* Re: [PATCH bpf-next v5 1/5] bpf: Factor out program return value calculation
[not found] <20260227154616.6846-2-emil@etsalapatis.com>
@ 2026-02-27 20:49 ` kernel test robot
2026-02-28 1:22 ` kernel test robot
1 sibling, 0 replies; 2+ messages in thread
From: kernel test robot @ 2026-02-27 20:49 UTC (permalink / raw)
To: Emil Tsalapatis, bpf
Cc: llvm, oe-kbuild-all, andrii, ast, daniel, eddyz87, martin.lau,
memxor, song, yonghong.song, Emil Tsalapatis
Hi Emil,
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/Emil-Tsalapatis/bpf-Factor-out-program-return-value-calculation/20260227-235723
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link: https://lore.kernel.org/r/20260227154616.6846-2-emil%40etsalapatis.com
patch subject: [PATCH bpf-next v5 1/5] bpf: Factor out program return value calculation
config: riscv-defconfig (https://download.01.org/0day-ci/archive/20260228/202602280401.OowzoAl1-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 9a109fbb6e184ec9bcce10615949f598f4c974a9)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260228/202602280401.OowzoAl1-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/202602280401.OowzoAl1-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> kernel/bpf/verifier.c:17864:3: warning: label at end of compound statement is a C23 extension [-Wc23-extensions]
17864 | }
| ^
kernel/bpf/verifier.c:17923:6: warning: unused variable 'ret' [-Wunused-variable]
17923 | int ret, err;
| ^~~
kernel/bpf/verifier.c:17926:7: warning: unused variable 'return_32bit' [-Wunused-variable]
17926 | bool return_32bit = false;
| ^~~~~~~~~~~~
3 warnings generated.
vim +17864 kernel/bpf/verifier.c
17805
17806
17807 static bool return_retval_range(struct bpf_verifier_env *env, struct bpf_retval_range *range)
17808 {
17809 enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
17810
17811 /* Default return value range. */
17812 *range = retval_range(0, 1);
17813
17814 switch (prog_type) {
17815 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
17816 switch (env->prog->expected_attach_type) {
17817 case BPF_CGROUP_UDP4_RECVMSG:
17818 case BPF_CGROUP_UDP6_RECVMSG:
17819 case BPF_CGROUP_UNIX_RECVMSG:
17820 case BPF_CGROUP_INET4_GETPEERNAME:
17821 case BPF_CGROUP_INET6_GETPEERNAME:
17822 case BPF_CGROUP_UNIX_GETPEERNAME:
17823 case BPF_CGROUP_INET4_GETSOCKNAME:
17824 case BPF_CGROUP_INET6_GETSOCKNAME:
17825 case BPF_CGROUP_UNIX_GETSOCKNAME:
17826 *range = retval_range(1, 1);
17827 break;
17828 case BPF_CGROUP_INET4_BIND:
17829 case BPF_CGROUP_INET6_BIND:
17830 *range = retval_range(0, 3);
17831 break;
17832 default:
17833 break;
17834 }
17835 break;
17836 case BPF_PROG_TYPE_CGROUP_SKB:
17837 if (env->prog->expected_attach_type == BPF_CGROUP_INET_EGRESS)
17838 *range = retval_range(0, 3);
17839 break;
17840 case BPF_PROG_TYPE_CGROUP_SOCK:
17841 case BPF_PROG_TYPE_SOCK_OPS:
17842 case BPF_PROG_TYPE_CGROUP_DEVICE:
17843 case BPF_PROG_TYPE_CGROUP_SYSCTL:
17844 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
17845 break;
17846 case BPF_PROG_TYPE_RAW_TRACEPOINT:
17847 if (!env->prog->aux->attach_btf_id)
17848 return false;
17849 *range = retval_range(0, 0);
17850 break;
17851 case BPF_PROG_TYPE_TRACING:
17852 switch (env->prog->expected_attach_type) {
17853 case BPF_TRACE_FENTRY:
17854 case BPF_TRACE_FEXIT:
17855 case BPF_TRACE_FSESSION:
17856 *range = retval_range(0, 0);
