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path: root/sound/core/seq/seq_ump_client.c
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2026-08-10ALSA: seq: Use RCU for the UMP client output substreamTakashi Iwai
The UMP sequencer client protects its output rawmidi file (out_rfile) with an rwlock (output_lock). seq_ump_process_event(), the port's event_input callback, reads out_rfile.output under read_lock on every delivered UMP event, while the open/close paths (serialized by ump->open_mutex) publish and clear out_rfile under write_lock. Output is opened/closed only on the subscribe/use lifecycle while delivery happens per event, so this is another read-mostly hot path. Convert it to RCU and drop the rwlock. out_rfile is an embedded struct rather than a pointer, so instead of restructuring it, add an RCU-protected shadow of the substream (out_substream) for the reader; out_rfile itself becomes writer-only state accessed solely under open_mutex. The reader now runs lock-free under rcu_read_lock() via rcu_dereference(), and open publishes the substream with rcu_assign_pointer(). On close the substream is cleared with rcu_assign_pointer(NULL) and the rawmidi is released only after synchronize_rcu(), so no reader in the delivery path can still be writing to the substream when snd_rawmidi_kernel_release() runs. Dropping write_lock_irqsave() from the writers is safe: they run in process context under open_mutex, and the sole atomic reader now uses RCU, which is IRQ-safe. Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://patch.msgid.link/20260810133711.42483-6-tiwai@suse.de
2026-05-20ALSA: seq: Serialize UMP output teardown with event_inputZhang Cen
seq_ump_process_event() borrows client->out_rfile.output without synchronizing with the first-open and last-close transition in seq_ump_client_open() and seq_ump_client_close(). The last output unuse can therefore drop opened[STR_OUT] to zero and release the rawmidi file while an in-flight event_input callback is still inside snd_rawmidi_kernel_write(). That leaves the rawmidi substream runtime exposed to teardown before the write path has taken its own buffer reference. Add a per-client rwlock for the event_input-visible output file. Publish a newly opened output file under the write side, and hold the read side from the output lookup through snd_rawmidi_kernel_write(). The last output close copies and clears the visible output file under the write side, then drops the lock and releases the saved rawmidi file. Use IRQ-safe rwlock guards because event_input can also be reached from atomic sequencer delivery. The buggy scenario involves two paths, with each column showing the order within that path: path A label: event_input path path B label: last unuse path 1. seq_ump_process_event() reads 1. seq_ump_client_close() client->out_rfile.output. drops opened[STR_OUT] to zero. 2. snd_rawmidi_kernel_write1() 2. snd_rawmidi_kernel_release() has not yet pinned runtime. closes the output file. 3. The writer continues using 3. close_substream() frees the borrowed substream. substream->runtime. This keeps the output substream and runtime alive for the full event_input write while keeping rawmidi release outside the rwlock. KASAN reproduced this as a slab-use-after-free in snd_rawmidi_kernel_write1(), with allocation through seq_ump_use()/snd_seq_port_connect() and free through seq_ump_unuse()/snd_seq_port_disconnect(). Suggested-by: Takashi Iwai <tiwai@suse.de> Validation reproduced this kernel report: KASAN slab-use-after-free in snd_rawmidi_kernel_write1+0x9d/0x400 RIP: 0033:0x7f5528af837f Read of size 8 Call trace: dump_stack_lvl+0x73/0xb0 (?:?) print_report+0xd1/0x650 (?:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x1a7/0x340 (?:?) kasan_complete_mode_report_info+0x64/0x200 (?:?) kasan_report+0xf7/0x130 (?:?) snd_rawmidi_kernel_write1+0x9d/0x400 (?:?) __asan_load8+0x82/0xb0 (?:?) update_stack_state+0x1ef/0x2d0 (?:?) snd_rawmidi_kernel_write+0x1a/0x20 (?:?) seq_ump_process_event+0xd4/0x120 (sound/core/seq/seq_ump_client.c:82) __snd_seq_deliver_single_event+0x8a/0xe0 (?:?) snd_seq_deliver_from_ump+0x2b2/0xd60 (?:?) lock_acquire+0x14e/0x2e0 (?:?) find_held_lock+0x31/0x90 (?:?) snd_seq_port_use_ptr+0xa6/0xe0 (?:?) __kasan_check_write+0x18/0x20 (?:?) do_raw_read_unlock+0x32/0xa0 (?:?) _raw_read_unlock+0x26/0x50 (?:?) snd_seq_deliver_single_event+0x45c/0x4b0 (?:?) snd_seq_deliver_event+0x10d/0x1b0 (?:?) snd_seq_client_enqueue_event+0x192/0x240 (?:?) snd_seq_write+0x2cd/0x450 (?:?) apparmor_file_permission+0x20/0x30 (?:?) security_file_permission+0x51/0x60 (?:?) vfs_write+0x1ce/0x850 (?:?) __fget_files+0x12b/0x220 (?:?) lock_release+0xc8/0x2a0 (?:?) __rcu_read_unlock+0x74/0x2d0 (?:?) __fget_files+0x135/0x220 (?:?) ksys_write+0x15a/0x180 (?:?) rcu_is_watching+0x24/0x60 (?:?) __x64_sys_write+0x46/0x60 (?:?) x64_sys_call+0x7d/0x20d0 (?:?) do_syscall_64+0xc1/0x360 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?) Fixes: 81fd444aa371 ("ALSA: seq: Bind UMP device") Signed-off-by: Zhang Cen <rollkingzzc@gmail.com> Link: https://patch.msgid.link/20260520103249.3048345-1-rollkingzzc@gmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
