X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/0cf90cca0c924622f3fee8d2a3fafa8238363dc6..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 c869db0..3007d45 100644 --- a/lunaix-os/kernel/asm/x86/interrupt.S +++ b/lunaix-os/kernel/asm/x86/interrupt.S @@ -1,6 +1,7 @@ #define __ASM__ #include -#include +#include +#include #include #define __ASM_INTR_DIAGNOSIS @@ -16,28 +17,117 @@ .section .bss .align 16 lo_tmp_stack: - .skip 128 + .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! + +*/ + +#define regsize 4 + +/* 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] > 76 - [esp] > 72 - eflags > 68 - cs > 64 - eip > 60 - err_code > 56 - vector > offset = 52 + 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 + esp > 12 * 4 = 48 gs fs es - ds > offset = 7 * 4 = 28 + 4 + ds > offset = 8 * 4 = 32 esi ebp edi @@ -52,7 +142,7 @@ */ cld - subl $52, %esp + subl $4, %esp pushl %esp subl $16, %esp @@ -70,11 +160,11 @@ pushl %eax movl __current, %eax - movl 8(%eax), %eax + movl proc_intr_ctx(%eax), %eax incl %eax pushl %eax # nested intr: current depth - movl 116(%esp), %eax /* 取出 %cs */ + movl ics(%esp), %eax /* 取出 %cs */ andl $0x3, %eax /* 判断 RPL */ jz 1f @@ -84,16 +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 + # FIXME: Save x87 context to user stack, rather than kernel's memory. # 保存x87FPU的状态 - movl 68(%eax), %ebx + movl proc_fxstate(%eax), %ebx fxsave (%ebx) - movl 124(%esp), %ebx # 取出esp - movl %ebx, 60(%eax) # 存入__current->ustack_top + # 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 @@ -111,16 +201,17 @@ #ifdef __ASM_INTR_DIAGNOSIS movl %eax, (debug_resv + 8) - movl 48(%esp), %eax - movl 60(%eax), %eax + movl iesp(%esp), %eax + movl exeip(%eax), %eax movl %eax, (debug_resv + 4) # eip #endif movl __current, %eax - movl 68(%eax), %eax + movl proc_fxstate(%eax), %eax test %eax, %eax # do we have stored x87 context? jz 1f - fxrstor (%eax) + fxrstor (%eax) + 1: popl %eax # discard isr_param::depth popl %eax @@ -140,20 +231,10 @@ 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 + popl proc_intr_ctx(%eax) addl $8, %esp @@ -170,8 +251,9 @@ shll $3, %eax addl $12, %eax addl %esp, %eax - movl %eax, (_tss + 4) + movl %eax, (_tss + tss_esp0_off) movl tmp_store, %eax + iret .global switch_to @@ -181,8 +263,8 @@ popl %ebx # next movl __current, %eax - movl 64(%eax), %ecx # __current->pagetable - movl 64(%ebx), %eax # next->pagetable + 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 @@ -194,27 +276,36 @@ # 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: - leal 8(%ebx), %eax + 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！ - leal 8(%eax), %ebx # arg1 in %eax: addr of proc_sig structure in user stack + # arg1 in %eax: addr of proc_sig structure in user stack + leal 12(%eax), %ebx # %ebx = &proc_sig->prev_context pushl $UDATA_SEG # proc_sig->prev_context.proc_regs.ss pushl %eax # esp + 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 @@ -222,21 +313,4 @@ 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 + iret \ No newline at end of file