linux-kernel - Re: [PATCH 5/6] kexec: add helper __crash_shrink

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Date:   Mon, 29 May 2023 08:37:22 +0800
From:   "Leizhen (ThunderTown)" <thunder.leizhen@...wei.com>
To:     kernel test robot <lkp@...el.com>,
        Eric Biederman <ebiederm@...ssion.com>,
        Baoquan He <bhe@...hat.com>, <kexec@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>
CC:     <llvm@...ts.linux.dev>, <oe-kbuild-all@...ts.linux.dev>,
        Michael Holzheu <holzheu@...ux.vnet.ibm.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Linux Memory Management List <linux-mm@...ck.org>,
        Amerigo Wang <amwang@...hat.com>
Subject: Re: [PATCH 5/6] kexec: add helper __crash_shrink_memory()



On 2023/5/28 8:08, kernel test robot wrote:
> 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: riscv-randconfig-r042-20230526 (https://download.01.org/0day-ci/archive/20230528/202305280717.Pw06aLkz-lkp@intel.com/config)
> compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project 4faf3aaf28226a4e950c103a14f6fc1d1fdabb1b)
> 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
>         # install riscv cross compiling tool for clang build
>         # apt-get install binutils-riscv64-linux-gnu
>         # 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=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=riscv olddefconfig
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp@...el.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202305280717.Pw06aLkz-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>>> kernel/kexec_core.c:1108:5: warning: no previous prototype for function '__crash_shrink_memory' [-Wmissing-prototypes]
>    int __crash_shrink_memory(struct resource *old_res, unsigned long new_size)
>        ^
>    kernel/kexec_core.c:1108:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
>    int __crash_shrink_memory(struct resource *old_res, unsigned long new_size)
>    ^
>    static 
>    1 warning generated.

Yes, thanks, a 'static' should be added.

> 
> 
> 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	
> 

-- 
Regards,
  Zhen Lei