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2023-02-21Merge tag 'hardening-v6.3-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: "Beyond some specific LoadPin, UBSAN, and fortify features, there are other fixes scattered around in various subsystems where maintainers were okay with me carrying them in my tree or were non-responsive but the patches were reviewed by others: - Replace 0-length and 1-element arrays with flexible arrays in various subsystems (Paulo Miguel Almeida, Stephen Rothwell, Kees Cook) - randstruct: Disable Clang 15 support (Eric Biggers) - GCC plugins: Drop -std=gnu++11 flag (Sam James) - strpbrk(): Refactor to use strchr() (Andy Shevchenko) - LoadPin LSM: Allow root filesystem switching when non-enforcing - fortify: Use dynamic object size hints when available - ext4: Fix CFI function prototype mismatch - Nouveau: Fix DP buffer size arguments - hisilicon: Wipe entire crypto DMA pool on error - coda: Fully allocate sig_inputArgs - UBSAN: Improve arm64 trap code reporting - copy_struct_from_user(): Add minimum bounds check on kernel buffer size" * tag 'hardening-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: randstruct: disable Clang 15 support uaccess: Add minimum bounds check on kernel buffer size arm64: Support Clang UBSAN trap codes for better reporting coda: Avoid partial allocation of sig_inputArgs gcc-plugins: drop -std=gnu++11 to fix GCC 13 build lib/string: Use strchr() in strpbrk() crypto: hisilicon: Wipe entire pool on error net/i40e: Replace 0-length array with flexible array io_uring: Replace 0-length array with flexible array ext4: Fix function prototype mismatch for ext4_feat_ktype i915/gvt: Replace one-element array with flexible-array member drm/nouveau/disp: Fix nvif_outp_acquire_dp() argument size LoadPin: Allow filesystem switch when not enforcing LoadPin: Move pin reporting cleanly out of locking LoadPin: Refactor sysctl initialization LoadPin: Refactor read-only check into a helper ARM: ixp4xx: Replace 0-length arrays with flexible arrays fortify: Use __builtin_dynamic_object_size() when available rxrpc: replace zero-lenth array with DECLARE_FLEX_ARRAY() helper
2023-01-31rxrpc: Remove local->defrag_semDavid Howells
We no longer need local->defrag_sem as all DATA packet transmission is now done from one thread, so remove it. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-31rxrpc: Simplify ACK handlingDavid Howells
Now that general ACK transmission is done from the same thread as incoming DATA packet wrangling, there's no possibility that the SACK table will be being updated by the latter whilst the former is trying to copy it to an ACK. This means that we can safely rotate the SACK table whilst updating it without having to take a lock, rather than keeping all the bits inside it in fixed place and copying and then rotating it in the transmitter. Therefore, simplify SACK handing by keeping track of starting point in the ring and rotate slots down as we consume them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-31rxrpc: De-atomic call->ackr_window and call->ackr_nr_unackedDavid Howells
call->ackr_window doesn't need to be atomic as ACK generation and ACK transmission are now done in the same thread, so drop the atomic64 handling and split it into two separate members. Similarly, call->ackr_nr_unacked doesn't need to be atomic now either. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-31rxrpc: Allow a delay to be injected into packet receptionDavid Howells
If CONFIG_AF_RXRPC_DEBUG_RX_DELAY=y, then a delay is injected between packets and errors being received and them being made available to the processing code, thereby allowing the RTT to be artificially increased. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-31rxrpc: Convert call->recvmsg_lock to a spinlockDavid Howells
Convert call->recvmsg_lock to a spinlock as it's only ever write-locked. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-07rxrpc: Fix incoming call setup raceDavid Howells
An incoming call can race with rxrpc socket destruction, leading to a leaked call. This may result in an oops when the call timer eventually expires: BUG: kernel NULL pointer dereference, address: 0000000000000874 RIP: 0010:_raw_spin_lock_irqsave+0x2a/0x50 Call Trace: <IRQ> try_to_wake_up+0x59/0x550 ? __local_bh_enable_ip+0x37/0x80 ? rxrpc_poke_call+0x52/0x110 [rxrpc] ? rxrpc_poke_call+0x110/0x110 [rxrpc] ? rxrpc_poke_call+0x110/0x110 [rxrpc] call_timer_fn+0x24/0x120 with a warning in the kernel log looking something like: rxrpc: Call 00000000ba5e571a still in use (1,SvAwtACK,1061d,0)! incurred during rmmod of rxrpc. The 1061d is the call flags: RECVMSG_READ_ALL, RX_HEARD, BEGAN_RX_TIMER, RX_LAST, EXPOSED, IS_SERVICE, RELEASED but no DISCONNECTED flag (0x800), so it's an incoming (service) call and it's still connected. The race appears to be that: (1) rxrpc_new_incoming_call() consults the service struct, checks sk_state and allocates a call - then pauses, possibly for an interrupt. (2) rxrpc_release_sock() sets RXRPC_CLOSE, nulls the service pointer, discards the prealloc and releases all calls attached to the socket. (3) rxrpc_new_incoming_call() resumes, launching the new call, including its timer and attaching it to the socket. Fix this by read-locking local->services_lock to access the AF_RXRPC socket providing the service rather than RCU in rxrpc_new_incoming_call(). There's no real need to use RCU here as local->services_lock is only write-locked by the socket side in two places: when binding and when shutting down. Fixes: 5e6ef4f1017c ("rxrpc: Make the I/O thread take over the call and local processor work") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Move client call connection to the I/O threadDavid Howells
