/*
* merge the list of memory segments if possible. Redundant vm_area_structs are freed. This assumes that the list is ordered by address.
* we don't need to traverse the entire list, only those segments which intersect or are adjacent to a given interval.
*/
void merge_segments (struct task_struct * task, unsigned long start_addr, unsigned long end_addr)
{
struct vm_area_struct *prev, *mpnt, *next;
mpnt = find_vma(task, start_addr);
if(!mpnt)
return;
avl_neighbours(mpnt, task->mm->mmap_avl, &prev, &next);
if(!prev)
{
prev = mpnt;
mpnt = next;
}
for(; mpnt && prev->vm_start < end_addr; prev = mpnt, mpnt = next)
{
next = mpnt->vm_next;
if(mpnt->vm_inode != prev->vm_inode)
continue;
if(mpnt->vm_pte != prev->vm_pte)
continue;
if(mpnt->vm_ops != prev->vm_ops)
continue;
if(mpnt->vm_flags != prev->vm_flags)
continue;
if(mpnt->vm_start != prev->vm_end)
continue;
if((mpnt->vm_inode != NULL) || (mpnt->vm_flags & VM_SHM))
{
if(prev->vm_offset + prev->vm_end - prev->vm_start != mpnt->vm_offset)
continue;
}
avl_remove(mpnt, &task->mm->mmap_avl);
prev->vm_end = mpnt->vm_end;
prev->vm_next = mpnt->vm_next;
if(mpnt->vm_ops && mpnt->vm_ops->close)
{
mpnt->vm_offset += mpnt->vm_end - mpnt->vm_start;
mpnt->vm_start = mpnt->vm_end;
mpnt->vm_ops->close(mpnt);
}
remove_shared_vm_struct(mpnt);
if(mpnt->vm_inode)
mpnt->vm_inode->i_count++;
kfree_s(mpnt,sizeof(*mpnt));
mpnt = prev;
}
return;
}
unsigned long do_munmap(unsigned long addr, int len)
{
struct vm_area_struct *mpnt, *prev, *next, **npp, *free;
if((addr & ~PAGE_MASK) || (addr > PAGE_OFFSET) || (addr + len) > PAGE_OFFSET)
return -EINVAL;
if((len = PAGE_ALIGN(len)) == 0)
return 0;
mpnt = find_vma(current, addr);
if(!mpnt)
return 0;
avl_neighbours(mpnt, current->mm->mmap_avl, &prev, &next);
npp = (prev? &prev->vm_next: ¤t->mm->mmap);
free = NULL;
for(; mpnt && mpnt->vm_start < addr + len; mpnt = *npp)
{
*npp = mpnt->vm_next;
mpnt->vm_next = free;
free = mpnt;
avl_remove(mpnt, ¤t->mm->mmap_avl);
}
if(free == NULL)
return 0;
while(free)
{
unsigned long st, end;
mpnt = free;
free = free->vm_next;
remove_shared_vm_struct(mpnt);
st = addr < mpnt->vm_start?mpnt->vm_start:addr;
end = addr + len;
end = end > mpnt->vm_end? mpnt->vm_end:end;
if(mpnt->vm_ops && mpnt->vm_ops->unmap)
mpnt->vm_ops->unmap(mpnt, st, end-st);
unmap_fixup(mpnt, st, end-st);
kfree(mpnt);
}
unmap_page_range(addr, len);
return 0;
}
int
osfmach3_split_vm_struct(
unsigned long addr,
size_t len)
{
struct mm_struct *mm;
struct vm_area_struct *vmp, *prev, *next, *new_vmp;
unsigned long start, end;
mm = current->mm;
start = addr;
end = addr + len;
for (vmp = find_vma(mm, addr);
vmp && vmp->vm_start < end;
vmp = vmp->vm_next) {
avl_neighbours(vmp, mm->mmap_avl, &prev, &next);
#ifdef VMA_DEBUG
if (vma_debug) {
printk("VMA: split(addr=%lx,len=%lx) "
"vmp=(s=%lx,e=%lx,o=%lx)\n",
addr, (unsigned long) len,
vmp->vm_start,
vmp->vm_end,
vmp->vm_offset);
}
#endif /* VAM_DEBUG */
if (vmp->vm_start < start) {
/*
* Need to split here.
