WarlockFish/linux-insides-zh
1
0
Fork 0
mirror of https://github.com/MintCN/linux-insides-zh.git synced 2026-05-12 03:27:52 +08:00
Code Issues Packages Projects Releases Wiki Activity

<上游3.1更新后的中文更新版本>

Browse Source
This commit is contained in:
Albertchamberlain
2020-05-12 20:19:03 +08:00
parent 95bc785248
commit 481bdfb2c5
3 changed files with 26 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
Interrupts/linux-interrupts-1.md
View File

@@ -422,34 +422,36 @@ SYM_DATA(initial_gs,
所有被 `IST` 切换到新栈的中断门描述符都由 `set_intr_gate_ist` 函数初始化。例如:
```C
set_intr_gate_ist(X86_TRAP_NMI, &nmi, NMI_STACK);
...
...
...
set_intr_gate_ist(X86_TRAP_DF, &double_fault, DOUBLEFAULT_STACK);
static const __initconst struct idt_data def_idts[] = {
...
INTG(X86_TRAP_NMI, nmi),
...
INTG(X86_TRAP_DF, double_fault),
```
其中 `&nmi` 和 `&double_fault` 是中断函数的入口地址：
其中 `&nmi` 和 `&double_fault` 在以下位置创建入口点：
[arch/x86/kernel/entry_64.S](https://github.com/torvalds/linux/blob/master/arch/x86/entry/entry_64.S)中
```assembly
idtentry double_fault do_double_fault has_error_code=1 paranoid=2 read_cr2=1
...
...
...
SYM_CODE_START(nmi)
...
...
...
SYM_CODE_END(nmi)
SYM_CODE_END(nmi)
```
在以下位置给出了中断处理程序的声明 [arch/x86/include/asm/traps.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/traps.h):
```C
asmlinkage void nmi(void);
asmlinkage void double_fault(void);
```
定义在 [arch/x86/kernel/entry_64.S](https://github.com/torvalds/linux/blob/master/arch/x86/kernel/entry_64.S)中
```assembly
idtentry double_fault do_double_fault has_error_code=1 paranoid=2
...
...
...
ENTRY(nmi)
...
...
...
END(nmi)
```
当一个中断或者异常发生时，新的 `ss` 选择器被强制置为 `NULL`，并且 `ss` 选择器的 `rpl` 域被设置为新的 `cpl`。旧的 `ss`、`rsp`、寄存器标志、`cs`、`rip` 被压入新栈。在 64 位模型下，中断栈帧大小固定为 8 字节，所以我们可以得到下面的栈:
```