// vma_destroy - free vma_struct
static void
vma_destroy(struct vma_struct *vma) {
if (vma->vm_flags & VM_SHARE) {
if (shmem_ref_dec(vma->shmem) == 0) {
shmem_destroy(vma->shmem);
}
}
kfree(vma);
}
// do_shmem - create a share memory with addr, len, flags(VM_READ/M_WRITE/VM_STACK)
int do_shmem(uintptr_t * addr_store, size_t len, uint32_t mmap_flags)
{
struct mm_struct *mm = current->mm;
if (mm == NULL) {
panic("kernel thread call mmap!!.\n");
}
if (addr_store == NULL || len == 0) {
return -E_INVAL;
}
int ret = -E_INVAL;
uintptr_t addr;
lock_mm(mm);
if (!copy_from_user(mm, &addr, addr_store, sizeof(uintptr_t), 1)) {
goto out_unlock;
}
uintptr_t start = ROUNDDOWN(addr, PGSIZE), end =
ROUNDUP(addr + len, PGSIZE);
addr = start, len = end - start;
uint32_t vm_flags = VM_READ;
if (mmap_flags & MMAP_WRITE)
vm_flags |= VM_WRITE;
if (mmap_flags & MMAP_STACK)
vm_flags |= VM_STACK;
ret = -E_NO_MEM;
if (addr == 0) {
if ((addr = get_unmapped_area(mm, len)) == 0) {
goto out_unlock;
}
}
struct shmem_struct *shmem;
if ((shmem = shmem_create(len)) == NULL) {
goto out_unlock;
}
if ((ret = mm_map_shmem(mm, addr, vm_flags, shmem, NULL)) != 0) {
assert(shmem_ref(shmem) == 0);
shmem_destroy(shmem);
goto out_unlock;
}
copy_to_user(mm, addr_store, &addr, sizeof(uintptr_t));
out_unlock:
unlock_mm(mm);
return ret;
}
ssize_t ipc_shmem_destroy (ipc_t *ipc){ // {{{
void *res;
ipc_shmem_userdata *userdata = (ipc_shmem_userdata *)ipc->userdata;
if(userdata->inited != 1)
return 0;
if(userdata->role == ROLE_SERVER){
// remove threads
if(pthread_cancel(userdata->server_thr) != 0)
goto error;
if(pthread_join(userdata->server_thr, &res) != 0)
goto error;
shmem_destroy(userdata);
}
error:
shmdt(userdata->shmaddr);
userdata->inited = 0;
return 0;
} // }}}
