Replace the open-coded of_address_to_resource() in get_of_data() and the
later ioremap() of the memory region with a single
devm_platform_get_and_ioremap_resource() call in probe(). This requests
the region and maps it once, instead of mapping it without a region
request, and removes the redundant second ioremap.
Similarly replace irq_of_parse_and_map() with platform_get_irq(), which
returns a negative errno on failure (including -EPROBE_DEFER) instead of
0.
Both substitutions are equivalent for a DT-backed platform device. The
remaining OF accessors are now covered by linux/of.h, so the unused
linux/of_address.h and linux/of_irq.h includes are dropped.
No functional change; the GPCM window is not claimed by any other driver
(fsl_lbc only of_iomap()s its own registers, and sibling eLBC-window
drivers use distinct windows), so the new region request cannot conflict.
Built for powerpc (allmodconfig + CONFIG_UIO_FSL_ELBC_GPCM) with LLVM=1;
drivers/uio/uio_fsl_elbc_gpcm.o compiles cleanly.
Assisted-by: opencode:hy3-free
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20260722204827.510133-1-rosenp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Update the of_device_id array to conform to the most used and generally
recommended coding style. That is:
- No comma after the list terminator;
- A comma after an initializer if (and only if) the closing } is not
directly following;
- No explicit zeros in the list terminator;
- A space after an opening { and before a closing }, a single space in
the list terminator;
Adapt the driver's array accordingly.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/2c35ea101e5eb28334137d9341a8b1e564102ae5.1784299069.git.u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.
The mentioned robustness is relevant for a planned change to struct
platform_device_id that replaces .driver_data by an anonymous union (though
this driver doesn't use .driver_data, so this patch isn't strictly
necessary for the plan, but still ok for consistency).
This patch doesn't modify the compiled array, only its representation
in source form benefits.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/9c4a5a5b086d4ce913e84dfa7d140a8b492d557b.1784299069.git.u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.
The mentioned robustness is relevant for a planned change to struct
spi_device_id that replaces .driver_data by an anonymous union.
While touching all these arrays, unify usage of whitespace.
This patch doesn't modify the compiled arrays, only their representation
in source form benefits.
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/ad1f0b3efcc3d9d362b33753734cfb064c079cd3.1784299069.git.u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.
The mentioned robustness is relevant for a planned change to struct
i2c_device_id that replaces .driver_data by an anonymous union.
While touching all these arrays, unify usage of whitespace.
This patch doesn't modify the compiled arrays, only their representation
in source form benefits.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/5a4fb64166ab7e06adf94e5fa3d46bb5f6493324.1784299069.git.u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.
While touching all these arrays, unify usage of whitespace.
This patch doesn't modify the compiled arrays, only their representation
in source form benefits.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/e9ad2fe1d850ffd64eb053cb03395e7ca6f848dc.1784299069.git.u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With no_console_suspend enabled, hvc console output can continue while
virtio_console is freezing. In that window, put_chars can still enqueue
buffers to the output virtqueue while virtcons_freeze is tearing queues
down, triggering a BUG_ON in virtqueue_detach_unused_buf_split:
BUG_ON(vq->vq.num_free != vq->split.vring.num)
Add a pm_freezing flag to ports_device. Set it via smp_store_release()
at the start of virtcons_freeze(); put_chars() and __send_to_port() drop
output while the flag is set, checked via smp_load_acquire().
The check in __send_to_port() is placed under outvq_lock, making it
atomic with remove_port_data() which also acquires outvq_lock. Once
remove_port_data() returns for a given port, no concurrent
__send_to_port() can add buffers before remove_vqs() tears down the vq.
After setting pm_freezing, acquire and release outvq_lock for each port
(protected by ports_lock to prevent list manipulation races) before
calling virtio_reset_device(). A TX thread that already passed the
pm_freezing check may still hold outvq_lock while spinning for host
acknowledgment; the drain loop ensures all such threads have completed
before the device is reset.
Clear pm_freezing in virtcons_restore() only after all port->out_vq
pointers have been reassigned to the newly allocated virtqueues,
preventing TX paths from dereferencing freed vqs during restore.
