[kbuild-all] arch/mips/kernel/relocate.c:41:12: warning: no previous prototype for function 'plat_post_relocation'

Tuesday, 25 January 2022

Hi Jinyang,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   dd81e1c7d5fb126e5fbc5c9e334d7b3ec29a16a0
commit: a307a4ce9ecd2e23c71318201330d9d648b3f818 MIPS: Loongson64: Add KASLR support
date:   1 year, 2 months ago
config: mips-randconfig-c004-20220120
(https://download.01.org/0day-ci/archive/20220124/202201242332.W7XuI6gI-lk...)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project
f7b7138a62648f4019c55e4671682af1f851f295)
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 mips cross compiling tool for clang build
        # apt-get install binutils-mips-linux-gnu
        #
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit...
        git remote add linus
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout a307a4ce9ecd2e23c71318201330d9d648b3f818
        # 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=mips SHELL=/bin/bash arch/mips/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com&gt;

All warnings (new ones prefixed by >>):

   In file included from include/asm-generic/preempt.h:5:
   In file included from include/linux/thread_info.h:38:
   In file included from arch/mips/include/asm/thread_info.h:16:
   In file included from arch/mips/include/asm/processor.h:14:
   In file included from include/linux/atomic.h:7:
   arch/mips/include/asm/atomic.h:257:1: warning: converting the result of
'<<' to a boolean always evaluates to true
[-Wtautological-constant-compare]
   ATOMIC_SIP_OP(atomic, int, subu, ll, sc)
   ^
   arch/mips/include/asm/atomic.h:251:7: note: expanded from macro
'ATOMIC_SIP_OP'
           if (!__SYNC_loongson3_war)                                      \
                ^
   arch/mips/include/asm/sync.h:147:34: note: expanded from macro
'__SYNC_loongson3_war'
   # define __SYNC_loongson3_war   (1 << 31)
                                      ^
   In file included from arch/mips/kernel/relocate.c:12:
   In file included from arch/mips/include/asm/cacheflush.h:13:
   In file included from include/linux/mm.h:10:
   In file included from include/linux/gfp.h:6:
   In file included from include/linux/mmzone.h:8:
   In file included from include/linux/spinlock.h:51:
   In file included from include/linux/preempt.h:78:
   In file included from ./arch/mips/include/generated/asm/preempt.h:1:
   In file included from include/asm-generic/preempt.h:5:
   In file included from include/linux/thread_info.h:38:
   In file included from arch/mips/include/asm/thread_info.h:16:
   In file included from arch/mips/include/asm/processor.h:14:
   In file included from include/linux/atomic.h:7:
   arch/mips/include/asm/atomic.h:261:1: warning: converting the result of
'<<' to a boolean always evaluates to true
[-Wtautological-constant-compare]
   ATOMIC_SIP_OP(atomic64, s64, dsubu, lld, scd)
   ^
   arch/mips/include/asm/atomic.h:251:7: note: expanded from macro
'ATOMIC_SIP_OP'
           if (!__SYNC_loongson3_war)                                      \
                ^
   arch/mips/include/asm/sync.h:147:34: note: expanded from macro
'__SYNC_loongson3_war'
   # define __SYNC_loongson3_war   (1 << 31)
                                      ^
   In file included from arch/mips/kernel/relocate.c:12:
   In file included from arch/mips/include/asm/cacheflush.h:13:
   In file included from include/linux/mm.h:10:
   In file included from include/linux/gfp.h:6:
   In file included from include/linux/mmzone.h:8:
   In file included from include/linux/spinlock.h:59:
   In file included from include/linux/lockdep.h:14:
   In file included from include/linux/smp.h:15:
   In file included from include/linux/smp_types.h:5:
   include/linux/llist.h:222:9: warning: converting the result of '<<' to a
boolean always evaluates to true [-Wtautological-constant-compare]
           return xchg(&head->first, NULL);
                  ^
   arch/mips/include/asm/cmpxchg.h:102:7: note: expanded from macro 'xchg'
           if (!__SYNC_loongson3_war)                                      \
                ^
   arch/mips/include/asm/sync.h:147:34: note: expanded from macro
'__SYNC_loongson3_war'
   # define __SYNC_loongson3_war   (1 << 31)
                                      ^
   In file included from arch/mips/kernel/relocate.c:12:
   In file included from arch/mips/include/asm/cacheflush.h:13:
   In file included from include/linux/mm.h:10:
   In file included from include/linux/gfp.h:6:
   In file included from include/linux/mmzone.h:8:
   In file included from include/linux/spinlock.h:59:
   In file included from include/linux/lockdep.h:27:
   include/linux/debug_locks.h:17:9: warning: converting the result of '<<'
to a boolean always evaluates to true [-Wtautological-constant-compare]
           return xchg(&debug_locks, 0);
                  ^
   arch/mips/include/asm/cmpxchg.h:102:7: note: expanded from macro 'xchg'
           if (!__SYNC_loongson3_war)                                      \
                ^
   arch/mips/include/asm/sync.h:147:34: note: expanded from macro
'__SYNC_loongson3_war'
   # define __SYNC_loongson3_war   (1 << 31)
                                      ^
   In file included from arch/mips/kernel/relocate.c:12:
   In file included from arch/mips/include/asm/cacheflush.h:13:
   In file included from include/linux/mm.h:33:
   In file included from include/linux/pgtable.h:6:
   arch/mips/include/asm/pgtable.h:200:3: warning: converting the result of
'<<' to a boolean always evaluates to true
[-Wtautological-constant-compare]
                   cmpxchg64(&buddy->pte, 0, _PAGE_GLOBAL);
                   ^
   arch/mips/include/asm/cmpxchg.h:220:2: note: expanded from macro 'cmpxchg64'
           cmpxchg((ptr), (o), (n));                                       \
           ^
   arch/mips/include/asm/cmpxchg.h:194:7: note: expanded from macro 'cmpxchg'
           if (!__SYNC_loongson3_war)                                      \
                ^
   arch/mips/include/asm/sync.h:147:34: note: expanded from macro
'__SYNC_loongson3_war'
   # define __SYNC_loongson3_war   (1 << 31)
                                      ^
   In file included from arch/mips/kernel/relocate.c:12:
   In file included from arch/mips/include/asm/cacheflush.h:13:
   In file included from include/linux/mm.h:33:
   In file included from include/linux/pgtable.h:6:
   arch/mips/include/asm/pgtable.h:200:3: warning: converting the result of
'<<' to a boolean always evaluates to true
[-Wtautological-constant-compare]
   arch/mips/include/asm/cmpxchg.h:220:2: note: expanded from macro 'cmpxchg64'
           cmpxchg((ptr), (o), (n));                                       \
           ^
   arch/mips/include/asm/cmpxchg.h:204:7: note: expanded from macro 'cmpxchg'
           if (!__SYNC_loongson3_war)                                      \
                ^
   arch/mips/include/asm/sync.h:147:34: note: expanded from macro
'__SYNC_loongson3_war'
   # define __SYNC_loongson3_war   (1 << 31)
                                      ^
...
> arch/mips/kernel/relocate.c:41:12: warning: no previous prototype
for function 'plat_post_relocation' [-Wmissing-prototypes]    int __weak
plat_post_relocation(long offset)
              ^
   arch/mips/kernel/relocate.c:41:1: note: declare 'static' if the function is not
intended to be used outside of this translation unit
   int __weak plat_post_relocation(long offset)
   ^
   static 
   arch/mips/kernel/relocate.c:135:12: warning: no previous prototype for function
'do_relocations' [-Wmissing-prototypes]
   int __init do_relocations(void *kbase_old, void *kbase_new, long offset)
              ^
   arch/mips/kernel/relocate.c:135:1: note: declare 'static' if the function is
not intended to be used outside of this translation unit
   int __init do_relocations(void *kbase_old, void *kbase_new, long offset)
   ^
   static 
...
> arch/mips/kernel/relocate.c:304:14: warning: no previous
prototype for function 'relocate_kernel' [-Wmissing-prototypes]    void
*__init relocate_kernel(void)
                ^
   arch/mips/kernel/relocate.c:304:1: note: declare 'static' if the function is
not intended to be used outside of this translation unit
   void *__init relocate_kernel(void)
   ^
   static 
   arch/mips/kernel/relocate.c:415:6: warning: no previous prototype for function
'show_kernel_relocation' [-Wmissing-prototypes]
   void show_kernel_relocation(const char *level)
        ^
   arch/mips/kernel/relocate.c:415:1: note: declare 'static' if the function is
not intended to be used outside of this translation unit
   void show_kernel_relocation(const char *level)
   ^
   static 
   16 warnings generated.

