Question

我需要打印一条消息，告知用户已从内核调用sys_fork分叉进程。我在sys_fork（）函数中添加了命令printf("process forked\n");但没有任何反应。这是正确的还是我必须做其他事情？有什么帮助吗？

代码是

#include "syslib.h"

PUBLIC int sys_fork(parent, child, child_endpoint, map_ptr, flags, msgaddr)
endpoint_t parent;      /* process doing the fork */
endpoint_t child;       /* which proc has been created by the fork */
endpoint_t *child_endpoint;
struct mem_map *map_ptr;
u32_t flags;
vir_bytes *msgaddr;
{
/* A process has forked.  Tell the kernel. */

  message m;
  int r;

  m.PR_ENDPT = parent;
  m.PR_SLOT = child;
  m.PR_MEM_PTR = (char *) map_ptr;
  m.PR_FORK_FLAGS = flags;
  r = _kernel_call(SYS_FORK, &m);
  *child_endpoint = m.PR_ENDPT;
  *msgaddr = (vir_bytes) m.PR_FORK_MSGADDR;

  printf("process forked\n"); //the modification I made

  return r;
}

Answer 1

来自CEID的anna_jennifer！

你必须将printf放在/kernel/system/do_fork.c中并在返回OK之前;

Minix sys_fork（）打印消息

1 个答案: