Hi All, The latest mainline kernel branch fails to build csky and mips allmodconfig with gcc-12. mips error is: In function 'memcmp', inlined from 'bacmp' at ./include/net/bluetooth/bluetooth.h:347:9, inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2003:15: ./include/linux/fortify-string.h:44:33: error: '__builtin_memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread] 44 | #define __underlying_memcmp __builtin_memcmp | ^ ./include/linux/fortify-string.h:420:16: note: in expansion of macro '__underlying_memcmp' 420 | return __underlying_memcmp(p, q, size); | ^~~~~~~~~~~~~~~~~~~ In function 'memcmp', inlined from 'bacmp' at ./include/net/bluetooth/bluetooth.h:347:9, inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2004:15: ./include/linux/fortify-string.h:44:33: error: '__builtin_memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread] 44 | #define __underlying_memcmp __builtin_memcmp | ^ ./include/linux/fortify-string.h:420:16: note: in expansion of macro '__underlying_memcmp' 420 | return __underlying_memcmp(p, q, size); | ^~~~~~~~~~~~~~~~~~~ csky error is: In file included from net/bluetooth/l2cap_core.c:37: In function 'bacmp', inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2003:15: ./include/net/bluetooth/bluetooth.h:347:16: error: 'memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread] 347 | return memcmp(ba1, ba2, sizeof(bdaddr_t)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In function 'bacmp', inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2004:15: ./include/net/bluetooth/bluetooth.h:347:16: error: 'memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread] 347 | return memcmp(ba1, ba2, sizeof(bdaddr_t)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ git bisect pointed to 332f1795ca20 ("Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression"). And, reverting that commit has fixed the build failure. Already reported at https://lore.kernel.org/lkml/YvVQEDs75pxSgxjM@debian/ and Jacub is looking at a fix, but this is just my usual build failure mail of mainline branch for Linus's information. -- Regards Sudip