根据在trap_init()中设置的系统陷阱门, 得到中断号0x80对应的中断服务程序的入口地址是system_call, 系统开始执行system_call。先确保不会返回到用户空间, 保护中断现场, 确保系统调用的功能号有效, 并根据该功能号得到系统调用表sys_call_table中的偏移, 从而得到该功能号对应的服务程序入口地址, 即得到sys_fork。
底层的_do_fork实现了对其的支持, dansh*/#ifndefCONFIG_HAVE_COPY_THREAD_TLS/* For compatibility with architectures that call do_fork directly rather than * using the syscall entry points below. */longdo_fork(unsigned long clone_flags,unsigned long stack_start,unsigned long stack_size,int __use...
The fork system call is used to create a new processes. The newly created process is the child process. The process which calls fork and creates a new process is the parent process. The child and parent processes are executed concurrently. But the child and parent processes reside on differen...
使用int 0x80中断后就会调用system_call函数,然后system_call会根据传递进来的函数索引从系统调用表sys_call_table中找到对应的函数,从而执行。所以执行fork函数就会执行system_call函数,但是再这之前,还有些事情要做,就是保存现场。**下面是操作系统执行系统调用前**,在内核栈里保存的寄存器,这个压入的寄存器和iret...
Fork() System Call and ProcessesCS449 Fall 2015Programs and Processes• Program: Executable binary (code and static data)• Process: A program loaded into memory–Program (executable binary with data and text section) – Execution state (heap, stack, and processor registers)int foo() { ...
Linux pipe() System Call POSIX Fork() and Pipes Example 请注意,以上代码和参考链接仅供参考,实际使用时可能需要根据具体需求进行调整。 相关搜索: 如何在exec参数中使用管道来查找命令? 在Linux上使用管道来获取用户的进程 标准输入到execvp()中,同时使用fork()和管道() ...
sys_call_table @ tbl为r8,这里是将sys_call_table的地址(相对于此指令的偏移量)存入r8 #if defined(CONFIG_OABI_COMPAT) /* * 在EABI体系中,如果swi跟着的立即数为0,这段代码不做处理,而如果是old abi体系,则根据系统调用号调用old abi体系的系统调用表(sys_oabi_call_table) * 其实说白了,在EABI体系...
Since version2.3.3,rather than invoking the kernel'sfork()system call,the glibcfork()wrapper that is providedaspartoftheNPTLthreading implementation invokesclone(2)withflags that provide the same effectasthe traditional system call.(Acall tofork()is equivalent to a call toclone(2)specifying flags...
fork() is a system call used to create a child process. Once a child process is created, both the parent process and the child process run the next line following the fork() command simultaneously. 'n' number of successive for() calls create 2n - 1 child processes. in P1: Ea...
*/ #include <sys/wait.h> /* defines the wait() system call. */ /* storage place for the pid of the child process, and its exit status. */ pid_t child_pid; int child_status; /* lets fork off a child process... */ child_pid = fork(); /* check what the fork() call ...