On Tue, Nov 27, 2018 at 05:25:55PM +0200, jackm wrote:
> On Tue, 27 Nov 2018 10:10:23 +0300
> Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> Thanks, Dan -- you are correct, all other kernel users of
> copy_to_user return -EFAULT to their callers if non-zero is returned by
> copy_to_user.
>
> I'll fix this; The fix needs to be submitted to
> netdev@xxxxxxxxxxxxxxx, since the bug is under drivers/net/ethernet.
>
> (Tariq Toukan will submit the fix when it is ready).
>
Yeah... That doesn't matter too much because the caller does this:
385 cq_context->mtt_base_addr_h = mtt_addr >> 32;
386 cq_context->mtt_base_addr_l = cpu_to_be32(mtt_addr & 0xffffffff);
387 cq_context->db_rec_addr = cpu_to_be64(db_rec);
388
389 if (sw_cq_init) {
390 if (user_cq) {
391 err = mlx4_init_user_cqes(buf_addr, nent,
392 dev->caps.cqe_size);
393 if (err)
394 sw_cq_init = false;
If mlx4_init_user_cqes() returns any non-zero it's treated the same.
We set sw_cq_init to false.
395 } else {
396 mlx4_init_kernel_cqes(buf_addr, nent,
397 dev->caps.cqe_size);
398 }
399 }
400
401 err = mlx4_SW2HW_CQ(dev, mailbox, cq->cqn, sw_cq_init);
^^^ ^^^^^^^^^^
Then use it here. The err is never returned to the user.
402
403 mlx4_free_cmd_mailbox(dev, mailbox);
404 if (err)
405 goto err_radix;
406
407 cq->cons_index = 0;
408 cq->arm_sn = 1;