Link: https://sashiko.dev/#/patchset/20260519162242.7324-1-baver.bae%40gmail.com
Signed-off-by: Sungho Bae <baver.bae@lge.com>
Link: https://patch.msgid.link/20260603183757.21587-5-baver.bae@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In virtcons_restore(), after virtio_device_ready() sets DRIVER_OK, the
device becomes active. If the control receive queue (c_ivq) is populated
immediately, the host can instantly deliver pending control messages
(e.g., VIRTIO_CONSOLE_PORT_REMOVE).
This triggers the control_work_handler(), which can modify the
portdev->ports list concurrently with the unprotected list_for_each_entry
loop in virtcons_restore(), leading to list corruption or Use-After-Free.
Fix this by deferring the population of the control receive queue
(fill_queue for c_ivq) until after the list iteration is complete. This
ensures the host cannot inject control messages during the vulnerable
window.
Signed-off-by: Sungho Bae <baver.bae@lge.com>
Link: https://patch.msgid.link/20260603183757.21587-4-baver.bae@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a port is hot-unplugged, unplug_port() nullifies port->portdev.
However, concurrent TX paths (__send_to_port, put_chars) could read a
stale pointer or encounter a NULL pointer dereference.
Add READ_ONCE(port->portdev) and NULL checks in the TX paths. In
__send_to_port(), move the out_vq assignment inside the outvq_lock and
check portdev under the lock. Correspondingly, update unplug_port() to
NULL out port->portdev while holding the outvq_lock to serialize with
__send_to_port().
In put_chars(), return count instead of 0 on unplug to prevent the hvc
layer from spinning in an infinite retry loop.
Signed-off-by: Sungho Bae <baver.bae@lge.com>
Link: https://patch.msgid.link/20260603183757.21587-3-baver.bae@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Modify __send_to_port() to take ownership of a struct port_buffer *
instead of a void * raw buffer.
Previously, put_chars() would pass a raw kmemdup'd buffer and free it
immediately after __send_to_port() returned. This caused a potential
Use-After-Free and data corruption if the virtqueue was shared with
nonblocking writers, as virtqueue_get_buf() might return an older
completed buffer, causing the newly added buffer to be kfree'd while the
host is still DMAing from it.
By transferring ownership of the allocated port_buffer to __send_to_port(),
we ensure that the exact buffer returned by the host is the one that gets
freed, resolving the memory lifecycle mismatch.
Signed-off-by: Sungho Bae <baver.bae@lge.com>
Link: https://patch.msgid.link/20260603183757.21587-2-baver.bae@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parse_inputs_from_commands() only caught CmdParsingError and IndexError
when dispatching to command parsers, but several parsers call
shlex.split() internally, which raises ValueError on malformed shell
quoting (e.g. an unterminated quote). This exception was not caught,
so a single malformed build command would abort SBOM generation
entirely, even with fail_on_unknown_build_command=False, defeating the
purpose of tolerant mode.
The issue was found while reviewing the exception handling around the
saved-command parser after running its existing tests. It can be
reproduced with:
parse_inputs_from_commands('gcc "unterminated',
fail_on_unknown_build_command=False)
Catch ValueError alongside CmdParsingError and IndexError so such
commands are logged as a warning/error and skipped instead of aborting
the whole run.
Add tests covering malformed shell quoting and a missing positional
argument.
Signed-off-by: Carlos Sampaio Ribeiro <otakurack@gmail.com>
Link: https://patch.msgid.link/20260719081859.1001-1-otakurack@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- document enums with the "enum" keyword
- add a description for @dbr_size
- add missing descriptions to struct most_interface (some just need
a ':' to be good)
- add missing descriptions to struct most_component
- use Returns: syntax for function return values
- convert most_deregister_interface() to kernel-doc notation and fix
its parameter name
Repairs these warnings:
Warning: include/linux/most.h:17 This comment starts with '/**',
but isn't a kernel-doc comment.
* Interface type
Warning: include/linux/most.h:32 This comment starts with '/**',
but isn't a kernel-doc comment.
* Channel direction.
Warning: include/linux/most.h:40 This comment starts with '/**',
but isn't a kernel-doc comment.
* Channel data type.
