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| author | Okash Khawaja <okash.khawaja@gmail.com> | 2017-09-05 14:51:59 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-09-18 13:25:31 +0300 |
| commit | e5f5d0e20b6cecc0ebe6fc8e7df6f8823ad2d594 (patch) | |
| tree | 807859644cdcbfbdd37853c8e5ec1da741dbd673 /drivers/staging/speakup | |
| parent | b72703e26b9478da531144ce5c4552dd22f1103d (diff) | |
| download | linux-e5f5d0e20b6cecc0ebe6fc8e7df6f8823ad2d594.tar.xz | |
staging: speakup: fix speakup-r empty line lockup
When cursor is at beginning of an empty or whitespace-only line and
speakup-r typed, kernel locks up. This happens because deadlock of in
input_event function over dev->event_lock, as demonstrated by lockdep
logs. The reason for that is speakup simulates a down arrow - because
cursor is at an empty line - while inside key press notifier handler
which is ultimately triggered from input_event function. The simulated
key press leads to input_event being called again, this time under its
own context. So the spinlock is dev->event_lock is acquired while still
being held.
This patch ensures that key press is not simulated from inside key press
notifier handler. Instead it delegates to cursor_timer. It starts the
timer and passes RA_DOWN_ARROW as argument. When timer handler runs and
sees RA_DOWN_ARROW, it will then call kbd_fakekey2(RA_DOWN_ARROW) which
will correctly simulate the keypress inside timer context.
When not inside key press notifier callback, the behaviour will remain
the same as before this patch.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/speakup')
| -rw-r--r-- | drivers/staging/speakup/main.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/staging/speakup/main.c b/drivers/staging/speakup/main.c index 67956e24779c..56f7be6af1f6 100644 --- a/drivers/staging/speakup/main.c +++ b/drivers/staging/speakup/main.c @@ -1376,6 +1376,8 @@ static void reset_highlight_buffers(struct vc_data *); static int read_all_key; +static int in_keyboard_notifier; + static void start_read_all_timer(struct vc_data *vc, int command); enum { @@ -1408,7 +1410,10 @@ static void read_all_doc(struct vc_data *vc) cursor_track = read_all_mode; spk_reset_index_count(0); if (get_sentence_buf(vc, 0) == -1) { - kbd_fakekey2(vc, RA_DOWN_ARROW); + del_timer(&cursor_timer); + if (!in_keyboard_notifier) + speakup_fake_down_arrow(); + start_read_all_timer(vc, RA_DOWN_ARROW); } else { say_sentence_num(0, 0); synth_insert_next_index(0); @@ -2212,8 +2217,10 @@ static int keyboard_notifier_call(struct notifier_block *nb, int ret = NOTIFY_OK; static int keycode; /* to hold the current keycode */ + in_keyboard_notifier = 1; + if (vc->vc_mode == KD_GRAPHICS) - return ret; + goto out; /* * First, determine whether we are handling a fake keypress on @@ -2225,7 +2232,7 @@ static int keyboard_notifier_call(struct notifier_block *nb, */ if (speakup_fake_key_pressed()) - return ret; + goto out; switch (code) { case KBD_KEYCODE: @@ -2266,6 +2273,8 @@ static int keyboard_notifier_call(struct notifier_block *nb, break; } } +out: + in_keyboard_notifier = 0; return ret; } |