[kbuild-all] [jwboyer-fedora:f30 69/98] include/asm-generic/termios.h:25:38: warning: comparison of unsigned expression < 0 is always false

tree: https://git.kernel.org/pub/scm/linux/kernel/git/jwboyer/fedora.git f30 head: 2a9c1e3b6c53a78a96a7fd9599f95172fb9e9ac9 commit: 2811f52835b76d7f45858f725b3ede99a57e5001 [69/98] ARM: fix __get_user_check() in case uaccess_* calls are not inlined config: arm-randconfig-r025-20200521 (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 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 git checkout 2811f52835b76d7f45858f725b3ede99a57e5001 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): In file included from ./arch/arm/include/generated/uapi/asm/termios.h:1, from include/uapi/linux/termios.h:6, from include/linux/tty.h:7, from drivers/tty/n_tracerouter.c:21: include/asm-generic/termios.h: In function 'user_termio_to_kernel_termios': 25 | if (get_user(tmp, &termio->c_iflag) < 0) | ^ include/asm-generic/termios.h:29:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 29 | if (get_user(tmp, &termio->c_oflag) < 0) | ^ include/asm-generic/termios.h:33:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 33 | if (get_user(tmp, &termio->c_cflag) < 0) | ^ include/asm-generic/termios.h:37:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 37 | if (get_user(tmp, &termio->c_lflag) < 0) | ^ include/asm-generic/termios.h:41:49: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 41 | if (get_user(termios->c_line, &termio->c_line) < 0) | ^ -- In file included from ./arch/arm/include/generated/uapi/asm/termios.h:1, from include/uapi/linux/termios.h:6, from include/linux/tty.h:7, from drivers/tty/tty_ldisc.c:7: include/asm-generic/termios.h: In function 'user_termio_to_kernel_termios': 25 | if (get_user(tmp, &termio->c_iflag) < 0) | ^ include/asm-generic/termios.h:29:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 29 | if (get_user(tmp, &termio->c_oflag) < 0) | ^ include/asm-generic/termios.h:33:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 33 | if (get_user(tmp, &termio->c_cflag) < 0) | ^ include/asm-generic/termios.h:37:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 37 | if (get_user(tmp, &termio->c_lflag) < 0) | ^ include/asm-generic/termios.h:41:49: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 41 | if (get_user(termios->c_line, &termio->c_line) < 0) | ^ drivers/tty/tty_ldisc.c: At top level: drivers/tty/tty_ldisc.c:884:6: warning: no previous prototype for 'tty_sysctl_init' [-Wmissing-prototypes] 884 | void tty_sysctl_init(void) | ^~~~~~~~~~~~~~~ -- In file included from ./arch/arm/include/generated/uapi/asm/termios.h:1, from include/uapi/linux/termios.h:6, from include/linux/serdev.h:10, from drivers/tty/serdev/core.c:19: include/asm-generic/termios.h: In function 'user_termio_to_kernel_termios': 25 | if (get_user(tmp, &termio->c_iflag) < 0) | ^ include/asm-generic/termios.h:29:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 29 | if (get_user(tmp, &termio->c_oflag) < 0) | ^ include/asm-generic/termios.h:33:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 33 | if (get_user(tmp, &termio->c_cflag) < 0) | ^ include/asm-generic/termios.h:37:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 37 | if (get_user(tmp, &termio->c_lflag) < 0) | ^ include/asm-generic/termios.h:41:49: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 41 | if (get_user(termios->c_line, &termio->c_line) < 0) | ^ drivers/tty/serdev/core.c: In function 'serdev_controller_remove': drivers/tty/serdev/core.c:791:6: warning: variable 'dummy' set but not used [-Wunused-but-set-variable] 791 | int dummy; | ^~~~~ -- In file included from ./arch/arm/include/generated/uapi/asm/termios.h:1, from include/uapi/linux/termios.h:6, from include/linux/tty.h:7, from include/linux/serial_core.h:17, from drivers/tty/serial/8250/serial_cs.c:42: include/asm-generic/termios.h: In function 'user_termio_to_kernel_termios': 25 | if (get_user(tmp, &termio->c_iflag) < 0) | ^ include/asm-generic/termios.h:29:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 29 | if (get_user(tmp, &termio->c_oflag) < 0) | ^ include/asm-generic/termios.h:33:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 33 | if (get_user(tmp, &termio->c_cflag) < 0) | ^ include/asm-generic/termios.h:37:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 37 | if (get_user(tmp, &termio->c_lflag) < 0) | ^ include/asm-generic/termios.h:41:49: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 41 | if (get_user(termios->c_line, &termio->c_line) < 0) | ^ drivers/tty/serial/8250/serial_cs.c: In function 'multi_config': drivers/tty/serial/8250/serial_cs.c:562:7: warning: variable 'err' set but not used [-Wunused-but-set-variable] 562 | int err; | ^~~ -- In file included from ./arch/arm/include/generated/uapi/asm/termios.h:1, from