uio_pci_sva allocates struct uio_pci_sva_dev with devm_kzalloc() in
probe(), but then calls kfree(udev) both on the probe() error path
(label out_free) and again in remove().
Because devm_kzalloc() allocations are devres-managed and are freed
automatically when the device is detached (including after a failing
probe() and during driver unbind), the explicit kfree() can lead to a
double free.
If probe() fails after devm_kzalloc(), the error path frees udev and
devres cleanup will free it again when the core unwinds the partially
bound device. On normal driver removal, remove() frees udev and devres
will free it again when the device is detached.
This issue was identified by a static analysis tool I developed and
confirmed by manual review. Fix by removing the manual kfree() calls
and dropping the now-unused label.
Fixes: 3397c3cd85 ("uio: Add SVA support for PCI devices via uio_pci_generic_sva.c")
Cc: stable <stable@kernel.org>
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Link: https://patch.msgid.link/20260505150256.614071-1-lgs201920130244@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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>
In a vain attempt to consolidate the email zoo switch everything to the
kernel.org account.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch introduces a new UIO driver, uio_pci_generic_sva, which
extends the functionality of uio_pci_generic by adding support for
Shared Virtual Addressing (SVA) when IOMMU is enabled in the system.
The key enhancement allows PCI devices to directly use user-space virtual
addresses for DMA operations, eliminating the need for bounce buffers or
explicit IOVA mapping. This is achieved by leveraging the kernel's IOMMU-SVA
subsystem, including process address space attachment, page fault handling,
and shared context management between CPU and device.
With this driver, userspace applications can perform zero-copy DMA using
native pointers:
void *addr = malloc(N);
set_dma_addr((uint64_t)addr); // Passing user VA directly
start_dma();
The device can now access 'addr' through the IOMMU's PASID-based translation,
provided that the underlying IOMMU hardware (e.g., Intel VT-d 3.1+, AMD-Vi,
ARM SMMU, RISCV IOMMU) and platform support SVA.
Dependencies:
- CONFIG_IOMMU_SVA must be enabled.
- The platform must support PRI (Page Request Interface) and PASID.
- Device drivers/userspace must handle page faults if demand-paging is used.
The implementation reuses core logic from uio_pci_generic.c while adding
PASID setting, and integration with the IOMMU SVA APIs.
Also, add a read-only sysfs attribute 'pasid' to expose the Process Address
Space ID assigned by IOMMU driver when binding an SVA-enabled device.
For details, refer to the ABI documentation for uio_pci_sva driver sysfs attribute
(Documentation/ABI/testing/sysfs-driver-uio_pci_sva-pasid).
Signed-off-by: Yaxing Guo <guoyaxing@bosc.ac.cn>
Link: https://patch.msgid.link/20250926095828.506-1-guoyaxing@bosc.ac.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull hyperv updates from Wei Liu:
- Unify guest entry code for KVM and MSHV (Sean Christopherson)
- Switch Hyper-V MSI domain to use msi_create_parent_irq_domain()
(Nam Cao)
- Add CONFIG_HYPERV_VMBUS and limit the semantics of CONFIG_HYPERV
(Mukesh Rathor)
- Add kexec/kdump support on Azure CVMs (Vitaly Kuznetsov)
- Deprecate hyperv_fb in favor of Hyper-V DRM driver (Prasanna
Kumar T S M)
- Miscellaneous enhancements, fixes and cleanups (Abhishek Tiwari,
Alok Tiwari, Nuno Das Neves, Wei Liu, Roman Kisel, Michael Kelley)
* tag 'hyperv-next-signed-20251006' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
hyperv: Remove the spurious null directive line
MAINTAINERS: Mark hyperv_fb driver Obsolete
fbdev/hyperv_fb: deprecate this in favor of Hyper-V DRM driver
Drivers: hv: Make CONFIG_HYPERV bool
Drivers: hv: Add CONFIG_HYPERV_VMBUS option
Drivers: hv: vmbus: Fix typos in vmbus_drv.c
Drivers: hv: vmbus: Fix sysfs output format for ring buffer index
Drivers: hv: vmbus: Clean up sscanf format specifier in target_cpu_store()
x86/hyperv: Switch to msi_create_parent_irq_domain()
mshv: Use common "entry virt" APIs to do work in root before running guest
entry: Rename "kvm" entry code assets to "virt" to genericize APIs
entry/kvm: KVM: Move KVM details related to signal/-EINTR into KVM proper
mshv: Handle NEED_RESCHED_LAZY before transferring to guest
x86/hyperv: Add kexec/kdump support on Azure CVMs
Drivers: hv: Simplify data structures for VMBus channel close message
Drivers: hv: util: Cosmetic changes for hv_utils_transport.c
mshv: Add support for a new parent partition configuration
clocksource: hyper-v: Skip unnecessary checks for the root partition
hyperv: Add missing field to hv_output_map_device_interrupt
At present VMBus driver is hinged off of CONFIG_HYPERV which entails
lot of builtin code and encompasses too much. It's not always clear
what depends on builtin hv code and what depends on VMBus. Setting
CONFIG_HYPERV as a module and fudging the Makefile to switch to builtin
adds even more confusion. VMBus is an independent module and should have
its own config option. Also, there are scenarios like baremetal dom0/root
where support is built in with CONFIG_HYPERV but without VMBus. Lastly,
there are more features coming down that use CONFIG_HYPERV and add more
dependencies on it.
