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minix/servers/vm/mmap.c
David van Moolenbroek b91295a8d2 vm: if mmap address is given, try that first 
Previously, the mmap address (if given) was merely used as a lower
bound, and then possibly overriden with a hint. Now, the mapping is
first tried at the exact given address. If that fails, the start of
the mmap range is used as lower bound (which is then still overridden
by the hint for efficiency).

This allows two pages to be mapped in at predefined addresses, where
the second address is lower than the first. That was not possible.
2012-03-24 19:51:14 +01:00

496 lines
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#define _SYSTEM 1
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/config.h>
#include <minix/const.h>
#include <minix/ds.h>
#include <minix/endpoint.h>
#include <minix/keymap.h>
#include <minix/minlib.h>
#include <minix/type.h>
#include <minix/ipc.h>
#include <minix/sysutil.h>
#include <minix/syslib.h>
#include <minix/safecopies.h>
#include <minix/bitmap.h>
#include <minix/debug.h>
#include <sys/mman.h>
#include <errno.h>
#include <assert.h>
#include <string.h>
#include <env.h>
#include <stdio.h>
#include <fcntl.h>
#include <memory.h>
#include "glo.h"
#include "proto.h"
#include "util.h"
#include "region.h"
/*===========================================================================*
* do_mmap *
*===========================================================================*/
PUBLIC int do_mmap(message *m)
{
int r, n;
struct vmproc *vmp;
int mfflags = 0;
vir_bytes addr;
struct vir_region *vr = NULL;
if((r=vm_isokendpt(m->m_source, &n)) != OK) {
panic("do_mmap: message from strange source: %d", m->m_source);
}
vmp = &vmproc[n];
if(!(vmp->vm_flags & VMF_HASPT))
return ENXIO;
if(m->VMM_FD == -1 || (m->VMM_FLAGS & MAP_ANON)) {
u32_t vrflags = VR_ANON | VR_WRITABLE;
size_t len = (vir_bytes) m->VMM_LEN;
if(m->VMM_FD != -1 || len <= 0) {
return EINVAL;
}
/* Contiguous phys memory has to be preallocated. */
if((m->VMM_FLAGS & (MAP_CONTIG|MAP_PREALLOC)) == MAP_CONTIG) {
return EINVAL;
}
if(m->VMM_FLAGS & MAP_PREALLOC) mfflags |= MF_PREALLOC;
if(m->VMM_FLAGS & MAP_LOWER16M) vrflags |= VR_LOWER16MB;
if(m->VMM_FLAGS & MAP_LOWER1M) vrflags |= VR_LOWER1MB;
if(m->VMM_FLAGS & MAP_ALIGN64K) vrflags |= VR_PHYS64K;
if(m->VMM_FLAGS & MAP_IPC_SHARED) {
vrflags |= VR_SHARED;
/* Shared memory has to be preallocated. */
if((m->VMM_FLAGS & (MAP_PREALLOC|MAP_ANON)) !=
(MAP_PREALLOC|MAP_ANON)) {
return EINVAL;
}
}
if(m->VMM_FLAGS & MAP_CONTIG) vrflags |= VR_CONTIG;
if(len % VM_PAGE_SIZE)
len += VM_PAGE_SIZE - (len % VM_PAGE_SIZE);
vr = NULL;
if (m->VMM_ADDR) {
/* An address is given, first try at that address. */
addr = arch_vir2map(vmp, m->VMM_ADDR);
vr = map_page_region(vmp, addr, 0, len, MAP_NONE,
vrflags, mfflags);
}
if (!vr) {
/* No address given or address already in use. */
addr = arch_vir2map(vmp, vmp->vm_stacktop);
vr = map_page_region(vmp, addr, VM_DATATOP, len,
MAP_NONE, vrflags, mfflags);
}
if (!vr) {
return ENOMEM;
}
} else {
return ENOSYS;
}
/* Return mapping, as seen from process. */
assert(vr);
m->VMM_RETADDR = arch_map2vir(vmp, vr->vaddr);
return OK;
}
/*===========================================================================*
* map_perm_check *
*===========================================================================*/
PUBLIC int map_perm_check(endpoint_t caller, endpoint_t target,
phys_bytes physaddr, phys_bytes len)
{
int r;
/* TTY and memory are allowed to do anything.
* They have to be special cases as they have to be able to do
* anything; TTY even on behalf of anyone for the TIOCMAPMEM
* ioctl. MEM just for itself.
*/
if(caller == TTY_PROC_NR)
return OK;
if(caller != target)
return EPERM;
if(caller == MEM_PROC_NR)
return OK;
/* Anyone else needs explicit permission from the kernel (ultimately
* set by PCI).