17857 break;
17858 case BPF_TRACE_RAW_TP:
17859 case BPF_MODIFY_RETURN:
17860 return false;
17861 case BPF_TRACE_ITER:
17862 break;
17863 default:
17864 }
17865 break;
17866 case BPF_PROG_TYPE_KPROBE:
17867 switch (env->prog->expected_attach_type) {
17868 case BPF_TRACE_KPROBE_SESSION:
17869 case BPF_TRACE_UPROBE_SESSION:
17870 break;
17871 default:
17872 return false;
17873 }
17874 break;
17875 case BPF_PROG_TYPE_SK_LOOKUP:
17876 *range = retval_range(SK_DROP, SK_PASS);
17877 break;
17878
17879 case BPF_PROG_TYPE_LSM:
17880 if (env->prog->expected_attach_type != BPF_LSM_CGROUP) {
17881 /* no range found, any return value is allowed */
17882 if (!get_func_retval_range(env->prog, range))
17883 return false;
17884 /* no restricted range, any return value is allowed */
17885 if (range->minval == S32_MIN && range->maxval == S32_MAX)
17886 return false;
17887 range->return_32bit = true;
17888 } else if (!env->prog->aux->attach_func_proto->type) {
17889 /* Make sure programs that attach to void
17890 * hooks don't try to modify return value.
17891 */
17892 *range = retval_range(1, 1);
17893 }
17894 break;
17895
17896 case BPF_PROG_TYPE_NETFILTER:
17897 *range = retval_range(NF_DROP, NF_ACCEPT);
17898 break;
17899 case BPF_PROG_TYPE_STRUCT_OPS:
17900 *range = retval_range(0, 0);
17901 break;
17902 case BPF_PROG_TYPE_EXT:
17903 /* freplace program can return anything as its return value
17904 * depends on the to-be-replaced kernel func or bpf program.
17905 */
17906 default:
17907 return false;
17908 }
17909
17910 /* Continue calculating. */
17911
17912 return true;
17913 }
17914
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH bpf-next v5 1/5] bpf: Factor out program return value calculation
[not found] <20260227154616.6846-2-emil@etsalapatis.com>
2026-02-27 20:49 ` [PATCH bpf-next v5 1/5] bpf: Factor out program return value calculation kernel test robot
@ 2026-02-28 1:22 ` kernel test robot
1 sibling, 0 replies; 2+ messages in thread
From: kernel test robot @ 2026-02-28 1:22 UTC (permalink / raw)
To: Emil Tsalapatis, bpf
Cc: llvm, oe-kbuild-all, andrii, ast, daniel, eddyz87, martin.lau,
memxor, song, yonghong.song, Emil Tsalapatis
Hi Emil,
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/Emil-Tsalapatis/bpf-Factor-out-program-return-value-calculation/20260227-235723
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link: https://lore.kernel.org/r/20260227154616.6846-2-emil%40etsalapatis.com
patch subject: [PATCH bpf-next v5 1/5] bpf: Factor out program return value calculation
config: arm-randconfig-001-20260228 (https://download.01.org/0day-ci/archive/20260228/202602280948.ZMhck27g-lkp@intel.com/config)
compiler: clang version 16.0.6 (https://github.com/llvm/llvm-project 7cbf1a2591520c2491aa35339f227775f4d3adf6)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260228/202602280948.ZMhck27g-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/202602280948.ZMhck27g-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> kernel/bpf/verifier.c:17864:3: warning: label at end of compound statement is a C2x extension [-Wc2x-extensions]
}
^
kernel/bpf/verifier.c:17923:6: warning: unused variable 'ret' [-Wunused-variable]
int ret, err;
^
kernel/bpf/verifier.c:17926:7: warning: unused variable 'return_32bit' [-Wunused-variable]
bool return_32bit = false;
^
3 warnings generated.
