Linux Virtualization - Dec 2019 - [vhost:linux-next 12/12] drivers/vhost/vhost.c:1968:11: note: in expansion of macro 'min'

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
head:   b072ae74df177c3ad7704c5fbe66e3f10aad9d4e
commit: b072ae74df177c3ad7704c5fbe66e3f10aad9d4e [12/12] vhost: use vhost_desc
instead of vhost_log
config: s390-debug_defconfig (attached as .config)
compiler: s390-linux-gcc (GCC) 7.5.0
reproduce:
        wget
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout b072ae74df177c3ad7704c5fbe66e3f10aad9d4e
        # save the attached .config to linux build tree
        GCC_VERSION=7.5.0 make.cross ARCH=s390 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp at intel.com>

All warnings (new ones prefixed by >>):

   In file included from include/linux/list.h:9:0,
                    from include/linux/wait.h:7,
                    from include/linux/eventfd.h:13,
                    from drivers/vhost/vhost.c:13:
   drivers/vhost/vhost.c: In function 'vhost_log_write':
   include/linux/kernel.h:844:29: warning: comparison of distinct pointer types
lacks a cast
      (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
                                ^
   include/linux/kernel.h:858:4: note: in expansion of macro
'__typecheck'
      (__typecheck(x, y) && __no_side_effects(x, y))
       ^~~~~~~~~~~
   include/linux/kernel.h:868:24: note: in expansion of macro
'__safe_cmp'
     __builtin_choose_expr(__safe_cmp(x, y), \
                           ^~~~~~~~~~
   include/linux/kernel.h:877:19: note: in expansion of macro
'__careful_cmp'
    #define min(x, y) __careful_cmp(x, y, <)
                      ^~~~~~~~~~~~~
>> drivers/vhost/vhost.c:1968:11: note: in expansion of macro
'min'
      u64 l = min(log[i].len, len);
              ^~~

vim +/min +1968 drivers/vhost/vhost.c

cc5e710759470b Jason Wang         2019-01-16  1948  
b072ae74df177c Michael S. Tsirkin 2019-12-11  1949  int vhost_log_write(struct
vhost_virtqueue *vq, struct vhost_desc *log,
cc5e710759470b Jason Wang         2019-01-16  1950  		    unsigned int log_num,
u64 len, struct iovec *iov, int count)
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1951  {
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1952  	int i, r;
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1953  
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1954  	/* Make sure data written
is seen before log. */
5659338c88963e Michael S. Tsirkin 2010-02-01  1955  	smp_wmb();
cc5e710759470b Jason Wang         2019-01-16  1956  
cc5e710759470b Jason Wang         2019-01-16  1957  	if (vq->iotlb) {
cc5e710759470b Jason Wang         2019-01-16  1958  		for (i = 0; i < count;
i++) {
cc5e710759470b Jason Wang         2019-01-16  1959  			r = log_write_hva(vq,
(uintptr_t)iov[i].iov_base,
cc5e710759470b Jason Wang         2019-01-16  1960  					  iov[i].iov_len);
cc5e710759470b Jason Wang         2019-01-16  1961  			if (r < 0)
cc5e710759470b Jason Wang         2019-01-16  1962  				return r;
cc5e710759470b Jason Wang         2019-01-16  1963  		}
cc5e710759470b Jason Wang         2019-01-16  1964  		return 0;
cc5e710759470b Jason Wang         2019-01-16  1965  	}
cc5e710759470b Jason Wang         2019-01-16  1966  
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1967  	for (i = 0; i < log_num;
++i) {
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14 @1968  		u64 l = min(log[i].len,
len);
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1969  		r =
log_write(vq->log_base, log[i].addr, l);
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1970  		if (r < 0)
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1971  			return r;
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1972  		len -= l;
5786aee8bf6d74 Michael S. Tsirkin 2010-09-22  1973  		if (!len) {
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1974  			if (vq->log_ctx)
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1975  			
eventfd_signal(vq->log_ctx, 1);
5786aee8bf6d74 Michael S. Tsirkin 2010-09-22  1976  			return 0;
5786aee8bf6d74 Michael S. Tsirkin 2010-09-22  1977  		}
5786aee8bf6d74 Michael S. Tsirkin 2010-09-22  1978  	}
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1979  	/* Length written exceeds
what we have stored. This is a bug. */
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1980  	BUG();
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1981  	return 0;
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1982  }
6ac1afbf6132df Asias He           2013-05-06  1983 
EXPORT_SYMBOL_GPL(vhost_log_write);
3a4d5c94e95935 Michael S. Tsirkin 2010-01-14  1984  

:::::: The code at line 1968 was first introduced by commit
:::::: 3a4d5c94e959359ece6d6b55045c3f046677f55c vhost_net: a kernel-level virtio
server

:::::: TO: Michael S. Tsirkin <mst at redhat.com>
:::::: CC: David S. Miller <davem at davemloft.net>

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