Input: mousedev - implement proper locking Signed-off-by: Dmitry Torokhov --- drivers/input/mousedev.c | 736 +++++++++++++++++++++++++++++------------------ 1 files changed, 464 insertions(+), 272 deletions(-) Index: work/drivers/input/mousedev.c =================================================================== --- work.orig/drivers/input/mousedev.c +++ work/drivers/input/mousedev.c @@ -61,9 +61,11 @@ struct mousedev { int open; int minor; char name[16]; + struct input_handle handle; wait_queue_head_t wait; struct list_head client_list; - struct input_handle handle; + spinlock_t client_lock; /* protects client_list */ + struct mutex mutex; struct device dev; struct list_head mixdev_node; @@ -113,108 +115,137 @@ static unsigned char mousedev_imex_seq[] static struct input_handler mousedev_handler; static struct mousedev *mousedev_table[MOUSEDEV_MINORS]; +static DEFINE_MUTEX(mousedev_table_mutex); static struct mousedev *mousedev_mix; static LIST_HEAD(mousedev_mix_list); +static void mixdev_open_devices(void); +static void mixdev_close_devices(void); + #define fx(i) (mousedev->old_x[(mousedev->pkt_count - (i)) & 03]) #define fy(i) (mousedev->old_y[(mousedev->pkt_count - (i)) & 03]) -static void mousedev_touchpad_event(struct input_dev *dev, struct mousedev *mousedev, unsigned int code, int value) +static void mousedev_touchpad_event(struct input_dev *dev, + struct mousedev *mousedev, + unsigned int code, int value) { int size, tmp; enum { FRACTION_DENOM = 128 }; switch (code) { - case ABS_X: - fx(0) = value; - if (mousedev->touch && mousedev->pkt_count >= 2) { - size = dev->absmax[ABS_X] - dev->absmin[ABS_X]; - if (size == 0) - size = 256 * 2; - tmp = ((value - fx(2)) * (256 * FRACTION_DENOM)) / size; - tmp += mousedev->frac_dx; - mousedev->packet.dx = tmp / FRACTION_DENOM; - mousedev->frac_dx = tmp - mousedev->packet.dx * FRACTION_DENOM; - } - break; - case ABS_Y: - fy(0) = value; - if (mousedev->touch && mousedev->pkt_count >= 2) { - /* use X size to keep the same scale */ - size = dev->absmax[ABS_X] - dev->absmin[ABS_X]; - if (size == 0) - size = 256 * 2; - tmp = -((value - fy(2)) * (256 * FRACTION_DENOM)) / size; - tmp += mousedev->frac_dy; - mousedev->packet.dy = tmp / FRACTION_DENOM; - mousedev->frac_dy = tmp - mousedev->packet.dy * FRACTION_DENOM; - } - break; + case ABS_X: + fx(0) = value; + if (mousedev->touch && mousedev->pkt_count >= 2) { + size = dev->absmax[ABS_X] - dev->absmin[ABS_X]; + if (size == 0) + size = 256 * 2; + tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size; + tmp += mousedev->frac_dx; + mousedev->packet.dx = tmp / FRACTION_DENOM; + mousedev->frac_dx = + tmp - mousedev->packet.dx * FRACTION_DENOM; + } + break; + + case ABS_Y: + fy(0) = value; + if (mousedev->touch && mousedev->pkt_count >= 2) { + /* use X size to keep the same scale */ + size = dev->absmax[ABS_X] - dev->absmin[ABS_X]; + if (size == 0) + size = 256 * 2; + tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size; + tmp += mousedev->frac_dy; + mousedev->packet.dy = tmp / FRACTION_DENOM; + mousedev->frac_dy = tmp - + mousedev->packet.dy * FRACTION_DENOM; + } + break; } } -static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev, unsigned int code, int value) +static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev, + unsigned int code, int value) { int size; switch (code) { - case ABS_X: - size = dev->absmax[ABS_X] - dev->absmin[ABS_X]; - if (size == 0) - size = xres ? : 1; - if (value > dev->absmax[ABS_X]) - value = dev->absmax[ABS_X]; - if (value < dev->absmin[ABS_X]) - value = dev->absmin[ABS_X]; - mousedev->packet.x = ((value - dev->absmin[ABS_X]) * xres) / size; - mousedev->packet.abs_event = 1; - break; - case ABS_Y: - size = dev->absmax[ABS_Y] - dev->absmin[ABS_Y]; - if (size == 0) - size = yres ? : 1; - if (value > dev->absmax[ABS_Y]) - value = dev->absmax[ABS_Y]; - if (value < dev->absmin[ABS_Y]) - value = dev->absmin[ABS_Y]; - mousedev->packet.y = yres - ((value - dev->absmin[ABS_Y]) * yres) / size; - mousedev->packet.abs_event = 1; - break; + case ABS_X: + size = dev->absmax[ABS_X] - dev->absmin[ABS_X]; + if (size == 0) + size = xres ? : 1; + if (value > dev->absmax[ABS_X]) + value = dev->absmax[ABS_X]; + if (value < dev->absmin[ABS_X]) + value = dev->absmin[ABS_X]; + mousedev->packet.x = + ((value - dev->absmin[ABS_X]) * xres) / size; + mousedev->packet.abs_event = 1; + break; + + case ABS_Y: + size = dev->absmax[ABS_Y] - dev->absmin[ABS_Y]; + if (size == 0) + size = yres ? : 1; + if (value > dev->absmax[ABS_Y]) + value = dev->absmax[ABS_Y]; + if (value < dev->absmin[ABS_Y]) + value = dev->absmin[ABS_Y]; + mousedev->packet.y = yres - + ((value - dev->absmin[ABS_Y]) * yres) / size; + mousedev->packet.abs_event = 1; + break; } } -static void mousedev_rel_event(struct mousedev *mousedev, unsigned int code, int value) +static void mousedev_rel_event(struct mousedev *mousedev, + unsigned int code, int value) { switch (code) { - case REL_X: mousedev->packet.dx += value; break; - case REL_Y: mousedev->packet.dy -= value; break; - case REL_WHEEL: mousedev->packet.dz -= value; break; + case REL_X: + mousedev->packet.dx += value; + break; + + case REL_Y: + mousedev->packet.dy -= value; + break; + + case REL_WHEEL: + mousedev->packet.dz -= value; + break; } } -static void mousedev_key_event(struct mousedev *mousedev, unsigned int code, int value) +static void mousedev_key_event(struct mousedev *mousedev, + unsigned int code, int value) { int index; switch (code) { - case BTN_TOUCH: - case BTN_0: - case BTN_LEFT: index = 0; break; - case BTN_STYLUS: - case BTN_1: - case BTN_RIGHT: index = 1; break; - case BTN_2: - case BTN_FORWARD: - case BTN_STYLUS2: - case BTN_MIDDLE: index = 2; break; - case BTN_3: - case BTN_BACK: - case BTN_SIDE: index = 3; break; - case BTN_4: - case BTN_EXTRA: index = 4; break; - default: return; + + case BTN_TOUCH: + case BTN_0: + case BTN_LEFT: index = 0; break; + + case BTN_STYLUS: + case BTN_1: + case BTN_RIGHT: index = 1; break; + + case BTN_2: + case BTN_FORWARD: + case BTN_STYLUS2: + case BTN_MIDDLE: index = 2; break; + + case BTN_3: + case BTN_BACK: + case BTN_SIDE: index = 3; break; + + case BTN_4: + case BTN_EXTRA: index = 4; break; + + default: return; } if (value) { @@ -226,19 +257,22 @@ static void mousedev_key_event(struct mo } } -static void mousedev_notify_readers(struct mousedev *mousedev, struct mousedev_hw_data *packet) +static void mousedev_notify_readers(struct mousedev *mousedev, + struct mousedev_hw_data *packet) { struct mousedev_client *client; struct mousedev_motion *p; - unsigned long flags; + unsigned int new_head; int wake_readers = 0; - list_for_each_entry(client, &mousedev->client_list, node) { - spin_lock_irqsave(&client->packet_lock, flags); + list_for_each_entry_rcu(client, &mousedev->client_list, node) { + + /* Just acquire the lock, interrupts already disabled */ + spin_lock(&client->packet_lock); p = &client->packets[client->head]; if (client->ready && p->buttons != mousedev->packet.buttons) { - unsigned int new_head = (client->head + 1) % PACKET_QUEUE_LEN; + new_head = (client->head + 1) % PACKET_QUEUE_LEN; if (new_head != client->tail) { p = &client->packets[client->head = new_head]; memset(p, 0, sizeof(struct mousedev_motion)); @@ -253,19 +287,22 @@ static void mousedev_notify_readers(stru } client->pos_x += packet->dx; - client->pos_x = client->pos_x < 0 ? 