So, create a fine grained HYPERV_VMBUS option and update Kconfigs for
dependency on VMBus.
Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # drivers/pci
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Remove the logic to set interrupt mask by default in uio_hv_generic
driver as the interrupt mask value is supposed to be controlled
completely by the user space. If the mask bit gets changed
by the driver, concurrently with user mode operating on the ring,
the mask bit may be set when it is supposed to be clear, and the
user-mode driver will miss an interrupt which will cause a hang.
For eg- when the driver sets inbound ring buffer interrupt mask to 1,
the host does not interrupt the guest on the UIO VMBus channel.
However, setting the mask does not prevent the host from putting a
message in the inbound ring buffer. So let’s assume that happens,
the host puts a message into the ring buffer but does not interrupt.
Subsequently, the user space code in the guest sets the inbound ring
buffer interrupt mask to 0, saying “Hey, I’m ready for interrupts”.
User space code then calls pread() to wait for an interrupt.
Then one of two things happens:
* The host never sends another message. So the pread() waits forever.
* The host does send another message. But because there’s already a
message in the ring buffer, it doesn’t generate an interrupt.
This is the correct behavior, because the host should only send an
interrupt when the inbound ring buffer transitions from empty to
not-empty. Adding an additional message to a ring buffer that is not
empty is not supposed to generate an interrupt on the guest.
Since the guest is waiting in pread() and not removing messages from
the ring buffer, the pread() waits forever.
This could be easily reproduced in hv_fcopy_uio_daemon if we delay
setting interrupt mask to 0.
Similarly if hv_uio_channel_cb() sets the interrupt_mask to 1,
there’s a race condition. Once user space empties the inbound ring
buffer, but before user space sets interrupt_mask to 0, the host could
put another message in the ring buffer but it wouldn’t interrupt.
Then the next pread() would hang.
Fix these by removing all instances where interrupt_mask is changed,
while keeping the one in set_event() unchanged to enable userspace
control the interrupt mask by writing 0/1 to /dev/uioX.
Fixes: 95096f2fbd ("uio-hv-generic: new userspace i/o driver for VMBus")
Suggested-by: John Starks <jostarks@microsoft.com>
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Cc: stable@vger.kernel.org
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Long Li <longli@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Tested-by: Tianyu Lan <tiala@microsoft.com>
Link: https://lore.kernel.org/r/20250828044200.492030-1-namjain@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The struct of_device_id list here is filled in at load time since
commit 05c3e0bb56 ("UIO: allow binding uio_pdrv_genirq.c to devices using
command line option").
However, this does not work with MODULE_DEVICE_TABLE, which generates an
alias at build time. In this case, it generates the aliases "of:N*T*"
and "of:N*T*C*", which matches *any* OF device node, which is obviously
not intended. It confuses userspace into loading this module for any OF
device, and confuses anyone trying to resolve an OF modalias.
Remove this broken MODULE_DEVICE_TABLE.
Suggested-by: Emily <hello@emily.moe>
Fixes: 05c3e0bb56 ("UIO: allow binding uio_pdrv_genirq.c to devices using command line option")
Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>
Link: https://lore.kernel.org/r/20250826-uio-no-modalias-v2-1-495afa9e8a5b@iscas.ac.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull char / misc / iio driver updates from Greg KH:
"Here is the big char/misc/iio and other small driver subsystem pull
request for 6.16-rc1.
Overall, a lot of individual changes, but nothing major, just the
normal constant forward progress of new device support and cleanups to
existing subsystems. Highlights in here are:
- Large IIO driver updates and additions and device tree changes
- Android binder bugfixes and logfile fixes
- mhi driver updates
- comedi driver updates
- counter driver updates and additions
- coresight driver updates and additions
- echo driver removal as there are no in-kernel users of it
- nvmem driver updates
- spmi driver updates
- new amd-sbi driver "subsystem" and drivers added
- rust miscdriver binding documentation fix
- other small driver fixes and updates (uio, w1, acrn, hpet,
xillybus, cardreader drivers, fastrpc and others)
All of these have been in linux-next for quite a while with no
reported problems"
* tag 'char-misc-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (390 commits)
binder: fix yet another UAF in binder_devices
counter: microchip-tcb-capture: Add watch validation support
dt-bindings: iio: adc: Add ROHM BD79100G
iio: adc: add support for Nuvoton NCT7201
dt-bindings: iio: adc: add NCT7201 ADCs
iio: chemical: Add driver for SEN0322
dt-bindings: trivial-devices: Document SEN0322
iio: adc: ad7768-1: reorganize driver headers
iio: bmp280: zero-init buffer
iio: ssp_sensors: optimalize -> optimize
HID: sensor-hub: Fix typo and improve documentation
iio: admv1013: replace redundant ternary operator with just len
iio: chemical: mhz19b: Fix error code in probe()
iio: adc: at91-sama5d2: use IIO_DECLARE_BUFFER_WITH_TS
iio: accel: sca3300: use IIO_DECLARE_BUFFER_WITH_TS
iio: adc: ad7380: use IIO_DECLARE_DMA_BUFFER_WITH_TS
iio: adc: ad4695: rename AD4695_MAX_VIN_CHANNELS
iio: adc: ad4695: use IIO_DECLARE_DMA_BUFFER_WITH_TS
iio: introduce IIO_DECLARE_BUFFER_WITH_TS macros
iio: make IIO_DMA_MINALIGN minimum of 8 bytes
...
