[PATCH 5/6] kexec: add helper __crash_shrink_memory()

[kernel test robot]

Hi Zhen,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on linus/master v6.4-rc3 next-20230525]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Zhen-Lei/kexec-fix-a-memory-leak-in-crash_shrink_memory/20230527-203821
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20230527123439.772-6-thunder.leizhen%40huawei.com
patch subject: [PATCH 5/6] kexec: add helper __crash_shrink_memory()
config: mips-randconfig-r012-20230528 (https://download.01.org/0day-ci/archive/20230528/202305280949.yYtbjy5B-lkp@intel.com/config)
compiler: mipsel-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/dea97cef503d26e05d0e11818ae44176056ddf64
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Zhen-Lei/kexec-fix-a-memory-leak-in-crash_shrink_memory/20230527-203821
        git checkout dea97cef503d26e05d0e11818ae44176056ddf64
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 ~/bin/make.cross W=1 O=build_dir ARCH=mips olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 ~/bin/make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp at intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202305280949.yYtbjy5B-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/kexec_core.c:1108:5: warning: no previous prototype for '__crash_shrink_memory' [-Wmissing-prototypes]
    1108 | int __crash_shrink_memory(struct resource *old_res, unsigned long new_size)
         |     ^~~~~~~~~~~~~~~~~~~~~


vim +/__crash_shrink_memory +1108 kernel/kexec_core.c

  1107	
> 1108	int __crash_shrink_memory(struct resource *old_res, unsigned long new_size)
  1109	{
  1110		struct resource *ram_res;
  1111	
  1112		ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
  1113		if (!ram_res)
  1114			return -ENOMEM;
  1115	
  1116		ram_res->start = old_res->start + new_size;
  1117		ram_res->end   = old_res->end;
  1118		ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
  1119		ram_res->name  = "System RAM";
  1120	
  1121		if (!new_size) {
  1122			release_resource(old_res);
  1123			old_res->start = 0;
  1124			old_res->end   = 0;
  1125		} else {
  1126			crashk_res.end = ram_res->start - 1;
  1127		}
  1128	
  1129		crash_free_reserved_phys_range(ram_res->start, ram_res->end);
  1130		insert_resource(&iomem_resource, ram_res);
  1131	
  1132		return 0;
  1133	}
  1134	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki