linux.git/rust/bindings, branch v6.18.21 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git mm/ksm: fix flag-dropping behavior in ksm_madvise 2025-10-07T21:01:12+00:00 Jakub Acs acsjakub@amazon.de 2025-10-01T09:03:52+00:00 f04aad36a07cc17b7a5d5b9a2d386ce6fae63e93 syzkaller discovered the following crash: (kernel BUG) [ 44.607039] ------------[ cut here ]------------ [ 44.607422] kernel BUG at mm/userfaultfd.c:2067! [ 44.608148] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI [ 44.608814] CPU: 1 UID: 0 PID: 2475 Comm: reproducer Not tainted 6.16.0-rc6 #1 PREEMPT(none) [ 44.609635] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 44.610695] RIP: 0010:userfaultfd_release_all+0x3a8/0x460 <snip other registers, drop unreliable trace> [ 44.617726] Call Trace: [ 44.617926] <TASK> [ 44.619284] userfaultfd_release+0xef/0x1b0 [ 44.620976] __fput+0x3f9/0xb60 [ 44.621240] fput_close_sync+0x110/0x210 [ 44.622222] __x64_sys_close+0x8f/0x120 [ 44.622530] do_syscall_64+0x5b/0x2f0 [ 44.622840] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 44.623244] RIP: 0033:0x7f365bb3f227 Kernel panics because it detects UFFD inconsistency during userfaultfd_release_all(). Specifically, a VMA which has a valid pointer to vma->vm_userfaultfd_ctx, but no UFFD flags in vma->vm_flags. The inconsistency is caused in ksm_madvise(): when user calls madvise() with MADV_UNMEARGEABLE on a VMA that is registered for UFFD in MINOR mode, it accidentally clears all flags stored in the upper 32 bits of vma->vm_flags. Assuming x86_64 kernel build, unsigned long is 64-bit and unsigned int and int are 32-bit wide. This setup causes the following mishap during the &= ~VM_MERGEABLE assignment. VM_MERGEABLE is a 32-bit constant of type unsigned int, 0x8000'0000. After ~ is applied, it becomes 0x7fff'ffff unsigned int, which is then promoted to unsigned long before the & operation. This promotion fills upper 32 bits with leading 0s, as we're doing unsigned conversion (and even for a signed conversion, this wouldn't help as the leading bit is 0). & operation thus ends up AND-ing vm_flags with 0x0000'0000'7fff'ffff instead of intended 0xffff'ffff'7fff'ffff and hence accidentally clears the upper 32-bits of its value. Fix it by changing `VM_MERGEABLE` constant to unsigned long, using the BIT() macro. Note: other VM_* flags are not affected: This only happens to the VM_MERGEABLE flag, as the other VM_* flags are all constants of type int and after ~ operation, they end up with leading 1 and are thus converted to unsigned long with leading 1s. Note 2: After commit 31defc3b01d9 ("userfaultfd: remove (VM_)BUG_ON()s"), this is no longer a kernel BUG, but a WARNING at the same place: [ 45.595973] WARNING: CPU: 1 PID: 2474 at mm/userfaultfd.c:2067 but the root-cause (flag-drop) remains the same. [akpm@linux-foundation.org: rust bindgen wasn't able to handle BIT(), from Miguel] Link: https://lore.kernel.org/oe-kbuild-all/202510030449.VfSaAjvd-lkp@intel.com/ Link: https://lkml.kernel.org/r/20251001090353.57523-2-acsjakub@amazon.de Fixes: 7677f7fd8be7 ("userfaultfd: add minor fault registration mode") Signed-off-by: Jakub Acs <acsjakub@amazon.de> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: SeongJae Park <sj@kernel.org> Tested-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: Xu Xin <xu.xin16@zte.com.cn> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Peter Xu <peterx@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
syzkaller discovered the following crash: (kernel BUG)

[   44.607039] ------------[ cut here ]------------
[   44.607422] kernel BUG at mm/userfaultfd.c:2067!
[   44.608148] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI
[   44.608814] CPU: 1 UID: 0 PID: 2475 Comm: reproducer Not tainted 6.16.0-rc6 #1 PREEMPT(none)
[   44.609635] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   44.610695] RIP: 0010:userfaultfd_release_all+0x3a8/0x460

<snip other registers, drop unreliable trace>

[   44.617726] Call Trace:
[   44.617926]  <TASK>
[   44.619284]  userfaultfd_release+0xef/0x1b0
[   44.620976]  __fput+0x3f9/0xb60
[   44.621240]  fput_close_sync+0x110/0x210
[   44.622222]  __x64_sys_close+0x8f/0x120
[   44.622530]  do_syscall_64+0x5b/0x2f0
[   44.622840]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   44.623244] RIP: 0033:0x7f365bb3f227

Kernel panics because it detects UFFD inconsistency during
userfaultfd_release_all().  Specifically, a VMA which has a valid pointer
to vma->vm_userfaultfd_ctx, but no UFFD flags in vma->vm_flags.

The inconsistency is caused in ksm_madvise(): when user calls madvise()
with MADV_UNMEARGEABLE on a VMA that is registered for UFFD in MINOR mode,
it accidentally clears all flags stored in the upper 32 bits of
vma->vm_flags.

Assuming x86_64 kernel build, unsigned long is 64-bit and unsigned int and
int are 32-bit wide.  This setup causes the following mishap during the &=
~VM_MERGEABLE assignment.

VM_MERGEABLE is a 32-bit constant of type unsigned int, 0x8000'0000. 
After ~ is applied, it becomes 0x7fff'ffff unsigned int, which is then
promoted to unsigned long before the & operation.  This promotion fills
upper 32 bits with leading 0s, as we're doing unsigned conversion (and
even for a signed conversion, this wouldn't help as the leading bit is 0).
& operation thus ends up AND-ing vm_flags with 0x0000'0000'7fff'ffff
instead of intended 0xffff'ffff'7fff'ffff and hence accidentally clears
the upper 32-bits of its value.

Fix it by changing `VM_MERGEABLE` constant to unsigned long, using the
BIT() macro.

Note: other VM_* flags are not affected: This only happens to the
VM_MERGEABLE flag, as the other VM_* flags are all constants of type int
and after ~ operation, they end up with leading 1 and are thus converted
to unsigned long with leading 1s.

Note 2:
After commit 31defc3b01d9 ("userfaultfd: remove (VM_)BUG_ON()s"), this is
no longer a kernel BUG, but a WARNING at the same place:

[   45.595973] WARNING: CPU: 1 PID: 2474 at mm/userfaultfd.c:2067

but the root-cause (flag-drop) remains the same.

