The poll() changes were not well thought out, and completely
unexplained.  They also caused a huge performance regression, because
"->poll()" was no longer a trivial file operation that just called down
to the underlying file operations, but instead did at least two indirect
calls.

Indirect calls are sadly slow now with the Spectre mitigation, but the
performance problem could at least be largely mitigated by changing the
"->get_poll_head()" operation to just have a per-file-descriptor pointer
to the poll head instead.  That gets rid of one of the new indirections.

But that doesn't fix the new complexity that is completely unwarranted
for the regular case.  The (undocumented) reason for the poll() changes
was some alleged AIO poll race fixing, but we don't make the common case
slower and more complex for some uncommon special case, so this all
really needs way more explanations and most likely a fundamental
redesign.

[ This revert is a revert of about 30 different commits, not reverted
  individually because that would just be unnecessarily messy  - Linus ]

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

In case of using BT_ERR and BT_INFO, convert to bt_dev_err and
bt_dev_info when possible. This allows for controller specific
reporting.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

bluetooth.h is not part of user API, so __ variants are not neccessary
here.
Signed-off-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

While the subsystem version information are purely informational,
increase the minor number due to the addition of user channel and
management control monitoring suppport. It is helpful for debugging
purposes to see the version numbers change.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

Instead of keeping a version string around, use version and revision
numbers and then stringify them for use as module parameter.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

To further allow unique identification and tracking of control socket,
store cookie and comm information when binding the socket.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The monitor channel can be used to send generic system notes as text
strings for debugging purposes. This adds the system note monitor code
and uses it for including kernel and subsystem version into traces.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

We can reduce the size of the hci_ctrl struct by converting
'bool req_start' to 'u8 req_flags' and making the two function
pointers a union (since only one is ever set at a time).
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The socket allocation functions will always memset skb->cb to zero so
there's no need to make other initializations needing the same thing.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

For all the HCI driver related variables accesssed via bt_cb(skb),
provide helper wrappers.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The SKB context buffer for HCI request is really not just for requests,
information in their are preserved for the whole HCI layer. So it makes
more sense to actually rename it into bt_cb()->hci and also call it then
struct hci_ctrl.

In addition that allows moving the decoded opcode for outgoing packets
into that struct. So far it was just consuming valuable space from the
main shared items. And opcode are not valid for L2CAP packets.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

Add warning logging macros to bluetooth subsystem logs.
Signed-off-by: NFrederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds ratelimited version of the BT_ERR macro.
Signed-off-by: NSzymon Janc <ext.szymon.janc@tieto.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Add specific bluetooth device logging macros since hci device name is
repeatedly referred in bluetooth subsystem logs.
Signed-off-by: NLoic Poulain <loic.poulain@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

SCO/eSCO link is supported by BR/EDR controller, it is
suitable to move them under BT_BREDR config option
Signed-off-by: NArron Wang <arron.wang@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds a second possible callback for HCI requests where the
callback will receive the full skb of the last successfully completed
HCI command. This API is useful for cases where we want to use a request
to read some data and the existing hci_event.c handlers do not store it
e.g. in the hci_dev struct.

The reason the patch is a bit bigger than just adding the new API is
because the hci_req_cmd_complete() functions required some refactoring
to enable it: now hci_req_cmd_complete() is simply used to request the
callback pointers if any, and the actual calling of them happens from a
single place at the end of hci_event_packet(). The reason for this is
that we need to pass the original skb (without any skb_pull, etc
modifications done to it) and it's simplest to keep track of it within
the hci_event_packet() function.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In order to shrink the size of bt_skb_cb, this patch moves the HCI
request related variables into their own req_ctrl struct. Additionall
the L2CAP and HCI request structs are placed inside the same union since
they will never be used at the same time for the same skb.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

We're getting very close to the maximum possible size of bt_skb_cb. To
prepare to shrink the struct with the help of a union this patch moves
all L2CAP related variables into the l2cap_ctrl struct. To later add
other 'ctrl' structs the L2CAP one is renamed simple 'l2cap' instead
of 'control'.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

We'll need to have access to which HCI channel a socket is bound to, in
order to manage pending mgmt commands in clean way. This patch adds a
helper for the purpose.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The management interface will need access to the socket flags and so
provide a helper function for checking them.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

To filter out certain actions for certain HCI sockets introcuce a flags
field that allows to configure specific settings on individual sockets.

