On Wed, Nov 02, 2022 at 10:51:23AM +0800, Liu Shixin wrote: > UBSAN reported a shift-out-of-bounds warning: > > left shift of 1 by 31 places cannot be represented in type 'int' > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0x8d/0xcf lib/dump_stack.c:106 > ubsan_epilogue+0xa/0x44 lib/ubsan.c:151 > __ubsan_handle_shift_out_of_bounds+0x1e7/0x208 lib/ubsan.c:322 > check_special_flags fs/binfmt_misc.c:241 [inline] > create_entry fs/binfmt_misc.c:456 [inline] > bm_register_write+0x9d3/0xa20 fs/binfmt_misc.c:654 > vfs_write+0x11e/0x580 fs/read_write.c:582 > ksys_write+0xcf/0x120 fs/read_write.c:637 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x34/0x80 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > RIP: 0033:0x4194e1 > > Since the type of Node's flags is unsigned long, we should define these > macros with same type too. We are limited to 32 bits anyway. More interesting question here is what's the point of having those bits that high anyway?