Re: [PATCH v32 2/6] fs/proc/task_mmu: Implement IOCTL to get and optionally clear info about PTEs

[Muhammad Usama Anjum]

On 8/18/23 12:16 PM, kernel test robot wrote:
> Hi Muhammad,
> 
> kernel test robot noticed the following build errors:
> 
> [auto build test ERROR on akpm-mm/mm-everything]
> [also build test ERROR on next-20230817]
> [cannot apply to linus/master v6.5-rc6]
> [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/Muhammad-Usama-Anjum/userfaultfd-UFFD_FEATURE_WP_ASYNC/20230816-193454
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link:    https://lore.kernel.org/r/20230816113049.1697849-3-usama.anjum%40collabora.com
> patch subject: [PATCH v32 2/6] fs/proc/task_mmu: Implement IOCTL to get and optionally clear info about PTEs
> config: arc-allyesconfig (https://download.01.org/0day-ci/archive/20230818/202308181520.yCq9Z26w-lkp@xxxxxxxxx/config)
> compiler: arceb-elf-gcc (GCC) 12.3.0
> reproduce: (https://download.01.org/0day-ci/archive/20230818/202308181520.yCq9Z26w-lkp@xxxxxxxxx/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@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202308181520.yCq9Z26w-lkp@xxxxxxxxx/
> 
> All errors (new ones prefixed by >>):
> 
>    fs/proc/task_mmu.c: In function 'pagemap_scan_thp_entry':
>>> fs/proc/task_mmu.c:2077:28: error: 'HPAGE_SIZE' undeclared (first use in this function); did you mean 'PAGE_SIZE'?
>     2077 |         if (end != start + HPAGE_SIZE) {
>          |                            ^~~~~~~~~~
>          |                            PAGE_SIZE
I've been emailing arc maintainers for resolution of this error from April,
but nobody replies there:
https://lore.kernel.org/all/0e6b318a-bbf8-3701-00af-1802c6347897@xxxxxxxxxxxxx

>    fs/proc/task_mmu.c:2077:28: note: each undeclared identifier is reported only once for each function it appears in
> 
> 
> vim +2077 fs/proc/task_mmu.c
> 
>   2044	
>   2045	static int pagemap_scan_thp_entry(pmd_t *pmd, unsigned long start,
>   2046					  unsigned long end, struct mm_walk *walk)
>   2047	{
>   2048	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
>   2049		struct pagemap_scan_private *p = walk->private;
>   2050		struct vm_area_struct *vma = walk->vma;
>   2051		unsigned long categories;
>   2052		spinlock_t *ptl;
>   2053		int ret = 0;
>   2054	
>   2055		ptl = pmd_trans_huge_lock(pmd, vma);
>   2056		if (!ptl)
>   2057			return -ENOENT;
>   2058	
>   2059		categories = p->cur_vma_category | pagemap_thp_category(*pmd);
>   2060	
>   2061		if (!pagemap_scan_is_interesting_page(categories, p))
>   2062			goto out_unlock;
>   2063	
>   2064		ret = pagemap_scan_output(categories, p, start, &end);
>   2065		if (start == end)
>   2066			goto out_unlock;
>   2067	
>   2068		if (~p->arg.flags & PM_SCAN_WP_MATCHING)
>   2069			goto out_unlock;
>   2070		if (~categories & PAGE_IS_WRITTEN)
>   2071			goto out_unlock;
>   2072	
>   2073		/*
>   2074		 * Break huge page into small pages if the WP operation
>   2075		 * needs to be performed on a portion of the huge page.
>   2076		 */
>> 2077		if (end != start + HPAGE_SIZE) {
>   2078			spin_unlock(ptl);
>   2079			split_huge_pmd(vma, pmd, start);
>   2080			pagemap_scan_backout_range(p, start, end);
>   2081			/* Report as if there was no THP */
>   2082			return -ENOENT;
>   2083		}
>   2084	
>   2085		make_uffd_wp_pmd(vma, start, pmd);
>   2086		flush_tlb_range(vma, start, end);
>   2087	out_unlock:
>   2088		spin_unlock(ptl);
>   2089		return ret;
>   2090	#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
>   2091		return -ENOENT;
>   2092	#endif
>   2093	}
>   2094	
> 

-- 
BR,
Muhammad Usama Anjum