xref: /minix3/minix/kernel/system/do_copy.c (revision 9624407e7addfd8b88486acfe3a0e056e2b92ee3)
1*433d6423SLionel Sambuc /* The kernel call implemented in this file:
2*433d6423SLionel Sambuc  *   m_type:	SYS_VIRCOPY, SYS_PHYSCOPY
3*433d6423SLionel Sambuc  *
4*433d6423SLionel Sambuc  * The parameters for this kernel call are:
5*433d6423SLionel Sambuc  *   m_lsys_krn_sys_copy.src_addr		source offset within segment
6*433d6423SLionel Sambuc  *   m_lsys_krn_sys_copy.src_endpt		source process number
7*433d6423SLionel Sambuc  *   m_lsys_krn_sys_copy.dst_addr		destination offset within segment
8*433d6423SLionel Sambuc  *   m_lsys_krn_sys_copy.dst_endpt		destination process number
9*433d6423SLionel Sambuc  *   m_lsys_krn_sys_copy.nr_bytes		number of bytes to copy
10*433d6423SLionel Sambuc  *   m_lsys_krn_sys_copy.flags
11*433d6423SLionel Sambuc  */
12*433d6423SLionel Sambuc 
13*433d6423SLionel Sambuc #include "kernel/system.h"
14*433d6423SLionel Sambuc #include "kernel/vm.h"
15*433d6423SLionel Sambuc #include <assert.h>
16*433d6423SLionel Sambuc 
17*433d6423SLionel Sambuc #if (USE_VIRCOPY || USE_PHYSCOPY)
18*433d6423SLionel Sambuc 
19*433d6423SLionel Sambuc /*===========================================================================*
20*433d6423SLionel Sambuc  *				do_copy					     *
21*433d6423SLionel Sambuc  *===========================================================================*/
do_copy(struct proc * caller,message * m_ptr)22*433d6423SLionel Sambuc int do_copy(struct proc * caller, message * m_ptr)
23*433d6423SLionel Sambuc {
24*433d6423SLionel Sambuc /* Handle sys_vircopy() and sys_physcopy().  Copy data using virtual or
25*433d6423SLionel Sambuc  * physical addressing. Although a single handler function is used, there
26*433d6423SLionel Sambuc  * are two different kernel calls so that permissions can be checked.
27*433d6423SLionel Sambuc  */
28*433d6423SLionel Sambuc   struct vir_addr vir_addr[2];	/* virtual source and destination address */
29*433d6423SLionel Sambuc   phys_bytes bytes;		/* number of bytes to copy */
30*433d6423SLionel Sambuc   int i;
31*433d6423SLionel Sambuc 
32*433d6423SLionel Sambuc #if 0
33*433d6423SLionel Sambuc   if (caller->p_endpoint != PM_PROC_NR && caller->p_endpoint != VFS_PROC_NR &&
34*433d6423SLionel Sambuc 	caller->p_endpoint != RS_PROC_NR && caller->p_endpoint != MEM_PROC_NR &&
35*433d6423SLionel Sambuc 	caller->p_endpoint != VM_PROC_NR)
36*433d6423SLionel Sambuc   {
37*433d6423SLionel Sambuc 	static int first=1;
38*433d6423SLionel Sambuc 	if (first)
39*433d6423SLionel Sambuc 	{
40*433d6423SLionel Sambuc 		first= 0;
41*433d6423SLionel Sambuc 		printf(
42*433d6423SLionel Sambuc "do_copy: got request from %d (source %d, destination %d)\n",
43*433d6423SLionel Sambuc 			caller->p_endpoint,
44*433d6423SLionel Sambuc 			m_ptr->m_lsys_krn_sys_copy.src_endpt,
45*433d6423SLionel Sambuc 			m_ptr->m_lsys_krn_sys_copy.dst_endpt);
46*433d6423SLionel Sambuc 	}
47*433d6423SLionel Sambuc   }
48*433d6423SLionel Sambuc #endif
49*433d6423SLionel Sambuc 
50*433d6423SLionel Sambuc   /* Dismember the command message. */
51*433d6423SLionel Sambuc   vir_addr[_SRC_].proc_nr_e = m_ptr->m_lsys_krn_sys_copy.src_endpt;
52*433d6423SLionel Sambuc   vir_addr[_DST_].proc_nr_e = m_ptr->m_lsys_krn_sys_copy.dst_endpt;
53*433d6423SLionel Sambuc 
54*433d6423SLionel Sambuc   vir_addr[_SRC_].offset = m_ptr->m_lsys_krn_sys_copy.src_addr;
55*433d6423SLionel Sambuc   vir_addr[_DST_].offset = m_ptr->m_lsys_krn_sys_copy.dst_addr;
56*433d6423SLionel Sambuc   bytes = m_ptr->m_lsys_krn_sys_copy.nr_bytes;
57*433d6423SLionel Sambuc 
58*433d6423SLionel Sambuc   /* Now do some checks for both the source and destination virtual address.