Since the hci_pinfo structure is private in hci_sock.c, provide helper
functions for setting and clearing a given flag.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

This patch converts the existing mgmt code to use the newly introduced
generic API for registering HCI channels with mgmt-like semantics.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

After TIPC doesn't depend on iocb argument in its internal
implementations of sendmsg() and recvmsg() hooks defined in proto
structure, no any user is using iocb argument in them at all now.
Then we can drop the redundant iocb argument completely from kinds of
implementations of both sendmsg() and recvmsg() in the entire
networking stack.

Cc: Christoph Hellwig <hch@lst.de>
Suggested-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert boolean fields incoming and req_start to bit fields and move
force_active in order save space in bt_skb_cb in an effort to use
a portion of skb->cb[] for storing skb->dropcount.
Signed-off-by: NEyal Birger <eyal.birger@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct hci_req_ctrl is never used outside of struct bt_skb_cb;
Inlining it frees 8 bytes on a 64 bit system in skb->cb[] allowing
the addition of more ancillary data.
Signed-off-by: NEyal Birger <eyal.birger@gmail.com>
Reviewed-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When hci_req_run() calls its provided complete function and one of the
HCI commands in the sequence fails, then provide the opcode of failing
command. In case of success HCI_OP_NOP is provided since all commands
completed.

This patch fixes the prototype of hci_req_complete_t and all its users.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

No caller or macro uses the return value so make all
the functions return void.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Bluetooth core already does processing of the HCI command header
and puts it together before sending it to the driver. It is not really
efficient for the driver to look at the HCI command header again in
case it has to make certain decisions about certain commands. To make
this easier, just provide the opcode as part of the SKB control buffer
information. The extra information about the opcode is optional and
only provided for HCI commands.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The struct l2cap_ctrl fields are wasting an unsigned int when all the
bits can fit into an __u8 field.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The security level 4 is a new strong security requirement that is based
around 128-bit equivalent strength for link and encryption keys required
using FIPS approved algorithms. Which means that E0, SAFER+ and P-192
are not allowed. Only connections created with P-256 resulting from
using Secure Connections support are allowed.

This security level needs to be enforced when Secure Connection Only
mode is enabled for a controller or a service requires FIPS compliant
strong security. Currently it is not possible to enable either of
these two cases. This patch just puts in the foundation for being
able to handle security level 4 in the future.

It should be noted that devices or services with security level 4
requirement can only communicate using Bluetooth 4.1 controllers
with support for Secure Connections. There is no backward compatibilty
if used with older hardware.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

This patch adds new socket options for LE sockets since the existing
L2CAP_OPTIONS socket option is not usable for LE. For now, the new
socket options also require LE CoC support to be explicitly enabled to
leave some playroom in case something needs to be changed in a backwards
incompatible way.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Adding the channel to the skb private data makes possible to us know which
channel the skb we have came from.

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The L2CAP connectionless channels use SOCK_DGRAM and recvmsg() and need
to receive the remote BD_ADDR and PSM information via msg_name from
the recvmsg() system call.

So in case the L2CAP socket is for connectionless channels, provide
a msg_name callback that can update the data. Also store the remote
BD_ADDR and PSM in the skb so it can be extracted later on.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

This allows to add a per socket msg_name callback that can be used
for updating the msg_name information for recvmsg() system calls.

This feature is used by another patch to support address information
on L2CAP connectionless channels.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

Every socket protocol now stores its own address information. So
just remove the generic src and dst fields since they are no longer
needed.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The BDADDR_LOCAL is a relict from userspace and has never been used
within the kernel. So remove that constant and replace it with a new
BDADDR_NONE that is similar to HCI_DEV_NONE with all bits set.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

There are a mix of function prototypes with and without extern
in the kernel sources.  Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler.  Its use is as unnecessary as
using auto to declare automatic/local variables in a block.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>