void *linux_regfile_mmap2(void *addr, size_t len, int prot, int flags, int fd,
size_t off)
{
int subret = -E_INVAL;
struct mm_struct *mm = current->mm;
assert(mm != NULL);
if (len == 0) {
return -1;
}
lock_mm(mm);
uintptr_t start = ROUNDDOWN(addr, PGSIZE);
len = ROUNDUP(len, PGSIZE);
uint32_t vm_flags = VM_READ;
if (prot & PROT_WRITE) {
vm_flags |= VM_WRITE;
}
if (prot & PROT_EXEC) {
vm_flags |= VM_EXEC;
}
if (flags & MAP_STACK) {
vm_flags |= VM_STACK;
}
if (flags & MAP_ANONYMOUS) {
vm_flags |= VM_ANONYMOUS;
}
subret = -E_NO_MEM;
if (start == 0 && (start = get_unmapped_area(mm, len)) == 0) {
goto out_unlock;
}
uintptr_t end = start + len;
struct vma_struct *vma = find_vma(mm, start);
if (vma == NULL || vma->vm_start >= end) {
vma = NULL;
} else if (!(flags & MAP_FIXED)) {
start = get_unmapped_area(mm, len);
vma = NULL;
} else if (!(vma->vm_flags & VM_ANONYMOUS)) {
goto out_unlock;
} else if (vma->vm_start == start && end == vma->vm_end) {
vma->vm_flags = vm_flags;
} else {
assert(vma->vm_start <= start && end <= vma->vm_end);
if ((subret = mm_unmap_keep_pages(mm, start, len)) != 0) {
goto out_unlock;
}
vma = NULL;
}
if (vma == NULL
&& (subret = mm_map(mm, start, len, vm_flags, &vma)) != 0) {
goto out_unlock;
}
if (!(flags & MAP_ANONYMOUS)) {
vma_mapfile(vma, fd, off << 12, NULL);
}
subret = 0;
out_unlock:
unlock_mm(mm);
return subret == 0 ? start : -1;
}
int do_mprotect(void *addr, size_t len, int prot)
{
/*
return 0;
*/
struct mm_struct *mm = current->mm;
assert(mm != NULL);
if (len == 0) {
return -E_INVAL;
}
uintptr_t start = ROUNDDOWN(addr, PGSIZE);
uintptr_t end = ROUNDUP(addr + len, PGSIZE);
int ret = -E_INVAL;
lock_mm(mm);
while (1) {
struct vma_struct *vma = find_vma(mm, start);
uintptr_t last_end;
if (vma != NULL) {
last_end = vma->vm_end;
}
if (vma == NULL) {
goto out;
} else if (vma->vm_start == start && vma->vm_end == end) {
if (prot & PROT_WRITE) {
vma->vm_flags |= VM_WRITE;
} else {
vma->vm_flags &= ~VM_WRITE;
}
} else {
uintptr_t this_end =
(end <= vma->vm_end) ? end : vma->vm_end;
uintptr_t this_start =
(start >= vma->vm_start) ? start : vma->vm_start;
struct mapped_file_struct mfile = vma->mfile;
mfile.offset += this_start - vma->vm_start;
uint32_t flags = vma->vm_flags;
if ((ret =
mm_unmap_keep_pages(mm, this_start,
this_end - this_start)) != 0) {
goto out;
}
if (prot & PROT_WRITE) {
flags |= VM_WRITE;
} else {
flags &= ~VM_WRITE;
}
if ((ret =
mm_map(mm, this_start, this_end - this_start,
flags, &vma)) != 0) {
goto out;
}
vma->mfile = mfile;
if (vma->mfile.file != NULL) {
filemap_acquire(mfile.file);
}
}
ret = 0;
if (end <= last_end)
break;
start = last_end;
}
out:
unlock_mm(mm);
return ret;
}
