#define __ASM__
#include <arch/x86/interrupts.h>
-// #define __ASM_INTR_DIAGNOSIS
+#include <lunaix/common.h>
+#include <lunaix/syscall.h>
+#define __ASM_INTR_DIAGNOSIS
.macro isr_template vector, no_error_code=1
.global _asm_isr\vector
.skip 16
#endif
+.section .bss
+ .align 16
+ lo_tmp_stack:
+ .skip 128
+ tmp_stack:
+
.section .text
isr_template FAULT_DIVISION_ERROR
isr_template FAULT_GENERAL_PROTECTION, no_error_code=0
isr_template FAULT_PAGE_FAULT, no_error_code=0
+ isr_template FAULT_STACK_SEG_FAULT, no_error_code=0
isr_template LUNAIX_SYS_PANIC
isr_template LUNAIX_SYS_CALL
isr_template PC_KBD_IV
interrupt_wrapper:
+ /*
+ Stack layout (layout of struct isr_param)
+ msa: [ss]
+ [esp]
+ eflags > offset = 48 + 16 = 64
+ cs
+ eip
+ err_code
+ vector > offset = 28 + 16 + 4 = 48
+ esp
+ gs
+ fs
+ es
+ ds > offset = 7 * 4 = 28
+ esi
+ ebp
+ edi
+ edx
+ ecx
+ ebx
+ lsa: eax > offset = 0
+
+ las: Least Significant Address
+ msa: Most Significant Address
+ */
+ cld
pushl %esp
+ subl $16, %esp
+ movw %gs, 12(%esp)
+ movw %fs, 8(%esp)
+ movw %es, 4(%esp)
+ movw %ds, (%esp)
+
pushl %esi
pushl %ebp
pushl %edi
pushl %ebx
pushl %eax
+ movl 60(%esp), %eax /* 取出 %cs */
+ andl $0x3, %eax /* 判断 RPL */
+ jz 1f
+
+ movw $KDATA_SEG, %ax /* 如果从用户模式转来，则切换至内核数据段 */
+ movw %ax, %gs
+ movw %ax, %fs
+ movw %ax, %ds
+ movw %ax, %es
+
+ # 保存用户栈顶指针。这是因为我们允许系统调用内进行上下文切换，而这样一来，我们就失去了用户栈的信息，
+ # 这样一来，就无法设置信号上下文。这主要是为了实现了pause()而做的准备
+ movl (__current), %eax
+ movl 68(%esp), %ebx # 取出esp
+ movl %ebx, 84(%eax) # 存入__current->ustack_top
+
+ 1:
movl %esp, %eax
andl $0xfffffff0, %esp
subl $16, %esp
call intr_handler
+ movl (%esp), %eax
+
.global soft_iret
soft_iret:
- popl %esp
+ movl %eax, %esp
popl %eax
popl %ebx
popl %edi
popl %ebp
popl %esi
- popl %esp
+
+ movw (%esp), %ds
+ movw 4(%esp), %es
+ movw 8(%esp), %fs
+ movw 12(%esp), %gs
+
+ movl 16(%esp), %esp
addl $8, %esp
+ pushl %eax
#ifdef __ASM_INTR_DIAGNOSIS
- cmpl $0, (%esp)
- jz 1f
- iret
-1:
- movl $__current, %eax
- movl (%esp), %ebx
- movl $debug_resv, %ecx
- ud2
-#else
- iret
+ movl 4(%esp), %eax
+ movl %eax, debug_resv
#endif
+ # 处理TSS.ESP的一些边界条件。如果是正常iret（即从内核模式*优雅地*退出）
+ # 那么TSS.ESP0应该为iret进行弹栈后，%esp的值。
+ # 所以这里的边界条件是：如返回用户模式，iret会额外弹出8个字节（ss,esp）
+ movl 8(%esp), %eax
+ andl $3, %eax
+ setnz %al
+ shll $3, %eax
+ addl $16, %eax
+ addl %esp, %eax
+ movl %eax, (_tss + 4)
+ popl %eax
+ iret
+
+ .global switch_to
+ switch_to:
+ # 约定
+ # arg1: 目标进程PCB地址 (next
+
+ popl %ecx # next
+ movl __current, %eax
+ movl 88(%eax), %ebx # __current->pagetable
+ movl 88(%ecx), %eax # next->pagetable
+
+ cmpl %ebx, %eax # if(next->pagtable != __current->pagetable) {
+ jz 1f
+ movl %eax, %cr3 # cpu_lcr3(next->pagetable)
+ # }
+ 1:
+ movl %ecx, __current # __current = next
+
+ # 我们已经处在了新的地址空间，为了避免影响其先前的栈布局
+ # 需要使用一个临时的栈空间
+ movl $tmp_stack, %esp
+ call signal_dispatch # kernel/signal.c
+
+ test %eax, %eax # do we have signal to handle?
+ jz 1f
+ jmp handle_signal
+ 1:
+ leal 8(%ecx), %eax
+ jmp soft_iret
+
+ .global handle_signal
+ handle_signal:
+ # 注意1：任何对proc_sig的布局改动，都须及时的保证这里的一致性！
+ # 注意2：handle_signal在调用之前，须确保proc_sig已经写入用户栈！
+ leal 8(%eax), %ebx # arg1 in %eax: addr of proc_sig structure in user stack
+
+ pushl $UDATA_SEG # proc_sig->prev_context.ss
+ pushl %eax # esp
+ pushl 64(%ebx) # proc_sig->prev_context.eflags
+ pushl $UCODE_SEG # cs
+ pushl $sig_wrapper # eip for sig wrapper
+
+ movw $UDATA_SEG, %cx # switch data seg to user mode
+ movw %cx, %es
+ movw %cx, %ds
+ movw %cx, %fs
+ movw %cx, %gs
+
+ iret
+
+.section .usrtext
+ sig_wrapper: # in user mode
+ movl %esp, %eax
+ and $0xfffffff0, %esp
+ subl $8, %esp
+ pushl %eax # Addr to proc_sig structure
+ pushl 4(%eax) # proc_sig->sig_num ---- 16 bytes aligned
+
+ call (%eax) # invoke signal handler
+
+ # invoke the sigreturn syscall to exit the signal wrapper
+ movl $__SYSCALL_sigreturn, %eax
+ movl 4(%esp), %ebx
+ int $LUNAIX_SYS_CALL
+
+ ud2 # never reach!
\ No newline at end of file
git://scm.lunaixsky.com / lunaix-os.git / blobdiff