Re: [PATCH v2 2/2] vsprintf: Move space out of string literals in fourcc_string()

Re: [PATCH v2 2/2] vsprintf: Move space out of string literals in fourcc_string()

[kernel test robot]

Hi Andy,

I love your patch! Yet something to improve:

[auto build test ERROR on linux/master]
[also build test ERROR on linus/master v5.17-rc1 next-20220124]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Andy-Shevchenko/vsprintf-Fix-potential-unaligned-access/20220124-224420
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 2c271fe77d52a0555161926c232cd5bc07178b39
config: riscv-randconfig-r042-20220124 (https://download.01.org/0day-ci/archive/20220125/202201250142.DtHQRlOS-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 2e58a18910867ba6795066e044293e6daf89edf5)
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 riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/0day-ci/linux/commit/f1895edcabdc5dae0528ffff9c3cb665a937223d
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Andy-Shevchenko/vsprintf-Fix-potential-unaligned-access/20220124-224420
        git checkout f1895edcabdc5dae0528ffff9c3cb665a937223d
        # 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=riscv SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> lib/vsprintf.c:1794:6: error: implicitly declaring library function 'stpcpy' with type 'char *(char *, const char *)' [-Werror,-Wimplicit-function-declaration]
           p = stpcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
               ^
   lib/vsprintf.c:1794:6: note: include the header <string.h> or explicitly provide a declaration for 'stpcpy'
   1 error generated.


vim +1794 lib/vsprintf.c

  1767	
  1768	static noinline_for_stack
  1769	char *fourcc_string(char *buf, char *end, const u32 *fourcc,
  1770			    struct printf_spec spec, const char *fmt)
  1771	{
  1772		char output[sizeof("0123 little-endian (0x01234567)")];
  1773		char *p = output;
  1774		unsigned int i;
  1775		u32 orig, val;
  1776	
  1777		if (fmt[1] != 'c' || fmt[2] != 'c')
  1778			return error_string(buf, end, "(%p4?)", spec);
  1779	
  1780		if (check_pointer(&buf, end, fourcc, spec))
  1781			return buf;
  1782	
  1783		orig = get_unaligned(fourcc);
  1784		val = orig & ~BIT(31);
  1785	
  1786		for (i = 0; i < sizeof(u32); i++) {
  1787			unsigned char c = val >> (i * 8);
  1788	
  1789			/* Print non-control ASCII characters as-is, dot otherwise */
  1790			*p++ = isascii(c) && isprint(c) ? c : '.';
  1791		}
  1792	
  1793		*p++ = ' ';
> 1794		p = stpcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
  1795	
  1796		*p++ = ' ';
  1797		*p++ = '(';
  1798		p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
  1799		*p++ = ')';
  1800		*p = '\0';
  1801	
  1802		return string(buf, end, output, spec);
  1803	}
  1804	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org