh_len), 0, hh_len);
6e6fddc7832353 Daniel Borkmann 2018-07-11 1111 }
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1112
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1113 if (kattr->test.flags & BPF_F_TEST_SKB_CHECKSUM_COMPLETE) {
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1114 const int off = skb_network_offset(skb);
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1115 int len = skb->len - off;
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1116 __wsum csum;
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1117
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1118 csum = skb_checksum(skb, off, len, 0);
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1119
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1120 if (csum_fold(skb->csum) != csum_fold(csum)) {
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1121 ret = -EBADMSG;
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1122 goto out;
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1123 }
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1124 }
a3cfe84cca28f2 Vadim Fedorenko 2024-06-06 1125
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1126 convert_skb_to___skb(skb, ctx);
6e6fddc7832353 Daniel Borkmann 2018-07-11 1127
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1128 size = skb->len;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1129 /* bpf program can never convert linear skb to non-linear */
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1130 if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1131 size = skb_headlen(skb);
7855e0db150ad8 Lorenzo Bianconi 2022-01-21 1132 ret = bpf_test_finish(kattr, uattr, skb->data, NULL, size, retval,
7855e0db150ad8 Lorenzo Bianconi 2022-01-21 1133 duration);
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1134 if (!ret)
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1135 ret = bpf_ctx_finish(kattr, uattr, ctx,
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1136 sizeof(struct __sk_buff));
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1137 out:
21594c44083c37 Dmitry Yakunin 2020-08-03 1138 if (dev && dev != net->loopback_dev)
21594c44083c37 Dmitry Yakunin 2020-08-03 1139 dev_put(dev);
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1140 kfree_skb(skb);
ed22fb43432aaa Paul Chaignon 2025-09-04 1141 kfree(data);
ed22fb43432aaa Paul Chaignon 2025-09-04 1142 if (sk)
435b08ec0094ac Daniel Borkmann 2021-09-27 1143 sk_free(sk);
b0b9395d865e30 Stanislav Fomichev 2019-04-09 1144 kfree(ctx);
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1145 return ret;
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1146 }
1cf1cae963c2e6 Alexei Starovoitov 2017-03-30 1147
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
next prev parent reply other threads:[~2025-09-05 12:58 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-04 12:07 [PATCH bpf-next 0/4] bpf: Support non-linear skbs for BPF_PROG_TEST_RUN Paul Chaignon
2025-09-04 12:09 ` [PATCH bpf-next 1/4] bpf: Refactor cleanup of bpf_prog_test_run_skb Paul Chaignon
2025-09-05 12:57 ` kernel test robot [this message]
2025-09-04 12:11 ` [PATCH bpf-next 2/4] bpf: Craft non-linear skbs in BPF_PROG_TEST_RUN Paul Chaignon
2025-09-04 15:56 ` Alexei Starovoitov
2025-09-04 16:02 ` Daniel Borkmann
2025-09-04 16:27 ` Amery Hung
2025-09-05 13:23 ` Paul Chaignon
2025-09-05 16:34 ` Amery Hung
2025-09-08 17:41 ` Paul Chaignon
2025-09-08 19:09 ` Martin KaFai Lau
2025-09-08 19:10 ` Amery Hung
2025-09-08 19:16 ` Paul Chaignon
2025-09-04 12:13 ` [PATCH bpf-next 3/4] selftests/bpf: Support non-linear flag in test loader Paul Chaignon
2025-09-04 12:13 ` [PATCH bpf-next 4/4] selftests/bpf: Test direct packet access on non-linear skbs Paul Chaignon
2025-09-04 18:08 ` [syzbot ci] Re: bpf: Support non-linear skbs for BPF_PROG_TEST_RUN syzbot ci
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