Hi Jiapeng, kernel test robot noticed the following build errors:
[auto build test ERROR on next-20250806] url: https://github.com/intel-lab-lkp/linux/commits/Jiapeng-Chong/um-Use-ARRAY_SIZE-for-array-length/20250807-103534 base: next-20250806 patch link: https://lore.kernel.org/r/20250807023227.2443863-1-jiapeng.chong%40linux.alibaba.com patch subject: [PATCH -next] um: Use ARRAY_SIZE for array length config: um-randconfig-001-20250807 (https://download.01.org/0day-ci/archive/20250807/202508072253.pvtujvov-...@intel.com/config) compiler: gcc-12 (Debian 12.2.0-14+deb12u1) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250807/202508072253.pvtujvov-...@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 <l...@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202508072253.pvtujvov-...@intel.com/ All errors (new ones prefixed by >>): arch/um/kernel/skas/stub_exe.c: In function 'real_init': >> arch/um/kernel/skas/stub_exe.c:196:32: error: implicit declaration of >> function 'ARRAY_SIZE' [-Werror=implicit-function-declaration] 196 | .len = ARRAY_SIZE(filter), | ^~~~~~~~~~ cc1: some warnings being treated as errors vim +/ARRAY_SIZE +196 arch/um/kernel/skas/stub_exe.c 12 13 noinline static void real_init(void) 14 { 15 struct stub_init_data init_data; 16 unsigned long res; 17 struct { 18 void *ss_sp; 19 int ss_flags; 20 size_t ss_size; 21 } stack = { 22 .ss_size = STUB_DATA_PAGES * UM_KERN_PAGE_SIZE, 23 }; 24 struct { 25 void *sa_handler_; 26 unsigned long sa_flags; 27 void *sa_restorer; 28 unsigned long long sa_mask; 29 } sa = { 30 /* Need to set SA_RESTORER (but the handler never returns) */ 31 .sa_flags = SA_ONSTACK | SA_NODEFER | SA_SIGINFO | 0x04000000, 32 }; 33 34 /* set a nice name */ 35 stub_syscall2(__NR_prctl, PR_SET_NAME, (unsigned long)"uml-userspace"); 36 37 /* Make sure this process dies if the kernel dies */ 38 stub_syscall2(__NR_prctl, PR_SET_PDEATHSIG, SIGKILL); 39 40 /* Needed in SECCOMP mode (and safe to do anyway) */ 41 stub_syscall5(__NR_prctl, PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 42 43 /* read information from STDIN and close it */ 44 res = stub_syscall3(__NR_read, 0, 45 (unsigned long)&init_data, sizeof(init_data)); 46 if (res != sizeof(init_data)) 47 stub_syscall1(__NR_exit, 10); 48 49 /* In SECCOMP mode, FD 0 is a socket and is later used for FD passing */ 50 if (!init_data.seccomp) 51 stub_syscall1(__NR_close, 0); 52 else 53 stub_syscall3(__NR_fcntl, 0, F_SETFL, O_NONBLOCK); 54 55 /* map stub code + data */ 56 res = stub_syscall6(STUB_MMAP_NR, 57 init_data.stub_start, UM_KERN_PAGE_SIZE, 58 PROT_READ | PROT_EXEC, MAP_FIXED | MAP_SHARED, 59 init_data.stub_code_fd, init_data.stub_code_offset); 60 if (res != init_data.stub_start) 61 stub_syscall1(__NR_exit, 11); 62 63 res = stub_syscall6(STUB_MMAP_NR, 64 init_data.stub_start + UM_KERN_PAGE_SIZE, 65 STUB_DATA_PAGES * UM_KERN_PAGE_SIZE, 66 PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, 67 init_data.stub_data_fd, init_data.stub_data_offset); 68 if (res != init_data.stub_start + UM_KERN_PAGE_SIZE) 69 stub_syscall1(__NR_exit, 12); 70 71 /* In SECCOMP mode, we only need the signalling FD from now on */ 72 if (init_data.seccomp) { 73 res = stub_syscall3(__NR_close_range, 1, ~0U, 0); 74 if (res != 0) 75 stub_syscall1(__NR_exit, 13); 76 } 77 78 /* setup signal stack inside stub data */ 79 stack.ss_sp = (void *)init_data.stub_start + UM_KERN_PAGE_SIZE; 80 stub_syscall2(__NR_sigaltstack, (unsigned long)&stack, 0); 81 82 /* register signal handlers */ 83 sa.sa_handler_ = (void *) init_data.signal_handler; 84 sa.sa_restorer = (void *) init_data.signal_restorer; 85 if (!init_data.seccomp) { 86 /* In ptrace mode, the SIGSEGV handler never returns */ 87 sa.sa_mask = 0; 88 89 res = stub_syscall4(__NR_rt_sigaction, SIGSEGV, 90 (unsigned long)&sa, 0, sizeof(sa.sa_mask)); 91 if (res != 0) 92 stub_syscall1(__NR_exit, 14); 93 } else { 94 /* SECCOMP mode uses rt_sigreturn, need to mask all signals */ 95 sa.sa_mask = ~0ULL; 96 97 res = stub_syscall4(__NR_rt_sigaction, SIGSEGV, 98 (unsigned long)&sa, 0, sizeof(sa.sa_mask)); 