From: acevest <zhaoyanbai@126.com>
Date: Wed, 31 Dec 2025 12:28:19 +0000 (+0800)
Subject: 继续优化ring3代码
X-Git-Url: http://repos.zhaoyanbai.com/?a=commitdiff_plain;h=2b64fa5fa98cd4b0d6bbe3ddd0210d25c8ee69dd;p=kernel.git

继续优化ring3代码
---

diff --git a/kernel/ring3.S b/kernel/ring3.S
index b4dc911..a187fa8 100644
--- a/kernel/ring3.S
+++ b/kernel/ring3.S
@@ -27,40 +27,62 @@ ring3_entry:
     nop
     nop
 
-    movl    $SYSC_RAND, %eax
+    pushl   $0                  # 模拟一个内核不需要的参数1
+    pushl   $SYSC_RAND          # 系统调用号
     call    ring3_syscall
+    addl    $8, %esp
 
 
     movl    %eax, %ecx
     andl    $0x000000FF, %ecx
-    movl    $SYSC_WAIT, %eax
+    pushl   %ecx                # 参数1
+    pushl   $SYSC_WAIT          # 系统调用号
     call    ring3_syscall
+    addl    $8, %esp
+
+
+    # 纯消耗CPU时间
+    movl    $0x0F0F0F0F, %ecx
+1:
+    loop    1b
+
 
     nop
     nop
     jmp ring3_entry
 
-# eax 系统调用号
-# ecx 参数1
+# 传入: 系统调用号, 参数1
 ring3_syscall:
     pushl   %ebp
+    movl    %esp, %ebp
+
+    pushl   %ebx # 用于保存参数1
+    pushl   %edi # 用于保存sysexit后返回用户态的地址
+                 # ebp用于保存sysexit后的用户态栈，不过已经保存了，这里不用再保存
 
-    pushl   %ebx
-    pushl   %edi
+    movl    0x08(%ebp), %eax # 系统调用号
+    movl    0x0C(%ebp), %ebx # 参数1
 
-    movl    %ecx, %ebx
+    # 获取call get_eip后的地址
     call    get_eip
 get_eip:
     # 这里popl取得的就是上一个call指令自动压入栈中的地址
     # 这个地址就是当前指令的地址
     popl    %edi
-    addl    $8,%edi
-    movl    %esp, %ebp;
+
+    # 算出sysenter后的地地址
+    addl    $8, %edi
+
+    # 设置sysexit返回用户态后的栈位置
+    movl    %esp, %ebp
 
     sysenter
 
+    # 从栈中恢复保存的易失寄存器
     popl    %edi
     popl    %ebx
+
+    #
     popl    %ebp
 
     ret
diff --git a/kernel/sched.c b/kernel/sched.c
index 73bfa5a..48dd2c0 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -172,10 +172,10 @@ const char *task_state(unsigned int state) {
 void debug_print_all_tasks() {
     task_t *p = 0;
     list_head_t *pos = 0, *t = 0;
-    printl(MPL_TASK_TITLE, "         NAME      STATE TK/PI REASON     SCHED      KEEP       TURN");
+    printl(MPL_TASK_TITLE, "         NAME      STATE TK/PI REASON     TICKS  SCHED     KEEP      TURN");
     list_for_each_safe(pos, t, &all_tasks) {
         p = list_entry(pos, task_t, list);
-        printl(MPL_TASK_0 + p->pid, "%08x %-6s:%u %s %02u/%02u %-10s %-10u %-10u %-10u", p, p->name, p->pid,
+        printl(MPL_TASK_0 + p->pid, "%08x %-6s:%u %s %02u/%02u %-10s %-9u %-9u %-9u", p, p->name, p->pid,
                task_state(p->state), p->ticks, p->priority, p->reason, p->sched_cnt, p->sched_keep_cnt, p->turn);
     }
 }
diff --git a/kernel/task_user.c b/kernel/task_user.c
index 231e019..535da79 100644
--- a/kernel/task_user.c
+++ b/kernel/task_user.c
@@ -28,11 +28,11 @@ void flush_tlb() {
 }
 
 void user_task_entry() {
-    current->priority = 7;
+    current->priority = 79;
 
     // ring3只占用一个page，页的起始位置放的是代码，页的末尾当栈用
     // ring3的地址直接是物理地址
-    extern char ring3_page_begin;
+    extern uint8_t ring3_page_begin;
 
     paddr_t ring3_page_addr = (paddr_t)&ring3_page_begin; // 不在内核空间的物理地址
     paddr_t ring3_stack_top = ring3_page_addr + PAGE_SIZE;
@@ -45,5 +45,15 @@ void user_task_entry() {
     // 这里减去PAGE_SIZE是因为栈是向下生长的，所以得把栈顶虚拟地址空间的前一页映射到ring3_page
     page_map((ring3_stack_top_vaddr-PAGE_SIZE), ring3_page_addr, PAGE_P | PAGE_US | PAGE_WR);
 
+
+    {
+        // 在ring3_page里非代码的地方插入特征值方便调试
+        extern uint8_t ring3_text_end;
+        uint32_t ring3_text_size = (&ring3_text_end) - (&ring3_page_begin);
+        for(uint32_t i = ring3_text_size; i<PAGE_SIZE; i++) {
+            ((uint8_t *)(pa2va(ring3_page_addr)))[i] = 0xCC;
+        }
+    }
+
     asm volatile("sysexit;" ::"d"(ring3_page_vaddr), "c"(ring3_stack_top_vaddr));
 }
diff --git a/scripts/link.ld b/scripts/link.ld
index ea3009b..0df91f9 100644
--- a/scripts/link.ld
+++ b/scripts/link.ld
@@ -56,6 +56,8 @@ SECTIONS
     .ring3 :
     {
         *(.ring3.entry)
+        . = ALIGN(0x100);
+        ring3_text_end = .;
     }
     . = ALIGN(0x1000);
     ring3_page_end = .;