From: acevest <zhaoyanbai@126.com>
Date: Tue, 2 Nov 2021 16:25:44 +0000 (+0800)
Subject: fix memcpy param in do_fork
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zlib_tech.html?a=commitdiff_plain;h=6979bb7885e5af76e8e1ae7d63f37756148f5e2f;p=kernel.git

fix memcpy param in do_fork
---

diff --git a/.bochsrc b/.bochsrc
index 9c88cd2..a2e7855 100644
--- a/.bochsrc
+++ b/.bochsrc
@@ -1243,7 +1243,7 @@ speaker: enabled=1, mode=sound, volume=15
 # Example:
 #   magic_break: enabled=1
 #=======================================================================
-#magic_break: enabled=1
+magic_break: enabled=1
 
 #=======================================================================
 # DEBUG_SYMBOLS:
diff --git a/kernel/fork.c b/kernel/fork.c
index 5caa1ca..77b8013 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -90,10 +90,13 @@ int do_fork(pt_regs_t *regs, unsigned long flags) {
 
     pt_regs_t *child_regs = ((pt_regs_t *)(TASK_SIZE + (unsigned long)tsk)) - 1;
 
-    *child_regs = *regs;
+    printk("child regs: %x %x %d\n", child_regs, regs, sizeof(regs));
+    //*child_regs = *regs;
+    memcpy(child_regs, regs, sizeof(*regs));
+    asm("xchg %bx, %bx");
 
     child_regs->eax = 0;
-    child_regs->eflags |= 0x200;  // enable IF
+    //child_regs->eflags |= 0x200;  // enable IF
 
     tsk->esp0 = TASK_SIZE + (unsigned long)tsk;
     tsk->esp = (unsigned long)child_regs;
diff --git a/kernel/init.c b/kernel/init.c
index ede85d5..41cff0a 100644
--- a/kernel/init.c
+++ b/kernel/init.c
@@ -46,35 +46,33 @@ 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) {
+extern void ret_from_fork_krnl();
+void kernel_task(char *name, void *entry) {
     pt_regs_t regs;
+    
     memset((void *)&regs, 0, sizeof(regs));
+    
+    // 内核任务入口
     regs.edx = (unsigned long)entry;
-    // int pid = do_fork(&regs, FORK_KRNL);
-    // int pid = kernel_fork();
+    
+    // 创建内核任务的时候就直接指定其在fork后走的路径
+    // 就不用走sysexit那个路径了
+    regs.eip = (unsigned long)ret_from_fork_krnl;
+    regs.cs = SELECTOR_KRNL_CS;
+    regs.ds = SELECTOR_KRNL_DS;
+    regs.es = SELECTOR_KRNL_DS;
+    regs.ss = SELECTOR_KRNL_DS;
+    regs.eflags = (1 << 9); // enable IF
+
     int pid = do_fork(&regs, FORK_KRNL);
+
     printk("kernel task pid is %d\n", pid);
+
     enable_irq();
 }
 
 void root_task_entry() {
-    kernel_task(init_task_entry);
+    kernel_task("init", init_task_entry);
     // kernel_task(user_task_entry);
     // kernel_task(init_task_entry);
 
diff --git a/kernel/syscall.S b/kernel/syscall.S
index ff8617e..072f9a3 100644
--- a/kernel/syscall.S
+++ b/kernel/syscall.S
@@ -83,10 +83,14 @@ ret_from_fork_user:
     sti        /* sysenter have cleared IF, and sysexit will not set IF. */
     sysexit
 
+
+// 内核线程fork出路
 ret_from_fork_krnl:
-    movl    PT_REGS_EDX(%esp), %edx
-    sti
+    RESTORE_REGS
+    addl    $24, %esp
     call    *%edx
+
+    # 还没有实现do_exit
     #call    do_exit