Warning: include/linux/most.h:131 struct member 'dbr_size' not
described in 'most_channel_config'
Warning: include/linux/most.h:191 This comment starts with '/**',
but isn't a kernel-doc comment.
* Interface instance description.
Warning: include/linux/most.h:274 struct member 'mod' not described
in 'most_component'
Warning: include/linux/most.h:274 struct member 'cfg_complete' not
described in 'most_component'
Warning: include/linux/most.h:288 This comment starts with '/**',
but isn't a kernel-doc comment.
* Deregisters instance of the interface.
Warning: include/linux/most.h:292 No description found for return value
of 'most_register_interface'
Warning: include/linux/most.h:298 function parameter 'iface' not
described in 'most_deregister_interface'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://patch.msgid.link/20260719051123.2458641-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
find_port_by_vq() returns a raw struct port pointer without taking a
reference on it, unlike find_port_by_devt_in_portdev() which does.
find_port_by_vq()'s only two callers, in_intr() and out_intr(), run as
virtqueue interrupt callbacks, entirely independent of and possibly
concurrently with unplug_port(), which itself runs from a workqueue when
the host sends a VIRTIO_CONSOLE_PORT_REMOVE control message.
unplug_port() removes the port from portdev->ports under ports_lock,
then later drops its last reference with kref_put(), freeing it via
remove_port(). find_port_by_vq() also walks portdev->ports under
ports_lock, so if it finds the port still on the list, the list removal,
and therefore the eventual kref_put(), has not happened yet, and taking
a reference at that point is always safe. Without doing so,
in_intr()/out_intr() can be left holding a pointer to a port that
unplug_port() frees on another core before they are done using it.
Both triggers are host-controlled as the host decides when to send the
PORT_REMOVE control message and when to kick the port's data vq. So a
malicious backend could race the two on purpose, without any guest side
cooperation. The freed object is a generic kmalloc allocation containing
a wait_queue_head_t, which in_intr()/out_intr() pass to
wake_up_interruptible() after touching the stale pointer.
wake_up_interruptible() invokes a function pointer read out of the wait
queue's entries. If the freed slab slot is reclaimed with attacker
influenced content before that call, then this is an arbitrary function
call primitive rather than just undefined behaviour.
Take a reference in find_port_by_vq() while still holding ports_lock,
matching find_port_by_devt_in_portdev(), and release it in in_intr() and
out_intr() once they are done with the port.
Signed-off-by: Hari Mishal <harimishal1@gmail.com>
Link: https://patch.msgid.link/20260717150622.23636-1-harimishal1@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The GRU TLB miss handler walks a process's page tables without holding
page-table locks or a reference to the mapped page. It also uses a kernel
page-table accessor on user page tables and supports only PMD-level large
mappings on x86-64.
Remove the direct walker. Send interrupt faults directly to user polling
mode so the existing call-OS fallback retries them in process context.
Remove the mmap-lock failure statistic that can no longer be incremented.
Fixes: 142586409c ("GRU Driver: page faults & exceptions")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@arm.com>
Link: https://patch.msgid.link/20260730111316.3672672-2-usama.anjum@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Transaction configuration flags are currently represented as raw integers
and manipulated via bitwise operations. This lacks type safety, making
it possible to mix up different flag types without compile-time warnings.
Use kernel::impl_flags! to migrate the transaction flags to a
strongly-typed bitmask, enforcing compile-time safety.
Key changes:
- Define `TransactionFlags(u32)` and `TransactionFlag` with 4 variants.
- Change flags field type to `TransactionFlags` in structs.
- Add `is_oneway` helper on `TransactionFlags` to simplify checks.
- Update `can_replace` logic to use type-safe combined flag checks.
- Convert `flags` to `u32` for FFI boundaries and logging.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Jahnavi MN <jahnavimn@google.com>
Link: https://patch.msgid.link/20260719-b4-rust_binder_impl_flags-v3-2-f8d0b3ea1b87@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Thread looper states are currently represented as raw integers and
manipulated via bitwise operations. This lacks type safety, making it
possible to mix up different flag types without compile-time warnings.
Use kernel::impl_flags! to migrate looper_flags to a strongly-typed
bitmask, enforcing compile-time safety.
