8:01 a.m.
Hi Sandor,
FYI, the error/warning still remains.
tree: https://github.com/Freescale/linux-fslc 5.10-2.1.x-imx
head: 3b81a70be1099d44fdafaa6766bf75a2bd9e297e
commit: 92123fc24af3d55dc3db2d862754fc2da1bccc8a [11497/15242] LF-3541: video/backligh:
fix Coverity Issue: 9551473 Copy into fixed size buffer
config: sparc64-randconfig-p001-20210927 (attached as .config)
compiler: sparc64-linux-gcc (GCC) 11.2.0
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
#
https://github.com/Freescale/linux-fslc/commit/92123fc24af3d55dc3db2d8627...
git remote add freescale-fslc https://github.com/Freescale/linux-fslc
git fetch --no-tags freescale-fslc 5.10-2.1.x-imx
git checkout 92123fc24af3d55dc3db2d862754fc2da1bccc8a
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=sparc64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com>
All warnings (new ones prefixed by >>):
drivers/video/backlight/pwm_bl.c: In function 'pwm_backlight_parse_dt':
> drivers/video/backlight/pwm_bl.c:261:17: warning:
'strncpy' specified bound 16 equals destination size [-Wstringop-truncation]
261 | strncpy(data->fb_id, names, sizeof(data->fb_id));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +/strncpy +261 drivers/video/backlight/pwm_bl.c
240
241 static int pwm_backlight_parse_dt(struct device *dev,
242 struct platform_pwm_backlight_data *data)
243 {
244 struct device_node *node = dev->of_node;
245 unsigned int num_levels = 0;
246 unsigned int levels_count;
247 unsigned int num_steps = 0;
248 struct property *prop;
249 unsigned int *table;
250 int length;
251 u32 value;
252 int ret;
253 const char *names;
254
255 if (!node)
256 return -ENODEV;
257
258 memset(data, 0, sizeof(*data));
259
260 if (!of_property_read_string(node, "fb-names", &names)) {
261 strncpy(data->fb_id, names, sizeof(data->fb_id));
262 data->check_fb = &pwm_backlight_check_fb_name;
263 }
264
265 /*
266 * These values are optional and set as 0 by default, the out values
267 * are modified only if a valid u32 value can be decoded.
268 */
269 of_property_read_u32(node, "post-pwm-on-delay-ms",
270 &data->post_pwm_on_delay);
271 of_property_read_u32(node, "pwm-off-delay-ms",
&data->pwm_off_delay);
272
273 /*
274 * Determine the number of brightness levels, if this property is not
275 * set a default table of brightness levels will be used.
276 */
277 prop = of_find_property(node, "brightness-levels", &length);
278 if (!prop)
279 return 0;
280
281 data->max_brightness = length / sizeof(u32);
282
283 /* read brightness levels from DT property */
284 if (data->max_brightness > 0) {
285 size_t size = sizeof(*data->levels) * data->max_brightness;
286 unsigned int i, j, n = 0;
287
288 data->levels = devm_kzalloc(dev, size, GFP_KERNEL);
289 if (!data->levels)
290 return -ENOMEM;
291
292 ret = of_property_read_u32_array(node, "brightness-levels",
293 data->levels,
294 data->max_brightness);
295 if (ret < 0)
296 return ret;
297
298 ret = of_property_read_u32(node, "default-brightness-level",
299 &value);
300 if (ret < 0)
301 return ret;
302
303 data->dft_brightness = value;
304
305 /*
306 * This property is optional, if is set enables linear
307 * interpolation between each of the values of brightness levels
308 * and creates a new pre-computed table.
309 */
310 of_property_read_u32(node, "num-interpolated-steps",
311 &num_steps);
312
313 /*
314 * Make sure that there is at least two entries in the
315 * brightness-levels table, otherwise we can't interpolate
316 * between two points.
317 */
318 if (num_steps) {
319 if (data->max_brightness < 2) {
320 dev_err(dev, "can't interpolate\n");
321 return -EINVAL;
322 }
323
324 /*
325 * Recalculate the number of brightness levels, now
326 * taking in consideration the number of interpolated
327 * steps between two levels.
328 */
329 for (i = 0; i < data->max_brightness - 1; i++) {
330 if ((data->levels[i + 1] - data->levels[i]) /
331 num_steps)
332 num_levels += num_steps;
333 else
334 num_levels++;
335 }
336 num_levels++;
337 dev_dbg(dev, "new number of brightness levels: %d\n",
338 num_levels);
339
340 /*
341 * Create a new table of brightness levels with all the
342 * interpolated steps.
343 */
344 size = sizeof(*table) * num_levels;
345 table = devm_kzalloc(dev, size, GFP_KERNEL);
346 if (!table)
347 return -ENOMEM;
348
349 /* Fill the interpolated table. */
350 levels_count = 0;
351 for (i = 0; i < data->max_brightness - 1; i++) {
352 value = data->levels[i];
353 n = (data->levels[i + 1] - value) / num_steps;
354 if (n > 0) {
355 for (j = 0; j < num_steps; j++) {
356 table[levels_count] = value;
357 value += n;
358 levels_count++;
359 }
360 } else {
361 table[levels_count] = data->levels[i];
362 levels_count++;
363 }
364 }
365 table[levels_count] = data->levels[i];
366
367 /*
368 * As we use interpolation lets remove current
369 * brightness levels table and replace for the
370 * new interpolated table.
371 */
372 devm_kfree(dev, data->levels);
373 data->levels = table;
374
375 /*
376 * Reassign max_brightness value to the new total number
377 * of brightness levels.
378 */
379 data->max_brightness = num_levels;
380 }
381
382 data->max_brightness--;
383 }
384 return 0;
385 }
386
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org