Hi Eric, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 2dac75696c6da3c848daa118a729827541c89d33 commit: fa17a6d8a5bd0cd7565b613cb804242cd0f6b7ab [5136/13299] ipv6: lockless IPV6_ADDR_PREFERENCES implementation config: alpha-defconfig (https://download.01.org/0day-ci/archive/20231018/202310181854.pKtHd7fD-lkp@xxxxxxxxx/config) compiler: alpha-linux-gcc (GCC) 13.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231018/202310181854.pKtHd7fD-lkp@xxxxxxxxx/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@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202310181854.pKtHd7fD-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from arch/alpha/include/asm/rwonce.h:33, from include/linux/compiler.h:246, from include/linux/string.h:5, from net/sunrpc/xprtsock.c:23: In function 'ip6_sock_set_addr_preferences', inlined from 'xs_tcp_finish_connecting' at net/sunrpc/xprtsock.c:2325:4, inlined from 'xs_tcp_setup_socket' at net/sunrpc/xprtsock.c:2405:11: >> include/asm-generic/rwonce.h:44:26: warning: array subscript 0 is outside array bounds of '__u8[0]' {aka 'unsigned char[]'} [-Warray-bounds=] 44 | #define __READ_ONCE(x) (*(const volatile __unqual_scalar_typeof(x) *)&(x)) | ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:55:40: note: in definition of macro '__WRITE_ONCE' 55 | *(volatile typeof(x) *)&(x) = (val); \ | ^~~ include/net/ipv6.h:1365:9: note: in expansion of macro 'WRITE_ONCE' 1365 | WRITE_ONCE(inet6_sk(sk)->srcprefs, | ^~~~~~~~~~ include/asm-generic/rwonce.h:50:9: note: in expansion of macro '__READ_ONCE' 50 | __READ_ONCE(x); \ | ^~~~~~~~~~~ include/net/ipv6.h:1366:21: note: in expansion of macro 'READ_ONCE' 1366 | (READ_ONCE(inet6_sk(sk)->srcprefs) & prefmask) | pref); | ^~~~~~~~~ In function 'xs_tcp_setup_socket': cc1: note: source object is likely at address zero In function 'ip6_sock_set_addr_preferences', inlined from 'xs_tcp_finish_connecting' at net/sunrpc/xprtsock.c:2325:4, inlined from 'xs_tcp_setup_socket' at net/sunrpc/xprtsock.c:2405:11: include/asm-generic/rwonce.h:55:37: warning: array subscript 0 is outside array bounds of '__u8[0]' {aka 'unsigned char[]'} [-Warray-bounds=] 55 | *(volatile typeof(x) *)&(x) = (val); \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~ include/asm-generic/rwonce.h:61:9: note: in expansion of macro '__WRITE_ONCE' 61 | __WRITE_ONCE(x, val); \ | ^~~~~~~~~~~~ include/net/ipv6.h:1365:9: note: in expansion of macro 'WRITE_ONCE' 1365 | WRITE_ONCE(inet6_sk(sk)->srcprefs, | ^~~~~~~~~~ In function 'xs_tcp_setup_socket': cc1: note: source object is likely at address zero In function 'ip6_sock_set_addr_preferences', inlined from 'xs_tcp_tls_finish_connecting' at net/sunrpc/xprtsock.c:2478:4: >> include/asm-generic/rwonce.h:44:26: warning: array subscript 0 is outside array bounds of '__u8[0]' {aka 'unsigned char[]'} [-Warray-bounds=] 44 | #define __READ_ONCE(x) (*(const volatile __unqual_scalar_typeof(x) *)&(x)) | ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:55:40: note: in definition of macro '__WRITE_ONCE' 55 | *(volatile typeof(x) *)&(x) = (val); \ | ^~~ include/net/ipv6.h:1365:9: note: in expansion of macro 'WRITE_ONCE' 1365 | WRITE_ONCE(inet6_sk(sk)->srcprefs, | ^~~~~~~~~~ include/asm-generic/rwonce.h:50:9: note: in expansion of macro '__READ_ONCE' 50 | __READ_ONCE(x); \ | ^~~~~~~~~~~ include/net/ipv6.h:1366:21: note: in expansion of macro 'READ_ONCE' 1366 | (READ_ONCE(inet6_sk(sk)->srcprefs) & prefmask) | pref); | ^~~~~~~~~ In function 'xs_tcp_tls_finish_connecting': cc1: note: source object is likely at address zero In function 'ip6_sock_set_addr_preferences', inlined from 'xs_tcp_tls_finish_connecting' at net/sunrpc/xprtsock.c:2478:4: include/asm-generic/rwonce.h:55:37: warning: array subscript 0 is outside array bounds of '__u8[0]' {aka 'unsigned char[]'} [-Warray-bounds=] 55 | *(volatile typeof(x) *)&(x) = (val); \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~ include/asm-generic/rwonce.h:61:9: note: in expansion of macro '__WRITE_ONCE' 61 | __WRITE_ONCE(x, val); \ | ^~~~~~~~~~~~ include/net/ipv6.h:1365:9: note: in expansion of macro 'WRITE_ONCE' 1365 | WRITE_ONCE(inet6_sk(sk)->srcprefs, | ^~~~~~~~~~ In function 'xs_tcp_tls_finish_connecting': cc1: note: source object is likely at address zero vim +44 include/asm-generic/rwonce.h e506ea451254ab Will Deacon 2019-10-15 28 e506ea451254ab Will Deacon 2019-10-15 29 /* e506ea451254ab Will Deacon 2019-10-15 30 * Yes, this permits 64-bit accesses on 32-bit architectures. These will e506ea451254ab Will Deacon 2019-10-15 31 * actually be atomic in some cases (namely Armv7 + LPAE), but for others we e506ea451254ab Will Deacon 2019-10-15 32 * rely on the access being split into 2x32-bit accesses for a 32-bit quantity e506ea451254ab Will Deacon 2019-10-15 33 * (e.g. a virtual address) and a strong prevailing wind. e506ea451254ab Will Deacon 2019-10-15 34 */ e506ea451254ab Will Deacon 2019-10-15 35 #define compiletime_assert_rwonce_type(t) \ e506ea451254ab Will Deacon 2019-10-15 36 compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ e506ea451254ab Will Deacon 2019-10-15 37 "Unsupported access size for {READ,WRITE}_ONCE().") e506ea451254ab Will Deacon 2019-10-15 38 e506ea451254ab Will Deacon 2019-10-15 39 /* e506ea451254ab Will Deacon 2019-10-15 40 * Use __READ_ONCE() instead of READ_ONCE() if you do not require any 3c9184109e78ea Will Deacon 2019-10-30 41 * atomicity. Note that this may result in tears! e506ea451254ab Will Deacon 2019-10-15 42 */ b78b331a3f5c07 Will Deacon 2019-10-15 43 #ifndef __READ_ONCE e506ea451254ab Will Deacon 2019-10-15 @44 #define __READ_ONCE(x) (*(const volatile __unqual_scalar_typeof(x) *)&(x)) b78b331a3f5c07 Will Deacon 2019-10-15 45 #endif e506ea451254ab Will Deacon 2019-10-15 46 :::::: The code at line 44 was first introduced by commit :::::: e506ea451254ab17e0bf918ca36232fec2a9b10c compiler.h: Split {READ,WRITE}_ONCE definitions out into rwonce.h :::::: TO: Will Deacon <will@xxxxxxxxxx> :::::: CC: Will Deacon <will@xxxxxxxxxx> -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