0 : (client->pos_x >= xres ? xres : client->pos_x); + client->pos_x = client->pos_x < 0 ? + 0 : (client->pos_x >= xres ? xres : client->pos_x); client->pos_y += packet->dy; - client->pos_y = client->pos_y < 0 ? 0 : (client->pos_y >= yres ? yres : client->pos_y); + client->pos_y = client->pos_y < 0 ? + 0 : (client->pos_y >= yres ? yres : client->pos_y); p->dx += packet->dx; p->dy += packet->dy; p->dz += packet->dz; p->buttons = mousedev->packet.buttons; - if (p->dx || p->dy || p->dz || p->buttons != client->last_buttons) + if (p->dx || p->dy || p->dz || + p->buttons != client->last_buttons) client->ready = 1; - spin_unlock_irqrestore(&client->packet_lock, flags); + spin_unlock(&client->packet_lock); if (client->ready) { kill_fasync(&client->fasync, SIGIO, POLL_IN); @@ -281,7 +318,8 @@ static void mousedev_touchpad_touch(stru { if (!value) { if (mousedev->touch && - time_before(jiffies, mousedev->touch + msecs_to_jiffies(tap_time))) { + time_before(jiffies, + mousedev->touch + msecs_to_jiffies(tap_time))) { /* * Toggle left button to emulate tap. * We rely on the fact that mousedev_mix always has 0 @@ -290,7 +328,8 @@ static void mousedev_touchpad_touch(stru set_bit(0, &mousedev->packet.buttons); set_bit(0, &mousedev_mix->packet.buttons); mousedev_notify_readers(mousedev, &mousedev_mix->packet); - mousedev_notify_readers(mousedev_mix, &mousedev_mix->packet); + mousedev_notify_readers(mousedev_mix, + &mousedev_mix->packet); clear_bit(0, &mousedev->packet.buttons); clear_bit(0, &mousedev_mix->packet.buttons); } @@ -302,54 +341,61 @@ static void mousedev_touchpad_touch(stru mousedev->touch = jiffies; } -static void mousedev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value) +static void mousedev_event(struct input_handle *handle, + unsigned int type, unsigned int code, int value) { struct mousedev *mousedev = handle->private; switch (type) { - case EV_ABS: - /* Ignore joysticks */ - if (test_bit(BTN_TRIGGER, handle->dev->keybit)) - return; - if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit)) - mousedev_touchpad_event(handle->dev, mousedev, code, value); + case EV_ABS: + /* Ignore joysticks */ + if (test_bit(BTN_TRIGGER, handle->dev->keybit)) + return; + + if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit)) + mousedev_touchpad_event(handle->dev, + mousedev, code, value); + else + mousedev_abs_event(handle->dev, mousedev, code, value); + + break; + + case EV_REL: + mousedev_rel_event(mousedev, code, value); + break; + + case EV_KEY: + if (value != 2) { + if (code == BTN_TOUCH && + test_bit(BTN_TOOL_FINGER, handle->dev->keybit)) + mousedev_touchpad_touch(mousedev, value); else - mousedev_abs_event(handle->dev, mousedev, code, value); - - break; - - case EV_REL: - mousedev_rel_event(mousedev, code, value); - break; + mousedev_key_event(mousedev, code, value); + } + break; - case EV_KEY: - if (value != 2) { - if (code == BTN_TOUCH && test_bit(BTN_TOOL_FINGER, handle->dev->keybit)) - mousedev_touchpad_touch(mousedev, value); - else - mousedev_key_event(mousedev, code, value); + case EV_SYN: + if (code == SYN_REPORT) { + if (mousedev->touch) { + mousedev->pkt_count++; + /* + * Input system eats duplicate events, + * but we need all of them to do correct + * averaging so apply present one forward + */ + fx(0) = fx(1); + fy(0) = fy(1); } - break; - - case EV_SYN: - if (code == SYN_REPORT) { - if (mousedev->touch) { - mousedev->pkt_count++; - /* Input system eats duplicate events, but we need all of them - * to do correct averaging so apply present one forward - */ - fx(0) = fx(1); - fy(0) = fy(1); - } - mousedev_notify_readers(mousedev, &mousedev->packet); - mousedev_notify_readers(mousedev_mix, &mousedev->packet); + mousedev_notify_readers(mousedev, &mousedev->packet); + mousedev_notify_readers(mousedev_mix, &mousedev->packet); - mousedev->packet.dx = mousedev->packet.dy = mousedev->packet.dz = 0; - mousedev->packet.abs_event = 0; - } - break; + mousedev->packet.dx = mousedev->packet.dy = + mousedev->packet.dz = 0; + mousedev->packet.abs_event = 0; + } + break; } } @@ -367,41 +413,45 @@ static void mousedev_free(struct device { struct mousedev *mousedev = container_of(dev, struct mousedev, dev); - mousedev_table[mousedev->minor] = NULL; kfree(mousedev); } -static int mixdev_add_device(struct mousedev *mousedev) +static int mousedev_open_device(struct mousedev *mousedev) { - int error; - - if (mousedev_mix->open) { - error = input_open_device(&mousedev->handle); - if (error) - return error; + int retval; - mousedev->open++; - mousedev->mixdev_open = 1; - } + retval = mutex_lock_interruptible(&mousedev->mutex); + if (retval) + return retval; - get_device(&mousedev->dev); - list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list); + if (mousedev->minor == MOUSEDEV_MIX) + mixdev_open_devices(); + else if (!mousedev->exist) + retval = -ENODEV; + else if (!mousedev->open++) + retval = input_open_device(&mousedev->handle); - return 0; + mutex_unlock(&mousedev->mutex); + return retval; } -static void mixdev_remove_device(struct mousedev *mousedev) +static void mousedev_close_device(struct mousedev *mousedev) { - if (mousedev->mixdev_open) { - mousedev->mixdev_open = 0; - if (!--mousedev->open && mousedev->exist) - input_close_device(&mousedev->handle); - } + mutex_lock(&mousedev->mutex); - list_del_init(&mousedev->mixdev_node); - put_device(&mousedev->dev); + if (mousedev->minor == MOUSEDEV_MIX) + mixdev_close_devices(); + else if (mousedev->exist && !--mousedev->open) + input_close_device(&mousedev->handle); + + mutex_unlock(&mousedev->mutex); } +/* + * Open all available devices so they can all be multiplexed in one. + * stream. Note that this function is called with mousedev_mix->mutex + * held. + */ static void mixdev_open_devices(void) { struct mousedev *mousedev; @@ -411,16 +461,19 @@ static void mixdev_open_devices(void) list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) { if (!mousedev->mixdev_open) { - if (!mousedev->open && mousedev->exist) - if (input_open_device(&mousedev->handle)) - continue; + if (mousedev_open_device(mousedev)); + continue; - mousedev->open++; mousedev->mixdev_open = 1; } } } +/* + * Close all devices that were opened as part of multiplexed + * device. Note that this function is called with mousedev_mix->mutex + * held. + */ static void mixdev_close_devices(void) { struct mousedev *mousedev; @@ -431,33 +484,50 @@ static void mixdev_close_devices(void) list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) { if (mousedev->mixdev_open) { mousedev->mixdev_open = 0; - if (!--mousedev->open && mousedev->exist) - input_close_device(&mousedev->handle); + mousedev_close_device(mousedev); } } } + +static void mousedev_attach_client(struct mousedev *mousedev, + struct mousedev_client *client) +{ + spin_lock(&mousedev->client_lock); + list_add_tail_rcu(&client->node, &mousedev->client_list); + spin_unlock(&mousedev->client_lock); + /* + * We don't use synchronize_rcu() here because read-size + * critical section is protected by a spinlock (dev->event_lock) + * instead of rcu_read_lock(). + */ + synchronize_sched(); +} + +static void mousedev_detach_client(struct mousedev *mousedev, + struct mousedev_client *client) +{ + spin_lock(&mousedev->client_lock); + list_del_rcu(&client->node); + spin_unlock(&mousedev->client_lock); + synchronize_sched(); +} + static int mousedev_release(struct inode *inode, struct file *file) { struct mousedev_client *client = file->private_data; struct mousedev *mousedev = client->mousedev; mousedev_fasync(-1, file, 0); - - list_del(&client->node); + mousedev_detach_client(mousedev, client); kfree(client); - if (mousedev->minor == MOUSEDEV_MIX) - mixdev_close_devices(); - else if (!