int ckpt_map_attach(char *node, pid_t gpid, unsigned long area, size_t size, int prot, int flags)
{
struct file *file;
unsigned long ret;
unsigned long populate;
char path[MAP_PATH_MAX];
ret = ckpt_map_get_path(node, gpid, area, path);
if (ret) {
log_err("failed to get path");
return ret;
}
file = filp_open(path, MAP_FLAG, MAP_MODE);
if (IS_ERR(file)) {
log_err("failed to open, path=%s", path);
return PTR_ERR(file);
}
ret = do_mmap_pgoff(file, area, size, prot, flags, 0, &populate);
if (populate)
mm_populate(ret, populate);
if (ret != area) {
log_err("failed to attach, ret=%d", (int)ret);
return -EINVAL;
}
log_map_attach(path);
return 0;
}
/*
* This is really a simplified "vm_mmap". it only handles MPX
* bounds tables (the bounds directory is user-allocated).
*
* Later on, we use the vma->vm_ops to uniquely identify these
* VMAs.
*/
static unsigned long mpx_mmap(unsigned long len)
{
unsigned long ret;
unsigned long addr, pgoff;
struct mm_struct *mm = current->mm;
vm_flags_t vm_flags;
struct vm_area_struct *vma;
/* Only bounds table and bounds directory can be allocated here */
if (len != MPX_BD_SIZE_BYTES && len != MPX_BT_SIZE_BYTES)
return -EINVAL;
down_write(&mm->mmap_sem);
/* Too many mappings? */
if (mm->map_count > sysctl_max_map_count) {
ret = -ENOMEM;
goto out;
}
/* Obtain the address to map to. we verify (or select) it and ensure
* that it represents a valid section of the address space.
*/
addr = get_unmapped_area(NULL, 0, len, 0, MAP_ANONYMOUS | MAP_PRIVATE);
if (addr & ~PAGE_MASK) {
ret = addr;
goto out;
}
vm_flags = VM_READ | VM_WRITE | VM_MPX |
mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
/* Set pgoff according to addr for anon_vma */
pgoff = addr >> PAGE_SHIFT;
ret = mmap_region(NULL, addr, len, vm_flags, pgoff);
if (IS_ERR_VALUE(ret))
goto out;
vma = find_vma(mm, ret);
if (!vma) {
ret = -ENOMEM;
goto out;
}
vma->vm_ops = &mpx_vma_ops;
if (vm_flags & VM_LOCKED) {
up_write(&mm->mmap_sem);
mm_populate(ret, len);
return ret;
}
out:
up_write(&mm->mmap_sem);
return ret;
}
/*
* This is really a simplified "vm_mmap". it only handles MPX
* bounds tables (the bounds directory is user-allocated).
*/
static unsigned long mpx_mmap(unsigned long len)
{
struct mm_struct *mm = current->mm;
unsigned long addr, populate;
/* Only bounds table can be allocated here */
if (len != mpx_bt_size_bytes(mm))
return -EINVAL;
down_write(&mm->mmap_sem);
addr = do_mmap(NULL, 0, len, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE, VM_MPX, 0, &populate, NULL);
up_write(&mm->mmap_sem);
if (populate)
mm_populate(addr, populate);
return addr;
}
