kernel/system/do_umap_remote.c

   1 /* The kernel call implemented in this file:
   2  *   m_type:    SYS_UMAP_REMOTE
   3  *
   4  * The parameters for this kernel call are:
   5  *    m5_i1:    CP_SRC_PROC_NR  (process number)
   6  *    m5_s1:    UMAP_SEG        (segment where address is: T, D, or S)
   7  *    m5_l1:    CP_SRC_ADDR     (virtual address)
   8  *    m5_i2:    CP_DST_ENDPT    (process number of grantee to check access for)
   9  *    m5_l2:    CP_DST_ADDR     (returns physical address)
  10  *    m5_l3:    CP_NR_BYTES     (size of datastructure)
  11  */
  12
  13 #include "kernel/system.h"
  14
  15 #include <minix/endpoint.h>
  16
  17 #if USE_UMAP || USE_UMAP_REMOTE
  18
  19 #if ! USE_UMAP_REMOTE
  20 #undef do_umap_remote
  21 #endif
  22
  23 /*==========================================================================*
  24  *                              do_umap_remote                              *
  25  *==========================================================================*/
  26 int do_umap_remote(struct proc * caller, message * m_ptr)
  27 {
  28 /* Map virtual address to physical, for non-kernel processes. */
  29   int seg_type = m_ptr->UMAP_SEG & SEGMENT_TYPE;
  30   int seg_index = m_ptr->UMAP_SEG & SEGMENT_INDEX;
  31   vir_bytes offset = m_ptr->CP_SRC_ADDR;
  32   int count = m_ptr->CP_NR_BYTES;
  33   int endpt = (int) m_ptr->CP_SRC_ENDPT;
  34   endpoint_t grantee = (endpoint_t) m_ptr->CP_DST_ENDPT;
  35   int proc_nr, proc_nr_grantee;
  36   phys_bytes phys_addr = 0, lin_addr = 0;
  37   struct proc *targetpr;
  38
  39   /* Verify process number. */
  40   if (endpt == SELF)
  41         okendpt(caller->p_endpoint, &proc_nr);
  42   else
  43         if (! isokendpt(endpt, &proc_nr))
  44                 return(EINVAL);
  45   targetpr = proc_addr(proc_nr);
  46
  47   /* Verify grantee endpoint */
  48   if (grantee == SELF) {
  49         grantee = caller->p_endpoint;
  50   } else if (grantee == NONE ||
  51         grantee == ANY ||
  52         seg_index != MEM_GRANT ||
  53         !isokendpt(grantee, &proc_nr_grantee)) {
  54         return EINVAL;
  55   }
  56
  57   /* See which mapping should be made. */
  58   switch(seg_type) {
  59   case LOCAL_VM_SEG:
  60     if(seg_index == MEM_GRANT) {
  61         vir_bytes newoffset;
  62         endpoint_t newep;
  63         int new_proc_nr;
  64         cp_grant_id_t grant = (cp_grant_id_t) offset;
  65
  66         if(verify_grant(targetpr->p_endpoint, grantee, grant, count,
  67                 0, 0, &newoffset, &newep) != OK) {
  68                 printf("SYSTEM: do_umap: verify_grant in %s, grant %d, bytes 0x%lx, failed, caller %s\n", targetpr->p_name, offset, count, caller->p_name);
  69                 proc_stacktrace(caller);
  70                 return EFAULT;
  71         }
  72
  73         if(!isokendpt(newep, &new_proc_nr)) {
  74                 printf("SYSTEM: do_umap: isokendpt failed\n");
  75                 return EFAULT;
  76         }
  77
  78         /* New lookup. */
  79         offset = newoffset;
  80         targetpr = proc_addr(new_proc_nr);
  81         seg_index = VIR_ADDR;
  82       }
  83
  84       if(seg_index == VIR_ADDR) {
  85         phys_addr = lin_addr = offset;
  86       } else {
  87         printf("SYSTEM: bogus seg type 0x%lx\n", seg_index);
  88         return EFAULT;
  89       }
  90       if(!lin_addr) {
  91         printf("SYSTEM:do_umap: umap_local failed\n");
  92         return EFAULT;
  93       }
  94       if(vm_lookup(targetpr, lin_addr, &phys_addr, NULL) != OK) {
  95         printf("SYSTEM:do_umap: vm_lookup failed\n");
  96         return EFAULT;
  97       }
  98       if(phys_addr == 0)
  99         panic("vm_lookup returned zero physical address");
 100       break;
 101   default:
 102         printf("umap: peculiar type\n");
 103         return EINVAL;
 104   }
 105
 106   if(vm_running && vm_lookup_range(targetpr, lin_addr, NULL, count) != count) {
 107         printf("SYSTEM:do_umap: not contiguous\n");
 108         return EFAULT;
 109   }
 110
 111   m_ptr->CP_DST_ADDR = phys_addr;
 112   if(phys_addr == 0) {
 113           printf("kernel: umap 0x%x done by %d / %s, pc 0x%lx, 0x%lx -> 0x%lx\n",
 114                 seg_type, caller->p_endpoint, caller->p_name,
 115                 caller->p_reg.pc, offset, phys_addr);
 116         printf("caller stack: ");
 117         proc_stacktrace(caller);
 118   }
 119   return (phys_addr == 0) ? EFAULT: OK;
 120 }
 121
 122 #endif /* USE_UMAP || USE_UMAP_REMOTE */