Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1285395

[PATCH 3.14 25/37] Bluetooth: hidp: fix device disconnect on idle timeout

Show all headers | View raw

3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Herrmann <dh.herrmann@gmail.com>

commit 660f0fc07d21114549c1862e67e78b1cf0c90c29 upstream.

The HIDP specs define an idle-timeout which automatically disconnects a
device. This has always been implemented in the HIDP layer and forced a
synchronous shutdown of the hidp-scheduler. This works just fine, but
lacks a forced disconnect on the underlying l2cap channels. This has been
broken since:

    commit 5205185d461d5902325e457ca80bd421127b7308
    Author: David Herrmann <dh.herrmann@gmail.com>
    Date:   Sat Apr 6 20:28:47 2013 +0200

        Bluetooth: hidp: remove old session-management

The old session-management always forced an l2cap error on the ctrl/intr
channels when shutting down. The new session-management skips this, as we
don't want to enforce channel policy on the caller. In other words, if
user-space removes an HIDP device, the underlying channels (which are
*owned* and *referenced* by user-space) are still left active. User-space
needs to call shutdown(2) or close(2) to release them.

Unfortunately, this does not work with idle-timeouts. There is no way to
signal user-space that the HIDP layer has been stopped. The API simply
does not support any event-passing except for poll(2). Hence, we restore
old behavior and force EUNATCH on the sockets if the HIDP layer is
disconnected due to idle-timeouts (behavior of explicit disconnects
remains unmodified). User-space can still call

    getsockopt(..., SO_ERROR, ...)

..to retrieve the EUNATCH error and clear sk_err. Hence, the channels can
still be re-used (which nobody does so far, though). Therefore, the API
still supports the new behavior, but with this patch it's also compatible
to the old implicit channel shutdown.

Reported-by: Mark Haun <haunma@keteu.org>
Reported-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/bluetooth/hidp/core.c |   14 ++++++++++++++
 1 file changed, 14 insertions(+)

--- a/net/bluetooth/hidp/core.c
+++ b/net/bluetooth/hidp/core.c
@@ -415,6 +415,20 @@ static void hidp_idle_timeout(unsigned l
 {
 	struct hidp_session *session = (struct hidp_session *) arg;
 
+	/* The HIDP user-space API only contains calls to add and remove
+	 * devices. There is no way to forward events of any kind. Therefore,
+	 * we have to forcefully disconnect a device on idle-timeouts. This is
+	 * unfortunate and weird API design, but it is spec-compliant and
+	 * required for backwards-compatibility. Hence, on idle-timeout, we
+	 * signal driver-detach events, so poll() will be woken up with an
+	 * error-condition on both sockets.
+	 */
+
+	session->intr_sock->sk->sk_err = EUNATCH;
+	session->ctrl_sock->sk->sk_err = EUNATCH;
+	wake_up_interruptible(sk_sleep(session->intr_sock->sk));
+	wake_up_interruptible(sk_sleep(session->ctrl_sock->sk));
+
 	hidp_session_terminate(session);
 }
 


--
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/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 3.14 00/37] 3.14.58-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:30 +0100
  [PATCH 3.14 24/37] staging: rtl8712: Add device ID for Sitecom WLA2100 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:30 +0100
  [PATCH 3.14 03/37] ppp: fix pppoe_dev deletion condition in pppoe_release() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:30 +0100
  [PATCH 3.14 21/37] mac80211: fix driver RSSI event calculations Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:30 +0100
  [PATCH 3.14 18/37] x86/setup: Fix low identity map for >= 2GB kernel range Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:30 +0100
  [PATCH 3.14 35/37] ALSA: usb-audio: add packet size quirk for the Medeli DD305 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:30 +0100
  [PATCH 3.14 20/37] x86/cpu: Fix SMAP check in PVOPS environments Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:30 +0100
  [PATCH 3.14 25/37] Bluetooth: hidp: fix device disconnect on idle timeout Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:30 +0100
  [PATCH 3.14 07/37] ipmr: fix possible race resulting from improper usage of IP_INC_STATS_BH() in preemptible context. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:30 +0100
  [PATCH 3.14 23/37] mwifiex: fix mwifiex_rdeeprom_read() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:30 +0100
  [PATCH 3.14 26/37] Bluetooth: ath3k: Add new AR3012 0930:021c id Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 14/37] ARM: 8427/1: dma-mapping: add support for offset parameter in dma_mmap() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 16/37] ARM: common: edma: Fix channel parameter for irq callbacks Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 37/37] ALSA: usb-audio: work around CH345 input SysEx corruption Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 28/37] can: sja1000: clear interrupts on start Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 04/37] RDS-TCP: Recover correctly from pskb_pull()/pksb_trim() failure in rds_tcp_data_recv Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 09/37] packet: race condition in packet_bind Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 02/37] macvtap: unbreak receiving of gro skb with frag list Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 17/37] x86/setup: Extend low identity map to cover whole kernel range Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 27/37] Bluetooth: ath3k: Add support of AR3012 0cf3:817b device Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 36/37] ALSA: usb-audio: prevent CH345 multiport output SysEx corruption Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 06/37] stmmac: Correctly report PTP capabilities. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 13/37] ARM: 8426/1: dma-mapping: add missing range check in dma_mmap() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 08/37] net: avoid NULL deref in inet_ctl_sock_destroy() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 29/37] arm64: Fix compat register mappings Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 05/37] net/mlx4: Copy/set only sizeof struct mlx4_eqe bytes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 30/37] usblp: do not set TASK_INTERRUPTIBLE before lock Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 15:40 +0100
  [PATCH 3.14 12/37] RDS: verify the underlying transport exists before creating a connection Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 17:30 +0100
  [PATCH 3.14 11/37] virtio-net: drop NETIF_F_FRAGLIST Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 17:30 +0100
  Re: [PATCH 3.14 00/37] 3.14.58-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2015-12-07 18:20 +0100
  Re: [PATCH 3.14 00/37] 3.14.58-stable review Guenter Roeck <linux@roeck-us.net> - 2015-12-07 22:20 +0100
    Re: [PATCH 3.14 00/37] 3.14.58-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-09 04:30 +0100

csiph-web