[ammarfaizi2-block:dhowells/linux-fs/netfs-linked-list 30/57] lib/iov_iter.c:1464:9: warning: comparison of distinct pointer types ('typeof (nr * ((1UL) << 12) - offset) *' (aka 'unsigned long *') and 'typeof (maxsize) *' (aka 'unsigned int *'))

From: kernel test robot
Date: Sat Jun 11 2022 - 03:46:14 EST


tree: https://github.com/ammarfaizi2/linux-block dhowells/linux-fs/netfs-linked-list
head: c19d336b7f0c53bd31e73f6d7d6c1524f0df55b8
commit: cce0a847405ef7d076fde956ba5dd1a4d7d901c2 [30/57] iov_iter: Fix iter_xarray_get_pages{,_alloc}()
config: arm-randconfig-r034-20220610 (https://download.01.org/0day-ci/archive/20220611/202206111500.VcHCpPMw-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project ff4abe755279a3a47cc416ef80dbc900d9a98a19)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm cross compiling tool for clang build
# apt-get install binutils-arm-linux-gnueabi
# https://github.com/ammarfaizi2/linux-block/commit/cce0a847405ef7d076fde956ba5dd1a4d7d901c2
git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
git fetch --no-tags ammarfaizi2-block dhowells/linux-fs/netfs-linked-list
git checkout cce0a847405ef7d076fde956ba5dd1a4d7d901c2
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash

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

All warnings (new ones prefixed by >>):

>> lib/iov_iter.c:1464:9: warning: comparison of distinct pointer types ('typeof (nr * ((1UL) << 12) - offset) *' (aka 'unsigned long *') and 'typeof (maxsize) *' (aka 'unsigned int *')) [-Wcompare-distinct-pointer-types]
return min(nr * PAGE_SIZE - offset, maxsize);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:45:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:36:24: note: expanded from macro '__careful_cmp'
__builtin_choose_expr(__safe_cmp(x, y), \
^~~~~~~~~~~~~~~~
include/linux/minmax.h:26:4: note: expanded from macro '__safe_cmp'
(__typecheck(x, y) && __no_side_effects(x, y))
^~~~~~~~~~~~~~~~~
include/linux/minmax.h:20:28: note: expanded from macro '__typecheck'
(!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~
lib/iov_iter.c:1628:9: warning: comparison of distinct pointer types ('typeof (nr * ((1UL) << 12) - offset) *' (aka 'unsigned long *') and 'typeof (maxsize) *' (aka 'unsigned int *')) [-Wcompare-distinct-pointer-types]
return min(nr * PAGE_SIZE - offset, maxsize);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:45:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:36:24: note: expanded from macro '__careful_cmp'
__builtin_choose_expr(__safe_cmp(x, y), \
^~~~~~~~~~~~~~~~
include/linux/minmax.h:26:4: note: expanded from macro '__safe_cmp'
(__typecheck(x, y) && __no_side_effects(x, y))
^~~~~~~~~~~~~~~~~
include/linux/minmax.h:20:28: note: expanded from macro '__typecheck'
(!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~
2 warnings generated.


vim +1464 lib/iov_iter.c

1430
1431 static ssize_t iter_xarray_get_pages(struct iov_iter *i,
1432 struct page **pages, size_t maxsize,
1433 unsigned maxpages, size_t *_start_offset)
1434 {
1435 unsigned nr, offset;
1436 pgoff_t index, count;
1437 size_t size = maxsize;
1438 loff_t pos;
1439
1440 if (!size || !maxpages)
1441 return 0;
1442
1443 pos = i->xarray_start + i->iov_offset;
1444 index = pos >> PAGE_SHIFT;
1445 offset = pos & ~PAGE_MASK;
1446 *_start_offset = offset;
1447
1448 count = 1;
1449 if (size > PAGE_SIZE - offset) {
1450 size -= PAGE_SIZE - offset;
1451 count += size >> PAGE_SHIFT;
1452 size &= ~PAGE_MASK;
1453 if (size)
1454 count++;
1455 }
1456
1457 if (count > maxpages)
1458 count = maxpages;
1459
1460 nr = iter_xarray_populate_pages(pages, i->xarray, index, count);
1461 if (nr == 0)
1462 return 0;
1463
> 1464 return min(nr * PAGE_SIZE - offset, maxsize);
1465 }
1466

--
0-DAY CI Kernel Test Service
https://01.org/lkp