drivers/w1/slaves/w1_ds28e04.c:360 crccheck_store() warn: assigning (-48) to unsigned variable 'val'

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   4b6c093e21d36bede0fd88fd0aeb3b03647260e4
commit: 80591e61a0f7e88deaada69844e4a31280c4a38f kbuild: tell sparse about the $ARCH
date:   9 months ago
config: s390-randconfig-m031-20200816 (attached as .config)
compiler: s390-linux-gcc (GCC) 9.3.0

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

New smatch warnings:
drivers/w1/slaves/w1_ds28e04.c:360 crccheck_store() warn: assigning (-48) to unsigned variable 'val'

Old smatch warnings:
arch/s390/include/asm/uaccess.h:113 __put_user_fn() error: uninitialized symbol 'rc'.
arch/s390/include/asm/uaccess.h:143 __get_user_fn() error: uninitialized symbol 'rc'.

vim +/val +360 drivers/w1/slaves/w1_ds28e04.c

fbf7f7b4e2ae40 Markus Franke      2012-05-26  347  
fa33a65a9cf7e2 Greg Kroah-Hartman 2013-08-21  348  static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
fbf7f7b4e2ae40 Markus Franke      2012-05-26  349  			      const char *buf, size_t count)
fbf7f7b4e2ae40 Markus Franke      2012-05-26  350  {
fbf7f7b4e2ae40 Markus Franke      2012-05-26  351  	char val;
fbf7f7b4e2ae40 Markus Franke      2012-05-26  352  
fbf7f7b4e2ae40 Markus Franke      2012-05-26  353  	if (count != 1 || !buf)
fbf7f7b4e2ae40 Markus Franke      2012-05-26  354  		return -EINVAL;
fbf7f7b4e2ae40 Markus Franke      2012-05-26  355  
fbf7f7b4e2ae40 Markus Franke      2012-05-26  356  	if (get_user(val, buf))
fbf7f7b4e2ae40 Markus Franke      2012-05-26  357  		return -EFAULT;
fbf7f7b4e2ae40 Markus Franke      2012-05-26  358  
fbf7f7b4e2ae40 Markus Franke      2012-05-26  359  	/* convert to decimal */
fbf7f7b4e2ae40 Markus Franke      2012-05-26 @360  	val = val - 0x30;
fbf7f7b4e2ae40 Markus Franke      2012-05-26  361  	if (val != 0 && val != 1)
fbf7f7b4e2ae40 Markus Franke      2012-05-26  362  		return -EINVAL;
fbf7f7b4e2ae40 Markus Franke      2012-05-26  363  
fbf7f7b4e2ae40 Markus Franke      2012-05-26  364  	/* set the new value */
fbf7f7b4e2ae40 Markus Franke      2012-05-26  365  	w1_enable_crccheck = val;
fbf7f7b4e2ae40 Markus Franke      2012-05-26  366  
fbf7f7b4e2ae40 Markus Franke      2012-05-26  367  	return sizeof(w1_enable_crccheck);
fbf7f7b4e2ae40 Markus Franke      2012-05-26  368  }
fbf7f7b4e2ae40 Markus Franke      2012-05-26  369  

:::::: The code at line 360 was first introduced by commit
:::::: fbf7f7b4e2ae40f790828c86d31beff2d49e9ac8 w1: Add 1-wire slave device driver for DS28E04-100

:::::: TO: Markus Franke <franm@xxxxxxxxxxxxxxxxxx>
:::::: CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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