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 <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Move the client conn cache management to the I/O threadDavid Howells
Move the management of the client connection cache to the I/O thread rather than managing it from the namespace as an aggregate across all the local endpoints within the namespace. This will allow a load of locking to be got rid of in a future patch as only the I/O thread will be looking at the this. The downside is that the total number of cached connections on the system can get higher because the limit is now per-local rather than per-netns. We can, however, keep the number of client conns in use across the entire netfs and use that to reduce the expiration time of idle connection. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Remove call->state_lockDavid Howells
All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Move call state changes from recvmsg to I/O threadDavid Howells
Move the call state changes that are made in rxrpc_recvmsg() to the I/O thread. This means that, thenceforth, only the I/O thread does this and the call state lock can be removed. This requires the Rx phase to be ended when the last packet is received, not when it is processed. Since this now changes the rxrpc call state to SUCCEEDED before we've consumed all the data from it, rxrpc_kernel_check_life() mustn't say the call is dead until the recvmsg queue is empty (unless the call has failed). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Wrap accesses to get call state to put the barrier in one placeDavid Howells
Wrap accesses to get the state of a call from outside of the I/O thread in a single place so that the barrier needed to order wrt the error code and abort code is in just that place. Also use a barrier when setting the call state and again when reading the call state such that the auxiliary completion info (error code, abort code) can be read without taking a read lock on the call state lock. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Split out the call state changing functions into their own fileDavid Howells
Split out the functions that change the state of an rxrpc call into their own file. The idea being to remove anything to do with changing the state of a call directly from the rxrpc sendmsg() and recvmsg() paths and have all that done in the I/O thread only, with the ultimate aim of removing the state lock entirely. Moving the code out of sendmsg.c and recvmsg.c makes that easier to manage. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Set up a connection bundle from a call, not rxrpc_conn_parametersDavid Howells
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 <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Offload the completion of service conn security to the I/O threadDavid Howells
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 <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Make the set of connection IDs per local endpointDavid Howells
Make the set of connection IDs per local endpoint so that endpoints don't cause each other's connections to get dismissed. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Tidy up abort generation infrastructureDavid Howells
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 <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Clean up connection abortDavid Howells
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 <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Implement a mechanism to send an event notification to a connectionDavid Howells
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 <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Only set/transmit aborts in the I/O threadDavid Howells
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 <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Separate call retransmission from other conn eventsDavid Howells
Call the rxrpc_conn_retransmit_call() directly from rxrpc_input_packet() rather than calling it via connection event handling. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Stash the network namespace pointer in rxrpc_localDavid Howells
Stash the network namespace pointer in the rxrpc_local struct in addition to a pointer to the rxrpc-specific net namespace info. Use this to remove some places where the socket is passed as a parameter. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-05rxrpc: replace zero-lenth array with DECLARE_FLEX_ARRAY() helperStephen Rothwell
