Re: [PATCH 2/2] nvmem: core: Expose cells through sysfs

Miquel Raynal
2023-05-29T10:15:00Z

Hi Dan,

dan.carpenter@linaro.org wrote on Mon, 29 May 2023 07:28:59 +0300:

> Hi Miquel,
>
> kernel test robot noticed the following build warnings:
>
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Miquel-Raynal/ABI-sysfs-nvmem-cells-Expose-cells-through-sysfs/20230523-203042
> base: char-misc/char-misc-testing
> patch link: https://lore.kernel.org/r/20230523100239.307574-3-miquel.raynal%40bootlin.com
> patch subject: [PATCH 2/2] nvmem: core: Expose cells through sysfs
> config: i386-randconfig-m021-20230525 (https://download.01.org/0day-ci/archive/20230528/202305280054.NloN5RLk-lkp@intel.com/config)
> compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
>
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp@intel.com>
> | Reported-by: Dan Carpenter <error27@gmail.com>
> | Closes: https://lore.kernel.org/r/202305280054.NloN5RLk-lkp@intel.com/
>
> smatch warnings:
> drivers/nvmem/core.c:380 nvmem_cell_attr_read() error: uninitialized symbol 'read_len'.
>
> vim +/read_len +380 drivers/nvmem/core.c
>
> 22c370b2163e59 Miquel Raynal 2023-05-23 328 static struct nvmem_cell *nvmem_create_cell(struct nvmem_cell_entry *entry,
> 22c370b2163e59 Miquel Raynal 2023-05-23 329 const char *id, int index);
> 22c370b2163e59 Miquel Raynal 2023-05-23 330
> 22c370b2163e59 Miquel Raynal 2023-05-23 331 static ssize_t nvmem_cell_attr_read(struct file *filp, struct kobject *kobj,
> 22c370b2163e59 Miquel Raynal 2023-05-23 332 struct bin_attribute *attr, char *buf,
> 22c370b2163e59 Miquel Raynal 2023-05-23 333 loff_t pos, size_t count)
> 22c370b2163e59 Miquel Raynal 2023-05-23 334 {
> 22c370b2163e59 Miquel Raynal 2023-05-23 335 struct nvmem_cell_entry *entry;
> 22c370b2163e59 Miquel Raynal 2023-05-23 336 struct nvmem_cell *cell = NULL;
> 22c370b2163e59 Miquel Raynal 2023-05-23 337 struct nvmem_device *nvmem;
> 22c370b2163e59 Miquel Raynal 2023-05-23 338 size_t cell_sz, read_len;
> 22c370b2163e59 Miquel Raynal 2023-05-23 339 struct device *dev;
> 22c370b2163e59 Miquel Raynal 2023-05-23 340 void *content;
> 22c370b2163e59 Miquel Raynal 2023-05-23 341
> 22c370b2163e59 Miquel Raynal 2023-05-23 342 if (attr->private)
> 22c370b2163e59 Miquel Raynal 2023-05-23 343 dev = attr->private;
> 22c370b2163e59 Miquel Raynal 2023-05-23 344 else
> 22c370b2163e59 Miquel Raynal 2023-05-23 345 dev = kobj_to_dev(kobj);
> 22c370b2163e59 Miquel Raynal 2023-05-23 346 nvmem = to_nvmem_device(dev);
> 22c370b2163e59 Miquel Raynal 2023-05-23 347
> 22c370b2163e59 Miquel Raynal 2023-05-23 348 mutex_lock(&nvmem_mutex);
> 22c370b2163e59 Miquel Raynal 2023-05-23 349 list_for_each_entry(entry, &nvmem->cells, node) {
> 22c370b2163e59 Miquel Raynal 2023-05-23 350 if (strncmp(entry->name, attr->attr.name, XATTR_NAME_MAX))
> 22c370b2163e59 Miquel Raynal 2023-05-23 351 continue;
> 22c370b2163e59 Miquel Raynal 2023-05-23 352
> 22c370b2163e59 Miquel Raynal 2023-05-23 353 cell = nvmem_create_cell(entry, entry->name, 0);
> 22c370b2163e59 Miquel Raynal 2023-05-23 354 if (IS_ERR(cell)) {
> 22c370b2163e59 Miquel Raynal 2023-05-23 355 mutex_unlock(&nvmem_mutex);
> 22c370b2163e59 Miquel Raynal 2023-05-23 356 return PTR_ERR(cell);
> 22c370b2163e59 Miquel Raynal 2023-05-23 357 }
> 22c370b2163e59 Miquel Raynal 2023-05-23 358
> 22c370b2163e59 Miquel Raynal 2023-05-23 359 break;
> 22c370b2163e59 Miquel Raynal 2023-05-23 360 }
> 22c370b2163e59 Miquel Raynal 2023-05-23 361 mutex_unlock(&nvmem_mutex);
> 22c370b2163e59 Miquel Raynal 2023-05-23 362
> 22c370b2163e59 Miquel Raynal 2023-05-23 363 if (!cell)
> 22c370b2163e59 Miquel Raynal 2023-05-23 364 return -EINVAL;
> 22c370b2163e59 Miquel Raynal 2023-05-23 365
> 22c370b2163e59 Miquel Raynal 2023-05-23 366 content = nvmem_cell_read(cell, &cell_sz);
> 22c370b2163e59 Miquel Raynal 2023-05-23 367 if (IS_ERR(content)) {
> 22c370b2163e59 Miquel Raynal 2023-05-23 368 count = PTR_ERR(content);
> 22c370b2163e59 Miquel Raynal 2023-05-23 369 goto destroy_cell;
>
> read_len not initialized on this goto path.

It should be: read_len = PTR_ERR...

I will correct this in the next version, thanks for the report.

>
> 22c370b2163e59 Miquel Raynal 2023-05-23 370 }
> 22c370b2163e59 Miquel Raynal 2023-05-23 371
> 22c370b2163e59 Miquel Raynal 2023-05-23 372 read_len = min_t(unsigned int, cell_sz - pos, count);
> 22c370b2163e59 Miquel Raynal 2023-05-23 373 memcpy(buf, content + pos, read_len);
> 22c370b2163e59 Miquel Raynal 2023-05-23 374 kfree(content);
> 22c370b2163e59 Miquel Raynal 2023-05-23 375
> 22c370b2163e59 Miquel Raynal 2023-05-23 376 destroy_cell:
> 22c370b2163e59 Miquel Raynal 2023-05-23 377 kfree_const(cell->id);
> 22c370b2163e59 Miquel Raynal 2023-05-23 378 kfree(cell);
> 22c370b2163e59 Miquel Raynal 2023-05-23 379
> 22c370b2163e59 Miquel Raynal 2023-05-23 @380 return read_len;
> ^^^^^^^^^^^^^^^
>
> 22c370b2163e59 Miquel Raynal 2023-05-23 381 }
>

Thanks,
Miquèl