vim +17864 kernel/bpf/verifier.c
17805
17806
17807 static bool return_retval_range(struct bpf_verifier_env *env, struct bpf_retval_range *range)
17808 {
17809 enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
17810
17811 /* Default return value range. */
17812 *range = retval_range(0, 1);
17813
17814 switch (prog_type) {
17815 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
17816 switch (env->prog->expected_attach_type) {
17817 case BPF_CGROUP_UDP4_RECVMSG:
17818 case BPF_CGROUP_UDP6_RECVMSG:
17819 case BPF_CGROUP_UNIX_RECVMSG:
17820 case BPF_CGROUP_INET4_GETPEERNAME:
17821 case BPF_CGROUP_INET6_GETPEERNAME:
17822 case BPF_CGROUP_UNIX_GETPEERNAME:
17823 case BPF_CGROUP_INET4_GETSOCKNAME:
17824 case BPF_CGROUP_INET6_GETSOCKNAME:
17825 case BPF_CGROUP_UNIX_GETSOCKNAME:
17826 *range = retval_range(1, 1);
17827 break;
17828 case BPF_CGROUP_INET4_BIND:
17829 case BPF_CGROUP_INET6_BIND:
17830 *range = retval_range(0, 3);
17831 break;
17832 default:
17833 break;
17834 }
17835 break;
17836 case BPF_PROG_TYPE_CGROUP_SKB:
17837 if (env->prog->expected_attach_type == BPF_CGROUP_INET_EGRESS)
17838 *range = retval_range(0, 3);
17839 break;
17840 case BPF_PROG_TYPE_CGROUP_SOCK:
17841 case BPF_PROG_TYPE_SOCK_OPS:
17842 case BPF_PROG_TYPE_CGROUP_DEVICE:
17843 case BPF_PROG_TYPE_CGROUP_SYSCTL:
17844 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
17845 break;
17846 case BPF_PROG_TYPE_RAW_TRACEPOINT:
17847 if (!env->prog->aux->attach_btf_id)
17848 return false;
17849 *range = retval_range(0, 0);
17850 break;
17851 case BPF_PROG_TYPE_TRACING:
17852 switch (env->prog->expected_attach_type) {
17853 case BPF_TRACE_FENTRY:
17854 case BPF_TRACE_FEXIT:
17855 case BPF_TRACE_FSESSION:
17856 *range = retval_range(0, 0);
17857 break;
17858 case BPF_TRACE_RAW_TP:
17859 case BPF_MODIFY_RETURN:
17860 return false;
17861 case BPF_TRACE_ITER:
17862 break;
17863 default:
17864 }
17865 break;
17866 case BPF_PROG_TYPE_KPROBE:
17867 switch (env->prog->expected_attach_type) {
17868 case BPF_TRACE_KPROBE_SESSION:
17869 case BPF_TRACE_UPROBE_SESSION:
17870 break;
17871 default:
17872 return false;
17873 }
17874 break;
17875 case BPF_PROG_TYPE_SK_LOOKUP:
17876 *range = retval_range(SK_DROP, SK_PASS);
17877 break;
17878
17879 case BPF_PROG_TYPE_LSM:
17880 if (env->prog->expected_attach_type != BPF_LSM_CGROUP) {
17881 /* no range found, any return value is allowed */
17882 if (!get_func_retval_range(env->prog, range))
17883 return false;
17884 /* no restricted range, any return value is allowed */
17885 if (range->minval == S32_MIN && range->maxval == S32_MAX)
17886 return false;
17887 range->return_32bit = true;
17888 } else if (!env->prog->aux->attach_func_proto->type) {
17889 /* Make sure programs that attach to void
17890 * hooks don't try to modify return value.
17891 */
17892 *range = retval_range(1, 1);
17893 }
17894 break;
17895
17896 case BPF_PROG_TYPE_NETFILTER:
17897 *range = retval_range(NF_DROP, NF_ACCEPT);
17898 break;
17899 case BPF_PROG_TYPE_STRUCT_OPS:
17900 *range = retval_range(0, 0);
17901 break;
17902 case BPF_PROG_TYPE_EXT:
17903 /* freplace program can return anything as its return value
17904 * depends on the to-be-replaced kernel func or bpf program.
17905 */
17906 default:
17907 return false;
17908 }
17909
17910 /* Continue calculating. */
17911
17912 return true;
17913 }
17914
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 2+ messages in thread