sys_sbrk 94 kernel/syscall.c extern uint64 sys_sbrk(void); sys_sbrk 119 kernel/syscall.c [SYS_sbrk] sys_sbrk, sys_sbrk 153 user/ulib.c return sys_sbrk(n, SBRK_EAGER); sys_sbrk 158 user/ulib.c return sys_sbrk(n, SBRK_LAZY); sys_sbrk 24 user/user.h char* sys_sbrk(int,int);