+#ifdef __ASM_INTR_DIAGNOSIS
+ pushl %eax
+ movl 4(%esp), %eax
+ movl %eax, debug_resv
+ popl %eax
+#endif
+ iret
+
+ 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
+
+ pushl 72(%ebx) # proc_sig->prev_context.ss
+ pushl %eax # esp
+ pushl 64(%ebx) # proc_sig->prev_context.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
+
+ 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