static int mappedfile_pagefault(struct vmproc *vmp, struct vir_region *region,
struct phys_region *ph, int write, vfs_callback_t cb,
void *state, int statelen, int *io)
{
u32_t allocflags;
int procfd = region->param.file.fdref->fd;
allocflags = vrallocflags(region->flags);
assert(ph->ph->refcount > 0);
assert(region->param.file.inited);
assert(region->param.file.fdref);
assert(region->param.file.fdref->dev != NO_DEV);
/* Totally new block? Create it. */
if(ph->ph->phys == MAP_NONE) {
struct cached_page *cp;
u64_t referenced_offset =
region->param.file.offset + ph->offset;
if(region->param.file.fdref->ino == VMC_NO_INODE) {
cp = find_cached_page_bydev(region->param.file.fdref->dev,
referenced_offset, VMC_NO_INODE, 0, 1);
} else {
cp = find_cached_page_byino(region->param.file.fdref->dev,
region->param.file.fdref->ino, referenced_offset, 1);
}
if(cp) {
int result = OK;
pb_unreferenced(region, ph, 0);
pb_link(ph, cp->page, ph->offset, region);
if(roundup(ph->offset+region->param.file.clearend,
VM_PAGE_SIZE) >= region->length) {
result = cow_block(vmp, region, ph,
region->param.file.clearend);
} else if(result == OK && write) {
result = cow_block(vmp, region, ph, 0);
}
return result;
}
if(!cb) {
#if 0
printf("VM: mem_file: no callback, returning EFAULT\n");
#endif
sys_diagctl_stacktrace(vmp->vm_endpoint);
return EFAULT;
}
if(vfs_request(VMVFSREQ_FDIO, procfd, vmp, referenced_offset,
VM_PAGE_SIZE, cb, NULL, state, statelen) != OK) {
printf("VM: mappedfile_pagefault: vfs_request failed\n");
return ENOMEM;
}
*io = 1;
return SUSPEND;
}
if(!write) {
#if 0
printf("mappedfile_pagefault: nonwrite fault?\n");
#endif
return OK;
}
return cow_block(vmp, region, ph, 0);
}
/*===========================================================================*
* do_mmap *
*===========================================================================*/
int do_mmap(message *m)
{
int r, n;
struct vmproc *vmp;
vir_bytes addr = (vir_bytes) m->m_mmap.addr;
struct vir_region *vr = NULL;
int execpriv = 0;
size_t len = (vir_bytes) m->m_mmap.len;
/* RS and VFS can do slightly more special mmap() things */
if(m->m_source == VFS_PROC_NR || m->m_source == RS_PROC_NR)
execpriv = 1;
if(m->m_mmap.flags & MAP_THIRDPARTY) {
if(!execpriv) return EPERM;
if((r=vm_isokendpt(m->m_mmap.forwhom, &n)) != OK)
return ESRCH;
} else {
/* regular mmap, i.e. for caller */
if((r=vm_isokendpt(m->m_source, &n)) != OK) {
panic("do_mmap: message from strange source: %d",
m->m_source);
}
}
vmp = &vmproc[n];
/* "SUSv3 specifies that mmap() should fail if length is 0" */
if(len <= 0) {
return EINVAL;
}
if(m->m_mmap.fd == -1 || (m->m_mmap.flags & MAP_ANON)) {
/* actual memory in some form */
mem_type_t *mt = NULL;
if(m->m_mmap.fd != -1) {
printf("VM: mmap: fd %d, len 0x%x\n", m->m_mmap.fd, len);
return EINVAL;
}
/* Contiguous phys memory has to be preallocated. */
if((m->m_mmap.flags & (MAP_CONTIG|MAP_PREALLOC)) == MAP_CONTIG) {
return EINVAL;
}
if(m->m_mmap.flags & MAP_CONTIG) {
mt = &mem_type_anon_contig;
} else mt = &mem_type_anon;
if(!(vr = mmap_region(vmp, addr, m->m_mmap.flags, len,
VR_WRITABLE | VR_ANON, mt, execpriv))) {
return ENOMEM;
}
} else {
/* File mapping might be disabled */
if(!enable_filemap) return ENXIO;
/* For files, we only can't accept writable MAP_SHARED
* mappings.
*/
if((m->m_mmap.flags & MAP_SHARED) && (m->m_mmap.prot & PROT_WRITE)) {
return ENXIO;
}
if(vfs_request(VMVFSREQ_FDLOOKUP, m->m_mmap.fd, vmp, 0, 0,
mmap_file_cont, NULL, m, sizeof(*m)) != OK) {
printf("VM: vfs_request for mmap failed\n");
return ENXIO;
}
/* request queued; don't reply. */
return SUSPEND;
}
/* Return mapping, as seen from process. */
m->m_mmap.retaddr = (void *) vr->vaddr;
return OK;
}
static int mappedfile_pagefault(struct vmproc *vmp, struct vir_region *region,
struct phys_region *ph, int write, vfs_callback_t cb,
void *state, int statelen, int *io)
{
u32_t allocflags;
int procfd = region->param.file.fdref->fd;
allocflags = vrallocflags(region->flags);
assert(ph->ph->refcount > 0);
assert(region->param.file.inited);
assert(region->param.file.fdref);
assert(region->param.file.fdref->dev != NO_DEV);
/* Totally new block? Create it. */
if(ph->ph->phys == MAP_NONE) {
struct cached_page *cp;
u64_t referenced_offset =
region->param.file.offset + ph->offset;
if(region->param.file.fdref->ino == VMC_NO_INODE) {
cp = find_cached_page_bydev(region->param.file.fdref->dev,
referenced_offset, VMC_NO_INODE, 0, 1);
} else {
cp = find_cached_page_byino(region->param.file.fdref->dev,
region->param.file.fdref->ino, referenced_offset, 1);
}
/*
* Normally, a cache hit saves a round-trip to the file system
* to load the page. However, if the page in the VM cache is
* marked for one-time use, then force a round-trip through the
* file system anyway, so that the FS can update the page by
* by readding it to the cache. Thus, for one-time use pages,
* no caching is performed. This approach is correct even in
* the light of concurrent requests and disappearing processes
* but relies on VM requests to VFS being fully serialized.
*/
if(cp && (!cb || !(cp->flags & VMSF_ONCE))) {
int result = OK;
pb_unreferenced(region, ph, 0);
pb_link(ph, cp->page, ph->offset, region);
if(roundup(ph->offset+region->param.file.clearend,
VM_PAGE_SIZE) >= region->length) {
result = cow_block(vmp, region, ph,
region->param.file.clearend);
} else if(result == OK && write) {
result = cow_block(vmp, region, ph, 0);
}
/* Discard one-use pages after mapping them in. */
if (result == OK && (cp->flags & VMSF_ONCE))
rmcache(cp);
return result;
}
if(!cb) {
#if 0
printf("VM: mem_file: no callback, returning EFAULT\n");
sys_diagctl_stacktrace(vmp->vm_endpoint);
#endif
return EFAULT;
}
if(vfs_request(VMVFSREQ_FDIO, procfd, vmp, referenced_offset,
VM_PAGE_SIZE, cb, NULL, state, statelen) != OK) {
printf("VM: mappedfile_pagefault: vfs_request failed\n");
return ENOMEM;
}
*io = 1;
return SUSPEND;
}
if(!write) {
#if 0
printf("mappedfile_pagefault: nonwrite fault?\n");
#endif
return OK;
}
return cow_block(vmp, region, ph, 0);
}