2026-05-06ALSA: seq: Fix UMP group 16 filteringCássio Gabriel
The sequencer UAPI defines group_filter as an unsigned int bitmap. Bit 0 filters groupless messages and bits 1-16 filter UMP groups 1-16. The internal snd_seq_client storage is only unsigned short, so bit 16 is truncated when userspace sets the filter. The same truncation affects the automatic UMP client filter used to avoid delivery to inactive groups, so events for group 16 cannot be filtered. Store the internal bitmap as unsigned int and keep both userspace-provided and automatically generated values limited to the defined UAPI bits. Fixes: d2b706077792 ("ALSA: seq: Add UMP group filter") Cc: stable@vger.kernel.org Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com> Link: https://patch.msgid.link/20260506-alsa-seq-ump-group16-filter-v1-1-b75160bf6993@gmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2025-12-17ALSA: seq: Relax __free() variable declarationsTakashi Iwai
We used to have a variable declaration with __free() initialized with NULL. This was to keep the old coding style rule, but recently it's relaxed and rather recommends to follow the new rule to declare in place of use for __free() -- which avoids potential deadlocks or UAFs with nested cleanups. Although the current code has no bug, per se, let's follow the new standard and move the declaration to the place of assignment (or directly assign the allocated result) instead of NULL initializations. Note that there is a remaining __free() with NULL initialization; it's because of the non-trivial code conditionally assigning the data. Fixes: 04a86185b785 ("ALSA: seq: Clean up queue locking with auto cleanup") Fixes: 0869afc958a0 ("ALSA: seq: Clean up port locking with auto cleanup") Fixes: 99e16633958b ("ALSA: seq: Use auto-cleanup for client refcounting") Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://patch.msgid.link/20251216140634.171890-7-tiwai@suse.de
2025-12-14ALSA: seq: ump: Convert to snd_seq bus probe mechanismUwe Kleine-König
The snd_seq bus got a dedicated probe function. Make use of that. This fixes a runtime warning about the driver needing to be converted to the bus probe method. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://patch.msgid.link/054f1a0536228ccfe5f539ce854804f789f2ee64.1765283601.git.u.kleine-koenig@baylibre.com
2025-07-11ALSA: seq: Use safer strscpy() instead of strcpy()Takashi Iwai
Use a safer function strscpy() instead of strcpy() for copying to arrays. Only idiomatic code replacement, and no functional changes. Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://patch.msgid.link/20250710100727.22653-4-tiwai@suse.de
2025-01-12ALSA: seq: Notify UMP EP and FB changesTakashi Iwai
So far we notify the sequencer client and port changes upon UMP FB changes, but those aren't really corresponding to the UMP updates. e.g. when a FB info gets updated, it's not notified but done only when some of sequencer port attribute is changed. This is no ideal behavior. This patch adds the two new sequencer event types for notifying the UMP EP and FB changes via the announce port. The new event takes snd_seq_ev_ump_notify type data, which is compatible with snd_seq_addr (where the port number is replaced with the block number). The events are sent when the EP and FB info gets updated explicitly via ioctl, or the backend UMP receives the corresponding UMP messages. The sequencer protocol version is bumped to 1.0.5 along with it. Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://patch.msgid.link/20250110155943.31578-9-tiwai@suse.de
2024-12-02ALSA: seq: Notify client and port info changesTakashi Iwai
It was supposed to be notified when a sequencer client info and a port info has changed (via SNDRV_SEQ_EVENT_CLIENT_CHANGE and SNDRV_SEQ_EVENT_PORT_CHANGE event, respectively), and there are already helper functions. But those aren't really sent from the driver so far, except for the recent support of UMP, simply due to the lack of implementations. This patch adds the missing notifications at updating the client and the port info. The formerly added notification for UMP is dropped because it's handled now in the port info side. Reported-by: Mark Lentczner <mark@glyphic.com> Link: https://lore.kernel.org/CAPnksqRok7xGa4bxq9WWimVV=28-7_j628OmrWLS=S0=hzaTHQ@mail.gmail.com Link: https://patch.msgid.link/20241128074734.32165-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-11-29ALSA: seq: ump: Fix seq port updates per FB info notifyTakashi Iwai
