[intel-tdx:guest 98/127] net/ipv4/fib_trie.c:324:13: warning: implicit conversion from 'unsigned long' to 'u32' (aka 'unsigned int') changes value from 2305843009213693946 to 4294967290

From: kernel test robot
Date: Tue Aug 31 2021 - 04:18:30 EST

tree: https://github.com/intel/tdx.git guest
head: 60fe4cbb60bc7f59aa2b9c5885c42b7a06b53a79
commit: 96d988b9f378bfacd90dd73b4bc9cc1b8f91febc [98/127] x86/tdx: Make RDRAND/RDSEED loop forever
config: x86_64-randconfig-r024-20210831 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 4b1fde8a2b681dad2ce0c082a5d6422caa06b0bc)
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
# https://github.com/intel/tdx/commit/96d988b9f378bfacd90dd73b4bc9cc1b8f91febc
git remote add intel-tdx https://github.com/intel/tdx.git
git fetch --no-tags intel-tdx guest
git checkout 96d988b9f378bfacd90dd73b4bc9cc1b8f91febc
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64

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

All warnings (new ones prefixed by >>):

In file included from net/ipv4/fib_trie.c:49:
In file included from include/linux/inet.h:42:
In file included from include/net/net_namespace.h:39:
In file included from include/linux/skbuff.h:26:
In file included from include/linux/net.h:18:
In file included from include/linux/random.h:121:
In file included from arch/x86/include/asm/archrandom.h:13:
include/linux/protected_guest.h:57:12: error: incomplete definition of type 'struct device'
return dev->authorized;
~~~^
include/linux/dynamic_debug.h:70:8: note: forward declaration of 'struct device'
struct device;
^
>> net/ipv4/fib_trie.c:324:13: warning: implicit conversion from 'unsigned long' to 'u32' (aka 'unsigned int') changes value from 2305843009213693946 to 4294967290 [-Wconstant-conversion]
if (bits > TNODE_VMALLOC_MAX)
^~~~~~~~~~~~~~~~~
net/ipv4/fib_trie.c:305:35: note: expanded from macro 'TNODE_VMALLOC_MAX'
ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/log2.h:162:14: note: expanded from macro 'ilog2'
__ilog2_u32(n) : \
~~~~~~~~~~~ ^
1 warning and 1 error generated.


vim +324 net/ipv4/fib_trie.c

37fd30f2da573c Alexander Duyck 2014-12-31 318
dc35dbeda3e00a Alexander Duyck 2015-03-06 319 static struct tnode *tnode_alloc(int bits)
f0e36f8cee8101 Patrick McHardy 2005-07-05 320 {
1de3d87bcd2c2e Alexander Duyck 2015-03-04 321 size_t size;
1de3d87bcd2c2e Alexander Duyck 2015-03-04 322
1de3d87bcd2c2e Alexander Duyck 2015-03-04 323 /* verify bits is within bounds */
1de3d87bcd2c2e Alexander Duyck 2015-03-04 @324 if (bits > TNODE_VMALLOC_MAX)
1de3d87bcd2c2e Alexander Duyck 2015-03-04 325 return NULL;
1de3d87bcd2c2e Alexander Duyck 2015-03-04 326
1de3d87bcd2c2e Alexander Duyck 2015-03-04 327 /* determine size and verify it is non-zero and didn't overflow */
1de3d87bcd2c2e Alexander Duyck 2015-03-04 328 size = TNODE_SIZE(1ul << bits);
1de3d87bcd2c2e Alexander Duyck 2015-03-04 329
2373ce1ca04dd4 Robert Olsson 2005-08-25 330 if (size <= PAGE_SIZE)
8d96544475b236 Eric Dumazet 2008-01-13 331 return kzalloc(size, GFP_KERNEL);
15be75cdb5db44 Stephen Hemminger 2008-04-10 332 else
7a1c8e5ab120a5 Eric Dumazet 2010-11-20 333 return vzalloc(size);
15be75cdb5db44 Stephen Hemminger 2008-04-10 334 }
2373ce1ca04dd4 Robert Olsson 2005-08-25 335

:::::: The code at line 324 was first introduced by commit
:::::: 1de3d87bcd2c2e631500b9e4f0c40b38ce0d0d57 fib_trie: Prevent allocating tnode if bits is too big for size_t

:::::: TO: Alexander Duyck <alexander.h.duyck@xxxxxxxxxx>
:::::: CC: David S. Miller <davem@xxxxxxxxxxxxx>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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