*/
r = sys_privquery_mem(caller, physaddr, len);
return r;
}
/*===========================================================================*
* do_map_phys *
*===========================================================================*/
PUBLIC int do_map_phys(message *m)
{
int r, n;
struct vmproc *vmp;
endpoint_t target;
struct vir_region *vr;
vir_bytes len;
phys_bytes startaddr;
size_t offset;
target = m->VMMP_EP;
len = m->VMMP_LEN;
if (len <= 0) return EINVAL;
if(target == SELF)
target = m->m_source;
if((r=vm_isokendpt(target, &n)) != OK)
return EINVAL;
startaddr = (vir_bytes)m->VMMP_PHADDR;
/* First check permission, then round range down/up. Caller can't
* help it if we can't map in lower than page granularity.
*/
if(map_perm_check(m->m_source, target, startaddr, len) != OK) {
printf("VM: unauthorized mapping of 0x%lx by %d\n",
startaddr, m->m_source);
return EPERM;
}
vmp = &vmproc[n];
if(!(vmp->vm_flags & VMF_HASPT))
return ENXIO;
offset = startaddr % VM_PAGE_SIZE;
len += offset;
startaddr -= offset;
if(len % VM_PAGE_SIZE)
len += VM_PAGE_SIZE - (len % VM_PAGE_SIZE);
if(!(vr = map_page_region(vmp, arch_vir2map(vmp, vmp->vm_stacktop),
VM_DATATOP, len, startaddr,
VR_DIRECT | VR_NOPF | VR_WRITABLE, 0))) {
return ENOMEM;
}
m->VMMP_VADDR_REPLY = (void *) (arch_map2vir(vmp, vr->vaddr) + offset);
return OK;
}
/*===========================================================================*
* do_unmap_phys *
*===========================================================================*/
PUBLIC int do_unmap_phys(message *m)
{
int r, n;
struct vmproc *vmp;
endpoint_t target;
struct vir_region *region;
target = m->VMUP_EP;
if(target == SELF)
target = m->m_source;
if((r=vm_isokendpt(target, &n)) != OK)
return EINVAL;
vmp = &vmproc[n];
if(!(region = map_lookup(vmp,
arch_vir2map(vmp, (vir_bytes) m->VMUM_ADDR)))) {
return EINVAL;
}
if(!(region->flags & VR_DIRECT)) {
return EINVAL;
}
if(map_unmap_region(vmp, region, region->length) != OK) {
return EINVAL;
}
return OK;
}
/*===========================================================================*
* do_remap *
*===========================================================================*/
PUBLIC int do_remap(message *m)
{
int dn, sn;
vir_bytes da, sa, startv;
size_t size;
struct vir_region *region;
struct vmproc *dvmp, *svmp;
int r;
int readonly;
if(m->m_type == VM_REMAP)
readonly = 0;
else if(m->m_type == VM_REMAP_RO)
readonly = 1;
else panic("do_remap: can't be");
da = (vir_bytes) m->VMRE_DA;
sa = (vir_bytes) m->VMRE_SA;
size = m->VMRE_SIZE;
if (size <= 0) return EINVAL;
if ((r = vm_isokendpt((endpoint_t) m->VMRE_D, &dn)) != OK)
return EINVAL;
if ((r = vm_isokendpt((endpoint_t) m->VMRE_S, &sn)) != OK)
return EINVAL;
dvmp = &vmproc[dn];
svmp = &vmproc[sn];
/* da is not translated by arch_vir2map(),
* it's handled a little differently,
* since in map_remap(), we have to know
* about whether the user needs to bind to
* THAT address or be chosen by the system.
