77 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			77 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* The kernel call implemented in this file:
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|  *   m_type:	SYS_RUNCTL
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|  *
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|  * The parameters for this kernel call are:
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|  *    m1_i1:	RC_ENDPT	process number to control
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|  *    m1_i2:	RC_ACTION	stop or resume the process
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|  *    m1_i3:	RC_FLAGS	request flags
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|  */
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| 
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| #include "kernel/system.h"
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| #include <assert.h>
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| 
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| #if USE_RUNCTL
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| 
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| /*===========================================================================*
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|  *				  do_runctl				     *
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|  *===========================================================================*/
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| int do_runctl(struct proc * caller, message * m_ptr)
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| {
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| /* Control a process's RTS_PROC_STOP flag. Used for process management.
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|  * If the process is queued sending a message or stopped for system call
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|  * tracing, and the RC_DELAY request flag is given, set MF_SIG_DELAY instead
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|  * of RTS_PROC_STOP, and send a SIGSNDELAY signal later when the process is done
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|  * sending (ending the delay). Used by PM for safe signal delivery.
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|  */
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|   int proc_nr, action, flags;
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|   register struct proc *rp;
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| 
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|   /* Extract the message parameters and do sanity checking. */
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|   if (!isokendpt(m_ptr->RC_ENDPT, &proc_nr)) return(EINVAL);
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|   if (iskerneln(proc_nr)) return(EPERM);
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|   rp = proc_addr(proc_nr);
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| 
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|   action = m_ptr->RC_ACTION;
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|   flags = m_ptr->RC_FLAGS;
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| 
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|   /* Is the target sending or syscall-traced? Then set MF_SIG_DELAY instead.
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|    * Do this only when the RC_DELAY flag is set in the request flags field.
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|    * The process will not become runnable before PM has called SYS_ENDKSIG.
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|    * Note that asynchronous messages are not covered: a process using SENDA
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|    * should not also install signal handlers *and* expect POSIX compliance.
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|    */
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| 
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|   if (action == RC_STOP && (flags & RC_DELAY)) {
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| 	if (RTS_ISSET(rp, RTS_SENDING) || (rp->p_misc_flags & MF_SC_DEFER))
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| 		rp->p_misc_flags |= MF_SIG_DELAY;
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| 
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| 	if (rp->p_misc_flags & MF_SIG_DELAY)
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| 		return (EBUSY);
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|   }
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| 
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|   /* Either set or clear the stop flag. */
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|   switch (action) {
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|   case RC_STOP:
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| #if CONFIG_SMP
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| 	  /* check if we must stop a process on a different CPU */
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| 	  if (rp->p_cpu != cpuid) {
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| 		  smp_schedule_stop_proc(rp);
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| 		  break;
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| 	  }
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| #endif
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| 	  RTS_SET(rp, RTS_PROC_STOP);
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| 	break;
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|   case RC_RESUME:
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| 	assert(RTS_ISSET(rp, RTS_PROC_STOP));
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| 	RTS_UNSET(rp, RTS_PROC_STOP);
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| 	break;
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|   default:
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| 	return(EINVAL);
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|   }
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| 
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|   return(OK);
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| }
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| 
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| #endif /* USE_RUNCTL */
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| 
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