X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/8fdcd1575a97862975fa019f09c00453a2a7d8bb..0eabc11fcf240415e39f3873dfce7cd9384b3042:/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 e941983..23df5b5 100644 --- a/lunaix-os/kernel/asm/x86/interrupt.S +++ b/lunaix-os/kernel/asm/x86/interrupt.S @@ -4,67 +4,65 @@ #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 - isr_template FAULT_STACK_SEG_FAULT, no_error_code=0 +.section .bss + .align 16 + lo_tmp_stack: + .skip 128 + tmp_stack: - isr_template LUNAIX_SYS_PANIC - isr_template LUNAIX_SYS_CALL +/* + 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. - 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 + Be aware the twists, offsets and hidden dependencies! +*/ + +.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 + msa: [ss] > 76 + [esp] > 72 + eflags > 68 + cs > 64 + eip > 60 + err_code > 56 + vector > offset = 52 + [saved_prev_ctx] > offset = 0 + --- esp gs fs es - ds > offset = 7 * 4 = 28 + ds > offset = 7 * 4 = 28 + 4 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 $52, %esp pushl %esp subl $16, %esp @@ -81,7 +79,12 @@ pushl %ebx pushl %eax - movl 60(%esp), %eax /* 取出 %cs */ + movl __current, %eax + movl 8(%eax), %eax + incl %eax + pushl %eax # nested intr: current depth + + movl 116(%esp), %eax /* 取出 %cs */ andl $0x3, %eax /* 判断 RPL */ jz 1f @@ -93,9 +96,14 @@ # 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 + + # 保存x87FPU的状态 + movl 68(%eax), %ebx + fxsave (%ebx) + + movl 124(%esp), %ebx # 取出esp + movl %ebx, 60(%eax) # 存入__current->ustack_top 1: movl %esp, %eax @@ -111,6 +119,20 @@ soft_iret: movl %eax, %esp +#ifdef __ASM_INTR_DIAGNOSIS + movl %eax, (debug_resv + 8) + movl 48(%esp), %eax + movl 60(%eax), %eax + movl %eax, (debug_resv + 4) # eip +#endif + movl __current, %eax + movl 68(%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 @@ -126,42 +148,69 @@ movl 16(%esp), %esp + movl %eax, tmp_store + movl __current, %eax + # nested intr: restore saved context + popl 8(%eax) # depth + popl 12(%eax) # eax + popl 16(%eax) # ebx + popl 20(%eax) # ecx + popl 24(%eax) # edx + popl 28(%eax) # edi + popl 32(%eax) # ebp + popl 36(%eax) # esi + popl 40(%eax) # ds + popl 44(%eax) # es + popl 48(%eax) # fs + popl 52(%eax) # gs + popl 56(%eax) # esp + 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 + 4) + movl tmp_store, %eax iret .global switch_to switch_to: # 约定 - # arg1: 目标进程PCB地址 (next) - popl %ecx # next - - call signal_dispatch # kernel/signal.c - movl %eax, %edx + # arg1: 目标进程PCB地址 (next + popl %ebx # next movl __current, %eax - movl 88(%eax), %ebx # __current->pagetable - movl 88(%ecx), %eax # next->pagetable + movl 64(%eax), %ecx # __current->pagetable + movl 64(%ebx), %eax # next->pagetable - cmpl %ebx, %eax # if(next->pagtable != __current->pagetable) { + cmpl %ecx, %eax # if(next->pagtable != __current->pagetable) { jz 1f movl %eax, %cr3 # cpu_lcr3(next->pagetable) # } 1: - movl %ecx, __current # __current = next + 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 + call signal_dispatch # kernel/signal.c - test %edx, %edx # do we have signal to handle? + test %eax, %eax # do we have signal to handle? jz 1f - movl %edx, %eax jmp handle_signal 1: - leal 8(%ecx), %eax + leal 8(%ebx), %eax jmp soft_iret .global handle_signal @@ -170,9 +219,10 @@ # 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 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 @@ -192,7 +242,7 @@ pushl %eax # Addr to proc_sig structure pushl 4(%eax) # proc_sig->sig_num ---- 16 bytes aligned - call (%eax) # invoke signal handler + call *(%eax) # invoke signal handler # invoke the sigreturn syscall to exit the signal wrapper movl $__SYSCALL_sigreturn, %eax