update_port_infos() is called when a UMP FB Info update notification is received, and this function is supposed to update the attributes of the corresponding sequencer port. However, the function had a few issues and it brought to the incorrect states. Namely: - It tried to get a wrong sequencer info for the update without correcting the port number with the group-offset 1 - The loop exited immediately when a sequencer port isn't present; this ended up with the truncation if a sequencer port in the middle goes away This patch addresses those bugs. Fixes: 4a16a3af0571 ("ALSA: seq: ump: Handle FB info update") Link: https://patch.msgid.link/20241128170423.23351-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-08-06ALSA: ump: Handle MIDI 1.0 Function Block in MIDI 2.0 protocolTakashi Iwai
The UMP v1.1 spec says in the section 6.2.1: "If a UMP Endpoint declares MIDI 2.0 Protocol but a Function Block represents a MIDI 1.0 connection, then may optionally be used for messages to/from that Function Block." It implies that the driver can (and should) keep MIDI 1.0 CVM exceptionally for those FBs even if UMP Endpoint is running in MIDI 2.0 protocol, and the current driver lacks of it. This patch extends the sequencer port info to indicate a MIDI 1.0 port, and tries to send/receive MIDI 1.0 CVM as is when this port is the source or sink. The sequencer port flag is set by the driver at parsing FBs and GTBs although application can set it to its own user-space clients, too. Link: https://patch.msgid.link/20240806070024.14301-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-07-30ALSA: ump: Update substream name from assigned FB namesTakashi Iwai
We had a nice name scheme in ALSA sequencer UMP binding for each sequencer port referring to each assigned Function Block name, while the legacy rawmidi refers only to the UMP Endpoint name. It's better to align both. This patch moves the UMP Group attribute update functions into the core UMP code from the sequencer binding code, and improve the substream name of the legacy rawmidi. Link: https://patch.msgid.link/20240729141315.18253-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-07-17ALSA: seq: ump: Skip useless ports for static blocksTakashi Iwai
When the UMP Endpoint is configured with static blocks, the block configuration will never change, hence the unused ports will be unchanged as well. Creating sequencer ports for those unused ports is simply useless, and it might be rather confusing for users. The idea behind the inactive ports was for allowing connections from/to ports that can become usable later, but this will never happen for inactive groups in static blocks. Let's change the sequencer UMP binding to skip those unused ports when the UMP EP is with static blocks. Fixes: 81fd444aa371 ("ALSA: seq: Bind UMP device") Cc: <stable@vger.kernel.org> Link: https://patch.msgid.link/20240717083322.25892-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-02-28ALSA: seq: ump: Use guard() for lockingTakashi Iwai
We can simplify the code gracefully with new guard() macro and co for automatic cleanup of locks. Only the code refactoring, and no functional changes. Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://lore.kernel.org/r/20240227085306.9764-19-tiwai@suse.de
2024-02-23ALSA: seq: ump: Use automatic cleanup of kfree()Takashi Iwai
There are common patterns where a temporary buffer is allocated and freed at the exit, and those can be simplified with the recent cleanup mechanism via __free(kfree). No functional changes, only code refactoring. Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://lore.kernel.org/r/20240222111509.28390-9-tiwai@suse.de
2023-09-15ALSA: seq: ump: Fix -Wformat-truncation warningTakashi Iwai
The filling of a port name string got a warning with W=1 due to the potentially too long group name. Add the string precision to limit the size. Fixes: 81fd444aa371 ("ALSA: seq: Bind UMP device") Link: https://lore.kernel.org/r/20230915082802.28684-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-09-12ALSA: seq: Avoid delivery of events for disabled UMP groupsTakashi Iwai
ALSA sequencer core still delivers events to the disabled UMP Group, leaving this handling to the device. But it's rather risky and it's easy to imagine that such an unexpected event may screw up the device firmware. This patch avoids the superfluous event deliveries by setting the group_filter of the UMP client as default, and evaluate the group_filter properly at delivery from non-UMP clients. The grouop_filter is updated upon the dynamic UMP Function Block updates, so that it follows the change of the disabled UMP Groups, too. Fixes: d2b706077792 ("ALSA: seq: Add UMP group filter") Link: https://lore.kernel.org/r/20230912085144.32534-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-07-21ALSA: seq: remove redundant unsigned comparison to zeroWang Weiyang
