minix/kernel/system/do_getinfo.c

/* The system call implemented in this file:
 *   m_type:	SYS_GETINFO
 *
 * The parameters for this system call are:
 *    m1_i3:	I_REQUEST	(what info to get)	
 *    m1_i4:	I_PROC_NR	(process to store value at)	
 *    m1_p1:	I_VAL_PTR 	(where to put it)	
 *    m1_i1:	I_VAL_LEN 	(maximum length expected, optional)	
 *    m1_p2:	I_KEY_PTR	(environment variable key)	
 *    m1_i2:	I_KEY_LEN	(lenght of environment variable key)	
 * 
 * Author:
 *    Jorrit N. Herder <jnherder@cs.vu.nl>
 */

#include "../system.h"

#if USE_GETINFO

/*===========================================================================*
 *			        do_getinfo				     *
 *===========================================================================*/
PUBLIC int do_getinfo(m_ptr)
register message *m_ptr;	/* pointer to request message */
{
/* Request system information to be copied to caller's address space. */
  size_t length;
  phys_bytes src_phys; 
  phys_bytes dst_phys; 
  int proc_nr, nr;

  /* Set source address and length based on request type. */      
  switch (m_ptr->I_REQUEST) {	
    case GET_MACHINE: {
    	length = sizeof(struct machine);
    	src_phys = vir2phys(&machine);
    	break;
    }
    case GET_KINFO: {
    	length = sizeof(struct kinfo);
    	src_phys = vir2phys(&kinfo);
    	break;
    }
    case GET_IMAGE: {
    	length = sizeof(struct system_image) * NR_BOOT_PROCS;
    	src_phys = vir2phys(image);
        break;
    }
    case GET_IRQHOOKS: {
    	length = sizeof(struct irq_hook) * NR_IRQ_HOOKS;
    	src_phys = vir2phys(irq_hooks);
        break;
    }
    case GET_SCHEDINFO: {
        /* This is slightly complicated because we need two data structures
         * at once, otherwise the scheduling information may be incorrect.
         * Copy the queue heads and fall through to copy the process table. 
         */
        length = sizeof(struct proc *) * NR_SCHED_QUEUES;
        src_phys = vir2phys(rdy_head);
        dst_phys = numap_local(m_ptr->m_source, (vir_bytes) m_ptr->I_KEY_PTR,
        	 length); 
        if (src_phys == 0 || dst_phys == 0) return(EFAULT);
        phys_copy(src_phys, dst_phys, length);
        /* fall through */
    }
    case GET_PROCTAB: {
    	length = sizeof(struct proc) * (NR_PROCS + NR_TASKS);
    	src_phys = vir2phys(proc);
        break;
    }
    case GET_PRIVTAB: {
    	length = sizeof(struct priv) * (NR_SYS_PROCS);
    	src_phys = vir2phys(priv);
        break;
    }
    case GET_PROC: {
    	nr = (m_ptr->I_KEY_LEN == SELF) ? m_ptr->m_source : m_ptr->I_KEY_LEN;
    	if (! isokprocn(nr)) return(EINVAL);	/* validate request */
    	length = sizeof(struct proc);
    	src_phys = vir2phys(proc_addr(nr));
        break;
    }
    case GET_MONPARAMS: {
    	src_phys = kinfo.params_base;		/* already is a physical */
    	length = kinfo.params_size;
    	break;
    }
    case GET_RANDOMNESS: {		
        struct randomness copy = krandom;	/* copy to keep counters */
  	krandom.r_next = krandom.r_size = 0;	/* invalidate random data */
    	length = sizeof(struct randomness);
    	src_phys = vir2phys(&copy);
    	break;
    }
    case GET_KMESSAGES: {
        length = sizeof(struct kmessages);
        src_phys = vir2phys(&kmess);
        break;
    }
#if DEBUG_TIME_LOCKS
    case GET_LOCKTIMING: {
	length = sizeof(timingdata);
	src_phys = vir2phys(timingdata);
	break;
    }
#endif
    default:
        return(EINVAL);
  }

  /* Try to make the actual copy for the requested data. */
  if (m_ptr->I_VAL_LEN > 0 && length > m_ptr->I_VAL_LEN) return (E2BIG);
  proc_nr = m_ptr->m_source;	/* only caller can request copy */
  dst_phys = numap_local(proc_nr, (vir_bytes) m_ptr->I_VAL_PTR, length); 
  if (src_phys == 0 || dst_phys == 0) return(EFAULT);
  phys_copy(src_phys, dst_phys, length);
  return(OK);
}

#endif /* USE_GETINFO */