Key changes:
- Define `LooperFlags(u32)` and `LooperFlag` enum with 7 variants.
- Change `InnerThread.looper_flags` type to `LooperFlags`.
- Update looper state transitions and checks to use type-safe methods.
- Convert `looper_flags` to `u32` for hex formatting in `debug_print`.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Jahnavi MN <jahnavimn@google.com>
Link: https://patch.msgid.link/20260719-b4-rust_binder_impl_flags-v3-1-f8d0b3ea1b87@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The `// SAFETY:` comment in NodeDeath::set_cleared assumes that a
NodeDeath is never inserted into the death list of any Node other than
its owner. However, this invariant is not enforced by the safe function
Node::add_death, which inserts NodeDeath into the death list without
checking that death.node == self, leaving a risk for future code that
may miss this implicit invariant and cause undefined behavior.
Add an assertion to make this precondition explicit and catch potential
violations early.
Link: https://github.com/Rust-for-Linux/linux/issues/1237
Signed-off-by: Georgios Androutsopoulos <georgeandrout13@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260616170956.2580772-1-georgeandrout13@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The length check in brcm_nvram_parse() validated header->len against
priv->nvmem_size (the full partition size) instead of priv->data_len
(the actual allocated data buffer). A malformed flash partition with
header->len between the two would pass the check, causing
brcm_nvram_add_cells() to read and write priv->data[len - 1] beyond
the heap allocation.
Also add a minimum bound: len < sizeof(*header) could underflow the
data[len - 1] access.
Fix both bounds by rejecting len outside [sizeof(*header), priv->data_len].
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260729094647.111468-14-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the partition is completely erased (all padding bytes), the trimming
loop reduces data_len to 0. devm_kzalloc(dev, 0, GFP_KERNEL) returns
ZERO_SIZE_PTR ((void *)16), which is non-NULL and bypasses the NULL
check. The subsequent cast of priv->data to struct brcm_nvram_header *
and dereference of header->magic causes a page fault on address 0x10.
Reject data_len smaller than the header before allocating.
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260729094647.111468-13-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver already depends on HAVE_ARM_SMCCC and ARCH_AIROHA, but both
are available for 32-bit and 64-bit targets. However, the smccc invocation
fails on thumb2 builds with clang:
drivers/nvmem/airoha-smc-efuses.c:38:2: error: write to reserved register 'R7'
38 | arm_smccc_1_1_invoke(AIROHA_SMC_EFUSE_FID,
| ^
note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
arch/arm/include/asm/opcodes.h:215:2: note: expanded from macro '__inst_arm_thumb32'
215 | __inst_thumb32(thumb_opcode)
| ^
Since the driver is only used on the 64-bit an7581 soc, avoid this
problem with a stricter dependency.
Fixes: b7846af2e6 ("nvmem: airoha: Add support for SMC eFUSE")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260729094647.111468-12-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For historical reasons EEPROM drivers have lived under
drivers/misc/eeprom/. Also for historical reasons changes to most of
them would go through the char-misc tree while some would be queued
through the I2C tree. Over the years some of them have also been
converted to using nvmem - the dedicated subsystem for non-volatile
memory - while get_maintainer.pl does not Cc the maintainer of nvmem on
patches changing them.
Move the EEPROM drivers using nvmem under drivers/nvmem/ for
consistency of the review process and path upstream.
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260729094647.111468-11-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
__nvmem_device_put() is wrapped by nvmem_device_put() but there's no
extra functionality offered by the latter so just fold one into the
other. There's still the corresponding __nvmem_device_get() so in order
to keep things symmetrical: rename it to nvmem_device_match() to better
reflect its functionality and not confuse users by its presence in the
absence of the similarly prefixed put() counterpart.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Tested-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260729094647.111468-6-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
__nvmem_reg_read/write() currently return -EINVAL if the relevant
callback is not present. User-space helpers again check the presence
of the callbacks to see if they should return -EPERM.
Ahead of adding SRCU synchronization: change the error code returned to
in-kernel users to -EOPNOTSUPP which is more indicative of the actual
reason for the failure.
