drivers/media/v4l2-core/v4l2-ioctl.c:303:28: warning: taking address of packed member 'pixelformat' of class or structure 'v4l2_pix_format_mplane' may result in an unaligned pointer value

From: kernel test robot
Date: Sun Jan 16 2022 - 22:41:33 EST


Hi Sakari,

FYI, the error/warning still remains.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 79e06c4c4950be2abd8ca5d2428a8c915aa62c24
commit: e927e1e0f0dd3e353d5556503a71484008692c82 v4l: ioctl: Use %p4cc printk modifier to print FourCC codes
date: 11 months ago
config: mips-randconfig-r002-20220116 (https://download.01.org/0day-ci/archive/20220117/202201171150.wl8T3ge0-lkp@xxxxxxxxx/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c63a3175c2947e8c1a2d3bbe16a8586600705c54)
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=e927e1e0f0dd3e353d5556503a71484008692c82
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout e927e1e0f0dd3e353d5556503a71484008692c82
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash drivers/hid/ drivers/iio/adc/ drivers/media/v4l2-core/ drivers/usb/gadget/

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/v4l2-core/v4l2-ioctl.c:303:28: warning: taking address of packed member 'pixelformat' of class or structure 'v4l2_pix_format_mplane' may result in an unaligned pointer value [-Waddress-of-packed-member]
mp->width, mp->height, &mp->pixelformat,
^~~~~~~~~~~~~~~
include/linux/printk.h:385:26: note: expanded from macro 'pr_cont'
printk(KERN_CONT fmt, ##__VA_ARGS__)
^~~~~~~~~~~
>> drivers/media/v4l2-core/v4l2-ioctl.c:347:37: warning: taking address of packed member 'pixelformat' of class or structure 'v4l2_sdr_format' may result in an unaligned pointer value [-Waddress-of-packed-member]
pr_cont(", pixelformat=%p4cc\n", &sdr->pixelformat);
^~~~~~~~~~~~~~~~
include/linux/printk.h:385:26: note: expanded from macro 'pr_cont'
printk(KERN_CONT fmt, ##__VA_ARGS__)
^~~~~~~~~~~
>> drivers/media/v4l2-core/v4l2-ioctl.c:353:5: warning: taking address of packed member 'dataformat' of class or structure 'v4l2_meta_format' may result in an unaligned pointer value [-Waddress-of-packed-member]
&meta->dataformat, meta->buffersize);
^~~~~~~~~~~~~~~~
include/linux/printk.h:385:26: note: expanded from macro 'pr_cont'
printk(KERN_CONT fmt, ##__VA_ARGS__)
^~~~~~~~~~~
3 warnings generated.


vim +303 drivers/media/v4l2-core/v4l2-ioctl.c

273
274 static void v4l_print_format(const void *arg, bool write_only)
275 {
276 const struct v4l2_format *p = arg;
277 const struct v4l2_pix_format *pix;
278 const struct v4l2_pix_format_mplane *mp;
279 const struct v4l2_vbi_format *vbi;
280 const struct v4l2_sliced_vbi_format *sliced;
281 const struct v4l2_window *win;
282 const struct v4l2_sdr_format *sdr;
283 const struct v4l2_meta_format *meta;
284 u32 planes;
285 unsigned i;
286
287 pr_cont("type=%s", prt_names(p->type, v4l2_type_names));
288 switch (p->type) {
289 case V4L2_BUF_TYPE_VIDEO_CAPTURE:
290 case V4L2_BUF_TYPE_VIDEO_OUTPUT:
291 pix = &p->fmt.pix;
292 pr_cont(", width=%u, height=%u, pixelformat=%p4cc, field=%s, bytesperline=%u, sizeimage=%u, colorspace=%d, flags=0x%x, ycbcr_enc=%u, quantization=%u, xfer_func=%u\n",
293 pix->width, pix->height, &pix->pixelformat,
294 prt_names(pix->field, v4l2_field_names),
295 pix->bytesperline, pix->sizeimage,
296 pix->colorspace, pix->flags, pix->ycbcr_enc,
297 pix->quantization, pix->xfer_func);
298 break;
299 case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
300 case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
301 mp = &p->fmt.pix_mp;
302 pr_cont(", width=%u, height=%u, format=%p4cc, field=%s, colorspace=%d, num_planes=%u, flags=0x%x, ycbcr_enc=%u, quantization=%u, xfer_func=%u\n",
> 303 mp->width, mp->height, &mp->pixelformat,
304 prt_names(mp->field, v4l2_field_names),
305 mp->colorspace, mp->num_planes, mp->flags,
306 mp->ycbcr_enc, mp->quantization, mp->xfer_func);
307 planes = min_t(u32, mp->num_planes, VIDEO_MAX_PLANES);
308 for (i = 0; i < planes; i++)
309 printk(KERN_DEBUG "plane %u: bytesperline=%u sizeimage=%u\n", i,
310 mp->plane_fmt[i].bytesperline,
311 mp->plane_fmt[i].sizeimage);
312 break;
313 case V4L2_BUF_TYPE_VIDEO_OVERLAY:
314 case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
315 win = &p->fmt.win;
316 /* Note: we can't print the clip list here since the clips
317 * pointer is a userspace pointer, not a kernelspace
318 * pointer. */
319 pr_cont(", wxh=%dx%d, x,y=%d,%d, field=%s, chromakey=0x%08x, clipcount=%u, clips=%p, bitmap=%p, global_alpha=0x%02x\n",
320 win->w.width, win->w.height, win->w.left, win->w.top,
321 prt_names(win->field, v4l2_field_names),
322 win->chromakey, win->clipcount, win->clips,
323 win->bitmap, win->global_alpha);
324 break;
325 case V4L2_BUF_TYPE_VBI_CAPTURE:
326 case V4L2_BUF_TYPE_VBI_OUTPUT:
327 vbi = &p->fmt.vbi;
328 pr_cont(", sampling_rate=%u, offset=%u, samples_per_line=%u, sample_format=%p4cc, start=%u,%u, count=%u,%u\n",
329 vbi->sampling_rate, vbi->offset,
330 vbi->samples_per_line, &vbi->sample_format,
331 vbi->start[0], vbi->start[1],
332 vbi->count[0], vbi->count[1]);
333 break;
334 case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
335 case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
336 sliced = &p->fmt.sliced;
337 pr_cont(", service_set=0x%08x, io_size=%d\n",
338 sliced->service_set, sliced->io_size);
339 for (i = 0; i < 24; i++)
340 printk(KERN_DEBUG "line[%02u]=0x%04x, 0x%04x\n", i,
341 sliced->service_lines[0][i],
342 sliced->service_lines[1][i]);
343 break;
344 case V4L2_BUF_TYPE_SDR_CAPTURE:
345 case V4L2_BUF_TYPE_SDR_OUTPUT:
346 sdr = &p->fmt.sdr;
> 347 pr_cont(", pixelformat=%p4cc\n", &sdr->pixelformat);
348 break;
349 case V4L2_BUF_TYPE_META_CAPTURE:
350 case V4L2_BUF_TYPE_META_OUTPUT:
351 meta = &p->fmt.meta;
352 pr_cont(", dataformat=%p4cc, buffersize=%u\n",
> 353 &meta->dataformat, meta->buffersize);
354 break;
355 }
356 }
357

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0-DAY CI Kernel Test Service, Intel Corporation
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