net: qrtr: ns: Return 0 if server port is not present

When a 'DEL_CLIENT' message is received from the remote, the corresponding
server port gets deleted. A DEL_SERVER message is then announced for this
server. As part of handling the subsequent DEL_SERVER message, the name-
server attempts to delete the server port which results in a '-ENOENT' error.
The return value from server_del() is then propagated back to qrtr_ns_worker,
causing excessive error prints.
To address this, return 0 from control_cmd_del_server() without checking the
return value of server_del(), since the above scenario is not an error case
and hence server_del() doesn't have any other error return value.

Signed-off-by: Sarannya Sasikumar <quic_sarannya@quicinc.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: ns: Change nodes radix tree to xarray

There is a use after free scenario while iterating through the nodes
radix tree despite the ns being a single threaded process. This can
happen when the radix tree APIs are not synchronized with the
rcu_read_lock() APIs.

Convert the radix tree for nodes to xarray to take advantage of the
built in rcu lock usage provided by xarray.

Signed-off-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Vignesh Viswanathan <quic_viswanat@quicinc.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: ns: Change servers radix tree to xarray

There is a use after free scenario while iterating through the servers
radix tree despite the ns being a single threaded process. This can
happen when the radix tree APIs are not synchronized with the
rcu_read_lock() APIs.

Convert the radix tree for servers to xarray to take advantage of the
built in rcu lock usage provided by xarray.

Signed-off-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Vignesh Viswanathan <quic_viswanat@quicinc.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: Use alloc_ordered_workqueue() to create ordered workqueues

BACKGROUND
==========

When multiple work items are queued to a workqueue, their execution order
doesn't match the queueing order. They may get executed in any order and
simultaneously. When fully serialized execution - one by one in the queueing
order - is needed, an ordered workqueue should be used which can be created
with alloc_ordered_workqueue().

However, alloc_ordered_workqueue() was a later addition. Before it, an
ordered workqueue could be obtained by creating an UNBOUND workqueue with
@max_active==1. This originally was an implementation side-effect which was
broken by 4c16bd327c74 ("workqueue: restore WQ_UNBOUND/max_active==1 to be
ordered"). Because there were users that depended on the ordered execution,
5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered")
made workqueue allocation path to implicitly promote UNBOUND workqueues w/
@max_active==1 to ordered workqueues.

While this has worked okay, overloading the UNBOUND allocation interface
this way creates other issues. It's difficult to tell whether a given
workqueue actually needs to be ordered and users that legitimately want a
min concurrency level wq unexpectedly gets an ordered one instead. With
planned UNBOUND workqueue updates to improve execution locality and more
prevalence of chiplet designs which can benefit from such improvements, this
isn't a state we wanna be in forever.

This patch series audits all callsites that create an UNBOUND workqueue w/
@max_active==1 and converts them to alloc_ordered_workqueue() as necessary.

WHAT TO LOOK FOR
================

The conversions are from

alloc_workqueue(WQ_UNBOUND | flags, 1, args..)

to

alloc_ordered_workqueue(flags, args...)

which don't cause any functional changes. If you know that fully ordered
execution is not necessary, please let me know. I'll drop the conversion and
instead add a comment noting the fact to reduce confusion while conversion
is in progress.

If you aren't fully sure, it's completely fine to let the conversion
through. The behavior will stay exactly the same and we can always
reconsider later.

As there are follow-up workqueue core changes, I'd really appreciate if the
patch can be routed through the workqueue tree w/ your acks. Thanks.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: netdev@vger.kernel.org

net: qrtr: Do not do DEL_SERVER broadcast after DEL_CLIENT

On the remote side, when QRTR socket is removed, af_qrtr will call
qrtr_port_remove() which broadcasts the DEL_CLIENT packet to all neighbours
including local NS. NS upon receiving the DEL_CLIENT packet, will remove
the lookups associated with the node:port and broadcasts the DEL_SERVER
packet.

But on the host side, due to the arrival of the DEL_CLIENT packet, the NS
would've already deleted the server belonging to that port. So when the
remote's NS again broadcasts the DEL_SERVER for that port, it throws below
error message on the host:

"failed while handling packet from 2:-2"

So fix this error by not broadcasting the DEL_SERVER packet when the
DEL_CLIENT packet gets processed."

Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Ram Kumar Dharuman <quic_ramd@quicinc.com>
Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sock: Introduce trace_sk_data_ready()

As suggested by Cong, introduce a tracepoint for all ->sk_data_ready()
callback implementations. For example:

<...>
iperf-609 [002] ..... 70.660425: sk_data_ready: family=2 protocol=6 func=sock_def_readable
iperf-609 [002] ..... 70.660436: sk_data_ready: family=2 protocol=6 func=sock_def_readable
<...>

Suggested-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: free memory on error path in radix_tree_insert()

Function radix_tree_insert() returns errors if the node hasn't
been initialized and added to the tree.

