Re: [PATCH v7 13/17] mm/debug: print vm_refcnt state when dumping the vma

[Suren Baghdasaryan <surenb@google.com>]

On Thu, Dec 26, 2024 at 11:41 AM kernel test robot <lkp@intel.com> wrote:
>
> Hi Suren,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on 431614f1580a03c1a653340c55ea76bd12a9403f]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Suren-Baghdasaryan/mm-introduce-vma_start_read_locked-_nested-helpers/20241227-010925
> base:   431614f1580a03c1a653340c55ea76bd12a9403f
> patch link:    https://lore.kernel.org/r/20241226170710.1159679-14-surenb%40google.com
> patch subject: [PATCH v7 13/17] mm/debug: print vm_refcnt state when dumping the vma
> config: hexagon-randconfig-002-20241227 (https://download.01.org/0day-ci/archive/20241227/202412270328.HiJX1mRt-lkp@intel.com/config)
> compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241227/202412270328.HiJX1mRt-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@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202412270328.HiJX1mRt-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
> >> mm/debug.c:189:54: error: no member named 'vm_refcnt' in 'struct vm_area_struct'

Ugh, ok. On architectures with ARCH_SUPPORTS_PER_VMA_LOCK=n this will
happen. Preparing a fix.

>      189 |                 vma->vm_flags, &vma->vm_flags, refcount_read(&vma->vm_refcnt));
>          |                                                               ~~~  ^
>    include/linux/printk.h:514:35: note: expanded from macro 'pr_emerg'
>      514 |         printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
>          |                                          ^~~~~~~~~~~
>    include/linux/printk.h:501:60: note: expanded from macro 'printk'
>      501 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
>          |                                                            ^~~~~~~~~~~
>    include/linux/printk.h:473:19: note: expanded from macro 'printk_index_wrap'
>      473 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
>          |                                 ^~~~~~~~~~~
>    1 error generated.
>
>
> vim +189 mm/debug.c
>
>    178
>    179  void dump_vma(const struct vm_area_struct *vma)
>    180  {
>    181          pr_emerg("vma %px start %px end %px mm %px\n"
>    182                  "prot %lx anon_vma %px vm_ops %px\n"
>    183                  "pgoff %lx file %px private_data %px\n"
>    184                  "flags: %#lx(%pGv) refcnt %x\n",
>    185                  vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_mm,
>    186                  (unsigned long)pgprot_val(vma->vm_page_prot),
>    187                  vma->anon_vma, vma->vm_ops, vma->vm_pgoff,
>    188                  vma->vm_file, vma->vm_private_data,
>  > 189                  vma->vm_flags, &vma->vm_flags, refcount_read(&vma->vm_refcnt));
>    190  }
>    191  EXPORT_SYMBOL(dump_vma);
>    192
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki