147 lines
		
	
	
		
			4.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			147 lines
		
	
	
		
			4.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* The system call implemented in this file:
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|  *   m_type:	SYS_TRACE
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|  *
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|  * The parameters for this system call are:
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|  *    m2_i1:	CTL_PROC_NR	process that is traced
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|  *    m2_i2:    CTL_REQUEST	trace request
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|  *    m2_l1:    CTL_ADDRESS     address at traced process' space
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|  *    m2_l2:    CTL_DATA        data to be written or returned here
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|  */
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| 
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| #include "../system.h"
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| #include <sys/ptrace.h>
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| 
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| #if USE_TRACE
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| 
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| /*==========================================================================*
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|  *				do_trace				    *
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|  *==========================================================================*/
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| #define TR_VLSIZE	((vir_bytes) sizeof(long))
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| 
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| PUBLIC int do_trace(m_ptr)
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| register message *m_ptr;
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| {
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| /* Handle the debugging commands supported by the ptrace system call
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|  * The commands are:
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|  * T_STOP	stop the process
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|  * T_OK		enable tracing by parent for this process
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|  * T_GETINS	return value from instruction space
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|  * T_GETDATA	return value from data space
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|  * T_GETUSER	return value from user process table
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|  * T_SETINS	set value from instruction space
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|  * T_SETDATA	set value from data space
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|  * T_SETUSER	set value in user process table
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|  * T_RESUME	resume execution
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|  * T_EXIT	exit
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|  * T_STEP	set trace bit
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|  *
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|  * The T_OK and T_EXIT commands are handled completely by the process manager,
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|  * all others come here.
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|  */
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| 
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|   register struct proc *rp;
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|   phys_bytes src, dst;
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|   vir_bytes tr_addr = (vir_bytes) m_ptr->CTL_ADDRESS;
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|   long tr_data = m_ptr->CTL_DATA;
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|   int tr_request = m_ptr->CTL_REQUEST;
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|   int tr_proc_nr = m_ptr->CTL_PROC_NR;
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|   int i;
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| 
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|   if (! isokprocn(tr_proc_nr)) return(EINVAL);
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|   if (iskerneln(tr_proc_nr)) return(EPERM);
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| 
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|   rp = proc_addr(tr_proc_nr);
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|   if (isemptyp(rp)) return(EIO);
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|   switch (tr_request) {
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|   case T_STOP:			/* stop process */
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| 	if (rp->p_rts_flags == 0) lock_dequeue(rp);
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| 	rp->p_rts_flags |= P_STOP;
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| 	rp->p_reg.psw &= ~TRACEBIT;	/* clear trace bit */
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| 	return(OK);
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| 
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|   case T_GETINS:		/* return value from instruction space */
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| 	if (rp->p_memmap[T].mem_len != 0) {
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| 		if ((src = umap_local(rp, T, tr_addr, TR_VLSIZE)) == 0) return(EIO);
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| 		phys_copy(src, vir2phys(&tr_data), (phys_bytes) sizeof(long));
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| 		m_ptr->CTL_DATA = tr_data;
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| 		break;
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| 	}
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| 	/* Text space is actually data space - fall through. */
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| 
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|   case T_GETDATA:		/* return value from data space */
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| 	if ((src = umap_local(rp, D, tr_addr, TR_VLSIZE)) == 0) return(EIO);
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| 	phys_copy(src, vir2phys(&tr_data), (phys_bytes) sizeof(long));
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| 	m_ptr->CTL_DATA= tr_data;
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| 	break;
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| 
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|   case T_GETUSER:		/* return value from process table */
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| 	if ((tr_addr & (sizeof(long) - 1)) != 0 ||
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| 	    tr_addr > sizeof(struct proc) - sizeof(long))
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| 		return(EIO);
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| 	m_ptr->CTL_DATA = *(long *) ((char *) rp + (int) tr_addr);
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| 	break;
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| 
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|   case T_SETINS:		/* set value in instruction space */
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| 	if (rp->p_memmap[T].mem_len != 0) {
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| 		if ((dst = umap_local(rp, T, tr_addr, TR_VLSIZE)) == 0) return(EIO);
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| 		phys_copy(vir2phys(&tr_data), dst, (phys_bytes) sizeof(long));
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| 		m_ptr->CTL_DATA = 0;
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| 		break;
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| 	}
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| 	/* Text space is actually data space - fall through. */
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| 
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|   case T_SETDATA:			/* set value in data space */
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| 	if ((dst = umap_local(rp, D, tr_addr, TR_VLSIZE)) == 0) return(EIO);
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| 	phys_copy(vir2phys(&tr_data), dst, (phys_bytes) sizeof(long));
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| 	m_ptr->CTL_DATA = 0;
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| 	break;
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| 
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|   case T_SETUSER:			/* set value in process table */
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| 	if ((tr_addr & (sizeof(reg_t) - 1)) != 0 ||
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| 	     tr_addr > sizeof(struct stackframe_s) - sizeof(reg_t))
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| 		return(EIO);
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| 	i = (int) tr_addr;
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| #if (CHIP == INTEL)
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| 	/* Altering segment registers might crash the kernel when it
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| 	 * tries to load them prior to restarting a process, so do
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| 	 * not allow it.
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| 	 */
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| 	if (i == (int) &((struct proc *) 0)->p_reg.cs ||
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| 	    i == (int) &((struct proc *) 0)->p_reg.ds ||
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| 	    i == (int) &((struct proc *) 0)->p_reg.es ||
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| #if _WORD_SIZE == 4
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| 	    i == (int) &((struct proc *) 0)->p_reg.gs ||
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| 	    i == (int) &((struct proc *) 0)->p_reg.fs ||
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| #endif
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| 	    i == (int) &((struct proc *) 0)->p_reg.ss)
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| 		return(EIO);
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| #endif
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| 	if (i == (int) &((struct proc *) 0)->p_reg.psw)
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| 		/* only selected bits are changeable */
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| 		SETPSW(rp, tr_data);
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| 	else
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| 		*(reg_t *) ((char *) &rp->p_reg + i) = (reg_t) tr_data;
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| 	m_ptr->CTL_DATA = 0;
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| 	break;
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| 
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|   case T_RESUME:		/* resume execution */
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| 	rp->p_rts_flags &= ~P_STOP;
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| 	if (rp->p_rts_flags == 0) lock_enqueue(rp);
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| 	m_ptr->CTL_DATA = 0;
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| 	break;
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| 
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|   case T_STEP:			/* set trace bit */
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| 	rp->p_reg.psw |= TRACEBIT;
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| 	rp->p_rts_flags &= ~P_STOP;
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| 	if (rp->p_rts_flags == 0) lock_enqueue(rp);
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| 	m_ptr->CTL_DATA = 0;
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| 	break;
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| 
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|   default:
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| 	return(EIO);
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|   }
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|   return(OK);
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| }
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| 
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| #endif /* USE_TRACE */
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