0-length arrays are deprecated, and cause problems with bounds checking. Replace with a flexible array: In file included from include/linux/string.h:253, from include/linux/bitmap.h:11, from include/linux/cpumask.h:12, from arch/x86/include/asm/paravirt.h:17, from arch/x86/include/asm/cpuid.h:62, from arch/x86/include/asm/processor.h:19, from arch/x86/include/asm/cpufeature.h:5, from arch/x86/include/asm/thread_info.h:53, from include/linux/thread_info.h:60, from arch/x86/include/asm/preempt.h:9, from include/linux/preempt.h:78, from include/linux/percpu.h:6, from include/linux/prandom.h:13, from include/linux/random.h:153, from include/linux/net.h:18, from net/rxrpc/output.c:10: In function 'fortify_memcpy_chk', inlined from 'rxrpc_fill_out_ack' at net/rxrpc/output.c:158:2: include/linux/fortify-string.h:520:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 520 | __write_overflow_field(p_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Link: https://lore.kernel.org/linux-next/20230105132535.0d65378f@canb.auug.org.au/ Cc: David Howells <dhowells@redhat.com> Cc: Marc Dionne <marc.dionne@auristor.com> 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-afs@lists.infradead.org Cc: netdev@vger.kernel.org Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Kees Cook <keescook@chromium.org>
2022-12-19rxrpc: Fix the return value of rxrpc_new_incoming_call()David Howells
Dan Carpenter sayeth[1]: The patch 5e6ef4f1017c: "rxrpc: Make the I/O thread take over the call and local processor work" from Jan 23, 2020, leads to the following Smatch static checker warning: net/rxrpc/io_thread.c:283 rxrpc_input_packet() warn: bool is not less than zero. Fix this (for now) by changing rxrpc_new_incoming_call() to return an int with 0 or error code rather than bool. Note that the actual return value of rxrpc_input_packet() is currently ignored. I have a separate patch to clean that up. Fixes: 5e6ef4f1017c ("rxrpc: Make the I/O thread take over the call and local processor work") Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2022-December/006123.html [1] Signed-off-by: David S. Miller <davem@davemloft.net>
2022-12-19rxrpc: Fix locking issues in rxrpc_put_peer_locked()David Howells
Now that rxrpc_put_local() may call kthread_stop(), it can't be called under spinlock as it might sleep. This can cause a problem in the peer keepalive code in rxrpc as it tries to avoid dropping the peer_hash_lock from the point it needs to re-add peer->keepalive_link to going round the loop again in rxrpc_peer_keepalive_dispatch(). Fix this by just dropping the lock when we don't need it and accepting that we'll have to take it again. This code is only called about every 20s for each peer, so not very often. This allows rxrpc_put_peer_unlocked() to be removed also. If triggered, this bug produces an oops like the following, as reproduced by a syzbot reproducer for a different oops[1]: BUG: sleeping function called from invalid context at kernel/sched/completion.c:101 ... RCU nest depth: 0, expected: 0 3 locks held by kworker/u9:0/50: #0: ffff88810e74a138 ((wq_completion)krxrpcd){+.+.}-{0:0}, at: process_one_work+0x294/0x636 #1: ffff8881013a7e20 ((work_completion)(&rxnet->peer_keepalive_work)){+.+.}-{0:0}, at: process_one_work+0x294/0x636 #2: ffff88817d366390 (&rxnet->peer_hash_lock){+.+.}-{2:2}, at: rxrpc_peer_keepalive_dispatch+0x2bd/0x35f ... Call Trace: <TASK> dump_stack_lvl+0x4c/0x5f __might_resched+0x2cf/0x2f2 __wait_for_common+0x87/0x1e8 kthread_stop+0x14d/0x255 rxrpc_peer_keepalive_dispatch+0x333/0x35f rxrpc_peer_keepalive_worker+0x2e9/0x449 process_one_work+0x3c1/0x636 worker_thread+0x25f/0x359 kthread+0x1a6/0x1b5 ret_from_fork+0x1f/0x30 Fixes: a275da62e8c1 ("rxrpc: Create a per-local endpoint receive queue and I/O thread") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/0000000000002b4a9f05ef2b616f@google.com/ [1] Signed-off-by: David S. Miller <davem@davemloft.net>
2022-12-19rxrpc: Fix I/O thread startup getting skippedDavid Howells
When starting a kthread, the __kthread_create_on_node() function, as called from kthread_run(), waits for a completion to indicate that the task_struct (or failure state) of the new kernel thread is available before continuing. This does not wait, however, for the thread function to be invoked and, indeed, will skip it if kthread_stop() gets called before it gets there. If this happens, though, kthread_run() will have returned successfully, indicating that the thread was started and returning the task_struct pointer. The actual error indication is returned by kthread_stop(). Note that this is ambiguous, as the caller cannot tell whether the -EINTR error code came from kthread() or from the thread function. This was encountered in the new rxrpc I/O thread, where if the system is being pounded hard by, say, syzbot, the check of KTHREAD_SHOULD_STOP can be delayed long enough for kthread_stop() to get called when rxrpc releases a socket - and this causes an oops because the I/O thread function doesn't get started and thus doesn't remove the rxrpc_local struct from the local_endpoints list. Fix this by using a completion to wait for the thread to actually enter rxrpc_io_thread(). This makes sure the thread can't be prematurely stopped and makes sure the relied-upon cleanup is done. Fixes: a275da62e8c1 ("rxrpc: Create a per-local endpoint receive queue and I/O thread") Reported-by: syzbot+3538a6a72efa8b059c38@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Hillf Danton <hdanton@sina.com> Link: https://lore.kernel.org/r/000000000000229f1505ef2b6159@google.com/ Signed-off-by: David S. Miller <davem@davemloft.net>