[akpm@linux-foundation.org: rust bindgen wasn't able to handle BIT(), from Miguel]
  Link: https://lore.kernel.org/oe-kbuild-all/202510030449.VfSaAjvd-lkp@intel.com/
Link: https://lkml.kernel.org/r/20251001090353.57523-2-acsjakub@amazon.de
Fixes: 7677f7fd8be7 ("userfaultfd: add minor fault registration mode")
Signed-off-by: Jakub Acs <acsjakub@amazon.de>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: SeongJae Park <sj@kernel.org>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Xu Xin <xu.xin16@zte.com.cn>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Merge tag 'char-misc-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc 2025-10-04T23:26:32+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-10-04T23:26:32+00:00 6093a688a07da07808f0122f9aa2a3eed250d853 Pull Char/Misc/IIO/Binder updates from Greg KH: "Here is the big set of char/misc/iio and other driver subsystem changes for 6.18-rc1. Loads of different stuff in here, it was a busy development cycle in lots of different subsystems, with over 27k new lines added to the tree. Included in here are: - IIO updates including new drivers, reworking of existing apis, and other goodness in the sensor subsystems - MEI driver updates and additions - NVMEM driver updates - slimbus removal for an unused driver and some other minor updates - coresight driver updates and additions - MHI driver updates - comedi driver updates and fixes - extcon driver updates - interconnect driver additions - eeprom driver updates and fixes - minor UIO driver updates - tiny W1 driver updates But the majority of new code is in the rust bindings and additions, which includes: - misc driver rust binding updates for read/write support, we can now write "normal" misc drivers in rust fully, and the sample driver shows how this can be done. - Initial framework for USB driver rust bindings, which are disabled for now in the build, due to limited support, but coming in through this tree due to dependencies on other rust binding changes that were in here. I'll be enabling these back on in the build in the usb.git tree after -rc1 is out so that developers can continue to work on these in linux-next over the next development cycle. - Android Binder driver implemented in Rust. This is the big one, and was driving a huge majority of the rust binding work over the past years. Right now there are two binder drivers in the kernel, selected only at build time as to which one to use as binder wants to be included in the system at boot time. The binder C maintainers all agreed on this, as eventually, they want the C code to be removed from the tree, but it will take a few releases to get there while both are maintained to ensure that the rust implementation is fully stable and compliant with the existing userspace apis. All of these have been in linux-next for a while" * tag 'char-misc-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (320 commits) rust: usb: keep usb::Device private for now rust: usb: don't retain device context for the interface parent USB: disable rust bindings from the build for now samples: rust: add a USB driver sample rust: usb: add basic USB abstractions coresight: Add label sysfs node support dt-bindings: arm: Add label in the coresight components coresight: tnoc: add new AMBA ID to support Trace Noc V2 coresight: Fix incorrect handling for return value of devm_kzalloc coresight: tpda: fix the logic to setup the element size coresight: trbe: Return NULL pointer for allocation failures coresight: Refactor runtime PM coresight: Make clock sequence consistent coresight: Refactor driver data allocation coresight: Consolidate clock enabling coresight: Avoid enable programming clock duplicately coresight: Appropriately disable trace bus clocks coresight: Appropriately disable programming clocks coresight: etm4x: Support atclk coresight: catu: Support atclk ... 
Pull Char/Misc/IIO/Binder updates from Greg KH:
 "Here is the big set of char/misc/iio and other driver subsystem
  changes for 6.18-rc1.

  Loads of different stuff in here, it was a busy development cycle in
  lots of different subsystems, with over 27k new lines added to the
  tree.

  Included in here are:

   - IIO updates including new drivers, reworking of existing apis, and
     other goodness in the sensor subsystems

   - MEI driver updates and additions

   - NVMEM driver updates

   - slimbus removal for an unused driver and some other minor updates

   - coresight driver updates and additions

   - MHI driver updates

   - comedi driver updates and fixes

   - extcon driver updates

   - interconnect driver additions

   - eeprom driver updates and fixes

   - minor UIO driver updates

   - tiny W1 driver updates

  But the majority of new code is in the rust bindings and additions,
  which includes:

   - misc driver rust binding updates for read/write support, we can now
     write "normal" misc drivers in rust fully, and the sample driver
     shows how this can be done.

   - Initial framework for USB driver rust bindings, which are disabled
     for now in the build, due to limited support, but coming in through
     this tree due to dependencies on other rust binding changes that
     were in here. I'll be enabling these back on in the build in the
     usb.git tree after -rc1 is out so that developers can continue to
     work on these in linux-next over the next development cycle.

   - Android Binder driver implemented in Rust.

     This is the big one, and was driving a huge majority of the rust
     binding work over the past years. Right now there are two binder
     drivers in the kernel, selected only at build time as to which one
     to use as binder wants to be included in the system at boot time.

     The binder C maintainers all agreed on this, as eventually, they
     want the C code to be removed from the tree, but it will take a few
     releases to get there while both are maintained to ensure that the
     rust implementation is fully stable and compliant with the existing
     userspace apis.

  All of these have been in linux-next for a while"

* tag 'char-misc-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (320 commits)
  rust: usb: keep usb::Device private for now
  rust: usb: don't retain device context for the interface parent
  USB: disable rust bindings from the build for now
  samples: rust: add a USB driver sample
  rust: usb: add basic USB abstractions
  coresight: Add label sysfs node support
  dt-bindings: arm: Add label in the coresight components
  coresight: tnoc: add new AMBA ID to support Trace Noc V2
  coresight: Fix incorrect handling for return value of devm_kzalloc
  coresight: tpda: fix the logic to setup the element size
  coresight: trbe: Return NULL pointer for allocation failures
  coresight: Refactor runtime PM
  coresight: Make clock sequence consistent
  coresight: Refactor driver data allocation
  coresight: Consolidate clock enabling
  coresight: Avoid enable programming clock duplicately
  coresight: Appropriately disable trace bus clocks
  coresight: Appropriately disable programming clocks
  coresight: etm4x: Support atclk
  coresight: catu: Support atclk
  ...
Merge tag 'drm-next-2025-10-01' of https://gitlab.freedesktop.org/drm/kernel 2025-10-02T19:47:25+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-10-02T19:47:25+00:00 58809f614e0e3f4e12b489bddf680bfeb31c0a20 Pull drm updates from Dave Airlie: "cross-subsystem: - i2c-hid: Make elan touch controllers power on after panel is enabled - dt bindings for STM32MP25 SoC - pci vgaarb: use screen_info helpers - rust pin-init updates - add MEI driver for late binding firmware update/load uapi: - add ioctl for reassigning GEM handles - provide boot_display attribute on boot-up devices core: - document DRM_MODE_PAGE_FLIP_EVENT - add vendor specific recovery method to drm device wedged uevent gem: - Simplify gpuvm locking ttm: - add interface to populate buffers sched: - Fix race condition in trace code atomic: - Reallow no-op async page flips display: - dp: Fix command length video: - Improve pixel-format handling for struct screen_info rust: - drop Opaque<> from ioctl args - Alloc: - BorrowedPage type and AsPageIter traits - Implement Vmalloc::to_page() and VmallocPageIter - DMA/Scatterlist: - Add dma::DataDirection and type alias for dma_addr_t - Abstraction for struct scatterlist and sg_table - DRM: - simplify use of generics - add DriverFile type alias - drop Object::SIZE - Rust: - pin-init tree merge - Various methods for AsBytes and FromBytes traits gpuvm: - Support madvice in Xe driver gpusvm: - fix hmm_pfn_to_map_order usage in gpusvm bridge: - Improve and fix ref counting on bridge management - cdns-dsi: Various improvements to mode setting - Support Solomon SSD2825 plus DT bindings - Support Waveshare DSI2DPI plus DT bindings - Support Content Protection property - display-connector: Improve DP display detection - Add support for Radxa Ra620 plus DT bindings - adv7511: Provide SPD and HDMI infoframes - it6505: Replace crypto_shash with sha() - synopsys: Add support for DW DPTX Controller plus DT bindings - adv7511: Write full Audio infoframe - ite6263: Support vendor-specific infoframes - simple: Add support for Realtek RTD2171 DP-to-HDMI plus DT bindings panel: - panel-edp: Support mt8189 Chromebooks; Support BOE NV140WUM-N64; Support SHP LQ134Z1; Fixes - panel-simple: Support Olimex LCD-OLinuXino-5CTS plus DT bindings - Support Samsung AMS561RA01 - Support Hydis HV101HD1 plus DT bindings - ilitek-ili9881c: Refactor mode setting; Add support for Bestar BSD1218-A101KL68 LCD plus DT bindings - lvds: Add support for Ampire AMP19201200B5TZQW-T03 to DT bindings - edp: Add support for additonal mt8189 Chromebook panels - lvds: Add DT bindings for EDT ETML0700Z8DHA amdgpu: - add CRIU support for gem objects - RAS updates - VCN SRAM load fixes - EDID read fixes - eDP ALPM support - Documentation updates - Rework PTE flag generation - DCE6 fixes - VCN devcoredump cleanup - MMHUB client id fixes - VCN 5.0.1 RAS support - SMU 13.0.x updates - Expanded PCIe DPC support - Expanded VCN reset support - VPE per queue reset support - give kernel jobs unique id for tracing - pre-populate exported buffers - cyan skillfish updates - make vbios build number available in sysfs - userq updates - HDCP updates - support MMIO remap page as ttm pool - JPEG parser updates - DCE6 DC updates - use devm for i2c buses - GPUVM locking updates - Drop non-DC DCE11 code - improve fallback handling for pixel encoding amdkfd: - SVM/page migration fixes - debugfs fixes - add CRIO support for gem objects - SVM updates radeon: - use dev_warn_once in CS parsers xe: - add madvise interface - add DRM_IOCTL_XE_VM_QUERY_MEMORY_RANGE_ATTRS to query VMA count and memory attributes - drop L# bank mask reporting from media GT3 on Xe3+. - add SLPC power_profile sysfs interface - add configs attribs to add post/mid context-switch commands - handle firmware reported hardware errors notifying userspace with device wedged uevent - use same dir structure across sysfs/debugfs - cleanup and future proof vram region init - add G-states and PCI link states to debugfs - Add SRIOV support for CCS surfaces on Xe2+ - Enable SRIOV PF mode by default on supported platforms - move flush to common code - extended core workarounds for Xe2/3 - use DRM scheduler for delayed GT TLB invalidations - configs improvements and allow VF device enablement - prep work to expose mmio regions to userspace - VF migration support added - prepare GPU SVM for THP migration - start fixing XE_PAGE_SIZE vs PAGE_SIZE - add PSMI support for hw validation - resize VF bars to max possible size according to number of VFs - Ensure GT is in C0 during resume - pre-populate exported buffers - replace xe_hmm with gpusvm - add more SVM GT stats to debugfs - improve fake pci and WA kunnit handle for new platform testing - Test GuC to GuC comms to add debugging - use attribute groups to simplify sysfs registration - add Late Binding firmware code to interact with MEI i915: - apply multiple JSL/EHL/Gen7/Gen6 workarounds properly - protect against overflow in active_engine() - Use try_cmpxchg64() in __active_lookup() - include GuC registers in error state - get rid of dev->struct_mutex - iopoll: generalize read_poll_timout - lots more display refactoring - Reject HBR3 in any eDP Panel - Prune modes for YUV420 - Display Wa fix, additions, and updates - DP: Fix 2.7 Gbps link training on g4x - DP: Adjust the idle pattern handling - DP: Shuffle the link training code a bit - Don't set/read the DSI C clock divider on GLK - Enable_psr kernel parameter changes - Type-C enabled/disconnected dp-alt sink - Wildcat Lake enabling - DP HDR updates - DRAM detection - wait PSR idle on dsb commit - Remove FBC modulo 4 restriction for ADL-P+ - panic: refactor framebuffer allocation habanalabs: - debug/visibility improvements - vmalloc-backed coherent mmap support - HLDIO infrastructure nova-core: - various register!() macro improvements - minor vbios/firmware fixes/refactoring - advance firmware boot stages; process Booter and patch signatures - process GSP and GSP bootloader - Add r570.144 firmware bindings and update to it - Move GSP boot code to own module - Use new pin-init features to store driver's private data in a single allocation - Update ARef import from sync::aref nova-drm: - Update ARef import from sync::aref tyr: - initial driver skeleton for a rust driver for ARM Mali GPUs - capable of powering up, query metadata and provide it to userspace. msm: - GPU and Core: - in DT bindings describe clocks per GPU type - GMU bandwidth voting for x1-85 - a623/a663 speedbins - cleanup some remaining no-iommu leftovers after VM_BIND conversion - fix GEM obj 32b size truncation - add missing VM_BIND param validation - IFPC for x1-85 and a750 - register xml and gen_header.py sync from mesa - Display: - add missing bindings for display on SC8180X - added DisplayPort MST bindings - conversion from round_rate() to determine_rate() amdxdna: - add IOCTL_AMDXDNA_GET_ARRAY - support user space allocated buffers - streamline PM interfaces - Refactoring wrt. hardware contexts - improve error reporting nouveau: - use GSP firmware by default - improve error reporting - Pre-populate exported buffers ast: - Clean up detection of DRAM config exynos: - add DSIM bridge driver support for Exynos7870 - Document Exynos7870 DSIM compatible in dt-binding panthor: - Print task/pid on errors - Add support for Mali G710, G510, G310, Gx15, Gx20, Gx25 - Improve cache flushing - Fail VM bind if BO has offset renesas: - convert to RUNTIME_PM_OPS rcar-du: - Make number of lanes configurable - Use RUNTIME_PM_OPS - Add support for DSI commands rocket: - Add driver for Rockchip NPU plus DT bindings - Use kfree() and sizeof() correctly - Test DMA status rockchip: - dsi2: Add support for RK3576 plus DT bindings - Add support for RK3588 DPTX output tidss: - Use crtc_ fields for programming display mode - Remove other drivers from aperture pixpaper: - Add support for Mayqueen Pixpaper plus DT bindings v3d: - Support querying nubmer of GPU resets for KHR_robustness stm: - Clean up logging - ltdc: Add support support for STM32MP257F-EV1 plus DT bindings sitronix: - st7571-i2c: Add support for inverted displays and 2-bit grayscale tidss: - Convert to kernel's FIELD_ macros vesadrm: - Support 8-bit palette mode imagination: - Improve power management - Add support for TH1520 GPU - Support Risc-V architectures v3d: - Improve job management and locking vkms: - Support variants of ARGB8888, ARGB16161616, RGB565, RGB888 and P01x - Spport YUV with 16-bit components" * tag 'drm-next-2025-10-01' of https://gitlab.freedesktop.org/drm/kernel: (1455 commits) drm/amd: Add name to modes from amdgpu_connector_add_common_modes() drm/amd: Drop some common modes from amdgpu_connector_add_common_modes() drm/amdgpu: update MODULE_PARM_DESC for freesync_video drm/amd: Use dynamic array size declaration for amdgpu_connector_add_common_modes() drm/amd/display: Share dce100_validate_global with DCE6-8 drm/amd/display: Share dce100_validate_bandwidth with DCE6-8 drm/amdgpu: Fix fence signaling race condition in userqueue amd/amdkfd: enhance kfd process check in switch partition amd/amdkfd: resolve a race in amdgpu_amdkfd_device_fini_sw drm/amd/display: Reject modes with too high pixel clock on DCE6-10 drm/amd: Drop unnecessary check in amdgpu_connector_add_common_modes() drm/amd/display: Only enable common modes for eDP and LVDS drm/amdgpu: remove the redeclaration of variable i drm/amdgpu/userq: assign an error code for invalid userq va drm/amdgpu: revert "rework reserved VMID handling" v2 drm/amdgpu: remove leftover from enforcing isolation by VMID drm/amdgpu: Add fallback to pipe reset if KCQ ring reset fails accel/habanalabs: add Infineon version check accel/habanalabs/gaudi2: read preboot status after recovering from dirty state accel/habanalabs: add HL_GET_P_STATE passthrough type ... 
Pull drm updates from Dave Airlie:
 "cross-subsystem:
   - i2c-hid: Make elan touch controllers power on after panel is
     enabled
   - dt bindings for STM32MP25 SoC
   - pci vgaarb: use screen_info helpers
   - rust pin-init updates
   - add MEI driver for late binding firmware update/load

  uapi:
   - add ioctl for reassigning GEM handles
   - provide boot_display attribute on boot-up devices

  core:
   - document DRM_MODE_PAGE_FLIP_EVENT
   - add vendor specific recovery method to drm device wedged uevent

  gem:
   - Simplify gpuvm locking

  ttm:
   - add interface to populate buffers

  sched:
   - Fix race condition in trace code

  atomic:
   - Reallow no-op async page flips

  display:
   - dp: Fix command length

  video:
   - Improve pixel-format handling for struct screen_info

  rust:
   - drop Opaque<> from ioctl args
   - Alloc:
       - BorrowedPage type and AsPageIter traits
       - Implement Vmalloc::to_page() and VmallocPageIter
   - DMA/Scatterlist:
       - Add dma::DataDirection and type alias for dma_addr_t
       - Abstraction for struct scatterlist and sg_table
   - DRM:
       - simplify use of generics
       - add DriverFile type alias
       - drop Object::SIZE
   - Rust:
       - pin-init tree merge
       - Various methods for AsBytes and FromBytes traits

  gpuvm:
   - Support madvice in Xe driver

  gpusvm:
   - fix hmm_pfn_to_map_order usage in gpusvm

  bridge:
   - Improve and fix ref counting on bridge management
   - cdns-dsi: Various improvements to mode setting
   - Support Solomon SSD2825 plus DT bindings
   - Support Waveshare DSI2DPI plus DT bindings
   - Support Content Protection property
   - display-connector: Improve DP display detection
   - Add support for Radxa Ra620 plus DT bindings
   - adv7511: Provide SPD and HDMI infoframes
   - it6505: Replace crypto_shash with sha()
   - synopsys: Add support for DW DPTX Controller plus DT bindings
   - adv7511: Write full Audio infoframe
   - ite6263: Support vendor-specific infoframes
   - simple: Add support for Realtek RTD2171 DP-to-HDMI plus DT bindings

  panel:
   - panel-edp: Support mt8189 Chromebooks; Support BOE NV140WUM-N64;
     Support SHP LQ134Z1; Fixes
   - panel-simple: Support Olimex LCD-OLinuXino-5CTS plus DT bindings
   - Support Samsung AMS561RA01
   - Support Hydis HV101HD1 plus DT bindings
   - ilitek-ili9881c: Refactor mode setting; Add support for Bestar
     BSD1218-A101KL68 LCD plus DT bindings
   - lvds: Add support for Ampire AMP19201200B5TZQW-T03 to DT bindings
   - edp: Add support for additonal mt8189 Chromebook panels
   - lvds: Add DT bindings for EDT ETML0700Z8DHA

  amdgpu:
   - add CRIU support for gem objects
   - RAS updates
   - VCN SRAM load fixes
   - EDID read fixes
   - eDP ALPM support
   - Documentation updates
   - Rework PTE flag generation
   - DCE6 fixes
   - VCN devcoredump cleanup
   - MMHUB client id fixes
   - VCN 5.0.1 RAS support
   - SMU 13.0.x updates
   - Expanded PCIe DPC support
   - Expanded VCN reset support
   - VPE per queue reset support
   - give kernel jobs unique id for tracing
   - pre-populate exported buffers
   - cyan skillfish updates
   - make vbios build number available in sysfs
   - userq updates
   - HDCP updates
   - support MMIO remap page as ttm pool
   - JPEG parser updates
   - DCE6 DC updates
   - use devm for i2c buses
   - GPUVM locking updates
   - Drop non-DC DCE11 code
   - improve fallback handling for pixel encoding

  amdkfd:
   - SVM/page migration fixes
   - debugfs fixes
   - add CRIO support for gem objects
   - SVM updates

  radeon:
   - use dev_warn_once in CS parsers

  xe:
   - add madvise interface
   - add DRM_IOCTL_XE_VM_QUERY_MEMORY_RANGE_ATTRS to query VMA count
     and memory attributes
   - drop L# bank mask reporting from media GT3 on Xe3+.
   - add SLPC power_profile sysfs interface
   - add configs attribs to add post/mid context-switch commands
   - handle firmware reported hardware errors notifying userspace with
     device wedged uevent
   - use same dir structure across sysfs/debugfs
   - cleanup and future proof vram region init
   - add G-states and PCI link states to debugfs
   - Add SRIOV support for CCS surfaces on Xe2+
   - Enable SRIOV PF mode by default on supported platforms
   - move flush to common code
   - extended core workarounds for Xe2/3
   - use DRM scheduler for delayed GT TLB invalidations
   - configs improvements and allow VF device enablement
   - prep work to expose mmio regions to userspace
   - VF migration support added
   - prepare GPU SVM for THP migration
   - start fixing XE_PAGE_SIZE vs PAGE_SIZE
   - add PSMI support for hw validation
   - resize VF bars to max possible size according to number of VFs
   - Ensure GT is in C0 during resume
   - pre-populate exported buffers
   - replace xe_hmm with gpusvm
   - add more SVM GT stats to debugfs
   - improve fake pci and WA kunnit handle for new platform testing
   - Test GuC to GuC comms to add debugging
   - use attribute groups to simplify sysfs registration
   - add Late Binding firmware code to interact with MEI

