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minix/servers/vm/mmap.c
Ben Gras 7e73260cf5 - enable remembering of device memory ranges set by PCI and 
told to kernel
  - makes VM ask the kernel if a certain process is allowed
    to map in a range of physical memory (VM rounds it to page
    boundaries afterwards - but it's impossible to map anything
    smaller otherwise so I assume this is safe, i.e. there won't
    be anything else in that page; certainly no regular memory)
  - VM permission check cleanup (no more hardcoded calls, less
    hardcoded logic, more readable main loop), a loose end left
    by GQ
  - remove do_copy warning, as the ipc server triggers this but
    it's no more harmful than the special cases already excluded
    explicitly (VFS, PM, etc).
2009-11-03 11:12:23 +00:00

438 lines
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#define _SYSTEM 1
#define VERBOSE 0
#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 <sys/mman.h>
#include <errno.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;
struct vir_region *vr = NULL;
if((r=vm_isokendpt(m->m_source, &n)) != OK) {
vm_panic("do_mmap: message from strange source", m->m_source);
}
vmp = &vmproc[n];
if(!(vmp->vm_flags & VMF_HASPT))
return ENXIO;
if(m->VMM_FD == -1 || (m->VMM_FLAGS & MAP_ANON)) {
int s;
vir_bytes v;
u32_t vrflags = VR_ANON | VR_WRITABLE;
size_t len = (vir_bytes) m->VMM_LEN;
if(m->VMM_FD != -1) {
return EINVAL;
}
if(m->VMM_FLAGS & MAP_CONTIG) mfflags |= MF_CONTIG;
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_SHARED) vrflags |= VR_SHARED;
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, MAP_NONE, vrflags, mfflags))) {
return ENOMEM;
}
} else {
return ENOSYS;
}
/* Return mapping, as seen from process. */
vm_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;
target = m->VMMP_EP;
len = m->VMMP_LEN;
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;
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);
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 d, dn, s, sn;
vir_bytes da, sa, startv;
size_t size;
struct vir_region *vr, *region;
struct vmproc *dvmp, *svmp;
int r;
d = m->VMRE_D;
s = m->VMRE_S;
da = (vir_bytes) m->VMRE_DA;
sa = (vir_bytes) m->VMRE_SA;
size = m->VMRE_SIZE;
if ((r = vm_isokendpt(d, &dn)) != OK)
return EINVAL;
if ((r = vm_isokendpt(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 ((r = map_remap(dvmp, da, size, region, &startv)) != 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 ((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)
vm_panic("do_shared_unmap: map_unmap_region failed", NO_NUM);
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) {
vm_panic("do_mmap: message from strange source", 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 {
vm_panic("do_munmap: strange type", NO_NUM);
}
if(!(vr = map_lookup(vmp, addr))) {
printf("VM: unmap: virtual address 0x%lx not found in %d\n",
m->VMUM_ADDR, vmp->vm_endpoint);
return EFAULT;
}
len = m->VMUM_LEN;
len -= 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)
vm_panic("do_munmap: map_unmap_region failed", NO_NUM);
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(&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 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 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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