From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934714AbaFIW5S (ORCPT ); Mon, 9 Jun 2014 18:57:18 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57075 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934225AbaFIWqA (ORCPT ); Mon, 9 Jun 2014 18:46:00 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Gevers , Ben Hutchings Subject: [PATCH 3.10 24/40] Staging: speakup: Move pasting into a work item Date: Mon, 9 Jun 2014 15:48:55 -0700 Message-Id: <20140609224839.966840222@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140609224839.127615063@linuxfoundation.org> References: <20140609224839.127615063@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings commit d7500135802ca55b3f4e01a16544e8b34082f8c3 upstream. Input is handled in softirq context, but when pasting we may need to sleep. speakup_paste_selection() currently tries to bodge this by busy-waiting if in_atomic(), but that doesn't help because the ldisc may also sleep. For bonus breakage, speakup_paste_selection() changes the state of current, even though it's not running in process context. Move it into a work item and make sure to cancel it on exit. References: https://bugs.debian.org/735202 References: https://bugs.debian.org/744015 Reported-by: Paul Gevers Reported-and-tested-by: Jarek Czekalski Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/staging/speakup/main.c | 1 drivers/staging/speakup/selection.c | 40 +++++++++++++++++++++++++++++------- drivers/staging/speakup/speakup.h | 1 3 files changed, 35 insertions(+), 7 deletions(-) --- a/drivers/staging/speakup/main.c +++ b/drivers/staging/speakup/main.c @@ -2219,6 +2219,7 @@ static void __exit speakup_exit(void) unregister_keyboard_notifier(&keyboard_notifier_block); unregister_vt_notifier(&vt_notifier_block); speakup_unregister_devsynth(); + speakup_cancel_paste(); del_timer(&cursor_timer); kthread_stop(speakup_task); speakup_task = NULL; --- a/drivers/staging/speakup/selection.c +++ b/drivers/staging/speakup/selection.c @@ -4,6 +4,8 @@ #include #include /* for dev_warn */ #include +#include +#include #include "speakup.h" @@ -121,20 +123,24 @@ int speakup_set_selection(struct tty_str return 0; } -/* TODO: move to some helper thread, probably. That'd fix having to check for - * in_atomic(). */ -int speakup_paste_selection(struct tty_struct *tty) -{ +struct speakup_paste_work { + struct work_struct work; + struct tty_struct *tty; +}; + +static void __speakup_paste_selection(struct work_struct *work) +{ + struct speakup_paste_work *spw = + container_of(work, struct speakup_paste_work, work); + struct tty_struct *tty = xchg(&spw->tty, NULL); struct vc_data *vc = (struct vc_data *) tty->driver_data; int pasted = 0, count; DECLARE_WAITQUEUE(wait, current); + add_wait_queue(&vc->paste_wait, &wait); while (sel_buffer && sel_buffer_lth > pasted) { set_current_state(TASK_INTERRUPTIBLE); if (test_bit(TTY_THROTTLED, &tty->flags)) { - if (in_atomic()) - /* if we are in an interrupt handler, abort */ - break; schedule(); continue; } @@ -146,6 +152,26 @@ int speakup_paste_selection(struct tty_s } remove_wait_queue(&vc->paste_wait, &wait); current->state = TASK_RUNNING; + tty_kref_put(tty); +} + +static struct speakup_paste_work speakup_paste_work = { + .work = __WORK_INITIALIZER(speakup_paste_work.work, + __speakup_paste_selection) +}; + +int speakup_paste_selection(struct tty_struct *tty) +{ + if (cmpxchg(&speakup_paste_work.tty, NULL, tty) != NULL) + return -EBUSY; + + tty_kref_get(tty); + schedule_work_on(WORK_CPU_UNBOUND, &speakup_paste_work.work); return 0; } +void speakup_cancel_paste(void) +{ + cancel_work_sync(&speakup_paste_work.work); + tty_kref_put(speakup_paste_work.tty); +} --- a/drivers/staging/speakup/speakup.h +++ b/drivers/staging/speakup/speakup.h @@ -77,6 +77,7 @@ extern void synth_buffer_clear(void); extern void speakup_clear_selection(void); extern int speakup_set_selection(struct tty_struct *tty); extern int speakup_paste_selection(struct tty_struct *tty); +extern void speakup_cancel_paste(void); extern void speakup_register_devsynth(void); extern void speakup_unregister_devsynth(void); extern void synth_write(const char *buf, size_t count);