--mousedev->open && mousedev->exist) - input_close_device(&mousedev->handle); - + mousedev_close_device(mousedev); put_device(&mousedev->dev); return 0; } - static int mousedev_open(struct inode *inode, struct file *file) { struct mousedev_client *client; @@ -475,12 +545,17 @@ static int mousedev_open(struct inode *i if (i >= MOUSEDEV_MINORS) return -ENODEV; + error = mutex_lock_interruptible(&mousedev_table_mutex); + if (error) + return error; mousedev = mousedev_table[i]; + if (mousedev) + get_device(&mousedev->dev); + mutex_unlock(&mousedev_table_mutex); + if (!mousedev) return -ENODEV; - get_device(&mousedev->dev); - client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL); if (!client) { error = -ENOMEM; @@ -491,21 +566,17 @@ static int mousedev_open(struct inode *i client->pos_x = xres / 2; client->pos_y = yres / 2; client->mousedev = mousedev; - list_add_tail(&client->node, &mousedev->client_list); + mousedev_attach_client(mousedev, client); - if (mousedev->minor == MOUSEDEV_MIX) - mixdev_open_devices(); - else if (!mousedev->open++ && mousedev->exist) { - error = input_open_device(&mousedev->handle); - if (error) - goto err_free_client; - } + error = mousedev_open_device(mousedev); + if (error) + goto err_free_client; file->private_data = client; return 0; err_free_client: - list_del(&client->node); + mousedev_detach_client(mousedev, client); kfree(client); err_put_mousedev: put_device(&mousedev->dev); @@ -517,41 +588,41 @@ static inline int mousedev_limit_delta(i return delta > limit ? limit : (delta < -limit ? -limit : delta); } -static void mousedev_packet(struct mousedev_client *client, signed char *ps2_data) +static void mousedev_packet(struct mousedev_client *client, + signed char *ps2_data) { - struct mousedev_motion *p; - unsigned long flags; - - spin_lock_irqsave(&client->packet_lock, flags); - p = &client->packets[client->tail]; + struct mousedev_motion *p = &client->packets[client->tail]; - ps2_data[0] = 0x08 | ((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07); + ps2_data[0] = 0x08 | + ((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07); ps2_data[1] = mousedev_limit_delta(p->dx, 127); ps2_data[2] = mousedev_limit_delta(p->dy, 127); p->dx -= ps2_data[1]; p->dy -= ps2_data[2]; switch (client->mode) { - case MOUSEDEV_EMUL_EXPS: - ps2_data[3] = mousedev_limit_delta(p->dz, 7); - p->dz -= ps2_data[3]; - ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1); - client->bufsiz = 4; - break; - - case MOUSEDEV_EMUL_IMPS: - ps2_data[0] |= ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1); - ps2_data[3] = mousedev_limit_delta(p->dz, 127); - p->dz -= ps2_data[3]; - client->bufsiz = 4; - break; - - case MOUSEDEV_EMUL_PS2: - default: - ps2_data[0] |= ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1); - p->dz = 0; - client->bufsiz = 3; - break; + case MOUSEDEV_EMUL_EXPS: + ps2_data[3] = mousedev_limit_delta(p->dz, 7); + p->dz -= ps2_data[3]; + ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1); + client->bufsiz = 4; + break; + + case MOUSEDEV_EMUL_IMPS: + ps2_data[0] |= + ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1); + ps2_data[3] = mousedev_limit_delta(p->dz, 127); + p->dz -= ps2_data[3]; + client->bufsiz = 4; + break; + + case MOUSEDEV_EMUL_PS2: + default: + ps2_data[0] |= + ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1); + p->dz = 0; + client->bufsiz = 3; + break; } if (!p->dx && !p->dy && !p->dz) { @@ -561,12 +632,50 @@ static void mousedev_packet(struct mouse } else client->tail = (client->tail + 