"kfree(node)" and return value "NULL" of node_get() help
to avoid using unclear node in other calls.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Cc: <stable@vger.kernel.org> # 5.7
Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")
Signed-off-by: Natalia Petrova <n.petrova@fintech.ru>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://lore.kernel.org/r/20230125134831.8090-1-n.petrova@fintech.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: qrtr: ns: Fix error return code in qrtr_ns_init()

Fix to return a negative error code -ENOMEM from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: c6e08d6251f3 ("net: qrtr: Allocate workqueue before kernel_bind")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: fix null-ptr-deref in qrtr_ns_remove

A null-ptr-deref bug is reported by Hulk Robot like this:
--------------
KASAN: null-ptr-deref in range [0x0000000000000128-0x000000000000012f]
Call Trace:
qrtr_ns_remove+0x22/0x40 [ns]
qrtr_proto_fini+0xa/0x31 [qrtr]
__x64_sys_delete_module+0x337/0x4e0
do_syscall_64+0x34/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x468ded
--------------

When qrtr_ns_init fails in qrtr_proto_init, qrtr_ns_remove which would
be called later on would raise a null-ptr-deref because qrtr_ns.workqueue
has been destroyed.

Fix it by making qrtr_ns_init have a return value and adding a check in
qrtr_proto_init.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: Allow forwarded services

A remote endpoint (immediate neighbors node) can forward services
from other nodes (non-immadiate), in that case ctrl packet node ID
(offering distant service) can differ from the qrtr source node
(forwarding the packet).

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: qrtr: ns: Fix the incorrect usage of rcu_read_lock()

The rcu_read_lock() is not supposed to lock the kernel_sendmsg() API
since it has the lock_sock() in qrtr_sendmsg() which will sleep. Hence,
fix it by excluding the locking for kernel_sendmsg().

While at it, let's also use radix_tree_deref_retry() to confirm the
validity of the pointer returned by radix_tree_deref_slot() and use
radix_tree_iter_resume() to resume iterating the tree properly before
releasing the lock as suggested by Doug.

Fixes: a7809ff90ce6 ("net: qrtr: ns: Protect radix_tree_deref_slot() using rcu read locks")
Reported-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Alex Elder <elder@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: ns: Protect radix_tree_deref_slot() using rcu read locks

The rcu read locks are needed to avoid potential race condition while
dereferencing radix tree from multiple threads. The issue was identified
by syzbot. Below is the crash report:

=============================
WARNING: suspicious RCU usage
5.7.0-syzkaller #0 Not tainted
-----------------------------
include/linux/radix-tree.h:176 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
2 locks held by kworker/u4:1/21:
#0: ffff88821b097938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: spin_unlock_irq include/linux/spinlock.h:403 [inline]
#0: ffff88821b097938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: process_one_work+0x6df/0xfd0 kernel/workqueue.c:2241
#1: ffffc90000dd7d80 ((work_completion)(&qrtr_ns.work)){+.+.}-{0:0}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2243

stack backtrace:
CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: qrtr_ns_handler qrtr_ns_worker
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1e9/0x30e lib/dump_stack.c:118
radix_tree_deref_slot include/linux/radix-tree.h:176 [inline]
ctrl_cmd_new_lookup net/qrtr/ns.c:558 [inline]
qrtr_ns_worker+0x2aff/0x4500 net/qrtr/ns.c:674
process_one_work+0x76e/0xfd0 kernel/workqueue.c:2268
worker_thread+0xa7f/0x1450 kernel/workqueue.c:2414
kthread+0x353/0x380 kernel/kthread.c:268

Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")
Reported-and-tested-by: syzbot+0f84f6eed90503da72fc@syzkaller.appspotmail.com
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: Allocate workqueue before kernel_bind

A null pointer dereference in qrtr_ns_data_ready() is seen if a client
opens a qrtr socket before qrtr_ns_init() can bind to the control port.
When the control port is bound, the ENETRESET error will be broadcasted
and clients will close their sockets. This results in DEL_CLIENT
packets being sent to the ns and qrtr_ns_data_ready() being called
without the workqueue being allocated.

Allocate the workqueue before setting sk_data_ready and binding to the
control port. This ensures that the work and workqueue structs are
allocated and initialized before qrtr_ns_data_ready can be called.

Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")
Signed-off-by: Chris Lew <clew@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: Add tracepoint support

Add tracepoint support for QRTR with NS as the first candidate. Later on
this can be extended to core QRTR and transport drivers.

The trace_printk() used in NS has been replaced by tracepoints.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: Fix FIXME related to qrtr_ns_init()

The 2 second delay before calling qrtr_ns_init() meant that the remote
processors would register as endpoints in qrtr and the say_hello() call
would therefor broadcast the outgoing HELLO to them. With the HELLO
handshake corrected this delay is no longer needed.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: Respond to HELLO message

Lost in the translation from the user space implementation was the
detail that HELLO mesages must be exchanged between each node pair. As
such the incoming HELLO must be replied to.

Similar to the previous implementation no effort is made to prevent two
Linux boxes from continuously sending HELLO messages back and forth,
this is left to a follow up patch.

say_hello() is moved, to facilitate the new call site.

Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: Fix error pointer vs NULL bugs

The callers only expect NULL pointers, so returning an error pointer
will lead to an Oops.

Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: fix spelling mistake "serivce" -> "service"

There is a spelling mistake in a pr_err message. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qrtr: Migrate nameservice to kernel from userspace

The QRTR nameservice has been maintained in userspace for some time. This
commit migrates it to Linux kernel. This change is required in order to
eliminate the need of starting a userspace daemon for making the WiFi
functional for ath11k based devices. Since the QRTR NS is not usually
packed in most of the distros, users need to clone, build and install it
to get the WiFi working. It will become a hassle when the user doesn't
have any other source of network connectivity.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>