minix/kernel/system/do_vcopy.c

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/* The system call implemented in this file:
* m_type: SYS_VIRVCOPY, SYS_PHYSVCOPY
*
* 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_VIRVCOPY || USE_PHYSVCOPY)
/* Buffer to hold copy request vector from user. */
PRIVATE struct vir_cp_req vir_cp_req[VCOPY_VEC_SIZE];
/*===========================================================================*
* do_vcopy *
*===========================================================================*/
PUBLIC int do_vcopy(m_ptr)
register message *m_ptr; /* pointer to request message */
{
/* Handle sys_virvcopy() and sys_physvcopy() that pass a vector with copy
* requests. Although a single handler function is used, there are two
* different system calls so that permissions can be checked.
*/
int nr_req;
int caller_pid;
vir_bytes caller_vir;
phys_bytes caller_phys;
phys_bytes kernel_phys;
phys_bytes bytes;
int i,s;
struct vir_cp_req *req;
/* Check if request vector size is ok. */
nr_req = (unsigned) m_ptr->VCP_VEC_SIZE;
if (nr_req > VCOPY_VEC_SIZE) return(EINVAL);
bytes = nr_req * sizeof(struct vir_cp_req);
/* Calculate physical addresses and copy (port,value)-pairs from user. */
caller_pid = (int) m_ptr->m_source;
caller_vir = (vir_bytes) m_ptr->VCP_VEC_ADDR;
caller_phys = umap_local(proc_addr(caller_pid), D, caller_vir, bytes);
if (0 == caller_phys) return(EFAULT);
kernel_phys = vir2phys(vir_cp_req);
phys_copy(caller_phys, kernel_phys, (phys_bytes) bytes);
/* Assume vector with requests is correct. Try to copy everything. */
for (i=0; i<nr_req; i++) {
req = &vir_cp_req[i];
/* Check if physical addressing is used without SYS_PHYSVCOPY. */
if (((req->src.segment | req->dst.segment) & PHYS_SEG) &&
m_ptr->m_type != SYS_PHYSVCOPY)
return(EPERM);
if ((s=virtual_copy(&req->src, &req->dst, req->count)) != OK)
return(s);
}
return(OK);
}
#endif /* (USE_VIRVCOPY || USE_PHYSVCOPY) */