X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/05b7549a0f980efa33265a091a5174a78851ce05..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 11fe3fd..23df5b5 100644 --- a/lunaix-os/kernel/asm/x86/interrupt.S +++ b/lunaix-os/kernel/asm/x86/interrupt.S @@ -1,32 +1,76 @@ #define __ASM__ #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 128 + 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. - isr_template LUNAIX_SYS_PANIC + Be aware the twists, offsets and hidden dependencies! - 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 +*/ +.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 + [saved_prev_ctx] > offset = 0 + --- + esp + gs + fs + es + ds > offset = 7 * 4 = 28 + 4 + esi + ebp + edi + edx + ecx + ebx + eax + lsa: depth > offset = 0 + + las: Least Significant Address + msa: Most Significant Address + */ + cld + + subl $52, %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 @@ -35,14 +79,60 @@ pushl %ebx pushl %eax + 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 + + 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 + + # 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 andl $0xfffffff0, %esp subl $16, %esp movl %eax, (%esp) call intr_handler - popl %esp + movl (%esp), %eax + + .global soft_iret + 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 @@ -50,8 +140,113 @@ 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 + + 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 - iret \ No newline at end of file +#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 + 4) + 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 64(%eax), %ecx # __current->pagetable + movl 64(%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 + 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 + 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.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 + + 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