drivers/media/platform/imx-jpeg/mxc-jpeg.c:652:12: warning: taking address of packed member 'height' of class or structure 'mxc_jpeg_sof' may result in an unaligned pointer value

From: kernel test robot
Date: Wed Jul 14 2021 - 12:35:06 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 40226a3d96ef8ab8980f032681c8bfd46d63874e
commit: 2db16c6ed72ce644d5639b3ed15e5817442db4ba media: imx-jpeg: Add V4L2 driver for i.MX8 JPEG Encoder/Decoder
date: 4 months ago
config: mips-randconfig-r004-20210714 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 8d69635ed9ecf36fd0ca85906bfde17949671cbe)
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/?id=2db16c6ed72ce644d5639b3ed15e5817442db4ba
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 2db16c6ed72ce644d5639b3ed15e5817442db4ba
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

>> drivers/media/platform/imx-jpeg/mxc-jpeg.c:652:12: warning: taking address of packed member 'height' of class or structure 'mxc_jpeg_sof' may result in an unaligned pointer value [-Waddress-of-packed-member]
_bswap16(&sof->height);
^~~~~~~~~~~
>> drivers/media/platform/imx-jpeg/mxc-jpeg.c:654:12: warning: taking address of packed member 'width' of class or structure 'mxc_jpeg_sof' may result in an unaligned pointer value [-Waddress-of-packed-member]
_bswap16(&sof->width);
^~~~~~~~~~
>> drivers/media/platform/imx-jpeg/mxc-jpeg.c:681:12: warning: taking address of packed member 'length' of class or structure 'mxc_jpeg_sof' may result in an unaligned pointer value [-Waddress-of-packed-member]
_bswap16(&sof->length);
^~~~~~~~~~~
>> drivers/media/platform/imx-jpeg/mxc-jpeg.c:713:12: warning: taking address of packed member 'length' of class or structure 'mxc_jpeg_sos' may result in an unaligned pointer value [-Waddress-of-packed-member]
_bswap16(&sos->length);
^~~~~~~~~~~
4 warnings generated.


vim +652 drivers/media/platform/imx-jpeg/mxc-jpeg.c

643
644 static int mxc_jpeg_fixup_sof(struct mxc_jpeg_sof *sof,
645 u32 fourcc,
646 u16 w, u16 h)
647 {
648 int sof_length;
649
650 sof->precision = 8; /* TODO allow 8/12 bit precision*/
651 sof->height = h;
> 652 _bswap16(&sof->height);
653 sof->width = w;
> 654 _bswap16(&sof->width);
655
656 switch (fourcc) {
657 case V4L2_PIX_FMT_NV12:
658 sof->components_no = 3;
659 sof->comp[0].v = 0x2;
660 sof->comp[0].h = 0x2;
661 break;
662 case V4L2_PIX_FMT_YUYV:
663 sof->components_no = 3;
664 sof->comp[0].v = 0x1;
665 sof->comp[0].h = 0x2;
666 break;
667 case V4L2_PIX_FMT_YUV24:
668 case V4L2_PIX_FMT_RGB24:
669 default:
670 sof->components_no = 3;
671 break;
672 case V4L2_PIX_FMT_ARGB32:
673 sof->components_no = 4;
674 break;
675 case V4L2_PIX_FMT_GREY:
676 sof->components_no = 1;
677 break;
678 }
679 sof_length = 8 + 3 * sof->components_no;
680 sof->length = sof_length;
> 681 _bswap16(&sof->length);
682
683 return sof_length; /* not swaped */
684 }
685
686 static int mxc_jpeg_fixup_sos(struct mxc_jpeg_sos *sos,
687 u32 fourcc)
688 {
689 int sos_length;
690 u8 *sof_u8 = (u8 *)sos;
691
692 switch (fourcc) {
693 case V4L2_PIX_FMT_NV12:
694 sos->components_no = 3;
695 break;
696 case V4L2_PIX_FMT_YUYV:
697 sos->components_no = 3;
698 break;
699 case V4L2_PIX_FMT_YUV24:
700 case V4L2_PIX_FMT_RGB24:
701 default:
702 sos->components_no = 3;
703 break;
704 case V4L2_PIX_FMT_ARGB32:
705 sos->components_no = 4;
706 break;
707 case V4L2_PIX_FMT_GREY:
708 sos->components_no = 1;
709 break;
710 }
711 sos_length = 6 + 2 * sos->components_no;
712 sos->length = sos_length;
> 713 _bswap16(&sos->length);
714
715 /* SOS ignorable bytes, not so ignorable after all */
716 sof_u8[sos_length - 1] = 0x0;
717 sof_u8[sos_length - 2] = 0x3f;
718 sof_u8[sos_length - 3] = 0x0;
719
720 return sos_length; /* not swaped */
721 }
722

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

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