From: acevest <zhaoyanbai@126.com>
Date: Wed, 3 Nov 2021 14:03:47 +0000 (+0800)
Subject: 进入ring3
X-Git-Url: http://zhaoyanbai.com/repos/man.dig.html?a=commitdiff_plain;h=4ebfe2ef702b36cc0ce8ba74ac3fc7e552a285da;p=kernel.git

进入ring3
---

diff --git a/kernel/init.c b/kernel/init.c
index 9ce0257..1d852dc 100644
--- a/kernel/init.c
+++ b/kernel/init.c
@@ -24,62 +24,71 @@ char idtr[6] __attribute__((__aligned__(4)));
 
 // int debug_wait_queue_get();
 
-#define __ring3text__ __attribute__((__section__(".ring3.text"), __aligned__(PAGE_SIZE)))
+#define __ring3text__ __attribute__((__section__(".ring3.text")))
 #define __ring3data__ __attribute__((__section__(".ring3.data"), __aligned__(PAGE_SIZE)))
 #define __ring3bss__ __attribute__((__section__(".ring3.bss"), __aligned__(PAGE_SIZE)))
 
 char __ring3data__ ring3_stack[PAGE_SIZE] = {0};
 char __ring3bss__ ring3_stack[PAGE_SIZE];
-void __ring3text__ ring3_entry() {
+int ring3_sysctest();
+void __ring3text__ __attribute__((__aligned__(PAGE_SIZE))) ring3_entry() {
     while (1) {
-        systest();
+        ring3_sysctest();
     }
 }
 
+
+static int __ring3text__ __volatile__ __ring3_syscall0(int nr) {
+    int __sysc_ret__ = 0;
+    extern void sysenter;
+    asm volatile("leal sysenter, %%ebx;call *%%ebx;" : "=a"(__sysc_ret__) : "a"(nr));
+    return __sysc_ret__;
+}
+int __ring3text__ _ring3_syscall0(int nr) { return __ring3_syscall0(nr); }
+int __ring3text__ ring3_sysctest() { return _ring3_syscall0(SYSC_TEST); }
+
 void user_task_entry() {
-    // // printk("user_task_entry: %08x\n", ring3_entry);
+    // printk("user_task_entry: %08x\n", ring3_entry);
 
     // unsigned long ring3_text_page = va2pa(alloc_one_page(0));
     // unsigned long ring3_data_page = va2pa(alloc_one_page(0));
     // unsigned long ring3_bss_page = va2pa(alloc_one_page(0));
-    // unsigned long *pt_text_page = (unsigned long *)va2pa(alloc_one_page(0));
-    // unsigned long *pt_data_page = (unsigned long *)va2pa(alloc_one_page(0));
-    // unsigned long *pt_bss_page = (unsigned long *)va2pa(alloc_one_page(0));
-    // unsigned long *p = (unsigned long *)((current->cr3 - 0xC0000000));
 
-    //  asm volatile("xchg %%bx, %%bx;mov %%eax, %%ebx;xchg %%bx, %%bx;"::"a"(p));
+    unsigned long ring3_text_page = va2pa(ring3_entry);
+    unsigned long ring3_data_page = va2pa(ring3_stack);
+    unsigned long ring3_bss_page = va2pa(alloc_one_page(0));
 
-    // // text: 0x0800_0000
-    // // data: 0x2000_0000
-    // //  bss: 0x3000_0000
-    // unsigned long text_at = 0x08000000;
-    // unsigned long data_at = 0x20000000;
-    // unsigned long bbs_at = 0x30000000;
+    unsigned long *pt_text_page = (unsigned long *)(alloc_one_page(0));
+    unsigned long *pt_data_page = (unsigned long *)(alloc_one_page(0));
+    unsigned long *pt_bss_page = (unsigned long *)(alloc_one_page(0));
+    unsigned long *p = (unsigned long *)(pa2va(current->cr3));
 
-    // unsigned long flag = 0;
+    //asm volatile("xchg %%bx, %%bx;mov %%eax, %%ebx;xchg %%bx, %%bx;"::"a"(p));
+    printk("page dir : %x %x %x %x\n", p, pt_text_page, ring3_text_page);
+    printk("pt bss page %x %x", pt_bss_page, ring3_bss_page);
 
-    // flag |= PAGE_P;
-    // flag |= PAGE_US;
+    // text: 0x0800_0000
+    // data: 0x2000_0000
+    //  bss: 0x3000_0000
+    unsigned long text_at = 0x08000000;
+    unsigned long data_at = 0x20000000;
+    unsigned long bbs_at = 0x30000000;
 
-    // p[text_at >> 22] = (unsigned long)pt_text_page | PAGE_P | PAGE_US;
-    // pt_text_page[0] = ring3_text_page;
-    // p[data_at >> 22] = (unsigned long)pt_data_page | PAGE_P | PAGE_WR | PAGE_US;
-    // pt_data_page[0] = ring3_data_page;
-    // p[bbs_at >> 22] = (unsigned long)pt_bss_page | PAGE_P | PAGE_WR | PAGE_US;
-    // pt_bss_page[0] = ring3_bss_page;
+    p[text_at >> 22] = (unsigned long)va2pa(pt_text_page) | PAGE_P | PAGE_WR | PAGE_US;
+    pt_text_page[0] = ring3_text_page | 7;
+    p[data_at >> 22] = (unsigned long)va2pa(pt_data_page) | PAGE_P | PAGE_WR | PAGE_US;
+    pt_data_page[0] = ring3_data_page | 7 ;
+    p[bbs_at >> 22] = (unsigned long)va2pa(pt_bss_page) | PAGE_P | PAGE_WR | PAGE_US;
+    pt_bss_page[0] = ring3_bss_page | 7 ;
 
