Hi Tetsuo,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[cannot apply to v5.3-rc4]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Tetsuo-Handa/dev-kmem-Debug-preadv-progress/20190813-044328
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 <lkp@intel.com>

All warnings (new ones prefixed by >>):

   drivers/char/mem.c: In function 'read_mem':
>> drivers/char/mem.c:145:27: warning: format '%ld' expects argument of type 'long int', but argument 2 has type 'ssize_t {aka int}' [-Wformat=]
       printk("read_mem: sz=%ld count=%ld\n", sz, count);
                            ~~^
                            %d
>> drivers/char/mem.c:145:37: warning: format '%ld' expects argument of type 'long int', but argument 3 has type 'size_t {aka unsigned int}' [-Wformat=]
       printk("read_mem: sz=%ld count=%ld\n", sz, count);
                                      ~~^
                                      %d
   drivers/char/mem.c:187:28: warning: format '%ld' expects argument of type 'long int', but argument 2 has type 'ssize_t {aka int}' [-Wformat=]
      printk("read_mem: read=%ld *ppos=%lld\n", read, *ppos);
                             ~~^
                             %d

vim +145 drivers/char/mem.c

   133	
   134		bounce = kmalloc(PAGE_SIZE, GFP_KERNEL);
   135		if (!bounce)
   136			return -ENOMEM;
   137	
   138		while (count > 0) {
   139			unsigned long remaining;
   140			int allowed, probe;
   141	
   142			sz = size_inside_page(p, count);
   143			if (IS_ENABLED(CONFIG_DEBUG_AID_FOR_SYZBOT) &&
   144			    fatal_signal_pending(current))
 > 145				printk("read_mem: sz=%ld count=%ld\n", sz, count);
   146	
   147			err = -EPERM;
   148			allowed = page_is_allowed(p >> PAGE_SHIFT);
   149			if (!allowed)
   150				goto failed;
   151	
   152			err = -EFAULT;
   153			if (allowed == 2) {
   154				/* Show zeros for restricted memory. */
   155				remaining = clear_user(buf, sz);
   156			} else {
   157				/*
   158				 * On ia64 if a page has been mapped somewhere as
   159				 * uncached, then it must also be accessed uncached
   160				 * by the kernel or data corruption may occur.
   161				 */
   162				ptr = xlate_dev_mem_ptr(p);
   163				if (!ptr)
   164					goto failed;
   165	
   166				probe = probe_kernel_read(bounce, ptr, sz);
   167				unxlate_dev_mem_ptr(p, ptr);
   168				if (probe)
   169					goto failed;
   170	
   171				remaining = copy_to_user(buf, bounce, sz);
   172			}
   173	
   174			if (remaining)
   175				goto failed;
   176	
   177			buf += sz;
   178			p += sz;
   179			count -= sz;
   180			read += sz;
   181		}
   182		kfree(bounce);
   183	
   184		*ppos += read;
   185		if (IS_ENABLED(CONFIG_DEBUG_AID_FOR_SYZBOT) &&
   186		    fatal_signal_pending(current))
   187			printk("read_mem: read=%ld *ppos=%lld\n", read, *ppos);
   188		return read;
   189	
   190	failed:
   191		if (IS_ENABLED(CONFIG_DEBUG_AID_FOR_SYZBOT) &&
   192		    fatal_signal_pending(current))
   193			printk("read_mem: err=%d\n", err);
   194		kfree(bounce);
   195		return err;
   196	}
   197	

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