  i915:
   - apply multiple JSL/EHL/Gen7/Gen6 workarounds properly
   - protect against overflow in active_engine()
   - Use try_cmpxchg64() in __active_lookup()
   - include GuC registers in error state
   - get rid of dev->struct_mutex
   - iopoll: generalize read_poll_timout
   - lots more display refactoring
   - Reject HBR3 in any eDP Panel
   - Prune modes for YUV420
   - Display Wa fix, additions, and updates
   - DP: Fix 2.7 Gbps link training on g4x
   - DP: Adjust the idle pattern handling
   - DP: Shuffle the link training code a bit
   - Don't set/read the DSI C clock divider on GLK
   - Enable_psr kernel parameter changes
   - Type-C enabled/disconnected dp-alt sink
   - Wildcat Lake enabling
   - DP HDR updates
   - DRAM detection
   - wait PSR idle on dsb commit
   - Remove FBC modulo 4 restriction for ADL-P+
   - panic: refactor framebuffer allocation

  habanalabs:
   - debug/visibility improvements
   - vmalloc-backed coherent mmap support
   - HLDIO infrastructure

  nova-core:
   - various register!() macro improvements
   - minor vbios/firmware fixes/refactoring
   - advance firmware boot stages; process Booter and patch signatures
   - process GSP and GSP bootloader
   - Add r570.144 firmware bindings and update to it
   - Move GSP boot code to own module
   - Use new pin-init features to store driver's private data in a
     single allocation
   - Update ARef import from sync::aref

  nova-drm:
   - Update ARef import from sync::aref

  tyr:
   - initial driver skeleton for a rust driver for ARM Mali GPUs
   - capable of powering up, query metadata and provide it to userspace.

  msm:
   - GPU and Core:
      - in DT bindings describe clocks per GPU type
      - GMU bandwidth voting for x1-85
      - a623/a663 speedbins
      - cleanup some remaining no-iommu leftovers after VM_BIND conversion
      - fix GEM obj 32b size truncation
      - add missing VM_BIND param validation
      - IFPC for x1-85 and a750
      - register xml and gen_header.py sync from mesa
   - Display:
      - add missing bindings for display on SC8180X
      - added DisplayPort MST bindings
      - conversion from round_rate() to determine_rate()

  amdxdna:
   - add IOCTL_AMDXDNA_GET_ARRAY
   - support user space allocated buffers
   - streamline PM interfaces
   - Refactoring wrt. hardware contexts
   - improve error reporting

  nouveau:
   - use GSP firmware by default
   - improve error reporting
   - Pre-populate exported buffers

  ast:
   - Clean up detection of DRAM config

  exynos:
   - add DSIM bridge driver support for Exynos7870
   - Document Exynos7870 DSIM compatible in dt-binding

  panthor:
   - Print task/pid on errors
   - Add support for Mali G710, G510, G310, Gx15, Gx20, Gx25
   - Improve cache flushing
   - Fail VM bind if BO has offset

  renesas:
   - convert to RUNTIME_PM_OPS

  rcar-du:
   - Make number of lanes configurable
   - Use RUNTIME_PM_OPS
   - Add support for DSI commands

  rocket:
   - Add driver for Rockchip NPU plus DT bindings
   - Use kfree() and sizeof() correctly
   - Test DMA status

  rockchip:
   - dsi2: Add support for RK3576 plus DT bindings
   - Add support for RK3588 DPTX output

  tidss:
   - Use crtc_ fields for programming display mode
   - Remove other drivers from aperture

  pixpaper:
   - Add support for Mayqueen Pixpaper plus DT bindings

  v3d:
   - Support querying nubmer of GPU resets for KHR_robustness

  stm:
   - Clean up logging
   - ltdc: Add support support for STM32MP257F-EV1 plus DT bindings

  sitronix:
   - st7571-i2c: Add support for inverted displays and 2-bit grayscale

  tidss:
   - Convert to kernel's FIELD_ macros

  vesadrm:
   - Support 8-bit palette mode

  imagination:
   - Improve power management
   - Add support for TH1520 GPU
   - Support Risc-V architectures

  v3d:
   - Improve job management and locking

  vkms:
   - Support variants of ARGB8888, ARGB16161616, RGB565, RGB888 and P01x
   - Spport YUV with 16-bit components"

* tag 'drm-next-2025-10-01' of https://gitlab.freedesktop.org/drm/kernel: (1455 commits)
  drm/amd: Add name to modes from amdgpu_connector_add_common_modes()
  drm/amd: Drop some common modes from amdgpu_connector_add_common_modes()
  drm/amdgpu: update MODULE_PARM_DESC for freesync_video
  drm/amd: Use dynamic array size declaration for amdgpu_connector_add_common_modes()
  drm/amd/display: Share dce100_validate_global with DCE6-8
  drm/amd/display: Share dce100_validate_bandwidth with DCE6-8
  drm/amdgpu: Fix fence signaling race condition in userqueue
  amd/amdkfd: enhance kfd process check in switch partition
  amd/amdkfd: resolve a race in amdgpu_amdkfd_device_fini_sw
  drm/amd/display: Reject modes with too high pixel clock on DCE6-10
  drm/amd: Drop unnecessary check in amdgpu_connector_add_common_modes()
  drm/amd/display: Only enable common modes for eDP and LVDS
  drm/amdgpu: remove the redeclaration of variable i
  drm/amdgpu/userq: assign an error code for invalid userq va
  drm/amdgpu: revert "rework reserved VMID handling" v2
  drm/amdgpu: remove leftover from enforcing isolation by VMID
  drm/amdgpu: Add fallback to pipe reset if KCQ ring reset fails
  accel/habanalabs: add Infineon version check
  accel/habanalabs/gaudi2: read preboot status after recovering from dirty state
  accel/habanalabs: add HL_GET_P_STATE passthrough type
  ...
Merge tag 'bitmap-for-6.18' of https://github.com/norov/linux 2025-10-02T15:57:03+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-10-02T15:57:03+00:00 77633c77eee37ddc160493a4cf6070c166f47dc0 Pull bitmap updates from Yury Norov: - FIELD_PREP_WM16() consolidation (Nicolas) - bitmaps for Rust (Burak) - __fls() fix for arc (Kees) * tag 'bitmap-for-6.18' of https://github.com/norov/linux: (25 commits) rust: add dynamic ID pool abstraction for bitmap rust: add find_bit_benchmark_rust module. rust: add bitmap API. rust: add bindings for bitops.h rust: add bindings for bitmap.h phy: rockchip-pcie: switch to FIELD_PREP_WM16 macro clk: sp7021: switch to FIELD_PREP_WM16 macro PCI: dw-rockchip: Switch to FIELD_PREP_WM16 macro PCI: rockchip: Switch to FIELD_PREP_WM16* macros net: stmmac: dwmac-rk: switch to FIELD_PREP_WM16 macro ASoC: rockchip: i2s-tdm: switch to FIELD_PREP_WM16_CONST macro drm/rockchip: dw_hdmi: switch to FIELD_PREP_WM16* macros phy: rockchip-usb: switch to FIELD_PREP_WM16 macro drm/rockchip: inno-hdmi: switch to FIELD_PREP_WM16 macro drm/rockchip: dw_hdmi_qp: switch to FIELD_PREP_WM16 macro phy: rockchip-samsung-dcphy: switch to FIELD_PREP_WM16 macro drm/rockchip: vop2: switch to FIELD_PREP_WM16 macro drm/rockchip: dsi: switch to FIELD_PREP_WM16* macros phy: rockchip-emmc: switch to FIELD_PREP_WM16 macro drm/rockchip: lvds: switch to FIELD_PREP_WM16 macro ... 
Pull bitmap updates from Yury Norov:

