linux-stable.git/include/trace/events/rxrpc.h, branch linux-6.2.y

rxrpc: Move client call connection to the I/O thread

2023-01-06T09:43:33+00:00

Move the connection setup of client calls to the I/O thread so that a whole
load of locking and barrierage can be eliminated.  This necessitates the
app thread waiting for connection to complete before it can begin
encrypting data.

This also completes the fix for a race that exists between call connection
and call disconnection whereby the data transmission code adds the call to
the peer error distribution list after the call has been disconnected (say
by the rxrpc socket getting closed).

The fix is to complete the process of moving call connection, data
transmission and call disconnection into the I/O thread and thus forcibly
serialising them.

Note that the issue may predate the overhaul to an I/O thread model that
were included in the merge window for v6.2, but the timing is very much
changed by the change given below.

Fixes: cf37b5987508 ("rxrpc: Move DATA transmission into call processor work item")
Reported-by: syzbot+c22650d2844392afdcfd@syzkaller.appspotmail.com
Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Set up a connection bundle from a call, not rxrpc_conn_parameters

2023-01-06T09:43:32+00:00

Use the information now stored in struct rxrpc_call to configure the
connection bundle and thence the connection, rather than using the
rxrpc_conn_parameters struct.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Offload the completion of service conn security to the I/O thread

2023-01-06T09:43:32+00:00

Offload the completion of the challenge/response cycle on a service
connection to the I/O thread.  After the RESPONSE packet has been
successfully decrypted and verified by the work queue, offloading the
changing of the call states to the I/O thread makes iteration over the
conn's channel list simpler.

Do this by marking the RESPONSE skbuff and putting it onto the receive
queue for the I/O thread to collect.  We put it on the front of the queue
as we've already received the packet for it.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Tidy up abort generation infrastructure

2023-01-06T09:43:32+00:00

Tidy up the abort generation infrastructure in the following ways:

 (1) Create an enum and string mapping table to list the reasons an abort
     might be generated in tracing.

 (2) Replace the 3-char string with the values from (1) in the places that
     use that to log the abort source.  This gets rid of a memcpy() in the
     tracepoint.

 (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint
     and use values from (1) to indicate the trace reason.

 (4) Always make a call to an abort function at the point of the abort
     rather than stashing the values into variables and using goto to get
     to a place where it reported.  The C optimiser will collapse the calls
     together as appropriate.  The abort functions return a value that can
     be returned directly if appropriate.

Note that this extends into afs also at the points where that generates an
abort.  To aid with this, the afs sources need to #define
RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header
because they don't have access to the rxrpc internal structures that some
of the tracepoints make use of.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Clean up connection abort

2023-01-06T09:43:32+00:00

Clean up connection abort, using the connection state_lock to gate access
to change that state, and use an rxrpc_call_completion value to indicate
the difference between local and remote aborts as these can be pasted
directly into the call state.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Implement a mechanism to send an event notification to a connection

2023-01-06T09:43:31+00:00

Provide a means by which an event notification can be sent to a connection
through such that the I/O thread can pick it up and handle it rather than
doing it in a separate workqueue.

This is then used to move the deferred final ACK of a call into the I/O
thread rather than a separate work queue as part of the drive to do all
transmission from the I/O thread.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Only disconnect calls in the I/O thread

2023-01-06T09:43:31+00:00

Only perform call disconnection in the I/O thread to reduce the locking
requirement.

This is the first part of a fix for a race that exists between call
connection and call disconnection whereby the data transmission code adds
the call to the peer error distribution list after the call has been
disconnected (say by the rxrpc socket getting closed).

The fix is to complete the process of moving call connection, data
transmission and call disconnection into the I/O thread and thus forcibly
serialising them.

Note that the issue may predate the overhaul to an I/O thread model that
were included in the merge window for v6.2, but the timing is very much
changed by the change given below.

Fixes: cf37b5987508 ("rxrpc: Move DATA transmission into call processor work item")
Reported-by: syzbot+c22650d2844392afdcfd@syzkaller.appspotmail.com
Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Only set/transmit aborts in the I/O thread

2023-01-06T09:43:31+00:00

Only set the abort call completion state in the I/O thread and only
transmit ABORT packets from there.  rxrpc_abort_call() can then be made to
actually send the packet.

Further, ABORT packets should only be sent if the call has been exposed to
the network (ie. at least one attempted DATA transmission has occurred for
it).

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Make the local endpoint hold a ref on a connected call

2023-01-06T09:43:31+00:00

Make the local endpoint and it's I/O thread hold a reference on a connected
call until that call is disconnected.  Without this, we're reliant on
either the AF_RXRPC socket to hold a ref (which is dropped when the call is
released) or a queued work item to hold a ref (the work item is being
replaced with the I/O thread).

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Fix a couple of potential use-after-frees

2022-12-28T09:59:23+00:00

At the end of rxrpc_recvmsg(), if a call is found, the call is put and then
a trace line is emitted referencing that call in a couple of places - but
the call may have been deallocated by the time those traces happen.

Fix this by stashing the call debug_id in a variable and passing that to
the tracepoint rather than the call pointer.

Fixes: 849979051cbc ("rxrpc: Add a tracepoint to follow what recvmsg does")
Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Signed-off-by: David S. Miller