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    /* 
     * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
     * Licensed under the GPL
     */
    
    #include "linux/errno.h"
    #include "linux/slab.h"
    #include "linux/signal.h"
    #include "linux/interrupt.h"
    #include "asm/irq.h"
    #include "irq_user.h"
    #include "irq_kern.h"
    #include "kern_util.h"
    #include "os.h"
    #include "xterm.h"
    
    struct xterm_wait {
    	struct completion ready;
    	int fd;
    	int pid;
    	int new_fd;
    };
    
    static irqreturn_t xterm_interrupt(int irq, void *data, struct pt_regs *regs)
    {
    	struct xterm_wait *xterm = data;
    	int fd;
    
    	fd = os_rcv_fd(xterm->fd, &xterm->pid);
    	if(fd == -EAGAIN)
    		return(IRQ_NONE);
    
    	xterm->new_fd = fd;
    	complete(&xterm->ready);
    	return(IRQ_HANDLED);
    }
    
    int xterm_fd(int socket, int *pid_out)
    {
    	struct xterm_wait *data;
    	int err, ret;
    
    	data = kmalloc(sizeof(*data), GFP_KERNEL);
    	if(data == NULL){
    		printk(KERN_ERR "xterm_fd : failed to allocate xterm_wait\n");
    		return(-ENOMEM);
    	}
    
    	/* This is a locked semaphore... */
    	*data = ((struct xterm_wait) 
    		{ .fd 		= socket,
    		  .pid 		= -1,
    		  .new_fd 	= -1 });
    	init_completion(&data->ready);
    
    	err = um_request_irq(XTERM_IRQ, socket, IRQ_READ, xterm_interrupt, 
    
    			     IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
    
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    			     "xterm", data);
    	if (err){
    		printk(KERN_ERR "xterm_fd : failed to get IRQ for xterm, "
    		       "err = %d\n",  err);
    		ret = err;
    		goto out;
    	}
    
    	/* ... so here we wait for an xterm interrupt.
    	 *
    	 * XXX Note, if the xterm doesn't work for some reason (eg. DISPLAY
    	 * isn't set) this will hang... */
    	wait_for_completion(&data->ready);
    
    	free_irq(XTERM_IRQ, data);
    
    	ret = data->new_fd;
    	*pid_out = data->pid;
     out:
    	kfree(data);
    
    	return(ret);
    }
    
    /*
     * Overrides for Emacs so that we follow Linus's tabbing style.
     * Emacs will notice this stuff at the end of the file and automatically
     * adjust the settings for this buffer only.  This must remain at the end
     * of the file.
     * ---------------------------------------------------------------------------
     * Local variables:
     * c-file-style: "linux"
     * End:
     */