*/
sa = arch_vir2map(svmp, sa);
if (!(region = map_lookup(svmp, sa)))
return EINVAL;
if(region->vaddr != sa) {
printf("VM: do_remap: not start of region.\n");
return EFAULT;
}
if(!(region->flags & VR_SHARED)) {
printf("VM: do_remap: not shared.\n");
return EFAULT;
}
if (size % VM_PAGE_SIZE)
size += VM_PAGE_SIZE - size % VM_PAGE_SIZE;
if(size != region->length) {
printf("VM: do_remap: not size of region.\n");
return EFAULT;
}
if ((r = map_remap(dvmp, da, size, region, &startv, readonly)) != OK)
return r;
m->VMRE_RETA = (char *) arch_map2vir(dvmp, startv);
return OK;
}
/*===========================================================================*
* do_shared_unmap *
*===========================================================================*/
PUBLIC int do_shared_unmap(message *m)
{
int r, n;
struct vmproc *vmp;
endpoint_t target;
struct vir_region *vr;
vir_bytes addr;
target = m->VMUN_ENDPT;
if (target == SELF)
target = m->m_source;
if ((r = vm_isokendpt(target, &n)) != OK)
return EINVAL;
vmp = &vmproc[n];
addr = arch_vir2map(vmp, m->VMUN_ADDR);
if(!(vr = map_lookup(vmp, addr))) {
printf("VM: addr 0x%lx not found.\n", m->VMUN_ADDR);
return EFAULT;
}
if(vr->vaddr != addr) {
printf("VM: wrong address for shared_unmap.\n");
return EFAULT;
}
if(!(vr->flags & VR_SHARED)) {
printf("VM: address does not point to shared region.\n");
return EFAULT;
}
if(map_unmap_region(vmp, vr, vr->length) != OK)
panic("do_shared_unmap: map_unmap_region failed");
return OK;
}
/*===========================================================================*
* do_get_phys *
*===========================================================================*/
PUBLIC int do_get_phys(message *m)
{
int r, n;
struct vmproc *vmp;
endpoint_t target;
phys_bytes ret;
vir_bytes addr;
target = m->VMPHYS_ENDPT;
addr = m->VMPHYS_ADDR;
if ((r = vm_isokendpt(target, &n)) != OK)
return EINVAL;
vmp = &vmproc[n];
addr = arch_vir2map(vmp, addr);
r = map_get_phys(vmp, addr, &ret);
m->VMPHYS_RETA = ret;
return r;
}
/*===========================================================================*
* do_get_refcount *
*===========================================================================*/
PUBLIC int do_get_refcount(message *m)
{
int r, n;
struct vmproc *vmp;
endpoint_t target;
u8_t cnt;
vir_bytes addr;
target = m->VMREFCNT_ENDPT;
addr = m->VMREFCNT_ADDR;
if ((r = vm_isokendpt(target, &n)) != OK)
return EINVAL;
vmp = &vmproc[n];
addr = arch_vir2map(vmp, addr);
r = map_get_ref(vmp, addr, &cnt);
m->VMREFCNT_RETC = cnt;
return r;
}
/*===========================================================================*
* do_munmap *
*===========================================================================*/
PUBLIC int do_munmap(message *m)
{
int r, n;
struct vmproc *vmp;
vir_bytes addr, len;
struct vir_region *vr;
if((r=vm_isokendpt(m->m_source, &n)) != OK) {
panic("do_mmap: message from strange source: %d", m->m_source);
}
vmp = &vmproc[n];
if(!(vmp->vm_flags & VMF_HASPT))
return ENXIO;
if(m->m_type == VM_MUNMAP) {
addr = (vir_bytes) arch_vir2map(vmp, (vir_bytes) m->VMUM_ADDR);
} else if(m->m_type == VM_MUNMAP_TEXT) {
addr = (vir_bytes) arch_vir2map_text(vmp, (vir_bytes) m->VMUM_ADDR);
} else {
panic("do_munmap: strange type");
}
if(!(vr = map_lookup(vmp, addr))) {
printf("VM: unmap: virtual address %p not found in %d\n",
m->VMUM_ADDR, vmp->vm_endpoint);
return EFAULT;
}
len = m->VMUM_LEN;
if (len % VM_PAGE_SIZE)
len += VM_PAGE_SIZE - (len % VM_PAGE_SIZE);
if(addr != vr->vaddr || len > vr->length || len < VM_PAGE_SIZE) {
return EFAULT;
}
if(map_unmap_region(vmp, vr, len) != OK)
panic("do_munmap: map_unmap_region failed");
return OK;
}
int unmap_ok = 0;
/*===========================================================================*
* munmap_lin (used for overrides for VM) *
*===========================================================================*/
PRIVATE int munmap_lin(vir_bytes addr, size_t len)
{
if(addr % VM_PAGE_SIZE) {
printf("munmap_lin: offset not page aligned\n");
return EFAULT;
}
if(len % VM_PAGE_SIZE) {
printf("munmap_lin: len not page aligned\n");
return EFAULT;
}
if(pt_writemap(NULL, &vmproc[VM_PROC_NR].vm_pt, addr, MAP_NONE, len, 0,
WMF_OVERWRITE | WMF_FREE) != OK) {
printf("munmap_lin: pt_writemap failed\n");
return EFAULT;
}
return OK;
}
/*===========================================================================*
* munmap (override for VM) *
*===========================================================================*/
PUBLIC int minix_munmap(void *addr, size_t len)
{
vir_bytes laddr;
if(!unmap_ok)
return ENOSYS;
laddr = (vir_bytes) arch_vir2map(&vmproc[VM_PROC_NR], (vir_bytes) addr);
return munmap_lin(laddr, len);
}
/*===========================================================================*
* munmap_text (override for VM) *
*===========================================================================*/
PUBLIC int minix_munmap_text(void *addr, size_t len)
{
vir_bytes laddr;
if(!unmap_ok)
return ENOSYS;
laddr = (vir_bytes) arch_vir2map_text(&vmproc[VM_PROC_NR],
(vir_bytes) addr);
return munmap_lin(laddr, len);
}
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