Hi.
On Mon, Sep 22, 2008 at 03:40:23PM -0700, Shasi Pulijala (spulijala@xxxxxxxx) wrote:
> This is Linux CryptoAPI user space interface support patch v6. This version adds:
> -Adds a reference count for checking the inappropriate deletion of allocated data in synchronous operations.
> -Also some minor changes like removal of double pointers etc.
Couple of comments inline.
> From: Shasi Pulijala <spulijala@xxxxxxxx>
>
>
> Signed-off-by: Shasi Pulijala <spulijala@xxxxxxxx>
> Acked-by: Loc Ho <lho@xxxxxxxx>
> diff --git a/crypto/Kconfig b/crypto/Kconfig
> index 69f1be6..0cd97c2 100644
> diff --git a/crypto/Makefile b/crypto/Makefile
> index 7cf3625..4ed5634 100644
This two constantly hangs to be applied. Please rebase against vanilla
tree. There are also number of trailing whitespaces in the patch.
> +
> +static int cryptodev_run_acipher(struct csession *ses_ptr,
> + struct crypto_item_op *cop,
> + struct kiocb *iocb);
> +static int cryptodev_run_ahash(struct csession *ses_ptr,
> + struct crypto_item_op *cop,
> + struct kiocb *iocb);
> +static int cryptodev_run_aead(struct csession *ses_ptr,
> + struct crypto_item_op *cop,
> + struct kiocb *iocb);
> +static void cryptodev_async_aio_complete(struct crypto_async_request *req,
> + int err);
Please drop forward declarations. They confuse readers and automatic
tools.
> +static int cryptodev_set_user_pages(char __user *src, struct scatterlist *sg,
> + struct page **pages, size_t bufsize,
> + int *nr_pages, char **null_buf)
> +{
> + unsigned long offset;
> + struct page *page = NULL;
> + int x;
> + int rop;
> + int err;
> +
> + if (!src) {
> + *nr_pages = 0;
> + CDPRINTK(1, KERN_INFO, "Case of null buffer\n");
> + *null_buf = kzalloc(bufsize, GFP_KERNEL);
> + if (!*null_buf)
> + return -ENOMEM;
> + sg_init_one(&sg[0], *null_buf, bufsize);
> + return 0;
> + }
> +
> + offset = (unsigned long) src & ~PAGE_MASK;
> + if (!pages) {
> + printk(KERN_ERR PFX "pages memory allocation failed\n");
> + return -ENOMEM;
> + }
> +
> + down_read(¤t->mm->mmap_sem);
> + err = get_user_pages(current, current->mm,
> + ((unsigned long) src) & PAGE_MASK,
> + *nr_pages, 1, 0, /* read, force */ pages, NULL);
> + up_read(¤t->mm->mmap_sem);
> +
> + if (err != *nr_pages) {
> + printk(KERN_ERR PFX "pages requested[%d] !="
> + " pages granted[%d]\n", *nr_pages, err);
> + return err < 0 ? err : -EINVAL;
> +
> + }
> +
> + if (sg_single) {
> + page = pages[0];
> + CDPRINTK(2, KERN_INFO, "single buffer implementation\n");
> + sg_set_page(&sg[0], page, bufsize, offset);
> + return 0;
> + }
> +
> + sg_init_table(sg, *nr_pages);
> + for (x = 0; x < *nr_pages; x++) {
> + page = pages[x] ;
> + if (!page || IS_ERR(page)) {
> + printk(KERN_ERR PFX "missing page in "
> + "DumpUserPages %d\n", x);
> + return -EFAULT;
> + }
> + sg_set_page(&sg[x], page, bufsize, offset);
> + rop = PAGE_SIZE - sg[x].offset;
> + if (bufsize > rop) {
> + sg[x].length = rop;
> + bufsize = bufsize - rop;
> + }
> + offset = 0;
What if bufsize is smaller than 'rop', but there are several pages?
This will initialize wrong buffers, but probably there is a check somewhere
above this layer.
> + if (cop->eop == COP_ENCRYPT)
> + ret = crypto_aead_encrypt(req);
> + else
> + ret = crypto_aead_decrypt(req);
> +
> + switch (ret) {
> + case 0:
> + if (!iocb)
> + atomic_dec(&result->opcnt);
> + break;
> + case -EINPROGRESS:
> + case -EBUSY:
> + if (iocb) {
> + CDPRINTK(2, KERN_INFO,
> + "Async Call AEAD:Returning Now\n");
> + return -EIOCBQUEUED;
> + }
> + ret = wait_for_completion_interruptible(
> + &result->crypto_completion);
> + if (!ret)
> + ret = result->err;
> + if (!ret) {
> + INIT_COMPLETION(result->crypto_completion);
> + break;
> + }
> + /* fall through */
> + default:
> + printk(KERN_ERR PFX "sid %p enc/dec failed error %d\n",
> + ses_ptr, -ret);
> + if (!iocb)
> + atomic_dec(&result->opcnt);
> + break;
> + }
> +
> + if (nopin && !ret) {
> + if (copy_to_user(dst, data, enc ? bufsize + authsize :
> + bufsize - authsize))
> + printk(KERN_ERR PFX
> + "failed to copy encrypted data "
> + "to user space\n");
> + CD_HEXDUMP(data, enc ? bufsize + authsize :
> + bufsize - authsize);
> + }
> +
> + /* Check if last reference */
> + if (atomic_dec_and_test(&ses_ptr->refcnt))
> + cryptodev_destroy_session(ses_ptr);
> + if (dst_flag)
> + cryptodev_release_pages(result->dpages, nr_dpages);
> +out_spages:
> + cryptodev_release_pages(result->spages, nr_spages);
> +
> +out_tmp:
> + if (atomic_dec_and_test(&result->opcnt))
> + cryptodev_destroy_res(result);
> + return ret;
> +}
Still this is not an async crypto.
Is it what you expect it to be? Since it is protected by the per-ctx
lock and waits for the crypto operation completion. Also, since waiting
is interruptible, it is possible to destroy session and/or release
pages, so actual crypto processing will crash the system.
Are there any benchmark of this approach?
--
Evgeniy Polyakov
--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
