X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/94a87fe25c5ec021daf16edd64058ed6a37aba7d..946c3fdd31300074cc78841795bd47af908ddddb:/lunaix-os/kernel/asm/x86/interrupt.S diff --git a/lunaix-os/kernel/asm/x86/interrupt.S b/lunaix-os/kernel/asm/x86/interrupt.S index 62c9ec5..3007d45 100644 --- a/lunaix-os/kernel/asm/x86/interrupt.S +++ b/lunaix-os/kernel/asm/x86/interrupt.S @@ -1,69 +1,148 @@ #define __ASM__ #include -#include +#include +#include #include #define __ASM_INTR_DIAGNOSIS -.macro isr_template vector, no_error_code=1 - .global _asm_isr\vector - .type _asm_isr\vector, @function - _asm_isr\vector: - .if \no_error_code - pushl $0x0 - .endif - pushl $\vector - jmp interrupt_wrapper -.endm - #ifdef __ASM_INTR_DIAGNOSIS .section .bss .global debug_resv debug_resv: .skip 16 + tmp_store: + .skip 4 #endif -.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 +.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! + +*/ - isr_template LUNAIX_SYS_PANIC - isr_template LUNAIX_SYS_CALL +#define regsize 4 - isr_template APIC_ERROR_IV - isr_template APIC_LINT0_IV - isr_template APIC_TIMER_IV - isr_template APIC_SPIV_IV - isr_template RTC_TIMER_IV - isr_template PC_KBD_IV +/* stack layout: saved interrupt context */ + .struct 0 +idepth: + .struct idepth + regsize +ieax: + .struct ieax + regsize +iebx: + .struct iebx + regsize +iecx: + .struct iecx + regsize +iedx: + .struct iedx + regsize +iedi: + .struct iedi + regsize +iebp: + .struct iebp + regsize +iesi: + .struct iesi + regsize +ids: + .struct ids + regsize +ies: + .struct ies + regsize +ifs: + .struct ifs + regsize +igs: + .struct igs + regsize +iesp: + .struct iesp + regsize +isave_prev: + .struct isave_prev + regsize +ivec: + .struct ivec + regsize +iecode: + .struct iecode + regsize +ieip: + .struct ieip + regsize +ics: + .struct ics + regsize +ieflags: + .struct ieflags + regsize +iuesp: + .struct iuesp + regsize +iuss: + +/* stack layout: execution (flow-control) state context */ + .struct 0 +exsave_prev: + .struct exsave_prev + regsize +exvec: + .struct exvec + regsize +execode: + .struct execode + regsize +exeip: + .struct exeip + regsize +excs: + .struct excs + regsize +exeflags: + .struct exeflags + regsize +exuesp: + .struct exuesp + regsize +exuss: + +/* struct layout: critical section of struct proc_info */ + .struct 0 +proc_pid: + .struct proc_pid + regsize +proc_parent: + .struct proc_parent + regsize +proc_intr_ctx: + .struct proc_intr_ctx + regsize +proc_ustack_top: + .struct proc_ustack_top + regsize +proc_page_table: + .struct proc_page_table + regsize +proc_fxstate: + +.section .text + .global interrupt_wrapper 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 + msa: [ss] > 76 -> 28 + [esp] > 72 -> 24 + eflags > 68 -> 20 + cs > 64 -> 16 + eip > 60 -> 12 + err_code > 56 -> 8 + vector > offset = 52 -> 4 + [saved_prev_ctx] > offset = 0 + --- + esp > 12 * 4 = 48 gs fs es - ds > offset = 7 * 4 = 28 + ds > offset = 8 * 4 = 32 esi ebp edi edx ecx ebx - lsa: eax > offset = 0 + eax + lsa: depth > offset = 0 las: Least Significant Address msa: Most Significant Address */ cld + + subl $4, %esp pushl %esp subl $16, %esp @@ -80,7 +159,12 @@ pushl %ebx pushl %eax - movl 60(%esp), %eax /* 取出 %cs */ + movl __current, %eax + movl proc_intr_ctx(%eax), %eax + incl %eax + pushl %eax # nested intr: current depth + + movl ics(%esp), %eax /* 取出 %cs */ andl $0x3, %eax /* 判断 RPL */ jz 1f @@ -90,11 +174,16 @@ 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 + movl __current, %eax + + # FIXME: Save x87 context to user stack, rather than kernel's memory. + # 保存x87FPU的状态 + movl proc_fxstate(%eax), %ebx + fxsave (%ebx) + + # 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 iuesp(%esp), %ebx # 取出esp + movl %ebx, proc_ustack_top(%eax) # 存入__current->ustack_top 1: movl %esp, %eax @@ -104,11 +193,27 @@ call intr_handler + movl (%esp), %eax + .global soft_iret soft_iret: - cli - popl %esp + 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 __current, %eax + movl proc_fxstate(%eax), %eax + + test %eax, %eax # do we have stored x87 context? + jz 1f + fxrstor (%eax) + +1: + popl %eax # discard isr_param::depth popl %eax popl %ebx popl %ecx @@ -124,27 +229,83 @@ movl 16(%esp), %esp + movl %eax, tmp_store + movl __current, %eax + + + # nested intr: restore saved context + popl proc_intr_ctx(%eax) + addl $8, %esp #ifdef __ASM_INTR_DIAGNOSIS - pushl %eax - movl 4(%esp), %eax + movl (%esp), %eax movl %eax, debug_resv - popl %eax #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 + .global switch_to + switch_to: + # 约定 + # arg1: 目标进程PCB地址 (next + + popl %ebx # next + movl __current, %eax + movl proc_page_table(%eax), %ecx # __current->pagetable + movl proc_page_table(%ebx), %eax # next->pagetable + + cmpl %ecx, %eax # if(next->pagtable != __current->pagetable) { + jz 1f + movl %eax, %cr3 # cpu_lcr3(next->pagetable) + # } + 1: + movl %ebx, __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 + + # 更新 tss + movl proc_intr_ctx(%ebx), %eax # proc->intr_ctx + movl iesp(%eax), %eax # intr_ctx->esp + movl %eax, (tss_esp0_off + _tss) + + call signal_dispatch # kernel/signal.c + + test %eax, %eax # do we have signal to handle? + jz 1f + jmp handle_signal + 1: + movl proc_intr_ctx(%ebx), %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！ - popl %eax # arg1: addr of proc_sig structure in user stack - leal 8(%eax), %ebx + # arg1 in %eax: addr of proc_sig structure in user stack + leal 12(%eax), %ebx # %ebx = &proc_sig->prev_context - pushl 72(%ebx) # proc_sig->prev_context.ss + pushl $UDATA_SEG # proc_sig->prev_context.proc_regs.ss pushl %eax # esp - pushl 64(%ebx) # proc_sig->prev_context.eflags + + movl 48(%ebx), %ebx + pushl 68(%ebx) # proc_sig->prev_context.proc_regs.execp->eflags + pushl $UCODE_SEG # cs - pushl $sig_wrapper # eip for sig wrapper + pushl 4(%eax) # %eip = proc_sig->sigact movw $UDATA_SEG, %cx # switch data seg to user mode movw %cx, %es @@ -152,20 +313,4 @@ movw %cx, %fs movw %cx, %gs - iret - - 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 + iret \ No newline at end of file