vim +/plat_post_relocation +41 arch/mips/kernel/relocate.c

4c9fff362261d6 Marcin Nowakowski 2016-11-23  35  
8cc709d7d4f013 Steven J. Hill    2016-12-09  36  /*
8cc709d7d4f013 Steven J. Hill    2016-12-09  37   * This function may be defined for a
platform to perform any post-relocation
8cc709d7d4f013 Steven J. Hill    2016-12-09  38   * fixup necessary.
8cc709d7d4f013 Steven J. Hill    2016-12-09  39   * Return non-zero to abort relocation
8cc709d7d4f013 Steven J. Hill    2016-12-09  40   */
8cc709d7d4f013 Steven J. Hill    2016-12-09 @41  int __weak plat_post_relocation(long
offset)
8cc709d7d4f013 Steven J. Hill    2016-12-09  42  {
8cc709d7d4f013 Steven J. Hill    2016-12-09  43  	return 0;
8cc709d7d4f013 Steven J. Hill    2016-12-09  44  }
8cc709d7d4f013 Steven J. Hill    2016-12-09  45  

:::::: The code at line 41 was first introduced by commit
:::::: 8cc709d7d4f013f51d38ceb2e3c8c82d230cf457 MIPS: Relocatable: Provide
plat_post_relocation hook

:::::: TO: Steven J. Hill <Steven.Hill(a)cavium.com&gt;
:::::: CC: Ralf Baechle <ralf(a)linux-mips.org&gt;

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

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[kbuild-all] arch/mips/kernel/relocate.c:41:12: warning: no previous prototype for function 'plat_post_relocation'