Remove the checks from the sysfs attribute callbacks as these are not
visible without the required callbacks.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Tested-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260729094647.111468-3-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newer DSP firmware implements a PD (Protection Domain) notification
framework that sends PD state notifications upon request. The PD exit
notification is unconditionally sent by the DSP with a fixed sentinel
0xABCDABCD in the context field.
fastrpc_rpmsg_callback() treats every inbound message as an invoke
response, so the sentinel is masked and shifted like any real response
((0xABCDABCD & 0xFF0) >> 4 == 188) and looked up in the channel's
context idr.
This is not merely cosmetic. In the common case idr slot 188 is empty,
the lookup fails, and the driver only logs a spurious "No context ID
matches response" error on every teardown. But the context idr is shared
by every protection domain and the listener thread on the channel and is
filled cyclically over [1, FASTRPC_CTX_MAX]. If slot 188 holds a live
context when the sentinel arrives, the sentinel's return value is written
into that unrelated in-flight invocation and it is completed early.
Since neither the fastrpc library nor the driver supports the DSP PD
notification framework, it is safe to drop the PD exit notification
before it is ever turned into a context lookup. This removes both the
log spam and the mis-completion race. A genuine response can never be
masked: a real context is (idr_index << 4) | pd (at most 0xFF3) and
can never equal the sentinel.
Assisted-by: Claude:claude-opus-4-8
Reviewed-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
Signed-off-by: Shawn Guo <shengchao.guo@oss.qualcomm.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260729094352.111065-11-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For any remote call to DSP, after sending an invocation message,
the fastRPC driver waits for a glink response, during which the CPU
can enter low power modes. This adds latency to the fastRPC call
due to CPU wakeup and scheduling overhead. Add polling mode support
where the fastRPC driver polls a shared memory location for
completion after sending the invocation, avoiding CPU wakeup and
scheduling latency and reducing fastRPC overhead. If the poll times
out, the call falls back to the normal interrupt/glink-based
completion path.
Poll mode is only applied to dynamic modules running in a user PD
(handle > FASTRPC_MAX_STATIC_HANDLE), since static/root-PD handles
are not expected to benefit from, or require, this optimization.
Support is advertised per SoC via fastrpc_soc_data, with a closed
exception list for older platforms whose DSP firmware is known to
support polling but which otherwise use the default soc_data.
Poll mode can be enabled by userspace via the FASTRPC_IOCTL_SET_OPTION
ioctl with the FASTRPC_POLL_MODE request id.
Since context IDs (ctxid) are allocated from a fixed-size, per-channel
cyclic IDR shared by all processes on a DSP, a context ID can be
recycled for a new request soon after it is freed. In poll mode the
context can be considered complete (and released) as soon as the poll
memory is updated, while the corresponding glink COMPLETE response
from the DSP may still be in flight. If that response arrives after
the ctxid has been reused, it would otherwise match the new context
and incorrectly signal completion for it while the DSP may still be
operating on the new context's buffers. To prevent this, embed a
monotonically increasing per-channel sequence number in the unused
upper bits of the ctxid/message context and validate it in the
rpmsg callback, dropping any response whose sequence number does not
match the current owner of that ctxid slot.
Signed-off-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260729094352.111065-8-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Current FastRPC context uses a 12-bit mask:
[ID(8 bits)][PD type(4 bits)] = GENMASK(11, 4)
This works for normal calls but fails for DSP polling mode.
Polling mode expects a 16-bit layout:
[15:8] = context ID (8 bits)
[7:5] = reserved
[4] = async mode bit
[3:0] = PD type (4 bits)
If async bit (bit 4) is set, DSP disables polling. With current
mask, odd IDs can set this bit, causing DSP to skip poll updates.
Update FASTRPC_CTXID_MASK to GENMASK(15, 8) so IDs occupy upper
byte and lower byte is left for DSP flags and PD type.
Reserved bits remain unused. This change is compatible with
polling mode and does not break non-polling behavior.
Bit layout:
[15:8] = CCCCCCCC (context ID)
[7:5] = xxx (reserved)
[4] = A (async mode)
[3:0] = PPPP (PD type)
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260729094352.111065-7-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
