Re: [PATCH v3 02/10] drm/gem: Introduce drm_gem_get_unmapped_area() fop
From: kernel test robot
Date: Fri Oct 10 2025 - 03:49:23 EST
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-20251009]
[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/20251004-173347
base: git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link: https://lore.kernel.org/r/20251004093054.21388-3-loic.molinari%40collabora.com
patch subject: [PATCH v3 02/10] drm/gem: Introduce drm_gem_get_unmapped_area() fop
config: riscv-randconfig-001-20251010 (https://download.01.org/0day-ci/archive/20251010/202510101507.UiRzhiAP-lkp@xxxxxxxxx/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 39f292ffa13d7ca0d1edff27ac8fd55024bb4d19)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251010/202510101507.UiRzhiAP-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/202510101507.UiRzhiAP-lkp@xxxxxxxxx/
All errors (new ones prefixed by >>):
In file included from drivers/gpu/drm/drm_gem.c:28:
In file included from include/linux/dma-buf.h:16:
In file included from include/linux/iosys-map.h:10:
In file included from include/linux/io.h:12:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:804:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
804 | insb(addr, buffer, count);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
arch/riscv/include/asm/io.h:104:53: note: expanded from macro 'insb'
104 | #define insb(addr, buffer, count) __insb(PCI_IOBASE + (addr), buffer, count)
| ~~~~~~~~~~ ^
In file included from drivers/gpu/drm/drm_gem.c:28:
In file included from include/linux/dma-buf.h:16:
In file included from include/linux/iosys-map.h:10:
In file included from include/linux/io.h:12:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:812:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
812 | insw(addr, buffer, count);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
arch/riscv/include/asm/io.h:105:53: note: expanded from macro 'insw'
105 | #define insw(addr, buffer, count) __insw(PCI_IOBASE + (addr), buffer, count)
| ~~~~~~~~~~ ^
In file included from drivers/gpu/drm/drm_gem.c:28:
In file included from include/linux/dma-buf.h:16:
In file included from include/linux/iosys-map.h:10:
In file included from include/linux/io.h:12:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:820:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
820 | insl(addr, buffer, count);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
arch/riscv/include/asm/io.h:106:53: note: expanded from macro 'insl'
106 | #define insl(addr, buffer, count) __insl(PCI_IOBASE + (addr), buffer, count)
| ~~~~~~~~~~ ^
In file included from drivers/gpu/drm/drm_gem.c:28:
In file included from include/linux/dma-buf.h:16:
In file included from include/linux/iosys-map.h:10:
In file included from include/linux/io.h:12:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:829:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
829 | outsb(addr, buffer, count);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
arch/riscv/include/asm/io.h:118:55: note: expanded from macro 'outsb'
118 | #define outsb(addr, buffer, count) __outsb(PCI_IOBASE + (addr), buffer, count)
| ~~~~~~~~~~ ^
In file included from drivers/gpu/drm/drm_gem.c:28:
In file included from include/linux/dma-buf.h:16:
In file included from include/linux/iosys-map.h:10:
In file included from include/linux/io.h:12:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:838:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
838 | outsw(addr, buffer, count);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
arch/riscv/include/asm/io.h:119:55: note: expanded from macro 'outsw'
119 | #define outsw(addr, buffer, count) __outsw(PCI_IOBASE + (addr), buffer, count)
| ~~~~~~~~~~ ^
In file included from drivers/gpu/drm/drm_gem.c:28:
In file included from include/linux/dma-buf.h:16:
In file included from include/linux/iosys-map.h:10:
In file included from include/linux/io.h:12:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:847:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
847 | outsl(addr, buffer, count);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
arch/riscv/include/asm/io.h:120:55: note: expanded from macro 'outsl'
120 | #define outsl(addr, buffer, count) __outsl(PCI_IOBASE + (addr), buffer, count)
| ~~~~~~~~~~ ^
In file included from drivers/gpu/drm/drm_gem.c:28:
In file included from include/linux/dma-buf.h:16:
In file included from include/linux/iosys-map.h:10:
In file included from include/linux/io.h:12:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:1175:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
1175 | return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
| ~~~~~~~~~~ ^
>> drivers/gpu/drm/drm_gem.c:1271:10: error: call to undeclared function 'mm_get_unmapped_area'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
1271 | return mm_get_unmapped_area(current->mm, filp, uaddr, len, 0,
| ^
drivers/gpu/drm/drm_gem.c:1271:10: note: did you mean '__get_unmapped_area'?
include/linux/mm.h:3337:1: note: '__get_unmapped_area' declared here
3337 | __get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
| ^
7 warnings and 1 error generated.
vim +/mm_get_unmapped_area +1271 drivers/gpu/drm/drm_gem.c
1239
1240 /**
1241 * drm_gem_get_unmapped_area - get memory mapping region routine for GEM objects
1242 * @filp: DRM file pointer
1243 * @uaddr: User address hint
1244 * @len: Mapping length
1245 * @pgoff: Offset (in pages)
1246 * @flags: Mapping flags
1247 *
1248 * If a driver supports GEM object mapping, before ending up in drm_gem_mmap(),
1249 * mmap calls on the DRM file descriptor will first try to find a free linear
1250 * address space large enough for a mapping. Since GEM objects are backed by
1251 * shmem buffers, this should preferably be handled by the shmem virtual memory
1252 * filesystem which can appropriately align addresses to huge page sizes when
1253 * needed.
1254 *
1255 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
1256 * contain the fake offset we created) and call shmem_get_unmapped_area() with
1257 * the right file pointer.
1258 *
1259 * If a GEM object is not available at the given offset or if the caller is not
1260 * granted access to it, fall back to mm_get_unmapped_area().
1261 */
1262 unsigned long drm_gem_get_unmapped_area(struct file *filp, unsigned long uaddr,
1263 unsigned long len, unsigned long pgoff,
1264 unsigned long flags)
1265 {
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 }
1280 EXPORT_SYMBOL(drm_gem_get_unmapped_area);
1281
--
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