1) % PACKET_QUEUE_LEN; } - - spin_unlock_irqrestore(&client->packet_lock, flags); } +static void mousedev_generate_response(struct mousedev_client *client, + int command) +{ + client->ps2[0] = 0xfa; /* ACK */ + + switch (command) { + + case 0xeb: /* Poll */ + mousedev_packet(client, &client->ps2[1]); + client->bufsiz++; /* account for leading ACK */ + break; + + case 0xf2: /* Get ID */ + switch (client->mode) { + case MOUSEDEV_EMUL_PS2: client->ps2[1] = 0; break; + case MOUSEDEV_EMUL_IMPS: client->ps2[1] = 3; break; + case MOUSEDEV_EMUL_EXPS: client->ps2[1] = 4; break; + } + client->bufsiz = 2; + break; + + case 0xe9: /* Get info */ + client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200; + client->bufsiz = 4; + break; + + case 0xff: /* Reset */ + client->impsseq = client->imexseq = 0; + client->mode = MOUSEDEV_EMUL_PS2; + client->ps2[1] = 0xaa; client->ps2[2] = 0x00; + client->bufsiz = 3; + break; + + default: + client->bufsiz = 1; + break; + } + client->buffer = client->bufsiz; +} -static ssize_t mousedev_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) +static ssize_t mousedev_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) { struct mousedev_client *client = file->private_data; unsigned char c; @@ -577,6 +686,8 @@ static ssize_t mousedev_write(struct fil if (get_user(c, buffer + i)) return -EFAULT; + spin_lock_irq(&client->packet_lock); + if (c == mousedev_imex_seq[client->imexseq]) { if (++client->imexseq == MOUSEDEV_SEQ_LEN) { client->imexseq = 0; @@ -593,68 +704,39 @@ static ssize_t mousedev_write(struct fil } else client->impsseq = 0; - client->ps2[0] = 0xfa; - - switch (c) { + mousedev_generate_response(client, c); - case 0xeb: /* Poll */ - mousedev_packet(client, &client->ps2[1]); - client->bufsiz++; /* account for leading ACK */ - break; - - case 0xf2: /* Get ID */ - switch (client->mode) { - case MOUSEDEV_EMUL_PS2: client->ps2[1] = 0; break; - case MOUSEDEV_EMUL_IMPS: client->ps2[1] = 3; break; - case MOUSEDEV_EMUL_EXPS: client->ps2[1] = 4; break; - } - client->bufsiz = 2; - break; - - case 0xe9: /* Get info */ - client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200; - client->bufsiz = 4; - break; - - case 0xff: /* Reset */ - client->impsseq = client->imexseq = 0; - client->mode = MOUSEDEV_EMUL_PS2; - client->ps2[1] = 0xaa; client->ps2[2] = 0x00; - client->bufsiz = 3; - break; - - default: - client->bufsiz = 1; - break; - } - - client->buffer = client->bufsiz; + spin_unlock_irq(&client->packet_lock); } kill_fasync(&client->fasync, SIGIO, POLL_IN); - wake_up_interruptible(&client->mousedev->wait); return count; } -static ssize_t mousedev_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) +static ssize_t mousedev_read(struct file *file, char __user *buffer, + size_t count, loff_t *ppos) { struct mousedev_client *client = file->private_data; + struct mousedev *mousedev = client->mousedev; + signed char data[sizeof(client->ps2)]; int retval = 0; - if (!client->ready && !client->buffer && (file->f_flags & O_NONBLOCK)) + if (!client->ready && !client->buffer && mousedev->exist && + (file->f_flags & O_NONBLOCK)) return -EAGAIN; - retval = wait_event_interruptible(client->mousedev->wait, - !client->mousedev->exist || client->ready || client->buffer); - + retval = wait_event_interruptible(mousedev->wait, + !mousedev->exist || client->ready || client->buffer); if (retval) return retval; - if (!client->mousedev->exist) + if (!mousedev->exist) return -ENODEV; + spin_lock_irq(&client->packet_lock); + if (!client->buffer && client->ready) { mousedev_packet(client, client->ps2); client->buffer = client->bufsiz; @@ -663,9 +745,12 @@ static ssize_t mousedev_read(struct file if (count > client->buffer) count = client->buffer; + memcpy(data, client->ps2 + client->bufsiz - client->buffer, count); client->buffer -= count; - if (copy_to_user(buffer, client->ps2 + client->bufsiz - client->buffer - count, count)) + spin_unlock_irq(&client->packet_lock); + + if (copy_to_user(buffer, data, count)) return -EFAULT; return count; @@ -692,6 +777,60 @@ static const struct file_operations mous .fasync = mousedev_fasync, }; +static int mousedev_install_chrdev(struct mousedev *mousedev) +{ + mousedev_table[mousedev->minor] = mousedev; + return 0; +} + +static void mousedev_remove_chrdev(struct mousedev *mousedev) +{ + mutex_lock(&mousedev_table_mutex); + mousedev_table[mousedev->minor] = NULL; + mutex_unlock(&mousedev_table_mutex); +} + +/* + * Mark device non-existent. This disables writes, ioctls and + * prevents new users from opening the device. Already posted + * blocking reads will stay, however new ones will fail. + */ +static void mousedev_mark_dead(struct mousedev *mousedev) +{ + mutex_lock(&mousedev->mutex); + mousedev->exist = 0; + mutex_unlock(&mousedev->mutex); +} + +/* + * Wake up users waiting for IO so they can disconnect from + * dead device. + */ +static void mousedev_hangup(struct mousedev *mousedev) +{ + struct mousedev_client *client; + + spin_lock(&mousedev->client_lock); + list_for_each_entry(client, &mousedev->client_list, node) + kill_fasync(&client->fasync, SIGIO, POLL_HUP); + spin_unlock(&mousedev->client_lock); + + wake_up_interruptible(&mousedev->wait); +} + +static void mousedev_cleanup(struct mousedev *mousedev) +{ + struct input_handle *handle = &mousedev->handle; + + mousedev_mark_dead(mousedev); + mousedev_hangup(mousedev); + mousedev_remove_chrdev(mousedev); + + /* mousedev is marked dead so no one else accesses mousedev->open */ + if (mousedev->open) + input_close_device(handle); +} + static struct mousedev *mousedev_create(struct input_dev *dev, struct input_handler *handler, int minor) @@ -707,6 +846,10 @@ static struct mousedev *mousedev_create( INIT_LIST_HEAD(&mousedev->client_list); INIT_LIST_HEAD(&mousedev->mixdev_node); + spin_lock_init(&mousedev->client_lock); + mutex_init(&mousedev->mutex); + lockdep_set_subclass(&mousedev->mutex, + minor == MOUSEDEV_MIX ? MOUSEDEV_MIX : 0); init_waitqueue_head(&mousedev->wait); if (minor == MOUSEDEV_MIX) @@ -731,14 +874,27 @@ static struct mousedev *mousedev_create( mousedev->dev.release = mousedev_free; device_initialize(&mousedev->dev); - mousedev_table[minor] = mousedev; + if (minor != MOUSEDEV_MIX) { + error = input_register_handle(&mousedev->handle); + if (error) + goto err_free_mousedev; + } + + error = mousedev_install_chrdev(mousedev); + if (error) + goto err_unregister_handle; error = device_add(&mousedev->dev); if (error) - goto err_free_mousedev; + goto err_cleanup_mousedev; return mousedev; + err_cleanup_mousedev: + mousedev_cleanup(mousedev); + err_unregister_handle: + if (minor != MOUSEDEV_MIX) + input_unregister_handle(&mousedev->handle); err_free_mousedev: put_device(&mousedev->dev); err_out: @@ -747,29 +903,64 @@ static struct mousedev *mousedev_create( static void mousedev_destroy(struct mousedev *mousedev) { - struct mousedev_client *client; - device_del(&mousedev->dev); - mousedev->exist = 0; + mousedev_cleanup(mousedev); + if (mousedev->minor != MOUSEDEV_MIX) + input_unregister_handle(&mousedev->handle); + put_device(&mousedev->dev); +} - if (mousedev->open) { - input_close_device(&mousedev->handle); - list_for_each_entry(client, &mousedev->client_list, node) - kill_fasync(&client->fasync, SIGIO, POLL_HUP); - wake_up_interruptible(&mousedev->wait); +static int mixdev_add_device(struct mousedev *mousedev) +{ + int retval; + + retval = mutex_lock_interruptible(&mousedev_mix->mutex); + if (retval) + return retval; + + if (mousedev_mix->open) { + retval = mousedev_open_device(mousedev); + if (retval) + goto out; + + mousedev->mixdev_open = 1; + } + + get_device(&mousedev->dev); + list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list); + + out: + mutex_unlock(&mousedev_mix->mutex); + return retval; +} + +static void mixdev_remove_device(struct mousedev *mousedev) +{ + mutex_lock(&mousedev_mix->mutex); + + if (mousedev->mixdev_open) { + mousedev->mixdev_open = 0; + mousedev_close_device(mousedev); } + list_del_init(&mousedev->mixdev_node); + mutex_unlock(&mousedev_mix->mutex); + put_device(&mousedev->dev); } -static int mousedev_connect(struct input_handler *handler, struct input_dev *dev, +static int mousedev_connect(struct input_handler *handler, + struct input_dev *dev, const struct input_device_id *id) { struct mousedev *mousedev; int minor; int error; - for (minor = 0; minor < MOUSEDEV_MINORS && mousedev_table[minor]; minor++); + for (minor = 0; minor < MOUSEDEV_MINORS; minor++) + if (!mousedev_table[minor]) + break; + if (minor == MOUSEDEV_MINORS) { printk(KERN_ERR "mousedev: no more free mousedev devices\n"); return -ENFILE; @@ -779,21 +970,13 @@ static int mousedev_connect(struct input if (IS_ERR(mousedev)) return PTR_ERR(mousedev); - error = input_register_handle(&mousedev->handle); - if (error) - goto err_delete_mousedev; - error = mixdev_add_device(mousedev); - if (error) - goto err_unregister_handle; + if (error) { + mousedev_destroy(mousedev); + return error; + } return 0; - - err_unregister_handle: - input_unregister_handle(&mousedev->handle); - err_delete_mousedev: - device_unregister(&mousedev->dev); - return error; } static void mousedev_disconnect(struct input_handle *handle) @@ -801,33 +984,42 @@ static void mousedev_disconnect(struct i struct mousedev *mousedev = handle->private; mixdev_remove_device(mousedev); - input_unregister_handle(handle); mousedev_destroy(mousedev); } static const struct input_device_id mousedev_ids[] = { { - .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_RELBIT, + .flags = INPUT_DEVICE_ID_MATCH_EVBIT | + INPUT_DEVICE_ID_MATCH_KEYBIT | + INPUT_DEVICE_ID_MATCH_RELBIT, .evbit = { BIT(EV_KEY) | BIT(EV_REL) }, .keybit = { [LONG(BTN_LEFT)] = BIT(BTN_LEFT) }, .relbit = { BIT(REL_X) | BIT(REL_Y) }, - }, /* A mouse like device, at least one button, two relative axes */ + }, /* A mouse like device, at least one button, + two relative axes */ { - .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_RELBIT, + .flags = INPUT_DEVICE_ID_MATCH_EVBIT | + INPUT_DEVICE_ID_MATCH_RELBIT, .evbit = { BIT(EV_KEY) | BIT(EV_REL) }, .relbit = { BIT(REL_WHEEL) }, }, /* A separate scrollwheel */ { - .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_ABSBIT, + .flags = INPUT_DEVICE_ID_MATCH_EVBIT | + INPUT_DEVICE_ID_MATCH_KEYBIT | + INPUT_DEVICE_ID_MATCH_ABSBIT, .evbit = { BIT(EV_KEY) | BIT(EV_ABS) }, .keybit = { [LONG(BTN_TOUCH)] = BIT(BTN_TOUCH) }, .absbit = { BIT(ABS_X) | BIT(ABS_Y) }, - }, /* A tablet like device, at least touch detection, two absolute axes */ + }, /* A tablet like device, at least touch detection, + two absolute axes */ { - .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_ABSBIT, + .flags = INPUT_DEVICE_ID_MATCH_EVBIT | + INPUT_DEVICE_ID_MATCH_KEYBIT | + INPUT_DEVICE_ID_MATCH_ABSBIT, .evbit = { BIT(EV_KEY) | BIT(EV_ABS) }, .keybit = { [LONG(BTN_TOOL_FINGER)] = BIT(BTN_TOOL_FINGER) }, - .absbit = { BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE) | BIT(ABS_TOOL_WIDTH) }, + .absbit = { BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE) | + BIT(ABS_TOOL_WIDTH) }, }, /* A touchpad */ { }, /* Terminating entry */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/