99 if (res != 0) 100 stub_syscall1(__NR_exit, 15); 101 102 res = stub_syscall4(__NR_rt_sigaction, SIGSYS, 103 (unsigned long)&sa, 0, sizeof(sa.sa_mask)); 104 if (res != 0) 105 stub_syscall1(__NR_exit, 16); 106 107 res = stub_syscall4(__NR_rt_sigaction, SIGALRM, 108 (unsigned long)&sa, 0, sizeof(sa.sa_mask)); 109 if (res != 0) 110 stub_syscall1(__NR_exit, 17); 111 112 res = stub_syscall4(__NR_rt_sigaction, SIGTRAP, 113 (unsigned long)&sa, 0, sizeof(sa.sa_mask)); 114 if (res != 0) 115 stub_syscall1(__NR_exit, 18); 116 117 res = stub_syscall4(__NR_rt_sigaction, SIGILL, 118 (unsigned long)&sa, 0, sizeof(sa.sa_mask)); 119 if (res != 0) 120 stub_syscall1(__NR_exit, 19); 121 122 res = stub_syscall4(__NR_rt_sigaction, SIGFPE, 123 (unsigned long)&sa, 0, sizeof(sa.sa_mask)); 124 if (res != 0) 125 stub_syscall1(__NR_exit, 20); 126 } 127 128 /* 129 * If in seccomp mode, install the SECCOMP filter and trigger a syscall. 130 * Otherwise set PTRACE_TRACEME and do a SIGSTOP. 131 */ 132 if (init_data.seccomp) { 133 struct sock_filter filter[] = { 134 #if __BITS_PER_LONG > 32 135 /* [0] Load upper 32bit of instruction pointer from seccomp_data */ 136 BPF_STMT(BPF_LD | BPF_W | BPF_ABS, 137 (offsetof(struct seccomp_data, instruction_pointer) + 4)), 138 139 /* [1] Jump forward 3 instructions if the upper address is not identical */ 140 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, (init_data.stub_start) >> 32, 0, 3), 141 #endif 142 /* [2] Load lower 32bit of instruction pointer from seccomp_data */ 143 BPF_STMT(BPF_LD | BPF_W | BPF_ABS, 144 (offsetof(struct seccomp_data, instruction_pointer))), 145 146 /* [3] Mask out lower bits */ 147 BPF_STMT(BPF_ALU | BPF_AND | BPF_K, 0xfffff000), 148 149 /* [4] Jump to [6] if the lower bits are not on the expected page */ 150 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, (init_data.stub_start) & 0xfffff000, 1, 0), 151 152 /* [5] Trap call, allow */ 153 BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_TRAP), 154 155 /* [6,7] Check architecture */ 156 BPF_STMT(BPF_LD | BPF_W | BPF_ABS, 157 offsetof(struct seccomp_data, arch)), 158 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 159 UM_SECCOMP_ARCH_NATIVE, 1, 0), 160 161 /* [8] Kill (for architecture check) */ 162 BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_KILL_PROCESS), 163 164 /* [9] Load syscall number */ 165 BPF_STMT(BPF_LD | BPF_W | BPF_ABS, 166 offsetof(struct seccomp_data, nr)), 167 168 /* [10-16] Check against permitted syscalls */ 169 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, __NR_futex, 170 7, 0), 171 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K,__NR_recvmsg, 172 6, 0), 173 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K,__NR_close, 174 5, 0), 175 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, STUB_MMAP_NR, 176 4, 0), 177 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, __NR_munmap, 178 3, 0), 179 #ifdef __i386__ 180 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, __NR_set_thread_area, 181 2, 0), 182 #else 183 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, __NR_arch_prctl, 184 2, 0), 185 #endif 186 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, __NR_rt_sigreturn, 187 1, 0), 188 189 /* [17] Not one of the permitted syscalls */ 190 BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_KILL_PROCESS), 191 192 /* [18] Permitted call for the stub */ 193 BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_ALLOW), 194 }; 195 struct sock_fprog prog = { > 196 .len = ARRAY_SIZE(filter), 197 .filter = filter, 198 }; 199 200 if (stub_syscall3(__NR_seccomp, SECCOMP_SET_MODE_FILTER, 201 SECCOMP_FILTER_FLAG_TSYNC, 202 (unsigned long)&prog) != 0) 203 stub_syscall1(__NR_exit, 21); 204 205 /* Fall through, the exit syscall will cause SIGSYS */ 206 } else { 207 stub_syscall4(__NR_ptrace, PTRACE_TRACEME, 0, 0, 0); 208 209 stub_syscall2(__NR_kill, stub_syscall0(__NR_getpid), SIGSTOP); 210 } 211 212 stub_syscall1(__NR_exit, 30); 213 214 __builtin_unreachable(); 215 } 216 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