*/
new_vmp = (struct vm_area_struct *)
kmalloc(sizeof *new_vmp, GFP_KERNEL);
if (!new_vmp) {
printk("osfmach3_split_vm_struct: no memory\n");
return -ENOMEM;
}
*new_vmp = *vmp;
if (new_vmp->vm_inode) {
struct vm_area_struct *share;
new_vmp->vm_inode->i_count++;
share = vmp->vm_inode->i_mmap;
ASSERT(share);
new_vmp->vm_next_share = share->vm_next_share;
new_vmp->vm_next_share->vm_prev_share = new_vmp;
share->vm_next_share = new_vmp;
new_vmp->vm_prev_share = share;
/* take an extra reference on the mem_obj */
inode_pager_setup(new_vmp->vm_inode);
}
if (new_vmp->vm_ops && new_vmp->vm_ops->open) {
new_vmp->vm_end = new_vmp->vm_start; /* XXX ? */
new_vmp->vm_ops->open(new_vmp);
}
new_vmp->vm_end = start;
new_vmp->vm_next = vmp;
vmp->vm_offset += start - vmp->vm_start;
vmp->vm_start = start;
if (prev)
prev->vm_next = new_vmp;
else
current->mm->mmap = new_vmp;
avl_insert(new_vmp, &mm->mmap_avl);
#ifdef VMA_DEBUG
if (vma_debug) {
printk("VMA: split: "
"new_vmp(s=%lx,e=%lx,o=%lx) -> "
"vmp(s=%lx,e=%lx,o=%lx)\n",
new_vmp->vm_start,
new_vmp->vm_end,
new_vmp->vm_offset,
vmp->vm_start,
vmp->vm_end,
vmp->vm_offset);
}
#endif /* VAM_DEBUG */
}
if (vmp->vm_end > end) {
/*
* Need to split here.
*/
new_vmp = (struct vm_area_struct *)
kmalloc(sizeof *new_vmp, GFP_KERNEL);
if (!new_vmp) {
printk("osfmach3_split_vm_struct: no memory\n");
return -ENOMEM;
}
*new_vmp = *vmp;
if (new_vmp->vm_inode) {
struct vm_area_struct *share;
new_vmp->vm_inode->i_count++;
share = vmp->vm_inode->i_mmap;
ASSERT(share);
new_vmp->vm_next_share = share->vm_next_share;
new_vmp->vm_next_share->vm_prev_share = new_vmp;
share->vm_next_share = new_vmp;
new_vmp->vm_prev_share = share;
/* take an extra reference on the mem_obj */
inode_pager_setup(new_vmp->vm_inode);
}
if (new_vmp->vm_ops && new_vmp->vm_ops->open) {
new_vmp->vm_start = new_vmp->vm_end;
new_vmp->vm_offset = vmp->vm_offset +
(vmp->vm_end - vmp->vm_start);
new_vmp->vm_ops->open(new_vmp);
}
new_vmp->vm_start = end;
new_vmp->vm_offset =
vmp->vm_offset + start - vmp->vm_start;
vmp->vm_end = end;
vmp->vm_next = new_vmp;
avl_insert(new_vmp, &mm->mmap_avl);
#ifdef VMA_DEBUG
if (vma_debug) {
printk("VMA: split: "
"vmp(s=%lx,e=%lx,o=%lx) -> "
"new_vmp(s=%lx,e=%lx,o=%lx)\n",
vmp->vm_start,
vmp->vm_end,
vmp->vm_offset,
new_vmp->vm_start,
new_vmp->vm_end,
new_vmp->vm_offset);
}
#endif /* VAM_DEBUG */
vmp = new_vmp;
}
}
return 0;
}
