minix/kernel/system/do_copy.c
Jorrit Herder 198c976f7e System processes can be signaled; signals are transformed in SYS_EVENT message
that passes signal map along. This mechanisms is also used for nonuser signals
like SIGKMESS, SIGKSTOP, SIGKSIG.

Revised comments of many system call handlers. Renamed setpriority to nice.
2005-07-19 12:21:36 +00:00

66 lines
2.2 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)
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) 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) */