minix/kernel/system/do_copy.c
Jorrit Herder 42ab148155 Reorganized system call library; uses separate file per call now.
New configuration header file to include/ exclude functionality.
Extracted privileged features from struct proc and create new struct priv.
Renamed various system calls for readability.
2005-07-14 15:12:12 +00:00

72 lines
2.4 KiB
C

/* The system call implemented in this file:
* m_type: SYS_VIRCOPY, SYS_PHYSCOPY
*
* 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 "../system.h"
#include <minix/type.h>
#if (USE_VIRCOPY || USE_PHYSCOPY)
/*===========================================================================*
* 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_NUM);
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_NUM);
return(E2BIG);
}
/* Now try to make the actual virtual copy. */
return( virtual_copy(&vir_addr[_SRC_], &vir_addr[_DST_], bytes) );
}
#endif /* (USE_VIRCOPY || USE_PHYSCOPY) */