59*433d6423SLionel Sambuc    * This is done once for _SRC_, then once for _DST_.
60*433d6423SLionel Sambuc    */
61*433d6423SLionel Sambuc   for (i=_SRC_; i<=_DST_; i++) {
62*433d6423SLionel Sambuc 	int p;
63*433d6423SLionel Sambuc       /* Check if process number was given implicitly with SELF and is valid. */
64*433d6423SLionel Sambuc       if (vir_addr[i].proc_nr_e == SELF)
65*433d6423SLionel Sambuc 	vir_addr[i].proc_nr_e = caller->p_endpoint;
66*433d6423SLionel Sambuc       if (vir_addr[i].proc_nr_e != NONE) {
67*433d6423SLionel Sambuc 	if(! isokendpt(vir_addr[i].proc_nr_e, &p)) {
68*433d6423SLionel Sambuc 	  printf("do_copy: %d: %d not ok endpoint\n", i, vir_addr[i].proc_nr_e);
69*433d6423SLionel Sambuc           return(EINVAL);
70*433d6423SLionel Sambuc         }
71*433d6423SLionel Sambuc       }
72*433d6423SLionel Sambuc   }
73*433d6423SLionel Sambuc 
74*433d6423SLionel Sambuc   /* Check for overflow. This would happen for 64K segments and 16-bit
75*433d6423SLionel Sambuc    * vir_bytes. Especially copying by the PM on do_fork() is affected.
76*433d6423SLionel Sambuc    */
77*433d6423SLionel Sambuc   if (bytes != (phys_bytes) (vir_bytes) bytes) return(E2BIG);
78*433d6423SLionel Sambuc 
79*433d6423SLionel Sambuc   /* Now try to make the actual virtual copy. */
80*433d6423SLionel Sambuc   if(m_ptr->m_lsys_krn_sys_copy.flags & CP_FLAG_TRY) {
81*433d6423SLionel Sambuc 	int r;
82*433d6423SLionel Sambuc 	assert(caller->p_endpoint == VFS_PROC_NR);
83*433d6423SLionel Sambuc 	r = virtual_copy(&vir_addr[_SRC_], &vir_addr[_DST_], bytes);
84*433d6423SLionel Sambuc 	if(r == EFAULT_SRC || r == EFAULT_DST) return r = EFAULT;
85*433d6423SLionel Sambuc 	return r;
86*433d6423SLionel Sambuc   } else {
87*433d6423SLionel Sambuc 	return( virtual_copy_vmcheck(caller, &vir_addr[_SRC_],
88*433d6423SLionel Sambuc 			  	&vir_addr[_DST_], bytes) );
89*433d6423SLionel Sambuc   }
90*433d6423SLionel Sambuc }
91*433d6423SLionel Sambuc #endif /* (USE_VIRCOPY || USE_PHYSCOPY) */
92