From: acevest <zhaoyanbai@126.com>
Date: Mon, 1 Nov 2021 10:53:10 +0000 (+0800)
Subject: add kernel_fork
X-Git-Url: http://zhaoyanbai.com/repos/readme1st.txt?a=commitdiff_plain;h=442b488b60a0802a3f35db4d1812d5a510a6772d;p=kernel.git

add kernel_fork
---

diff --git a/kernel/fork.c b/kernel/fork.c
index bb72222..fd3d368 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -22,6 +22,7 @@ extern void ret_from_fork_user();
 extern void ret_from_fork_krnl();
 extern pid_t get_next_pid();
 extern list_head_t all_tasks;
+
 int do_fork(pt_regs_t *regs, unsigned long flags)
 {
     task_union *tsk;
diff --git a/kernel/init.c b/kernel/init.c
index 794abbf..73b8fc6 100644
--- a/kernel/init.c
+++ b/kernel/init.c
@@ -49,12 +49,30 @@ void init_task_entry()
     }
 }
 
+int kernel_fork()
+{
+    int pid = 0;
+
+    pt_regs_t *regs = ((pt_regs_t *)(TASK_SIZE + ((unsigned long)current))) - 1;
+    unsigned long *pedx = &(regs->edx);
+
+    asm volatile(
+        "movl $1f, %[pedx];"
+        "call do_fork;"
+        "1:"
+        : "=a"(pid)
+        : [pedx] "m"(pedx));
+
+    return pid;
+}
+
 void kernel_task(void *entry)
 {
     pt_regs_t regs;
     memset((void *)&regs, 0, sizeof(regs));
     regs.edx = (unsigned long)entry;
-    int pid = do_fork(&regs, FORK_KRNL);
+    //int pid = do_fork(&regs, FORK_KRNL);
+    int pid = kernel_fork();
     printk("kernel task pid is %d\n", pid);
     enable_irq();
 }