2022-12-01rxrpc: Transmit ACKs at the point of generationDavid Howells
For ACKs generated inside the I/O thread, transmit the ACK at the point of generation. Where the ACK is generated outside of the I/O thread, it's offloaded to the I/O thread to transmit it. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Fold __rxrpc_unuse_local() into rxrpc_unuse_local()David Howells
Fold __rxrpc_unuse_local() into rxrpc_unuse_local() as the latter is now the only user of the former. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Move the cwnd degradation after transmitting packetsDavid Howells
When we've gone for >1RTT without transmitting a packet, we should reduce the ssthresh and cut the cwnd by half (as suggested in RFC2861 sec 3.1). However, we may receive ACK packets in a batch and the first of these may cut the cwnd, preventing further transmission, and each subsequent one cuts the cwnd yet further, reducing it to the floor and killing performance. Fix this by moving the cwnd reset to after doing the transmission and resetting the base time such that we don't cut the cwnd by half again for at least another RTT. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Trace/count transmission underflows and cwnd resetsDavid Howells
Add a tracepoint to log when a cwnd reset occurs due to lack of transmission on a call. Add stat counters to count transmission underflows (ie. when we have tx window space, but sendmsg doesn't manage to keep up), cwnd resets and transmission failures. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Make the I/O thread take over the call and local processor workDavid Howells
Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Extract the peer address from an incoming packet earlierDavid Howells
Extract the peer address from an incoming packet earlier, at the beginning of rxrpc_input_packet() and thence pass a pointer to it to various functions that use it as part of the lookup rather than doing it on several separate paths. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Reduce the use of RCU in packet inputDavid Howells
Shrink the region of rxrpc_input_packet() that is covered by the RCU read lock so that it only covers the connection and call lookup. This means that the bits now outside of that can call sleepable functions such as kmalloc and sendmsg. Also take a ref on the conn or call we're going to use before we drop the RCU read lock. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Move DATA transmission into call processor work itemDavid Howells
Move DATA transmission into the call processor work item. In a future patch, this will be called from the I/O thread rather than being itsown work item. This will allow DATA transmission to be driven directly by incoming ACKs, pokes and timers as those are processed. The Tx queue is also split: The queue of packets prepared by sendmsg is now places in call->tx_sendmsg and the packet dispatcher decants the packets into call->tx_buffer as space becomes available in the transmission window. This allows sendmsg to run ahead of the available space to try and prevent an underflow in transmission. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Copy client call parameters into rxrpc_call earlierDavid Howells
Copy client call parameters into rxrpc_call earlier so that that can be used to convey them to the connection code - which can then be offloaded to the I/O thread. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Implement a mechanism to send an event notification to a callDavid Howells
Provide a means by which an event notification can be sent to a call such that the I/O thread can process it rather than it being done in a separate workqueue. This will allow a lot of locking to be removed. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Remove call->input_lockDavid Howells
Remove call->input_lock as it was only necessary to serialise access to the state stored in the rxrpc_call struct by simultaneous softirq handlers presenting received packets. They now dump the packets in a queue and a single process-context handler now processes them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Move error processing into the local endpoint I/O threadDavid Howells
Move the processing of error packets into the local endpoint I/O thread, leaving the handover from UDP to merely transfer them into the local endpoint queue. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Move packet reception processing into I/O threadDavid Howells
Split the packet input handler to make the softirq side just dump the received packet into the local endpoint receive queue and then call the remainder of the input function from the I/O thread. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Create a per-local endpoint receive queue and I/O threadDavid Howells
Create a per-local receive queue to which, in a future patch, all incoming packets will be directed and an I/O thread that will process those packets and perform all transmission of packets. Destruction of the local endpoint is also moved from the local processor work item (which will be absorbed) to the thread. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Split the receive codeDavid Howells
