extern void my_dummy();
static char dummy_stack[DUMMY_STACK_SIZE] __attribute__((aligned(16)));
- // 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 + DUMMY_STACK_SIZE - 20 },
+ 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,
- .eflags = cpu_reflags() | 0x0200
};
- *(u32_t*)(&dummy_stack[DUMMY_STACK_SIZE - 4]) = dummy_proc.intr_ctx.eflags;
- *(u32_t*)(&dummy_stack[DUMMY_STACK_SIZE - 8]) = KCODE_SEG;
- *(u32_t*)(&dummy_stack[DUMMY_STACK_SIZE - 12]) = dummy_proc.intr_ctx.eip;
+ // 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 },
+ .execp = execp };
dummy_proc.page_table = cpu_rcr3();
dummy_proc.state = PS_READY;
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();