X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/32b9a6d76790c73d3d2d36d9081a2581cc65d184..28c176b668c841a3b7fb093faccf0efa39257603:/lunaix-os/arch/i386/exceptions/interrupt.S diff --git a/lunaix-os/arch/i386/exceptions/interrupt.S b/lunaix-os/arch/i386/exceptions/interrupt.S deleted file mode 100644 index 8d82d10..0000000 --- a/lunaix-os/arch/i386/exceptions/interrupt.S +++ /dev/null @@ -1,230 +0,0 @@ -#define __ASM__ -#include -#include -#include - -#include - -#define __ASM_INTR_DIAGNOSIS - -#ifdef __ASM_INTR_DIAGNOSIS -.section .bss - .global debug_resv - debug_resv: - .skip 16 - tmp_store: - .skip 4 -#endif - -.section .bss - .align 16 - lo_tmp_stack: - .skip 256 - tmp_stack: - -/* - This perhaps the ugliest part in the project. - It contains code to handle arbitrary depth of - nested interrupt and all those corner cases and - nasty gotchas. - - Be aware the twists, offsets and hidden dependencies! - -*/ - -.section .text - .type interrupt_wrapper, @function - .global interrupt_wrapper - interrupt_wrapper: - cld - - subl $4, %esp - 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 %edx - pushl %ecx - pushl %ebx - pushl %eax - - pushl $0 // placeholder for depth accounting - - movl ics(%esp), %eax /* 取出 %cs */ - andl $0x3, %eax /* 判断 RPL */ - jz 1f - - /* crossing the user/kernel boundary */ - movw $KDATA_SEG, %ax - movw %ax, %gs - movw %ax, %fs - movw %ax, %ds - movw %ax, %es - - movl current_thread, %ebx - movl iuesp(%esp), %eax - - # Save x87 context to user stack, rather than kernel's memory. - # XXX what will happen if we triggered a page fault during fxsave? - # FIXME I think we should defer this to scheduler, and pratice lazy save/load - # Doing this will also make it safe from nested interrupt due to potential - # page fault when saving - # FIXME Also, generalise it to any FPU context, without constraining it to x87. - - #andl $stack_alignment, %eax - #subl $512, %eax - #fxsave (%eax) - - # 保存用户栈顶指针。因为我们允许同级中断的产生，所以需要该手段跟踪用户栈的地址。 - movl %eax, thread_ustack_top(%ebx) # 存入__current->ustack_top - - /* kernel space same-level switch */ - 1: - movl %esp, %eax - andl $stack_alignment, %esp - subl $16, %esp - movl %eax, (%esp) - - xorl %ebp, %ebp # marks the boundary of stack walking - call intr_handler - - movl (%esp), %eax - - .global soft_iret - soft_iret: - movl %eax, %esp - -#ifdef __ASM_INTR_DIAGNOSIS - movl %eax, (debug_resv + 8) - movl iesp(%esp), %eax - movl exeip(%eax), %eax - movl %eax, (debug_resv + 4) # eip -#endif - - movl ics(%esp), %eax - andl $3, %eax - jz 1f - - # # FIXME x87 fpu context - # movl current_thread, %eax - # movl thread_ustack_top(%eax), %eax - # test %eax, %eax - # jz 1f - # fxrstor (%eax) - -1: - popl %eax # discard struct hart_state::depth - popl %eax - popl %ebx - popl %ecx - popl %edx - popl %edi - popl %ebp - popl %esi - - movw (%esp), %ds - movw 4(%esp), %es - movw 8(%esp), %fs - movw 12(%esp), %gs - - movl 16(%esp), %esp - - movl %eax, tmp_store - movl current_thread, %eax - - # nested intr: restore saved context - popl thread_hstate(%eax) - - addl $8, %esp - -#ifdef __ASM_INTR_DIAGNOSIS - movl (%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 4(%esp), %eax - andl $3, %eax - setnz %al - shll $3, %eax - addl $12, %eax - addl %esp, %eax - movl %eax, (_tss + tss_esp0_off) - movl tmp_store, %eax - - iret - - .type do_switch, @function - .global do_switch - do_switch: - # Assumption: __current already hold the target process - - call proc_vmroot - - movl %eax, %ebx - movl %cr3, %eax - xorl %ebx, %eax # avoid setting cr3 if just local thread switch. - jz 1f - - movl %ebx, %cr3 - - 1: - # the address space could be changed. A temporary stack - # is required to prevent corrupt existing stack - movl $tmp_stack, %esp - - call signal_dispatch # kernel/signal.c - - movl current_thread, %ebx - test %eax, %eax # do we have signal to handle? - jz 1f - - /* - 将tss.esp0设置为上次调度前的esp值。 - 当处理信号时，上下文信息是不会恢复的，而是保存在用户栈中，然后直接跳转进位于用户空间的sig_wrapper进行 - 信号的处理。当用户自定义的信号处理函数返回时，sigreturn的系统调用才开始进行上下文的恢复（或者说是进行 - 另一次调度。 - 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） - */ - movl thread_hstate(%ebx), %ecx # __current->hstate - movl %ecx, (tss_esp0_off + _tss) - - jmp handle_signal - - 1: - movl thread_hstate(%ebx), %eax - jmp soft_iret - - .type handle_signal, @function - .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！ - # arg1 in %eax: addr of proc_sig structure in user stack - movl psig_saved_hstate(%eax), %ebx # %ebx = &proc_sig->saved_hstate - - pushl $UDATA_SEG - pushl %eax # esp - - movl iexecp(%ebx), %ebx - pushl exeflags(%ebx) # proc_sig->saved_hstate->execp->eflags - - pushl $UCODE_SEG # cs - pushl psig_sigact(%eax) # %eip = proc_sig->sigact - - movw $UDATA_SEG, %cx # switch data seg to user mode - movw %cx, %es - movw %cx, %ds - movw %cx, %fs - movw %cx, %gs - - iret \ No newline at end of file