-    // // 
-    // asm("xchg %bx, %bx");
-    // LOAD_CR3((unsigned long)p);
+    // 
+    LoadCR3(current->cr3);
 
     // 现在要准备返回用户态
     // eip --> edx
     // esp --> ecx
-    asm("xchg %bx, %bx");
-    // asm("sysexit;" ::"d"(0x08000000), "c"(0x30000000 + PAGE_SIZE));
-    while (1) {
-        asm("hlt;");
-    }
+   asm volatile("xchg %bx, %bx");
+   asm volatile("sysexit;" ::"d"(0x08000000), "c"(0x30000000 + PAGE_SIZE - 100));
 }
 
 void init_task_entry() {
@@ -96,7 +105,7 @@ void init_task_entry() {
     }
 
     while (1) {
-        sysc_test();
+        //sysc_test();
         printl(MPL_TASK_1 + id - 1, "task:%d [%08x] weight %d cnt %d", id, current, current->weight, cnt++);
         // printl(MPL_TASK_1, "task:%d [%08x] weight %d cnt %d", id, current, current->weight, cnt++);
         int v = 0;  // debug_wait_queue_get();
@@ -138,12 +147,12 @@ void root_task_entry() {
 
     int cnt = 0;
     while (1) {
-        sysc_test();
+        //sysc_test();
         printl(MPL_ROOT, "root:0 [%08x] weight %d cnt %d", current, root_task.weight, cnt++);
         // printk("root:0 [%08x] weight %d cnt %d", current, current->weight, cnt++);
         asm("sti;hlt;");
         // asm("nop;nop;nop;");
-        sysc_test();
+        //sysc_test();
         // syscall0(SYSC_TEST);
     }
 }
diff --git a/kernel/syscall.S b/kernel/syscall.S
index 0a6f290..906d65c 100644
--- a/kernel/syscall.S
+++ b/kernel/syscall.S
@@ -27,7 +27,6 @@
 .global syscall_entry
 .global ret_from_fork_user
 .global ret_from_fork_krnl
-.global sysexit
 //.global syscall_exit
 
 syscall_entry:
@@ -78,7 +77,7 @@ ret_from_fork_user:
 
     // 在系统调用前，用户态的esp保存在ebp中
     // sysexit指令从ecx中恢复用户态esp
-    movl    %ebp, %ecx
+    xchgl   %ebp, %ecx
 
     sti        /* sysenter have cleared IF, and sysexit will not set IF. */
     sysexit
@@ -102,8 +101,21 @@ ret_from_fork_krnl:
 # this page is shared by the kernel and userspace
 # the reason why i use this method is because of that the user program
 # no need to pay attention on the return address
+.global sysenter
+.section .sysenter
+.align 0x1000
+sysenter:
+    pushl   %ecx;
+    pushl   %edx;
+    pushl   %ebp;
+    movl    %esp, %ebp;
+    sysenter;
+
+
+
+.global sysexit
 .section .sysexit
-.align 0x1000 
+.align 0x1000
 sysexit:
     popl    %ebp;
     popl    %edx;
diff --git a/kernel/syscall.c b/kernel/syscall.c
index 3c11103..59edd80 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -52,9 +52,9 @@ int sysc_test()
 {
     static unsigned int cnt = 0;
     current->cnt++;
-    printl(MPL_TEST, "systest cnt %u current %08x cnt %u          ",
-           cnt++, current, cnt);
-
+    // printl(MPL_TEST, "systest cnt %u current %08x cnt %u          ",
+    //        cnt++, current, cnt);
+    printk("systest cnt %u current %08x cnt %u\n",cnt++, current, cnt);
     return 0;
 }
 
diff --git a/mm/mm.c b/mm/mm.c
index 06bdad7..a9d8c49 100644
--- a/mm/mm.c
+++ b/mm/mm.c
@@ -39,8 +39,6 @@ void set_page_shared(void *x) {
     pte[get_npt(addr)] |= PAGE_US;
 }
 
-extern void sysexit();
-
 void init_paging() {
     unsigned int i;
     unsigned long pfn = 0;
@@ -74,6 +72,9 @@ void init_paging() {
     }
 
     // paging for user space
+    extern void sysenter();
+    extern void sysexit();
+    set_page_shared(sysenter);
     set_page_shared(sysexit);
 
     LoadCR3(va2pa(init_pgd));
diff --git a/scripts/link.ld b/scripts/link.ld
index ce2afbd..1f9d6f0 100644
--- a/scripts/link.ld
+++ b/scripts/link.ld
@@ -30,6 +30,7 @@ SECTIONS
         *(.multiboot_header)
         *(.text)
 
+        *(.sysenter) /* last */
         *(.sysexit) /* last */
     }
     etext = .;