Hi Kees, I love your patch! Perhaps something to improve: [auto build test WARNING on linus/master] [also build test WARNING on v4.15 next-20180201] [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/Kees-Cook/socket-Provide-bounce-buffer-for-constant-sized-put_cmsg/20180202-113637 reproduce: # apt-get install sparse make ARCH=x86_64 allmodconfig make C=1 CF=-D__CHECK_ENDIAN__ sparse warnings: (new ones prefixed by >>) >> net/bluetooth/hci_sock.c:1406:17: sparse: incorrect type in initializer (invalid types) @@ expected void _val @@ got void _val @@ net/bluetooth/hci_sock.c:1406:17: expected void _val net/bluetooth/hci_sock.c:1406:17: got void <noident> >> net/bluetooth/hci_sock.c:1406:17: sparse: expression using sizeof(void) In file included from include/linux/compat.h:16:0, from include/linux/ethtool.h:17, from include/linux/netdevice.h:41, from include/net/sock.h:51, from include/net/bluetooth/bluetooth.h:29, from net/bluetooth/hci_sock.c:32: net/bluetooth/hci_sock.c: In function 'hci_sock_cmsg': include/linux/socket.h:355:19: error: variable or field '_val' declared void _val = 14- ^ net/bluetooth/hci_sock.c:1406:3: note: in expansion of macro 'put_cmsg' put_cmsg(msg, SOL_HCI, HCI_CMSG_TSTAMP, len, data); ^~~~~~~~ include/linux/socket.h:355:26: warning: dereferencing 'void pointer _val = 20- ^~~~~~~ net/bluetooth/hci_sock.c:1406:3: note: in expansion of macro 'put_cmsg' put_cmsg(msg, SOL_HCI, HCI_CMSG_TSTAMP, len, data); ^~~~~~~~ include/linux/socket.h:355:26: error: void value not ignored as it ought to be _val = 26- ^ net/bluetooth/hci_sock.c:1406:3: note: in expansion of macro 'put_cmsg' put_cmsg(msg, SOL_HCI, HCI_CMSG_TSTAMP, len, data); ^~~~~~~~ vim +1406 net/bluetooth/hci_sock.c 767c5eb5 Marcel Holtmann 2007-09-09 1405 767c5eb5 Marcel Holtmann 2007-09-09 @1406 put_cmsg(msg, SOL_HCI, HCI_CMSG_TSTAMP, len, data); a61bbcf2 Patrick McHardy 2005-08-14 1407 } ^1da177e Linus Torvalds 2005-04-16 1408 } ^1da177e Linus Torvalds 2005-04-16 1409 :::::: The code at line 1406 was first introduced by commit :::::: 767c5eb5d35aeb85987143f0a730bc21d3ecfb3d [Bluetooth] Add compat handling for timestamp structure :::::: TO: Marcel Holtmann <marcel@xxxxxxxxxxxx> :::::: CC: Marcel Holtmann <marcel@xxxxxxxxxxxx> --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>