 - FIELD_PREP_WM16() consolidation (Nicolas)

 - bitmaps for Rust (Burak)

 - __fls() fix for arc (Kees)

* tag 'bitmap-for-6.18' of https://github.com/norov/linux: (25 commits)
  rust: add dynamic ID pool abstraction for bitmap
  rust: add find_bit_benchmark_rust module.
  rust: add bitmap API.
  rust: add bindings for bitops.h
  rust: add bindings for bitmap.h
  phy: rockchip-pcie: switch to FIELD_PREP_WM16 macro
  clk: sp7021: switch to FIELD_PREP_WM16 macro
  PCI: dw-rockchip: Switch to FIELD_PREP_WM16 macro
  PCI: rockchip: Switch to FIELD_PREP_WM16* macros
  net: stmmac: dwmac-rk: switch to FIELD_PREP_WM16 macro
  ASoC: rockchip: i2s-tdm: switch to FIELD_PREP_WM16_CONST macro
  drm/rockchip: dw_hdmi: switch to FIELD_PREP_WM16* macros
  phy: rockchip-usb: switch to FIELD_PREP_WM16 macro
  drm/rockchip: inno-hdmi: switch to FIELD_PREP_WM16 macro
  drm/rockchip: dw_hdmi_qp: switch to FIELD_PREP_WM16 macro
  phy: rockchip-samsung-dcphy: switch to FIELD_PREP_WM16 macro
  drm/rockchip: vop2: switch to FIELD_PREP_WM16 macro
  drm/rockchip: dsi: switch to FIELD_PREP_WM16* macros
  phy: rockchip-emmc: switch to FIELD_PREP_WM16 macro
  drm/rockchip: lvds: switch to FIELD_PREP_WM16 macro
  ...
Merge tag 'driver-core-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core 2025-10-01T15:39:23+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-10-01T15:39:23+00:00 eb3289fc474f74105e0627bf508e3f9742fd3b63 Pull driver core updates from Danilo Krummrich: "Auxiliary: - Drop call to dev_pm_domain_detach() in auxiliary_bus_probe() - Optimize logic of auxiliary_match_id() Rust: - Auxiliary: - Use primitive C types from prelude - DebugFs: - Add debugfs support for simple read/write files and custom callbacks through a File-type-based and directory-scope-based API - Sample driver code for the File-type-based API - Sample module code for the directory-scope-based API - I/O: - Add io::poll module and implement Rust specific read_poll_timeout() helper - IRQ: - Implement support for threaded and non-threaded device IRQs based on (&Device<Bound>, IRQ number) tuples (IrqRequest) - Provide &Device<Bound> cookie in IRQ handlers - PCI: - Support IRQ requests from IRQ vectors for a specific pci::Device<Bound> - Implement accessors for subsystem IDs, revision, devid and resource start - Provide dedicated pci::Vendor and pci::Class types for vendor and class ID numbers - Implement Display to print actual vendor and class names; Debug to print the raw ID numbers - Add pci::DeviceId::from_class_and_vendor() helper - Use primitive C types from prelude - Various minor inline and (safety) comment improvements - Platform: - Support IRQ requests from IRQ vectors for a specific platform::Device<Bound> - Nova: - Use pci::DeviceId::from_class_and_vendor() to avoid probing non-display/compute PCI functions - Misc: - Add helper for cpu_relax() - Update ARef import from sync::aref sysfs: - Remove bin_attrs_new field from struct attribute_group - Remove read_new() and write_new() from struct bin_attribute Misc: - Document potential race condition in get_dev_from_fwnode() - Constify node_group argument in software node registration functions - Fix order of kernel-doc parameters in various functions - Set power.no_pm flag for faux devices - Set power.no_callbacks flag along with the power.no_pm flag - Constify the pmu_bus bus type - Minor spelling fixes" * tag 'driver-core-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (43 commits) rust: pci: display symbolic PCI vendor names rust: pci: display symbolic PCI class names rust: pci: fix incorrect platform reference in PCI driver probe doc comment rust: pci: fix incorrect platform reference in PCI driver unbind doc comment perf: make pmu_bus const samples: rust: Add scoped debugfs sample driver rust: debugfs: Add support for scoped directories samples: rust: Add debugfs sample driver rust: debugfs: Add support for callback-based files rust: debugfs: Add support for writable files rust: debugfs: Add support for read-only files rust: debugfs: Add initial support for directories driver core: auxiliary bus: Optimize logic of auxiliary_match_id() driver core: auxiliary bus: Drop dev_pm_domain_detach() call driver core: Fix order of the kernel-doc parameters driver core: get_dev_from_fwnode(): document potential race drivers: base: fix "publically"->"publicly" driver core/PM: Set power.no_callbacks along with power.no_pm driver core: faux: Set power.no_pm for faux devices rust: pci: inline several tiny functions ... 
Pull driver core updates from Danilo Krummrich:
 "Auxiliary:
   - Drop call to dev_pm_domain_detach() in auxiliary_bus_probe()
   - Optimize logic of auxiliary_match_id()

  Rust:
   - Auxiliary:
      - Use primitive C types from prelude

   - DebugFs:
      - Add debugfs support for simple read/write files and custom
        callbacks through a File-type-based and directory-scope-based
        API
      - Sample driver code for the File-type-based API
      - Sample module code for the directory-scope-based API

   - I/O:
      - Add io::poll module and implement Rust specific
        read_poll_timeout() helper

   - IRQ:
      - Implement support for threaded and non-threaded device IRQs
        based on (&Device<Bound>, IRQ number) tuples (IrqRequest)
      - Provide &Device<Bound> cookie in IRQ handlers

   - PCI:
      - Support IRQ requests from IRQ vectors for a specific
        pci::Device<Bound>
      - Implement accessors for subsystem IDs, revision, devid and
        resource start
      - Provide dedicated pci::Vendor and pci::Class types for vendor
        and class ID numbers
      - Implement Display to print actual vendor and class names; Debug
        to print the raw ID numbers
      - Add pci::DeviceId::from_class_and_vendor() helper
      - Use primitive C types from prelude
      - Various minor inline and (safety) comment improvements

   - Platform:
      - Support IRQ requests from IRQ vectors for a specific
        platform::Device<Bound>

   - Nova:
      - Use pci::DeviceId::from_class_and_vendor() to avoid probing
        non-display/compute PCI functions

   - Misc:
      - Add helper for cpu_relax()
      - Update ARef import from sync::aref

  sysfs:
   - Remove bin_attrs_new field from struct attribute_group
   - Remove read_new() and write_new() from struct bin_attribute

