kernel/system/do_vcopy.c

   1 /* The kernel call implemented in this file:
   2  *   m_type:    SYS_VIRVCOPY, SYS_PHYSVCOPY
   3  *
   4  * The parameters for this kernel call are:
   5  *    m1_i3:    VCP_VEC_SIZE            size of copy request vector
   6  *    m1_p1:    VCP_VEC_ADDR            address of vector at caller
   7  *    m1_i2:    VCP_NR_OK               number of successfull copies
   8  */
   9
  10 #include "../system.h"
  11 #include <minix/type.h>
  12
  13 #if (USE_VIRVCOPY || USE_PHYSVCOPY)
  14
  15 /* Buffer to hold copy request vector from user. */
  16 PRIVATE struct vir_cp_req vir_cp_req[VCOPY_VEC_SIZE];
  17
  18 /*===========================================================================*
  19  *                              do_vcopy                                             *
  20  *===========================================================================*/
  21 PUBLIC int do_vcopy(m_ptr)
  22 register message *m_ptr;        /* pointer to request message */
  23 {
  24 /* Handle sys_virvcopy() and sys_physvcopy() that pass a vector with copy
  25  * requests. Although a single handler function is used, there are two
  26  * different kernel calls so that permissions can be checked.
  27  */
  28   int nr_req;
  29   vir_bytes caller_vir;
  30   phys_bytes caller_phys;
  31   phys_bytes kernel_phys;
  32   phys_bytes bytes;
  33   int i,s;
  34   struct vir_cp_req *req;
  35
  36   { static int first=1;
  37         if (first)
  38         {
  39                 first= 0;
  40                 kprintf("do_vcopy: got request from %d\n", m_ptr->m_source);
  41         }
  42   }
  43
  44   /* Check if request vector size is ok. */
  45   nr_req = (unsigned) m_ptr->VCP_VEC_SIZE;
  46   if (nr_req > VCOPY_VEC_SIZE) return(EINVAL);
  47   bytes = nr_req * sizeof(struct vir_cp_req);
  48
  49   /* Calculate physical addresses and copy (port,value)-pairs from user. */
  50   caller_vir = (vir_bytes) m_ptr->VCP_VEC_ADDR;
  51   caller_phys = umap_local(proc_addr(who_p), D, caller_vir, bytes);
  52   if (0 == caller_phys) return(EFAULT);
  53   kernel_phys = vir2phys(vir_cp_req);
  54   phys_copy(caller_phys, kernel_phys, (phys_bytes) bytes);
  55
  56   /* Assume vector with requests is correct. Try to copy everything. */
  57   m_ptr->VCP_NR_OK = 0;
  58   for (i=0; i<nr_req; i++) {
  59
  60       req = &vir_cp_req[i];
  61
  62       /* Check if physical addressing is used without SYS_PHYSVCOPY. */
  63       if (((req->src.segment | req->dst.segment) & PHYS_SEG) &&
  64               m_ptr->m_type != SYS_PHYSVCOPY) return(EPERM);
  65       if ((s=virtual_copy(&req->src, &req->dst, req->count)) != OK)
  66           return(s);
  67       m_ptr->VCP_NR_OK ++;
  68   }
  69   return(OK);
  70 }
  71
  72 #endif /* (USE_VIRVCOPY || USE_PHYSVCOPY) */
  73