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=1793207298; b=LoYFQNswBVOvPULfqExL0MHuOklFwUToZuFf9Smkeb+ZtzvqbY4MbzTXTdQ4Zj70+EUT 0yc0gv4XIEeFUAFjjfoZVk5zfFih+rpV+n2MVjibPu9nmnR+c/0fnwzr7JncrqbHRfPj2 wCRdpMmztbPezyHAqu1pfAFxV2S+XwQ7PNd2r+4Zswyn1XrLnms9tbZAtDXQ2iQHXH8on iQLuUNvzD9UWjpS2UE7LIMLf3sh2n4H/QjbNkMy387iju7ccngDLlufbu644tVyoORNrk 1uoLvWTsbdoHCg+w0EI4beQtLGCR7T//p8S3sHdsQcrcD0Uv9eb12koHeFt5OWprN0A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793207298; 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=i7Sas8833d9mWeP7fGn9kAmbVho96oIeroVhBRzvohA=; b=p4I5lWz1bX+M/qbD5jbA9jHr7MGsn52R9iQb5onKoWw/TyP3wh+OILGzf2/gxBJSk/lk ppfml4w1pFJBWerbPMPY6BVfNRZyBeX0a2bHr3Nt0grH9RBpsqygJHUJjzJGuxTk+XHbp y1HSqo5HVzQwyeejmxIdKAp2JAz5pwMFz52dSO+XQOLxnaJx6VFLpfDm13AFgydfDZpIq cuCDlJZj4d7xw96njJqZ28NhFv9NJ2fLSsfHXN+76Rf2G5oCzwYmUft1K8xXZl7tDHkG8 2/yC6H1Vg0vIQSjI87JghzeG4DW4TS6v28xZ3iWV3S1Ty0iJgMMtg6a7OSG69rPRvgg== 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=fTst679u; 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 13B1B606A31A; Wed, 28 Oct 2026 17:08:17 +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=fTst679u Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3707D1F01828; Wed, 28 Oct 2026 17:08:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793207297; bh=i7Sas8833d9mWeP7fGn9kAmbVho96oIeroVhBRzvohA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fTst679uhPwpI2x2+ZYJMLbZJICLGI2HRwQ3JVm1vvlUWKl8iV9M5ZVeyh1c+grUf ieTDJ3VFH3ZNUXSz8sr6RfmZQrUQ8vafs6j81Hpodx/wSlXFEQ7LyLKcKdRKSq0cpl RbURJfrRS8Lzip/+jdx6ie5UKWKwJpcsFZz1jY20= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Josef Bacik , Jens Axboe Subject: [PATCH 7.2 55/88] io_uring: dont pass restart error codes to userspace Date: Wed, 28 Oct 2026 18:00:03 +0100 Message-ID: <20261028165943.407156486@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028165942.107695352@linuxfoundation.org> References: <20261028165942.107695352@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 7.2-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 @@ -1425,6 +1425,9 @@ 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 @@ -1439,6 +1442,8 @@ static int io_issue_sqe(struct io_kiocb if (req->flags & REQ_F_IOPOLL) 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 @@ -349,6 +349,24 @@ 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 @@ -624,24 +624,6 @@ 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);