On 10/1/19 8:09 AM, Jens Axboe wrote: > On 9/30/19 2:20 PM, Arnd Bergmann wrote: >> All system calls use struct __kernel_timespec instead of the old struct >> timespec, but this one was just added with the old-style ABI. Change it >> now to enforce the use of __kernel_timespec, avoiding ABI confusion and >> the need for compat handlers on 32-bit architectures. >> >> Any user space caller will have to use __kernel_timespec now, but this >> is unambiguous and works for any C library regardless of the time_t >> definition. A nicer way to specify the timeout would have been a less >> ambiguous 64-bit nanosecond value, but I suppose it's too late now to >> change that as this would impact both 32-bit and 64-bit users. > > Thanks for catching that, Arnd. Applied. On second thought - since there appears to be no good 64-bit timespec available to userspace, the alternative here is including on in liburing. That seems kinda crappy in terms of API, so why not just use a 64-bit nsec value as you suggest? There's on released kernel with this feature yet, so there's nothing stopping us from just changing the API to be based on a single 64-bit nanosecond timeout. diff --git a/fs/io_uring.c b/fs/io_uring.c index dd094b387cab..de3d14fe3025 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1892,16 +1892,13 @@ static int io_timeout(struct io_kiocb *req, const struct io_uring_sqe *sqe) unsigned count, req_dist, tail_index; struct io_ring_ctx *ctx = req->ctx; struct list_head *entry; - struct timespec ts; + u64 timeout; if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; if (sqe->flags || sqe->ioprio || sqe->buf_index || sqe->timeout_flags || sqe->len != 1) return -EINVAL; - if (copy_from_user(&ts, (void __user *) (unsigned long) sqe->addr, - sizeof(ts))) - return -EFAULT; /* * sqe->off holds how many events that need to occur for this @@ -1932,9 +1929,10 @@ static int io_timeout(struct io_kiocb *req, const struct io_uring_sqe *sqe) list_add(&req->list, entry); spin_unlock_irq(&ctx->completion_lock); + timeout = READ_ONCE(sqe->addr); hrtimer_init(&req->timeout.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); req->timeout.timer.function = io_timeout_fn; - hrtimer_start(&req->timeout.timer, timespec_to_ktime(ts), + hrtimer_start(&req->timeout.timer, ns_to_ktime(timeout), HRTIMER_MODE_REL); return 0; } -- Jens Axboe
