Symbol: LINUX_VSYSCALL_SIZE
sys/compat/linux/arch/amd64/linux_machdep.c
479
if ((tf->tf_rip & (LINUX_VSYSCALL_SIZE - 1)) != 0)
sys/compat/linux/arch/amd64/linux_machdep.c
482
vsyscallnr = (tf->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SIZE;