On regular bootup, devices get registered to VMBus first, so when
uio_hv_generic driver for a particular device type is probed,
the device is already initialized and added, so sysfs creation in
hv_uio_probe() works fine. However, when the device is removed
and brought back, the channel gets rescinded and the device again gets
registered to VMBus. However this time, the uio_hv_generic driver is
already registered to probe for that device and in this case sysfs
creation is tried before the device's kobject gets initialized
completely.
Fix this by moving the core logic of sysfs creation of ring buffer,
from uio_hv_generic to HyperV's VMBus driver, where the rest of the
sysfs attributes for the channels are defined. While doing that, make
use of attribute groups and macros, instead of creating sysfs
directly, to ensure better error handling and code flow.
Problematic path:
vmbus_process_offer (A new offer comes for the VMBus device)
vmbus_add_channel_work
vmbus_device_register
|-> device_register
| |...
| |-> hv_uio_probe
| |...
| |-> sysfs_create_bin_file (leads to a warning as
| the primary channel's kobject, which is used to
| create the sysfs file, is not yet initialized)
|-> kset_create_and_add
|-> vmbus_add_channel_kobj (initialization of the primary
channel's kobject happens later)
Above code flow is sequential and the warning is always reproducible in
this path.
Fixes: 9ab877a6cc ("uio_hv_generic: make ring buffer attribute for primary channel")
Cc: stable@kernel.org
Suggested-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Suggested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250502074811.2022-2-namjain@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Hyper-V may offer a non latency sensitive device with subchannels without
monitor bit enabled. The decision is entirely on the Hyper-V host not
configurable within guest.
When a device has subchannels, also signal events for the subchannel
if its monitor bit is disabled.
This patch also removes the memory barrier when monitor bit is enabled
as it is not necessary. The memory barrier is only needed between
setting up interrupt mask and calling vmbus_set_event() when monitor
bit is disabled.
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Link: https://lore.kernel.org/r/1741644721-20389-1-git-send-email-longli@linuxonhyperv.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull Char/Misc/IIO driver updates from Greg KH:
"Here is the "big" set of char/misc/iio and other smaller driver
subsystem updates for 6.14-rc1. Loads of different things in here this
development cycle, highlights are:
- ntsync "driver" to handle Windows locking types enabling Wine to
work much better on many workloads (i.e. games). The driver
framework was in 6.13, but now it's enabled and fully working
properly. Should make many SteamOS users happy. Even comes with
tests!
- Large IIO driver updates and bugfixes
- FPGA driver updates
- Coresight driver updates
- MHI driver updates
- PPS driver updatesa
- const bin_attribute reworking for many drivers
- binder driver updates
- smaller driver updates and fixes
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (311 commits)
ntsync: Fix reference leaks in the remaining create ioctls.
spmi: hisi-spmi-controller: Drop duplicated OF node assignment in spmi_controller_probe()
spmi: Set fwnode for spmi devices
ntsync: fix a file reference leak in drivers/misc/ntsync.c
scripts/tags.sh: Don't tag usages of DECLARE_BITMAP
dt-bindings: interconnect: qcom,msm8998-bwmon: Add SM8750 CPU BWMONs
dt-bindings: interconnect: OSM L3: Document sm8650 OSM L3 compatible
dt-bindings: interconnect: qcom-bwmon: Document QCS615 bwmon compatibles
interconnect: sm8750: Add missing const to static qcom_icc_desc
memstick: core: fix kernel-doc notation
intel_th: core: fix kernel-doc warnings
binder: log transaction code on failure
iio: dac: ad3552r-hs: clear reset status flag
iio: dac: ad3552r-common: fix ad3541/2r ranges
iio: chemical: bme680: Fix uninitialized variable in __bme680_read_raw()
misc: fastrpc: Fix copy buffer page size
misc: fastrpc: Fix registered buffer page address
misc: fastrpc: Deregister device nodes properly in error scenarios
nvmem: core: improve range check for nvmem_cell_write()
nvmem: qcom-spmi-sdam: Set size in struct nvmem_config
...