Split the code that handles packet reception in softirq mode as a prelude to moving all the packet processing beyond routing to the appropriate call and setting up of a new call out into process context. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Don't hold a ref for connection workqueueDavid Howells
Currently, rxrpc gives the connection's work item a ref on the connection when it queues it - and this is called from the timer expiration function. The problem comes when queue_work() fails (ie. the work item is already queued): the timer routine must put the ref - but this may cause the cleanup code to run. This has the unfortunate effect that the cleanup code may then be run in softirq context - which means that any spinlocks it might need to touch have to be guarded to disable softirqs (ie. they need a "_bh" suffix). (1) Don't give a ref to the work item. (2) Simplify handling of service connections by adding a separate active count so that the refcount isn't also used for this. (3) Connection destruction for both client and service connections can then be cleaned up by putting rxrpc_put_connection() out of line and making a tidy progression through the destruction code (offloaded to a workqueue if put from softirq or processor function context). The RCU part of the cleanup then only deals with the freeing at the end. (4) Make rxrpc_queue_conn() return immediately if it sees the active count is -1 rather then queuing the connection. (5) Make sure that the cleanup routine waits for the work item to complete. (6) Stash the rxrpc_net pointer in the conn struct so that the rcu free routine can use it, even if the local endpoint has been freed. Unfortunately, neither the timer nor the work item can simply get around the problem by just using refcount_inc_not_zero() as the waits would still have to be done, and there would still be the possibility of having to put the ref in the expiration function. Note the connection work item is mostly going to go away with the main event work being transferred to the I/O thread, so the wait in (6) will become obsolete. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Don't hold a ref for call timer or workqueueDavid Howells
Currently, rxrpc gives the call timer a ref on the call when it starts it and this is passed along to the workqueue by the timer expiration function. The problem comes when queue_work() fails (ie. the work item is already queued): the timer routine must put the ref - but this may cause the cleanup code to run. This has the unfortunate effect that the cleanup code may then be run in softirq context - which means that any spinlocks it might need to touch have to be guarded to disable softirqs (ie. they need a "_bh" suffix). Fix this by: (1) Don't give a ref to the timer. (2) Making the expiration function not do anything if the refcount is 0. Note that this is more of an optimisation. (3) Make sure that the cleanup routine waits for timer to complete. However, this has a consequence that timer cannot give a ref to the work item. Therefore the following fixes are also necessary: (4) Don't give a ref to the work item. (5) Make the work item return asap if it sees the ref count is 0. (6) Make sure that the cleanup routine waits for the work item to complete. Unfortunately, neither the timer nor the work item can simply get around the problem by just using refcount_inc_not_zero() as the waits would still have to be done, and there would still be the possibility of having to put the ref in the expiration function. Note the call work item is going to go away with the work being transferred to the I/O thread, so the wait in (6) will become obsolete. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Trace rxrpc_bundle refcountDavid Howells
Add a tracepoint for the rxrpc_bundle refcounting. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: trace: Don't use __builtin_return_address for rxrpc_call tracingDavid Howells
In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the rxrpc_call tracepoint Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: trace: Don't use __builtin_return_address for rxrpc_conn tracingDavid Howells
In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the rxrpc_conn tracepoint Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: trace: Don't use __builtin_return_address for rxrpc_peer tracingDavid Howells
In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the rxrpc_peer tracepoint Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: trace: Don't use __builtin_return_address for rxrpc_local tracingDavid Howells
In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the rxrpc_local tracepoint Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Drop rxrpc_conn_parameters from rxrpc_connection and rxrpc_bundleDavid Howells
Remove the rxrpc_conn_parameters struct from the rxrpc_connection and rxrpc_bundle structs and emplace the members directly. These are going to get filled in from the rxrpc_call struct in future. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Remove the [_k]net() debugging macrosDavid Howells
Remove the _net() and knet() debugging macros in favour of tracepoints. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org