  Misc:
   - Document potential race condition in get_dev_from_fwnode()
   - Constify node_group argument in software node registration
     functions
   - Fix order of kernel-doc parameters in various functions
   - Set power.no_pm flag for faux devices
   - Set power.no_callbacks flag along with the power.no_pm flag
   - Constify the pmu_bus bus type
   - Minor spelling fixes"

* tag 'driver-core-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (43 commits)
  rust: pci: display symbolic PCI vendor names
  rust: pci: display symbolic PCI class names
  rust: pci: fix incorrect platform reference in PCI driver probe doc comment
  rust: pci: fix incorrect platform reference in PCI driver unbind doc comment
  perf: make pmu_bus const
  samples: rust: Add scoped debugfs sample driver
  rust: debugfs: Add support for scoped directories
  samples: rust: Add debugfs sample driver
  rust: debugfs: Add support for callback-based files
  rust: debugfs: Add support for writable files
  rust: debugfs: Add support for read-only files
  rust: debugfs: Add initial support for directories
  driver core: auxiliary bus: Optimize logic of auxiliary_match_id()
  driver core: auxiliary bus: Drop dev_pm_domain_detach() call
  driver core: Fix order of the kernel-doc parameters
  driver core: get_dev_from_fwnode(): document potential race
  drivers: base: fix "publically"->"publicly"
  driver core/PM: Set power.no_callbacks along with power.no_pm
  driver core: faux: Set power.no_pm for faux devices
  rust: pci: inline several tiny functions
  ...
USB: disable rust bindings from the build for now 2025-09-25T12:53:47+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2025-09-25T12:42:40+00:00 c584a1c7c8a192c13637bc51c7b63a9f15fe6474 The rust USB bindings as submitted are a good start, but they don't really seem to be correct in a number of minor places, so just disable them from the build entirely at this point in time. When they are ready to be re-enabled, this commit can be reverted. Acked-by: Daniel Almeida <daniel.almeida@collabora.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The rust USB bindings as submitted are a good start, but they don't
really seem to be correct in a number of minor places, so just disable
them from the build entirely at this point in time.  When they are ready
to be re-enabled, this commit can be reverted.

Acked-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rust: usb: add basic USB abstractions 2025-09-24T11:13:04+00:00 Daniel Almeida daniel.almeida@collabora.com 2025-08-25T18:18:05+00:00 e7e2296b0ecf9b6e934f7a1118cee91d4d486a84 Add basic USB abstractions, consisting of usb::{Device, Interface, Driver, Adapter, DeviceId} and the module_usb_driver macro. This is the first step in being able to write USB device drivers, which paves the way for USB media drivers - for example - among others. This initial support will then be used by a subsequent sample driver, which constitutes the only user of the USB abstractions so far. Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com> Link: https://lore.kernel.org/r/20250825-b4-usb-v1-1-7aa024de7ae8@collabora.com [ force USB = y for now - gregkh ] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Add basic USB abstractions, consisting of usb::{Device, Interface,
Driver, Adapter, DeviceId} and the module_usb_driver macro. This is the
first step in being able to write USB device drivers, which paves the
way for USB media drivers - for example - among others.

This initial support will then be used by a subsequent sample driver,
which constitutes the only user of the USB abstractions so far.

Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://lore.kernel.org/r/20250825-b4-usb-v1-1-7aa024de7ae8@collabora.com
[ force USB = y for now - gregkh ]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rust: add find_bit_benchmark_rust module. 2025-09-22T19:52:44+00:00 Burak Emir bqe@google.com 2025-09-08T07:21:54+00:00 38cc91db2e87ab55bfca2b194e791867b77f9e55 Microbenchmark protected by a config FIND_BIT_BENCHMARK_RUST, following `find_bit_benchmark.c` but testing the Rust Bitmap API. We add a fill_random() method protected by the config in order to maintain the abstraction. The sample output from the benchmark, both C and Rust version: find_bit_benchmark.c output: ``` Start testing find_bit() with random-filled bitmap [ 438.101937] find_next_bit: 860188 ns, 163419 iterations [ 438.109471] find_next_zero_bit: 912342 ns, 164262 iterations [ 438.116820] find_last_bit: 726003 ns, 163419 iterations [ 438.130509] find_nth_bit: 7056993 ns, 16269 iterations [ 438.139099] find_first_bit: 1963272 ns, 16270 iterations [ 438.173043] find_first_and_bit: 27314224 ns, 32654 iterations [ 438.180065] find_next_and_bit: 398752 ns, 73705 iterations [ 438.186689] Start testing find_bit() with sparse bitmap [ 438.193375] find_next_bit: 9675 ns, 656 iterations [ 438.201765] find_next_zero_bit: 1766136 ns, 327025 iterations [ 438.208429] find_last_bit: 9017 ns, 656 iterations [ 438.217816] find_nth_bit: 2749742 ns, 655 iterations [ 438.225168] find_first_bit: 721799 ns, 656 iterations [ 438.231797] find_first_and_bit: 2819 ns, 1 iterations [ 438.238441] find_next_and_bit: 3159 ns, 1 iterations ``` find_bit_benchmark_rust.rs output: ``` [ 451.182459] find_bit_benchmark_rust: [ 451.186688] Start testing find_bit() Rust with random-filled bitmap [ 451.194450] next_bit: 777950 ns, 163644 iterations [ 451.201997] next_zero_bit: 918889 ns, 164036 iterations [ 451.208642] Start testing find_bit() Rust with sparse bitmap [ 451.214300] next_bit: 9181 ns, 654 iterations [ 451.222806] next_zero_bit: 1855504 ns, 327026 iterations ``` Here are the results from 32 samples, with 95% confidence interval. The microbenchmark was built with RUST_BITMAP_HARDENED=n and run on a machine that did not execute other processes. Random-filled bitmap: +-----------+-------+-----------+--------------+-----------+-----------+ | Benchmark | Lang | Mean (ms) | Std Dev (ms) | 95% CI Lo | 95% CI Hi | +-----------+-------+-----------+--------------+-----------+-----------+ | find_bit/ | C | 825.07 | 53.89 | 806.40 | 843.74 | | next_bit | Rust | 870.91 | 46.29 | 854.88 | 886.95 | +-----------+-------+-----------+--------------+-----------+-----------+ | find_zero/| C | 933.56 | 56.34 | 914.04 | 953.08 | | next_zero | Rust | 945.85 | 60.44 | 924.91 | 966.79 | +-----------+-------+-----------+--------------+-----------+-----------+ Rust appears 5.5% slower for next_bit, 1.3% slower for next_zero. Sparse bitmap: +-----------+-------+-----------+--------------+-----------+-----------+ | Benchmark | Lang | Mean (ms) | Std Dev (ms) | 95% CI Lo | 95% CI Hi | +-----------+-------+-----------+--------------+-----------+-----------+ | find_bit/ | C | 13.17 | 6.21 | 11.01 | 15.32 | | next_bit | Rust | 14.30 | 8.27 | 11.43 | 17.17 | +-----------+-------+-----------+--------------+-----------+-----------+ | find_zero/| C | 1859.31 | 82.30 | 1830.80 | 1887.83 | | next_zero | Rust | 1908.09 | 139.82 | 1859.65 | 1956.54 | +-----------+-------+-----------+--------------+-----------+-----------+ Rust appears 8.5% slower for next_bit, 2.6% slower for next_zero. In summary, taking the arithmetic mean of all slow-downs, we can say the Rust API has a 4.5% slowdown. Suggested-by: Alice Ryhl <aliceryhl@google.com> Suggested-by: Yury Norov (NVIDIA) <yury.norov@gmail.com> Reviewed-by: Yury Norov (NVIDIA) <yury.norov@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Burak Emir <bqe@google.com> Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com> 
Microbenchmark protected by a config FIND_BIT_BENCHMARK_RUST,
following `find_bit_benchmark.c` but testing the Rust Bitmap API.

