[kbuild-all] scripts/sorttable.h:380:6: warning: variable 'mcount_sort_thread' is used uninitialized whenever 'if' condition is true

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: e3a8b6a1e70c37702054ae3c7c07ed828435d8ee commit: 72b3942a173c387b27860ba1069636726e208777 scripts: ftrace - move the sort-processing in ftrace_init date: 5 days ago config: s390-randconfig-r044-20220116 (https://download.01.org/0day-ci/archive/20220118/202201181730.mj1jL8Vy-lk...) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c10cbb243cafc0cf42c3e922cb29183279444432) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install s390 cross compiling tool for clang build # apt-get install binutils-s390x-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 72b3942a173c387b27860ba1069636726e208777 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 prepare If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): In file included from scripts/sorttable.c:195: if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ scripts/sorttable.h:479:6: note: uninitialized use occurs here if (mcount_sort_thread) { ^~~~~~~~~~~~~~~~~~ scripts/sorttable.h:380:2: note: remove the 'if' if its condition is always false if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ scripts/sorttable.h:479:6: note: uninitialized use occurs here if (mcount_sort_thread) { ^~~~~~~~~~~~~~~~~~ scripts/sorttable.h:380:6: note: remove the '||' if its condition is always false if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~ scripts/sorttable.h:479:6: note: uninitialized use occurs here if (mcount_sort_thread) { ^~~~~~~~~~~~~~~~~~ scripts/sorttable.h:380:6: note: remove the '||' if its condition is always false if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~~~~ scripts/sorttable.h:288:30: note: initialize the variable 'mcount_sort_thread' to silence this warning pthread_t mcount_sort_thread; ^ = 0 In file included from scripts/sorttable.c:197: if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ scripts/sorttable.h:479:6: note: uninitialized use occurs here if (mcount_sort_thread) { ^~~~~~~~~~~~~~~~~~ scripts/sorttable.h:380:2: note: remove the 'if' if its condition is always false if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ scripts/sorttable.h:479:6: note: uninitialized use occurs here if (mcount_sort_thread) { ^~~~~~~~~~~~~~~~~~ scripts/sorttable.h:380:6: note: remove the '||' if its condition is always false if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~ scripts/sorttable.h:479:6: note: uninitialized use occurs here if (mcount_sort_thread) { ^~~~~~~~~~~~~~~~~~ scripts/sorttable.h:380:6: note: remove the '||' if its condition is always false if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) { ^~~~~~~~~~~~~~~~~~~~~~~~~ scripts/sorttable.h:288:30: note: initialize the variable 'mcount_sort_thread' to silence this warning pthread_t mcount_sort_thread; ^ = 0 6 warnings generated. In file included from arch/s390/kernel/asm-offsets.c:11: In file included from include/linux/kvm_host.h:35: In file included from include/linux/kvm_para.h:5: In file included from include/uapi/linux/kvm_para.h:37: In file included from arch/s390/include/asm/kvm_para.h:25: In file included from arch/s390/include/asm/diag.h:12: In file included from include/linux/if_ether.h:19: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __raw_readb(PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:36:59: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x)) ^ include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16' #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) ^ In file included from arch/s390/kernel/asm-offsets.c:11: In file included from include/linux/kvm_host.h:35: In file included from include/linux/kvm_para.h:5: In file included from include/uapi/linux/kvm_para.h:37: In file included from arch/s390/include/asm/kvm_para.h:25: In file included from arch/s390/include/asm/diag.h:12: In file included from include/linux/if_ether.h:19: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32' #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x)) ^ In file included from arch/s390/kernel/asm-offsets.c:11: In file included from include/linux/kvm_host.h:35: In file included from include/linux/kvm_para.h:5: In file included from include/uapi/linux/kvm_para.h:37: In file included from arch/s390/include/asm/kvm_para.h:25: In file included from arch/s390/include/asm/diag.h:12: In file included from include/linux/if_ether.h:19: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ 12 warnings generated. vim +380 scripts/sorttable.h 378 379 #ifdef MCOUNT_SORT_ENABLED 381 fprintf(stderr, 382 "incomplete mcount's sort in file: %s\n", 383 fname); 384 goto out; 385 } 386 387 /* create thread to sort mcount_loc concurrently */ 388 if (pthread_create(&mcount_sort_thread, NULL, &sort_mcount_loc, &mstruct)) { 389 fprintf(stderr, 390 "pthread_create mcount_sort_thread failed '%s': %s\n", 391 strerror(errno), fname); 392 goto out; 393 } 394 #endif 395 if (!extab_sec) { 396 fprintf(stderr, "no __ex_table in file: %s\n", fname); 397 goto out; 398 } 399 400 if (!symtab_sec) { 401 fprintf(stderr, "no .symtab in file: %s\n", fname); 402 goto out; 403 } 404 405 if (!strtab_sec) { 406 fprintf(stderr, "no .strtab in file: %s\n", fname); 407 goto out; 408 } 409 410 extab_image = (void *)ehdr + _r(&extab_sec->sh_offset); 411 strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset); 412 symtab = (const Elf_Sym *)((const char *)ehdr + 413 _r(&symtab_sec->sh_offset)); 414 415 if (custom_sort) { 416 custom_sort(extab_image, _r(&extab_sec->sh_size)); 417 } else { 418 int num_entries = _r(&extab_sec->sh_size) / extable_ent_size; 419 qsort(extab_image, num_entries, 420 extable_ent_size, compare_extable); 421 } 422 423 /* If there were relocations, we no longer need them. */ 424 if (relocs) 425 memset(relocs, 0, relocs_size); 426 427 /* find the flag main_extable_sort_needed */ 428 for (sym = (void *)ehdr + _r(&symtab_sec->sh_offset); 429 sym < sym + _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); 430 sym++) { 431 if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT) 432 continue; 433 if (!strcmp(strtab + r(&sym->st_name), 434 "main_extable_sort_needed")) { 435 sort_needed_sym = sym; 436 break; 437 } 438 } 439 440 if (!sort_needed_sym) { 441 fprintf(stderr, 442 "no main_extable_sort_needed symbol in file: %s\n", 443 fname); 444 goto out; 445 } 446 447 sort_needed_sec = &shdr[get_secindex(r2(&sym->st_shndx), 448 sort_needed_sym - symtab, 449 symtab_shndx)]; 450 sort_needed_loc = (void *)ehdr + 451 _r(&sort_needed_sec->sh_offset) + 452 _r(&sort_needed_sym->st_value) - 453 _r(&sort_needed_sec->sh_addr); 454 455 /* extable has been sorted, clear the flag */ 456 w(0, sort_needed_loc); 457 rc = 0; 458 459 out: 460 #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) 461 if (orc_sort_thread) { 462 void *retval = NULL; 463 /* wait for ORC tables sort done */ 464 rc = pthread_join(orc_sort_thread, &retval); 465 if (rc) { 466 fprintf(stderr, 467 "pthread_join failed '%s': %s\n", 468 strerror(errno), fname); 469 } else if (retval) { 470 rc = -1; 471 fprintf(stderr, 472 "failed to sort ORC tables '%s': %s\n", 473 (char *)retval, fname); 474 } 475 } 476 #endif 477 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org