minix/kernel/system/copying.c

/* The system call implemented in this file:
 *   m_type:	SYS_VIRCOPY, SYS_PHYSCOPY, SYS_PHYSZERO
 *
 * The parameters for this system call are:
 *    m5_c1:	CP_SRC_SPACE
 *    m5_l1:	CP_SRC_ADDR
 *    m5_i1:	CP_SRC_PROC_NR	
 *    m5_c2:	CP_DST_SPACE
 *    m5_l2:	CP_DST_ADDR	
 *    m5_i2:	CP_DST_PROC_NR	
 *    m5_l3:	CP_NR_BYTES
 */

#include "../kernel.h"
#include "../system.h"
#include <minix/type.h>

/*===========================================================================*
 *				do_copy					     *
 *===========================================================================*/
PUBLIC int do_copy(m_ptr)
register message *m_ptr;	/* pointer to request message */
{
/* Handle sys_vircopy() and sys_physcopy().  Copy data using virtual or
 * physical addressing. 
 */
  struct vir_addr vir_addr[2];	/* virtual source and destination address */
  vir_bytes bytes;		/* number of bytes to copy */
  int i;

  /* Dismember the command message. */
  vir_addr[_SRC_].proc_nr = m_ptr->CP_SRC_PROC_NR;
  vir_addr[_SRC_].segment = m_ptr->CP_SRC_SPACE;
  vir_addr[_SRC_].offset = (vir_bytes) m_ptr->CP_SRC_ADDR;
  vir_addr[_DST_].proc_nr = m_ptr->CP_DST_PROC_NR;
  vir_addr[_DST_].segment = m_ptr->CP_DST_SPACE;
  vir_addr[_DST_].offset = (vir_bytes) m_ptr->CP_DST_ADDR;
  bytes = (phys_bytes) m_ptr->CP_NR_BYTES;

  /* Now do some checks for both the source and destination virtual address.
   * This is done once for _SRC_, then once for _DST_. 
   */
  for (i=_SRC_; i<=_DST_; i++) {

      /* Check if process number was given implictly with SELF and is valid. */
      if (vir_addr[i].proc_nr == SELF) vir_addr[i].proc_nr = m_ptr->m_source;
      if (! isokprocn(vir_addr[i].proc_nr) && vir_addr[i].segment != PHYS_SEG) {
          kprintf("do_vircopy: illegal proc nr, while not phys addr\n",NO_ARG);
          return(EINVAL); 
      }

      /* Check if physical addressing is used without SYS_PHYSCOPY. */
      if ((vir_addr[i].segment & PHYS_SEG) &&
          m_ptr->m_type != SYS_PHYSCOPY) return(EPERM);
  }

  /* Check for overflow. This would happen for 64K segments and 16-bit 
   * vir_bytes. Especially copying by the PM on do_fork() is affected. 
   */
  if (bytes != (vir_bytes) bytes) {
	kprintf("do_vircopy: overflow\n", NO_ARG);
	return(E2BIG);
  }

  /* Now try to make the actual virtual copy. */
  return( virtual_copy(&vir_addr[_SRC_], &vir_addr[_DST_], bytes) );
}


/* Buffer to hold copy request vector from user. */
PRIVATE struct vir_cp_req vir_cp_req[VCOPY_VEC_SIZE];

/*===========================================================================*
 *				do_vcopy					     *
 *===========================================================================*/
PUBLIC int do_vcopy(m_ptr)
register message *m_ptr;	/* pointer to request message */
{
/* Handle sys_virvcopy(). Handle virtual copy requests from vector. */
  int nr_req;
  int caller_pid;
  vir_bytes caller_vir;
  phys_bytes caller_phys;
  phys_bytes kernel_phys;
  phys_bytes bytes;
  int i,s;
  struct vir_cp_req *req;

  /* Check if request vector size is ok. */
  nr_req = (unsigned) m_ptr->VCP_VEC_SIZE;
  if (nr_req > VCOPY_VEC_SIZE) return(EINVAL);
  bytes = nr_req * sizeof(struct vir_cp_req);

  /* Calculate physical addresses and copy (port,value)-pairs from user. */
  caller_pid = (int) m_ptr->m_source; 
  caller_vir = (vir_bytes) m_ptr->VCP_VEC_ADDR;
  caller_phys = umap_local(proc_addr(caller_pid), D, caller_vir, bytes);
  if (0 == caller_phys) return(EFAULT);
  kernel_phys = vir2phys(vir_cp_req);
  phys_copy(caller_phys, kernel_phys, (phys_bytes) bytes);

  /* Assume vector with requests is correct. Try to copy everything. */
  for (i=0; i<nr_req; i++) {

      req = &vir_cp_req[i];

      /* Check if physical addressing is used without SYS_PHYSVCOPY. */
      if (((req->src.segment | req->dst.segment) & PHYS_SEG) &&
              m_ptr->m_type != SYS_PHYSVCOPY) 
          return(EPERM);
      if ((s=virtual_copy(&req->src, &req->dst, req->count)) != OK) 
          return(s);
  }
  return(OK);
}

/*===========================================================================*
 *				do_physzero				     *
 *===========================================================================*/
PUBLIC int do_physzero(m_ptr)
register message *m_ptr;
{
/* Handle sys_physzero(). */
  phys_zero((phys_bytes) m_ptr->PZ_MEM_PTR, (phys_bytes) m_ptr->PZ_COUNT);
  return(OK);
}


/* The system call implemented in this file:
 *   m_type:	SYS_UMAP
 *
 * The parameters for this system call are:
 *    m5_i1:	CP_SRC_PROC_NR	(process number)	
 *    m5_c1:	CP_SRC_SPACE	(segment where address is: T, D, or S)
 *    m5_l1:	CP_SRC_ADDR	(virtual address)	
 *    m5_l2:	CP_DST_ADDR	(returns physical address)	
 *    m5_l3:	CP_NR_BYTES	(size of datastructure) 	
 */

/*==========================================================================*
 *				do_umap					    *
 *==========================================================================*/
PUBLIC int do_umap(m_ptr)
register message *m_ptr;	/* pointer to request message */
{
/* Map virtual address to physical, for non-kernel processes. */
  int seg_type = m_ptr->CP_SRC_SPACE & SEGMENT_TYPE;
  int seg_index = m_ptr->CP_SRC_SPACE & SEGMENT_INDEX;
  vir_bytes offset = m_ptr->CP_SRC_ADDR;
  int count = m_ptr->CP_NR_BYTES;
  int proc_nr = (int) m_ptr->CP_SRC_PROC_NR;
  phys_bytes phys_addr;

  /* Verify process number. */
  if (proc_nr == SELF) proc_nr = m_ptr->m_source;
  if (! isokprocn(proc_nr)) return(EINVAL);

  /* See which mapping should be made. */
  switch(seg_type) {
  case LOCAL_SEG:
      phys_addr = umap_local(proc_addr(proc_nr), seg_index, offset, count); 
      break;
  case REMOTE_SEG:
      phys_addr = umap_remote(proc_addr(proc_nr), seg_index, offset, count); 
      break;
  case BIOS_SEG:
      phys_addr = umap_bios(proc_addr(proc_nr), offset, count); 
      break;
  default:
      return(EINVAL);
  }
  m_ptr->CP_DST_ADDR = phys_addr;
  return (phys_addr == 0) ? EFAULT: OK;
}