Re: [PATCH v24 12/12] LRNG - add interface for gathering of raw entropy

Am Dienstag, 12. November 2019, 21:55:10 CET schrieb kbuild test robot:

Hi kbuild,

Hi "Stephan,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on v5.4-rc7 next-20191111]
[if your patch is applied to the wrong git tree, please drop us a note to
help improve the system. BTW, we also suggest to use '--base' option to
specify the base tree in git format-patch, please see
https://stackoverflow.com/a/37406982]

url:   
https://github.com/0day-ci/linux/commits/Stephan-M-ller/dev-random-a-new-ap
proach-with-full-SP800-90B-compliance/20191113-040847 base:  
https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
01b59c763fe2de845b65900485b141fdd7bbf93e config: sh-allmodconfig (attached
as .config)
compiler: sh4-linux-gcc (GCC) 7.4.0
reproduce:
        wget
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.4.0 make.cross ARCH=sh

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <redacted>

All warnings (new ones prefixed by >>):

   drivers/char/lrng/lrng_testing.c: In function 'lrng_raw_extract_user':

quoted

quoted

drivers/char/lrng/lrng_testing.c:237:1: warning: the frame size of 1076
bytes is larger than 1024 bytes [-Wframe-larger-than=]

    }
    ^

vim +237 drivers/char/lrng/lrng_testing.c

   196
  
197	/**********************************************************************
**** 198	 * Debugfs interface
   199	
**************************************************************************/
200	static int lrng_raw_extract_user(void __user *buf, size_t nbytes) 201	{
   202		u8 tmp[LRNG_TESTING_RINGBUFFER_SIZE] 

__aligned(sizeof(u32));

This is the offending line.

I will need to kzalloc the code here.

Thank you.

   203		int ret = 0, large_request = (nbytes > 256);
   204
   205		while (nbytes) {
   206			int i;
   207
   208			if (large_request && need_resched()) {
   209				if (signal_pending(current)) {
   210					if (ret == 0)
   211						ret = -ERESTARTSYS;
   212					break;
   213				}
   214				schedule();
   215			}
   216
   217			i = min_t(int, nbytes, sizeof(tmp));
   218			i = lrng_raw_entropy_reader(tmp, i);
   219			if (i <= 0) {
   220				if (i < 0)
   221					ret = i;
   222				break;
   223			}
   224			if (copy_to_user(buf, tmp, i)) {
   225				ret = -EFAULT;
   226				break;
   227			}
   228
   229			nbytes -= i;
   230			buf = (u8 *)buf + i;
   231			ret += i;
   232		}
   233
   234		memzero_explicit(tmp, sizeof(tmp));
   235
   236		return ret;

 > 237	}

   238

---
0-DAY kernel test infrastructure                 Open Source Technology
Center https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel
Corporation

Ciao
Stephan