[dhowells-fs:ceph-iter 43/43] include/linux/poll.h:134:27: warning: division by zero is undefined

[dhowells-fs:ceph-iter 43/43] include/linux/poll.h:134:27: warning: division by zero is undefined

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git ceph-iter
head:   99bca1b95b54b7a3e7260c2431b587639482a71d
commit: 99bca1b95b54b7a3e7260c2431b587639482a71d [43/43] ceph: Use netfslib
config: mips-jazz_defconfig (https://download.01.org/0day-ci/archive/20250130/202501301508.7Z6gbNaF-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 19306351a2c45e266fa11b41eb1362b20b6ca56d)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250130/202501301508.7Z6gbNaF-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202501301508.7Z6gbNaF-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from fs/smb/client/smb2pdu.c:27:
   include/trace/events/netfs.h:249:25: error: redefinition of enumerator 'netfs_sreq_trace_need_retry'
     249 | enum netfs_sreq_trace { netfs_sreq_traces } __mode(byte);
         |                         ^
   include/trace/events/netfs.h:110:5: note: expanded from macro 'netfs_sreq_traces'
     110 |         EM(netfs_sreq_trace_need_retry,         "ND-RT")        \
         |            ^
   include/trace/events/netfs.h:249:25: note: previous definition is here
   include/trace/events/netfs.h:107:5: note: expanded from macro 'netfs_sreq_traces'
     107 |         EM(netfs_sreq_trace_need_retry,         "NRTRY")        \
         |            ^
   In file included from fs/smb/client/smb2pdu.c:28:
   In file included from fs/smb/client/cifsglob.h:28:
   In file included from fs/smb/client/smb2pdu.h:14:
   In file included from include/net/sock.h:60:
>> include/linux/poll.h:134:27: warning: division by zero is undefined [-Wdivision-by-zero]
     134 |                 M(RDNORM) | M(RDBAND) | M(WRNORM) | M(WRBAND) |
         |                                         ^~~~~~~~~
   include/linux/poll.h:132:32: note: expanded from macro 'M'
     132 | #define M(X) (__force __poll_t)__MAP(val, POLL##X, (__force __u16)EPOLL##X)
         |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/poll.h:118:51: note: expanded from macro '__MAP'
     118 |         (from < to ? (v & from) * (to/from) : (v & from) / (from/to))
         |                                                          ^ ~~~~~~~~~
   include/linux/poll.h:134:39: warning: division by zero is undefined [-Wdivision-by-zero]
     134 |                 M(RDNORM) | M(RDBAND) | M(WRNORM) | M(WRBAND) |
         |                                                     ^~~~~~~~~
   include/linux/poll.h:132:32: note: expanded from macro 'M'
     132 | #define M(X) (__force __poll_t)__MAP(val, POLL##X, (__force __u16)EPOLL##X)
         |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/poll.h:118:51: note: expanded from macro '__MAP'
     118 |         (from < to ? (v & from) * (to/from) : (v & from) / (from/to))
         |                                                          ^ ~~~~~~~~~
   2 warnings and 1 error generated.


vim +134 include/linux/poll.h

7a163b2195cda0 Al Viro 2018-02-01  129  
7a163b2195cda0 Al Viro 2018-02-01  130  static inline __poll_t demangle_poll(u16 val)
7a163b2195cda0 Al Viro 2018-02-01  131  {
7a163b2195cda0 Al Viro 2018-02-01  132  #define M(X) (__force __poll_t)__MAP(val, POLL##X, (__force __u16)EPOLL##X)
7a163b2195cda0 Al Viro 2018-02-01  133  	return M(IN) | M(OUT) | M(PRI) | M(ERR) | M(NVAL) |
7a163b2195cda0 Al Viro 2018-02-01 @134  		M(RDNORM) | M(RDBAND) | M(WRNORM) | M(WRBAND) |
7a163b2195cda0 Al Viro 2018-02-01  135  		M(HUP) | M(RDHUP) | M(MSG);
7a163b2195cda0 Al Viro 2018-02-01  136  #undef M
7a163b2195cda0 Al Viro 2018-02-01  137  }
7a163b2195cda0 Al Viro 2018-02-01  138  #undef __MAP
7a163b2195cda0 Al Viro 2018-02-01  139  
7a163b2195cda0 Al Viro 2018-02-01  140  

:::::: The code at line 134 was first introduced by commit
:::::: 7a163b2195cda0cddf47b5caf14a7229d4e2bea3 unify {de,}mangle_poll(), get rid of kernel-side POLL...

:::::: TO: Al Viro <viro@zeniv.linux.org.uk>
:::::: CC: Linus Torvalds <torvalds@linux-foundation.org>

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