[PATCH 1/3] arm64: kdump: Allocate crash low memory in the bottom-up direction

[Leizhen (ThunderTown)]

On 2023/7/22 5:22, kernel test robot wrote:
> Hi,
> 
> kernel test robot noticed the following build errors:
> 
> [auto build test ERROR on arm64/for-next/core]
> [also build test ERROR on linus/master v6.5-rc2 next-20230721]
> [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/thunder-leizhen-huaweicloud-com/arm64-kdump-Allocate-crash-low-memory-in-the-bottom-up-direction/20230721-162312
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
> patch link:    https://lore.kernel.org/r/20230721081726.882-2-thunder.leizhen%40huaweicloud.com
> patch subject: [PATCH 1/3] arm64: kdump: Allocate crash low memory in the bottom-up direction
> config: arm64-allnoconfig (https://download.01.org/0day-ci/archive/20230722/202307220500.1I73fZ5Z-lkp@intel.com/config)
> compiler: aarch64-linux-gcc (GCC) 12.3.0
> reproduce: (https://download.01.org/0day-ci/archive/20230722/202307220500.1I73fZ5Z-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp at intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202307220500.1I73fZ5Z-lkp@intel.com/
> 
> All errors (new ones prefixed by >>):

Oh, thanks. I got it. The CONFIG_KEXEC_CORE build control is move into reserve_crashkernel().
Function late_reserve_crashkernel() needs to do the same. I forgot to test turning off options
like CONFIG_KEXEC_CORE. I will do it tomorrow. Sorry.

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index b544ed0ab04193d..d444721011d0b2f 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -122,6 +122,9 @@ static void __init late_reserve_crashkernel(void)
        unsigned long long low_base, low_size;
        unsigned long long crash_base, crash_size;

+       if (!IS_ENABLED(CONFIG_KEXEC_CORE))
+               return;


> 
>    aarch64-linux-ld: arch/arm64/mm/init.o: in function `late_reserve_crashkernel':
>>> init.c:(.init.text+0x58): undefined reference to `crashk_res'
>    aarch64-linux-ld: arch/arm64/mm/init.o: relocation R_AARCH64_ADR_PREL_PG_HI21 against symbol `crashk_res' which may bind externally can not be used when making a shared object; recompile with -fPIC
>    init.c:(.init.text+0x58): dangerous relocation: unsupported relocation
>>> aarch64-linux-ld: init.c:(.init.text+0x5c): undefined reference to `crashk_res'
>>> aarch64-linux-ld: init.c:(.init.text+0x88): undefined reference to `crashk_low_res'
>    aarch64-linux-ld: arch/arm64/mm/init.o: relocation R_AARCH64_ADR_PREL_PG_HI21 against symbol `crashk_low_res' which may bind externally can not be used when making a shared object; recompile with -fPIC
>    init.c:(.init.text+0x88): dangerous relocation: unsupported relocation
>    aarch64-linux-ld: init.c:(.init.text+0x90): undefined reference to `crashk_res'
>    aarch64-linux-ld: init.c:(.init.text+0x9c): undefined reference to `crashk_low_res'
>    aarch64-linux-ld: init.c:(.init.text+0xd0): undefined reference to `crashk_res'
>    aarch64-linux-ld: init.c:(.init.text+0x13c): undefined reference to `crashk_res'
>    aarch64-linux-ld: init.c:(.init.text+0x150): undefined reference to `crashk_res'
>    aarch64-linux-ld: init.c:(.init.text+0x18c): undefined reference to `crashk_low_res'
>    aarch64-linux-ld: init.c:(.init.text+0x1b0): undefined reference to `crashk_low_res'
>    aarch64-linux-ld: init.c:(.init.text+0x204): undefined reference to `crashk_low_res'
>    aarch64-linux-ld: init.c:(.init.text+0x234): undefined reference to `crashk_low_res'
>    aarch64-linux-ld: init.c:(.init.text+0x248): undefined reference to `crashk_low_res'
>    aarch64-linux-ld: arch/arm64/mm/init.o:init.c:(.init.text+0x25c): more undefined references to `crashk_low_res' follow
> 

-- 
Regards,
  Zhen Lei