From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793209788; b=yWOSBQigbkNNvgsw1krohgS+ARYNCln1ZW2J2qQCQKYsELQwtbd5cdsOGhzRtpPhrwB8 rAqEOzuYRaf5Br7gfbfhH5aj9Iv5Iq7cDGQdXN1T43Cd7jUC76bsnBcCMg+GkubwWXJ8y V9WvBrG6uJiBsf9fJCGHB/fKcHzP27bB25nJ6xWEZyMw2nJcGmLvRz7QsAxnUPqurms/2 dr23gEhlKZk10N1YUqnsJJUCbNGugO6DJmbXCqoUXG/Dongf072qzyKMEaWFqHjuuWcGe 5NskYgwNBjlTMHXW2AJBYM3Y3qdetAc66yxNLqHjqWSwHhzMkO9e89ttfsTYC+r+LyQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793209788; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=sadm7/RVKmpxwLwinsJ53MGj5Ke/t4WJOxPdFp7cIeA=; b=0jxoh3BNlXAkrSZX6pcXp2Sa2Hp4516Ao30eITxHg0z7kLCR0rJ+6OMhlXZmGLvS5PTK jdYMaCO0KLPK0O/sEW0t2pwkT99ksZUpi1DIp21J/rFDsDx2oGtuKkY1Zd9GIc0VNl6Y+ Kc2n4Z9WYjSrOxnpKFKQykqXgYsWHBlrDbZlaW1vMC0qUC05mqgemmoNXBYugZMW/5Kb6 jNBpqvji2y0+AyBQ88vE5PQhWNYkVVV6K8n1WiH4z2KLxVtK9c9V0hnywTteMmDkuYcrp 4HWGj+LOBi2Ab3wwn6G23g1UpbGK/oc6hrDUHcOkcLFNZSOTK7S9jU1bhsBuEAnHxag== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=J11dUT5g; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F26FD606A31A; Wed, 28 Oct 2026 17:49:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=J11dUT5g Received: by smtp.kernel.org (Postfix) with ESMTPSA id 487091F01825; Wed, 28 Oct 2026 17:49:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793209787; bh=sadm7/RVKmpxwLwinsJ53MGj5Ke/t4WJOxPdFp7cIeA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=J11dUT5gUBZlhoB2fbWSXvdeG8ub8saX7GVHdu7hUOfyXYKCwjYOfCDhSPSW0I9ie vBubzLWtVwXRqZqXep04njYQhWM/AvdMRHpUodz+suzqIGqE8kp/m+ADfz0zzMZXfA XsEMAy1d/Nuc/YyopsAiHT4aFWs5HvvAQvY1Hfr4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Josef Bacik , Jens Axboe Subject: [PATCH 6.18 076/109] io_uring: dont pass restart error codes to userspace Date: Wed, 28 Oct 2026 18:01:00 +0100 Message-ID: <20261028165944.147101583@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028165942.357251485@linuxfoundation.org> References: <20261028165942.357251485@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josef Bacik Commit e1a64bc64897f4c2fe460922c345f2ed8f889b5f upstream. -ERESTARTSYS and friends are instructions for the system call exit code, which either restarts the call or turns them into -EINTR. They are not supposed to be seen by applications. A request isn't a system call, nobody looks at what it returns before that is put into a CQE. The read/write and the networking opcodes convert these codes to -EINTR by hand. The others don't. An io-wq worker that is blocked in the open of a FIFO, a tty or some other device, or in a splice from an empty pipe, and that gets interrupted because the request is cancelled, completes it with -512: IORING_OP_OPENAT, IOSQE_ASYNC // FIFO without a writer IORING_OP_ASYNC_CANCEL // -EALREADY, worker is signalled CQE of the open: res == -512 There are more candidates, like whatever a file system or driver returns from ->flush(), ->fsync(), ->fallocate() or ->uring_cmd(), or breaking a lease or delegation. Take care of it in io_issue_sqe(), which all of them go through. The helper is moved from rw.c as is. The cost is a compare and a branch that is not taken per request. Fixes: 15b71abe7b52 ("io_uring: add support for IORING_OP_OPENAT") Assisted-by: LLM Signed-off-by: Josef Bacik Link: https://patch.msgid.link/20261015-b4-io-uring-fixes-v1-39-c1556f5d7bf5@toxicpanda.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/io_uring.c | 5 +++++ io_uring/io_uring.h | 18 ++++++++++++++++++ io_uring/rw.c | 18 ------------------ 3 files changed, 23 insertions(+), 18 deletions(-) --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -1890,6 +1890,9 @@ static int io_issue_sqe(struct io_kiocb ret = __io_issue_sqe(req, issue_flags, def); if (ret == IOU_COMPLETE) { + /* not all handlers take care of the internal restart codes */ + if (unlikely(req->cqe.res <= -ERESTARTSYS)) + req->cqe.res = io_fixup_restart_res(req->cqe.res); if (issue_flags & IO_URING_F_COMPLETE_DEFER) io_req_complete_defer(req); else @@ -1905,6 +1908,8 @@ static int io_issue_sqe(struct io_kiocb if ((req->ctx->flags & IORING_SETUP_IOPOLL) && def->iopoll_queue) io_iopoll_req_issued(req, issue_flags); } + if (unlikely(ret <= -ERESTARTSYS)) + ret = io_fixup_restart_res(ret); return ret; } --- a/io_uring/io_uring.h +++ b/io_uring/io_uring.h @@ -334,6 +334,24 @@ static inline void io_req_set_res32(stru req->big_cqe.extra2 = extra2; } +static inline ssize_t io_fixup_restart_res(ssize_t ret) +{ + switch (ret) { + case -ERESTARTSYS: + case -ERESTARTNOINTR: + case -ERESTARTNOHAND: + case -ERESTART_RESTARTBLOCK: + /* + * We can't just restart the syscall, since previously + * submitted sqes may already be in progress. Just fail + * this IO with EINTR. + */ + return -EINTR; + default: + return ret; + } +} + static inline void *io_uring_alloc_async_data(struct io_alloc_cache *cache, struct io_kiocb *req) { --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -625,24 +625,6 @@ static void io_complete_rw_iopoll(struct smp_store_release(&req->iopoll_completed, 1); } -static inline ssize_t io_fixup_restart_res(ssize_t ret) -{ - switch (ret) { - case -ERESTARTSYS: - case -ERESTARTNOINTR: - case -ERESTARTNOHAND: - case -ERESTART_RESTARTBLOCK: - /* - * We can't just restart the syscall, since previously - * submitted sqes may already be in progress. Just fail - * this IO with EINTR. - */ - return -EINTR; - default: - return ret; - } -} - static inline void io_rw_done(struct io_kiocb *req, ssize_t ret) { struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);