On Thu, May 05, 2022 at 07:38:31AM -0600, Jens Axboe wrote: > > + req = nvme_alloc_user_request(q, &c, nvme_to_user_ptr(cmd->addr), > > + cmd->data_len, nvme_to_user_ptr(cmd->metadata), > > + cmd->metadata_len, 0, cmd->timeout_ms ? > > + msecs_to_jiffies(cmd->timeout_ms) : 0, 0, rq_flags, > > + blk_flags); > > You need to be careful with reading/re-reading the shared memory. For > example, you do: Uh, yes. With ioucmd->cmd pointing to the user space mapped SQ we need to be very careful here. To the point where I'd almost prfer to memcpy it out first, altough there might be performance implications. On something unrelated while looking over the code again: the cast when asssigning cmd in nvme_uring_cmd_io should not be needed any more.