include/uapi/linux/termios.h:6, from include/linux/tty.h:7, from drivers/tty/serial/8250/8250_core.c:26: include/asm-generic/termios.h: In function 'user_termio_to_kernel_termios': 25 | if (get_user(tmp, &termio->c_iflag) < 0) | ^ include/asm-generic/termios.h:29:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 29 | if (get_user(tmp, &termio->c_oflag) < 0) | ^ include/asm-generic/termios.h:33:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 33 | if (get_user(tmp, &termio->c_cflag) < 0) | ^ include/asm-generic/termios.h:37:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 37 | if (get_user(tmp, &termio->c_lflag) < 0) | ^ include/asm-generic/termios.h:41:49: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 41 | if (get_user(termios->c_line, &termio->c_line) < 0) | ^ drivers/tty/serial/8250/8250_core.c: In function 'serial8250_isa_init_ports': drivers/tty/serial/8250/8250_core.c:537:9: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 537 | i < ARRAY_SIZE(old_serial_port) && i < nr_uarts; | ^ -- In file included from ./arch/arm/include/generated/uapi/asm/termios.h:1, from include/uapi/linux/termios.h:6, from include/linux/tty.h:7, from drivers/tty/serial/jsm/jsm_cls.c:23: include/asm-generic/termios.h: In function 'user_termio_to_kernel_termios': 25 | if (get_user(tmp, &termio->c_iflag) < 0) | ^ include/asm-generic/termios.h:29:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 29 | if (get_user(tmp, &termio->c_oflag) < 0) | ^ include/asm-generic/termios.h:33:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 33 | if (get_user(tmp, &termio->c_cflag) < 0) | ^ include/asm-generic/termios.h:37:38: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 37 | if (get_user(tmp, &termio->c_lflag) < 0) | ^ include/asm-generic/termios.h:41:49: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] 41 | if (get_user(termios->c_line, &termio->c_line) < 0) | ^ drivers/tty/serial/jsm/jsm_cls.c: In function 'cls_copy_data_from_uart_to_queue': drivers/tty/serial/jsm/jsm_cls.c:400:7: warning: variable 'discard' set but not used [-Wunused-but-set-variable] 400 | u8 discard; | ^~~~~~~ vim +25 include/asm-generic/termios.h 6103ec56c65c33 Arnd Bergmann 2009-05-13 16 6103ec56c65c33 Arnd Bergmann 2009-05-13 17 /* 6103ec56c65c33 Arnd Bergmann 2009-05-13 18 * Translate a "termio" structure into a "termios". Ugh. 6103ec56c65c33 Arnd Bergmann 2009-05-13 19 */ 6103ec56c65c33 Arnd Bergmann 2009-05-13 20 static inline int user_termio_to_kernel_termios(struct ktermios *termios, 6103ec56c65c33 Arnd Bergmann 2009-05-13 21 const struct termio __user *termio) 6103ec56c65c33 Arnd Bergmann 2009-05-13 22 { 6103ec56c65c33 Arnd Bergmann 2009-05-13 23 unsigned short tmp; 6103ec56c65c33 Arnd Bergmann 2009-05-13 24 6103ec56c65c33 Arnd Bergmann 2009-05-13 @25 if (get_user(tmp, &termio->c_iflag) < 0) 6103ec56c65c33 Arnd Bergmann 2009-05-13 26 goto fault; 6103ec56c65c33 Arnd Bergmann 2009-05-13 27 termios->c_iflag = (0xffff0000 & termios->c_iflag) | tmp; 6103ec56c65c33 Arnd Bergmann 2009-05-13 28 6103ec56c65c33 Arnd Bergmann 2009-05-13 29 if (get_user(tmp, &termio->c_oflag) < 0) 6103ec56c65c33 Arnd Bergmann 2009-05-13 30 goto fault; 6103ec56c65c33 Arnd Bergmann 2009-05-13 31 termios->c_oflag = (0xffff0000 & termios->c_oflag) | tmp; 6103ec56c65c33 Arnd Bergmann 2009-05-13 32 6103ec56c65c33 Arnd Bergmann 2009-05-13 33 if (get_user(tmp, &termio->c_cflag) < 0) 6103ec56c65c33 Arnd Bergmann 2009-05-13 34 goto fault; 6103ec56c65c33 Arnd Bergmann 2009-05-13 35 termios->c_cflag = (0xffff0000 & termios->c_cflag) | tmp; 6103ec56c65c33 Arnd Bergmann 2009-05-13 36 6103ec56c65c33 Arnd Bergmann 2009-05-13 37 if (get_user(tmp, &termio->c_lflag) < 0) 6103ec56c65c33 Arnd Bergmann 2009-05-13 38 goto fault; 6103ec56c65c33 Arnd Bergmann 2009-05-13 39 termios->c_lflag = (0xffff0000 & termios->c_lflag) | tmp; 6103ec56c65c33 Arnd Bergmann 2009-05-13 40 6103ec56c65c33 Arnd Bergmann 2009-05-13 41 if (get_user(termios->c_line, &termio->c_line) < 0) 6103ec56c65c33 Arnd Bergmann 2009-05-13 42 goto fault; 6103ec56c65c33 Arnd Bergmann 2009-05-13 43 6103ec56c65c33 Arnd Bergmann 2009-05-13 44 if (copy_from_user(termios->c_cc, termio->c_cc, NCC) != 0) 6103ec56c65c33 Arnd Bergmann 2009-05-13 45 goto fault; 6103ec56c65c33 Arnd Bergmann 2009-05-13 46 6103ec56c65c33 Arnd Bergmann 2009-05-13 47 return 0; 6103ec56c65c33 Arnd Bergmann 2009-05-13 48 6103ec56c65c33 Arnd Bergmann 2009-05-13 49 fault: 6103ec56c65c33 Arnd Bergmann 2009-05-13 50 return -EFAULT; 6103ec56c65c33 Arnd Bergmann 2009-05-13 51 } 6103ec56c65c33 Arnd Bergmann 2009-05-13 52 :::::: The code at line 25 was first introduced by commit :::::: 6103ec56c65c33774c7c38652c8204120c3c7519 asm-generic: add generic ABI headers :::::: TO: Arnd Bergmann <arnd(a)arndb.de&gt; :::::: CC: Arnd Bergmann <arnd(a)klappe2.(none)&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org