fix: previous interrupt context lost after a nested interrupt

[lunaix-os.git] / lunaix-os / kernel / process / sched.c

diff --git a/lunaix-os/kernel/process/sched.c b/lunaix-os/kernel/process/sched.c
index 91932ca3dd5d7d4aa3ac3c7c9e170b89cc8d2cb2..4ed9d3438ad9c2d818ee0421de6463cea8ca12da 100644 (file)
--- a/lunaix-os/kernel/process/sched.c
+++ b/lunaix-os/kernel/process/sched.c
@@ -47,6 +47,8 @@ sched_init()
     sched_init_dummy();
 }
 
+#define DUMMY_STACK_SIZE 2048
+
 void
 sched_init_dummy()
 {
@@ -54,28 +56,30 @@ sched_init_dummy()
     // It is a living nightmare!
 
     extern void my_dummy();
-    static char dummy_stack[1024] __attribute__((aligned(16)));
+    static char dummy_stack[DUMMY_STACK_SIZE] __attribute__((aligned(16)));
+
+    struct exec_param* execp =
+      (void*)dummy_stack + DUMMY_STACK_SIZE - sizeof(struct exec_param);
+
+    *execp = (struct exec_param){
+        .cs = KCODE_SEG,
+        .eflags = cpu_reflags() | 0x0200,
+        .eip = (void*)my_dummy,
+        .ss = KDATA_SEG,
+    };
 
     // memset to 0
     dummy_proc = (struct proc_info){};
-    dummy_proc.intr_ctx =
-      (isr_param){ .registers = { .ds = KDATA_SEG,
-                                  .es = KDATA_SEG,
-                                  .fs = KDATA_SEG,
-                                  .gs = KDATA_SEG,
-                                  .esp = (void*)dummy_stack + 1004 },
-                   .cs = KCODE_SEG,
-                   .eip = (void*)my_dummy,
-                   .ss = KDATA_SEG,
-                   .eflags = cpu_reflags() | 0x0200 };
-
-    *(u32_t*)(&dummy_stack[1020]) = dummy_proc.intr_ctx.eflags;
-    *(u32_t*)(&dummy_stack[1016]) = KCODE_SEG;
-    *(u32_t*)(&dummy_stack[1012]) = dummy_proc.intr_ctx.eip;
+    dummy_proc.intr_ctx = (isr_param){ .registers = { .ds = KDATA_SEG,
+                                                      .es = KDATA_SEG,
+                                                      .fs = KDATA_SEG,
+                                                      .gs = KDATA_SEG },
+                                       .execp = execp };
 
     dummy_proc.page_table = cpu_rcr3();
     dummy_proc.state = PS_READY;
     dummy_proc.parent = &dummy_proc;
+    dummy_proc.pid = KERNEL_PID;
 
     __current = &dummy_proc;
 }
@@ -93,7 +97,7 @@ run(struct proc_info* proc)
         由于这中间没有进行地址空间的交换，所以第二次跳转使用的是同一个内核栈，而之前默认tss.esp0的值是永远指向最顶部
         这样一来就有可能会覆盖更早的上下文信息（比如嵌套的信号捕获函数）
     */
-    tss_update_esp(proc->intr_ctx.registers.esp);
+    tss_update_esp(proc->intr_ctx.esp);
 
     apic_done_servicing();