Question

我想处理NMI并在NMI发生时做一些事情。首先，我写了一个天真的nmi处理程序：

static irqreturn_t nmi_handler(int irq, void* dev_id) {
  printk("-#_#- I'm TT, I am handling NMI.\n");
  return IRQ_HANDLED;
}

编写一个模块来注册我的nmi处理程序，然后使用APIC触发NMI 5次：

static void __init ipi_init(void) {
  printk("-#_#- I'm coming again, hahaha!\n");

  int result = request_irq(NMI_VECTOR, 
      nmi_handler, IRQF_DISABLED, "NMI Watchdog", NULL);
  printk("--- the result of request_irq is: %d\n", result);
  int i;
  for (i = 0; i < 5; ++i) {
    apic->send_IPI_allbutself(NMI_VECTOR);
    ssleep(1);
  }
}

现在我输入“insmod xxx.ko”来安装这个模块，然后检查/ var / log / syslog：

kernel: [ 1166.231005] -#_#- I'm coming again, hahaha!
kernel: [ 1166.231028] --- the result of request_irq is: 0
kernel: [ 1166.231050] Uhhuh. NMI received for unknown reason 00 on CPU 1.
kernel: [ 1166.231055] Do you have a strange power saving mode enabled?
kernel: [ 1166.231058] Dazed and confused, but trying to continue
kernel: [ 1167.196293] Uhhuh. NMI received for unknown reason 00 on CPU 1.
kernel: [ 1167.196293] Do you have a strange power saving mode enabled?
kernel: [ 1167.196293] Dazed and confused, but trying to continue
kernel: [ 1168.201288] Uhhuh. NMI received for unknown reason 00 on CPU 1.
kernel: [ 1168.201288] Do you have a strange power saving mode enabled?
kernel: [ 1168.201288] Dazed and confused, but trying to continue
kernel: [ 1169.235553] Uhhuh. NMI received for unknown reason 00 on CPU 1.
kernel: [ 1169.235553] Do you have a strange power saving mode enabled?
kernel: [ 1169.235553] Dazed and confused, but trying to continue
kernel: [ 1170.236343] Uhhuh. NMI received for unknown reason 00 on CPU 1.
kernel: [ 1170.236343] Do you have a strange power saving mode enabled?
kernel: [ 1170.236343] Dazed and confused, but trying to continue

它显示我成功注册了nmi_handler（结果= 0），并且NMI被触发了5次，但我没有发现应该在nmi_handler中输出的刺痛。我在Ubuntu 10.04 LTS，Intel Pentium 4双核上工作。

这是否意味着我的NMI处理程序没有执行？
如何在Linux中处理NMI？

Answer 1

没人？我的伙伴给了我3天，所以我读了源代码和ULK3，现在我可以回答问题1：

这是否意味着我的NMI句柄没有执行？

事实上， IRQ编号和 INT矢量编号 不同！函数request_irq（）调用setup_irq（）：

/**
 *  setup_irq - setup an interrupt
 *  @irq: Interrupt line to setup
 *  @act: irqaction for the interrupt
 *
 * Used to statically setup interrupts in the early boot process.
 */
int setup_irq(unsigned int irq, struct irqaction *act)
{
    struct irq_desc *desc = irq_to_desc(irq);

    return __setup_irq(irq, desc, act);
}

看看这个：@irq: Interrupt line to setup 。参数 irq 是中断行号，而不是中断向量号。查找ULK3 PDF，P203，定时器中断有IRQ 0，但其INT nr为32！所以我触发INT2（NMI），但我的处理程序实际上处理INT34！我想在源代码中找到更多的证据（例如如何将IRQ转换为INT？我修改我的处理程序和init，我请求irq = 2，并且Linux分配INT = 50），但什么都没有，期望linux-xxx/arch/x86/include/asm/irq_vectors.h < / p>

/*
 * IDT vectors usable for external interrupt sources start
 * at 0x20:
 */
#define FIRST_EXTERNAL_VECTOR       0x20

等我一段时间......让我阅读更多代码来回答问题2.

为什么我不能处理NMI？

1 个答案: