[kbuild-all] fs/select.c:970:12: warning: stack frame size of 1032 bytes in function 'do_sys_poll'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 1c273e10bc0cc7efb933e0ca10e260cdfc9f0b8c commit: 8b3165e54566e8bb8f4b7d4e5f12ced78ce462bb MIPS: Enable GCOV date: 4 months ago config: mips-randconfig-r022-20210320 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 436c6c9c20cc522c92a923440a5fc509c342a7db) 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 mips cross compiling tool for clang build # apt-get install binutils-mips-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 8b3165e54566e8bb8f4b7d4e5f12ced78ce462bb # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips 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 >>): fs/select.c:621:5: warning: stack frame size of 1032 bytes in function 'core_sys_select' [-Wframe-larger-than=] int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp, ^ static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, ^ 2 warnings generated. vim +/do_sys_poll +970 fs/select.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 966 70674f95c0a2ea Andi Kleen 2006-03-28 967 #define N_STACK_PPS ((sizeof(stack_pps) - sizeof(struct poll_list)) / \ 70674f95c0a2ea Andi Kleen 2006-03-28 968 sizeof(struct pollfd)) 70674f95c0a2ea Andi Kleen 2006-03-28 969 e99ca56ce03dd9 Al Viro 2017-04-08 @970 static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, 766b9f928bd5b9 Deepa Dinamani 2016-05-19 971 struct timespec64 *end_time) ^1da177e4c3f41 Linus Torvalds 2005-04-16 972 { ^1da177e4c3f41 Linus Torvalds 2005-04-16 973 struct poll_wqueues table; 43e11fa2d1d3b6 Gustavo A. R. Silva 2019-07-16 974 int err = -EFAULT, fdcount, len; 30c14e40ed8546 Jes Sorensen 2006-03-31 975 /* Allocate small arguments on the stack to save memory and be 30c14e40ed8546 Jes Sorensen 2006-03-31 976 faster - use long to make sure the buffer is aligned properly 30c14e40ed8546 Jes Sorensen 2006-03-31 977 on 64 bit archs to avoid unaligned access */ 30c14e40ed8546 Jes Sorensen 2006-03-31 978 long stack_pps[POLL_STACK_ALLOC/sizeof(long)]; 252e5725cfb55a Oleg Nesterov 2007-10-16 979 struct poll_list *const head = (struct poll_list *)stack_pps; 252e5725cfb55a Oleg Nesterov 2007-10-16 980 struct poll_list *walk = head; 252e5725cfb55a Oleg Nesterov 2007-10-16 981 unsigned long todo = nfds; ^1da177e4c3f41 Linus Torvalds 2005-04-16 982 d554ed895dc8f2 Jiri Slaby 2010-03-05 983 if (nfds > rlimit(RLIMIT_NOFILE)) ^1da177e4c3f41 Linus Torvalds 2005-04-16 984 return -EINVAL; ^1da177e4c3f41 Linus Torvalds 2005-04-16 985 252e5725cfb55a Oleg Nesterov 2007-10-16 986 len = min_t(unsigned int, nfds, N_STACK_PPS); 252e5725cfb55a Oleg Nesterov 2007-10-16 987 for (;;) { 252e5725cfb55a Oleg Nesterov 2007-10-16 988 walk->next = NULL; 252e5725cfb55a Oleg Nesterov 2007-10-16 989 walk->len = len; 252e5725cfb55a Oleg Nesterov 2007-10-16 990 if (!len) 252e5725cfb55a Oleg Nesterov 2007-10-16 991 break; ^1da177e4c3f41 Linus Torvalds 2005-04-16 992 252e5725cfb55a Oleg Nesterov 2007-10-16 993 if (copy_from_user(walk->entries, ufds + nfds-todo, 252e5725cfb55a Oleg Nesterov 2007-10-16 994 sizeof(struct pollfd) * walk->len)) ^1da177e4c3f41 Linus Torvalds 2005-04-16 995 goto out_fds; ^1da177e4c3f41 Linus Torvalds 2005-04-16 996 252e5725cfb55a Oleg Nesterov 2007-10-16 997 todo -= walk->len; 252e5725cfb55a Oleg Nesterov 2007-10-16 998 if (!todo) 252e5725cfb55a Oleg Nesterov 2007-10-16 999 break; 252e5725cfb55a Oleg Nesterov 2007-10-16 1000 252e5725cfb55a Oleg Nesterov 2007-10-16 1001 len = min(todo, POLLFD_PER_PAGE); 43e11fa2d1d3b6 Gustavo A. R. Silva 2019-07-16 1002 walk = walk->next = kmalloc(struct_size(walk, entries, len), 43e11fa2d1d3b6 Gustavo A. R. Silva 2019-07-16 1003 GFP_KERNEL); 252e5725cfb55a Oleg Nesterov 2007-10-16 1004 if (!walk) { 252e5725cfb55a Oleg Nesterov 2007-10-16 1005 err = -ENOMEM; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1006 goto out_fds; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1007 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 1008 } 9f72949f679df0 David Woodhouse 2006-01-18 1009 252e5725cfb55a Oleg Nesterov 2007-10-16 1010 poll_initwait(&table); ccec5ee302d5cb Mateusz Guzik 2016-01-06 1011 fdcount = do_poll(head, &table, end_time); 252e5725cfb55a Oleg Nesterov 2007-10-16 1012 poll_freewait(&table); ^1da177e4c3f41 Linus Torvalds 2005-04-16 1013 252e5725cfb55a Oleg Nesterov 2007-10-16 1014 for (walk = head; walk; walk = walk->next) { ^1da177e4c3f41 Linus Torvalds 2005-04-16 1015 struct pollfd *fds = walk->entries; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1016 int j; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1017 252e5725cfb55a Oleg Nesterov 2007-10-16 1018 for (j = 0; j < walk->len; j++, ufds++) ^1da177e4c3f41 Linus Torvalds 2005-04-16 1019 if (__put_user(fds[j].revents, &ufds->revents)) ^1da177e4c3f41 Linus Torvalds 2005-04-16 1020 goto out_fds; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1021 } 252e5725cfb55a Oleg Nesterov 2007-10-16 1022 ^1da177e4c3f41 Linus Torvalds 2005-04-16 1023 err = fdcount; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1024 out_fds: 252e5725cfb55a Oleg Nesterov 2007-10-16 1025 walk = head->next; 252e5725cfb55a Oleg Nesterov 2007-10-16 1026 while (walk) { 252e5725cfb55a Oleg Nesterov 2007-10-16 1027 struct poll_list *pos = walk; 252e5725cfb55a Oleg Nesterov 2007-10-16 1028 walk = walk->next; 252e5725cfb55a Oleg Nesterov 2007-10-16 1029 kfree(pos); ^1da177e4c3f41 Linus Torvalds 2005-04-16 1030 } 252e5725cfb55a Oleg Nesterov 2007-10-16 1031 ^1da177e4c3f41 Linus Torvalds 2005-04-16 1032 return err; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1033 } 9f72949f679df0 David Woodhouse 2006-01-18 1034 :::::: The code at line 970 was first introduced by commit :::::: e99ca56ce03dd90991025878152bae8b53484147 move compat select-related syscalls to fs/select.c :::::: TO: Al Viro <viro(a)zeniv.linux.org.uk&gt; :::::: CC: Al Viro <viro(a)zeniv.linux.org.uk&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org