Re: [PATCH 2/8] drm/gem: Introduce drm_gem_get_unmapped_area() fop

[kernel test robot <lkp@intel.com>]

Hi Loïc,

kernel test robot noticed the following build errors:

[auto build test ERROR on drm-misc/drm-misc-next]
[also build test ERROR on linus/master v6.17 next-20250929]
[cannot apply to akpm-mm/mm-everything]
[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/Lo-c-Molinari/drm-shmem-helper-Add-huge-page-fault-handler/20250930-040600
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20250929200316.18417-3-loic.molinari%40collabora.com
patch subject: [PATCH 2/8] drm/gem: Introduce drm_gem_get_unmapped_area() fop
config: arm-randconfig-002-20250930 (https://download.01.org/0day-ci/archive/20250930/202509301702.DL6CeU62-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250930/202509301702.DL6CeU62-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/202509301702.DL6CeU62-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/gpu/drm/drm_gem.c: In function 'drm_gem_get_unmapped_area':
>> drivers/gpu/drm/drm_gem.c:1280:9: error: implicit declaration of function 'mm_get_unmapped_area'; did you mean 'shmem_get_unmapped_area'? [-Werror=implicit-function-declaration]
     return mm_get_unmapped_area(current->mm, filp, uaddr, len, 0, flags);
            ^~~~~~~~~~~~~~~~~~~~
            shmem_get_unmapped_area
   cc1: some warnings being treated as errors


vim +1280 drivers/gpu/drm/drm_gem.c

  1238	
  1239	/**
  1240	 * drm_gem_get_unmapped_area - get memory mapping region routine for GEM objects
  1241	 * @filp: DRM file pointer
  1242	 * @uaddr: User address hint
  1243	 * @len: Mapping length
  1244	 * @pgoff: Offset (in pages)
  1245	 * @flags: Mapping flags
  1246	 *
  1247	 * If a driver supports GEM object mapping, before ending up in drm_gem_mmap(),
  1248	 * mmap calls on the DRM file descriptor will first try to find a free linear
  1249	 * address space large enough for a mapping. Since GEM objects are backed by
  1250	 * shmem buffers, this should preferably be handled by the shmem virtual memory
  1251	 * filesystem which can appropriately align addresses to huge page sizes when
  1252	 * needed.
  1253	 *
  1254	 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
  1255	 * contain the fake offset we created) and call shmem_get_unmapped_area() with
  1256	 * the right file pointer.
  1257	 *
  1258	 * If a GEM object is not available at the given offset or if the caller is not
  1259	 * granted access to it, fall back to mm_get_unmapped_area().
  1260	 */
  1261	unsigned long drm_gem_get_unmapped_area(struct file *filp, unsigned long uaddr,
  1262						unsigned long len, unsigned long pgoff,
  1263						unsigned long flags)
  1264	{
  1265	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
  1266		struct drm_gem_object *obj;
  1267		unsigned long ret;
  1268	
  1269		obj = drm_gem_object_lookup_from_offset(filp, pgoff, len >> PAGE_SHIFT);
  1270		if (IS_ERR(obj))
  1271			return mm_get_unmapped_area(current->mm, filp, uaddr, len, 0,
  1272						    flags);
  1273	
  1274		ret = shmem_get_unmapped_area(obj->filp, uaddr, len, 0, flags);
  1275	
  1276		drm_gem_object_put(obj);
  1277	
  1278		return ret;
  1279	#else
> 1280		return mm_get_unmapped_area(current->mm, filp, uaddr, len, 0, flags);
  1281	#endif
  1282	}
  1283	EXPORT_SYMBOL(drm_gem_get_unmapped_area);
  1284	

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