Since struct snd_ump_block_info::first_group is unsigned char, comparison to zero is redundant Signed-off-by: Wang Weiyang <wangweiyang2@huawei.com> Fixes: 81fd444aa371 ("ALSA: seq: Bind UMP device") Link: https://lore.kernel.org/r/20230721103124.18522-1-wangweiyang2@huawei.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-06-12ALSA: seq: ump: Notify UMP protocol change to sequencerTakashi Iwai
UMP v1.1 supports the protocol switch via a UMP Stream message. When it's received, we need to take care of the midi_version field in the corresponding sequencer client, too. This patch introduces a new ops to notify the protocol change to snd_seq_ump_ops for handling it. Link: https://lore.kernel.org/r/20230612081054.17200-9-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-06-12ALSA: seq: ump: Notify port changes to system portTakashi Iwai
For allowing applications to track the FB active changes, this patch adds the notification from the system port at each time a FB change is handled and the active flag or re-grouping happens. Link: https://lore.kernel.org/r/20230612081054.17200-8-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-06-12ALSA: seq: ump: Handle FB info updateTakashi Iwai
This patch implements the handling of the dynamic update of FB info. When the FB info update is received after the initial parsing, it means the dynamic FB info update. We compare the result, and if the actual update is detected, it's notified via a new ops, notify_fb_change, to the sequencer client, and the corresponding sequencer ports are updated accordingly. Link: https://lore.kernel.org/r/20230612081054.17200-7-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-06-12ALSA: seq: ump: Handle groupless messagesTakashi Iwai
The UMP Utility and Stream messages are "groupless", i.e. an incoming groupless packet should be sent only to the UMP EP port, and the event with the groupless message is sent to UMP EP as is without the group translation per port. Also, the former reserved bit 0 for the client group filter is now used for groupless events. When the bit 0 is set, the groupless events are filtered out and skipped. Link: https://lore.kernel.org/r/20230612081054.17200-6-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-05-23ALSA: seq: Add ioctls for client UMP info query and setupTakashi Iwai
Add new ioctls for sequencer clients to query and set the UMP endpoint and block information. As a sequencer client corresponds to a UMP Endpoint, one UMP Endpoint information can be assigned at most to a single sequencer client while multiple UMP block infos can be assigned by passing the type with the offset of block id (i.e. type = block_id + 1). For the kernel client, only SNDRV_SEQ_IOCTL_GET_CLIENT_UMP_INFO is allowed. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20230523075358.9672-35-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-05-23ALSA: seq: ump: Create UMP Endpoint port for broadcastTakashi Iwai
Create a sequencer port for broadcasting the all group inputs at the port number 0. This corresponds to a UMP Endpoint connection; application can read all UMP events from this port no matter which group the UMP packet belongs to. Unlike seq ports for other UMP groups, a UMP Endpoint port has no SND_SEQ_PORT_TYPE_MIDI_GENERIC bit, so that it won't be treated as a normal MIDI 1.0 device from legacy applications. The port is named as "MIDI 2.0" to align with representations on other operation systems. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20230523075358.9672-34-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-05-23ALSA: seq: Bind UMP deviceTakashi Iwai
This patch introduces a new ALSA sequencer client for the kernel UMP object, snd-seq-ump-client. It's a UMP version of snd-seq-midi driver, while this driver creates a sequencer client per UMP endpoint which contains (fixed) 16 ports. The UMP rawmidi device is opened in APPEND mode for output, so that multiple sequencer clients can share the same UMP endpoint, as well as the legacy UMP rawmidi devices that are opened in APPEND mode, too. For input, on the other hand, the incoming data is processed on the fly in the dedicated hook, hence it doesn't open a rawmidi device. The UMP packet group is updated upon delivery depending on the target sequencer port (which corresponds to the actual UMP group). Each sequencer port sets a new port type bit, SNDRV_SEQ_PORT_TYPE_MIDI_UMP, in addition to the other standard types for MIDI. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20230523075358.9672-33-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>