We add a fill_random() method protected by the config in order to
maintain the abstraction.

The sample output from the benchmark, both C and Rust version:

find_bit_benchmark.c output:
```
Start testing find_bit() with random-filled bitmap
[  438.101937] find_next_bit:                  860188 ns, 163419 iterations
[  438.109471] find_next_zero_bit:             912342 ns, 164262 iterations
[  438.116820] find_last_bit:                  726003 ns, 163419 iterations
[  438.130509] find_nth_bit:                  7056993 ns,  16269 iterations
[  438.139099] find_first_bit:                1963272 ns,  16270 iterations
[  438.173043] find_first_and_bit:           27314224 ns,  32654 iterations
[  438.180065] find_next_and_bit:              398752 ns,  73705 iterations
[  438.186689]
               Start testing find_bit() with sparse bitmap
[  438.193375] find_next_bit:                    9675 ns,    656 iterations
[  438.201765] find_next_zero_bit:            1766136 ns, 327025 iterations
[  438.208429] find_last_bit:                    9017 ns,    656 iterations
[  438.217816] find_nth_bit:                  2749742 ns,    655 iterations
[  438.225168] find_first_bit:                 721799 ns,    656 iterations
[  438.231797] find_first_and_bit:               2819 ns,      1 iterations
[  438.238441] find_next_and_bit:                3159 ns,      1 iterations
```

find_bit_benchmark_rust.rs output:
```
[  451.182459] find_bit_benchmark_rust:
[  451.186688] Start testing find_bit() Rust with random-filled bitmap
[  451.194450] next_bit:                       777950 ns, 163644 iterations
[  451.201997] next_zero_bit:                  918889 ns, 164036 iterations
[  451.208642] Start testing find_bit() Rust with sparse bitmap
[  451.214300] next_bit:                         9181 ns,    654 iterations
[  451.222806] next_zero_bit:                 1855504 ns, 327026 iterations
```

Here are the results from 32 samples, with 95% confidence interval.
The microbenchmark was built with RUST_BITMAP_HARDENED=n and run on a
machine that did not execute other processes.

Random-filled bitmap:
+-----------+-------+-----------+--------------+-----------+-----------+
| Benchmark | Lang  | Mean (ms) | Std Dev (ms) | 95% CI Lo | 95% CI Hi |
+-----------+-------+-----------+--------------+-----------+-----------+
| find_bit/ | C     |    825.07 |        53.89 |    806.40 |    843.74 |
| next_bit  | Rust  |    870.91 |        46.29 |    854.88 |    886.95 |
+-----------+-------+-----------+--------------+-----------+-----------+
| find_zero/| C     |    933.56 |        56.34 |    914.04 |    953.08 |
| next_zero | Rust  |    945.85 |        60.44 |    924.91 |    966.79 |
+-----------+-------+-----------+--------------+-----------+-----------+

Rust appears 5.5% slower for next_bit, 1.3% slower for next_zero.

Sparse bitmap:
+-----------+-------+-----------+--------------+-----------+-----------+
| Benchmark | Lang  | Mean (ms) | Std Dev (ms) | 95% CI Lo | 95% CI Hi |
+-----------+-------+-----------+--------------+-----------+-----------+
| find_bit/ | C     |     13.17 |         6.21 |     11.01 |     15.32 |
| next_bit  | Rust  |     14.30 |         8.27 |     11.43 |     17.17 |
+-----------+-------+-----------+--------------+-----------+-----------+
| find_zero/| C     |   1859.31 |        82.30 |   1830.80 |   1887.83 |
| next_zero | Rust  |   1908.09 |       139.82 |   1859.65 |   1956.54 |
+-----------+-------+-----------+--------------+-----------+-----------+

Rust appears 8.5% slower for next_bit, 2.6% slower for next_zero.

In summary, taking the arithmetic mean of all slow-downs, we can say
the Rust API has a 4.5% slowdown.

Suggested-by: Alice Ryhl <aliceryhl@google.com>
Suggested-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Reviewed-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Burak Emir <bqe@google.com>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
rust: add bindings for bitmap.h 2025-09-22T19:52:44+00:00 Burak Emir bqe@google.com 2025-09-08T07:21:51+00:00 0452b4ab2961093f23bb289b0112351b917fb23c Makes the bitmap_copy_and_extend inline function available to Rust. Adds F: to existing MAINTAINERS section BITMAP API BINDINGS [RUST]. - Suggested-by: Alice Ryhl <aliceryhl@google.com> Suggested-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Burak Emir <bqe@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Yury Norov (NVIDIA) <yury.norov@gmail.com> Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com> 
Makes the bitmap_copy_and_extend inline function available to Rust.
Adds F: to existing MAINTAINERS section BITMAP API BINDINGS [RUST].

-

Suggested-by: Alice Ryhl <aliceryhl@google.com>
Suggested-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Burak Emir <bqe@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
rust_binder: add Rust Binder driver 2025-09-19T07:40:46+00:00 Alice Ryhl aliceryhl@google.com 2025-09-19T06:42:07+00:00 eafedbc7c050c44744fbdf80bdf3315e860b7513 We're generally not proponents of rewrites (nasty uncomfortable things that make you late for dinner!). So why rewrite Binder? Binder has been evolving over the past 15+ years to meet the evolving needs of Android. Its responsibilities, expectations, and complexity have grown considerably during that time. While we expect Binder to continue to evolve along with Android, there are a number of factors that currently constrain our ability to develop/maintain it. Briefly those are: 1. Complexity: Binder is at the intersection of everything in Android and fulfills many responsibilities beyond IPC. It has become many things to many people, and due to its many features and their interactions with each other, its complexity is quite high. In just 6kLOC it must deliver transactions to the right threads. It must correctly parse and translate the contents of transactions, which can contain several objects of different types (e.g., pointers, fds) that can interact with each other. It controls the size of thread pools in userspace, and ensures that transactions are assigned to threads in ways that avoid deadlocks where the threadpool has run out of threads. It must track refcounts of objects that are shared by several processes by forwarding refcount changes between the processes correctly. It must handle numerous error scenarios and it combines/nests 13 different locks, 7 reference counters, and atomic variables. Finally, It must do all of this as fast and efficiently as possible. Minor performance regressions can cause a noticeably degraded user experience. 2. Things to improve: Thousand-line functions [1], error-prone error handling [2], and confusing structure can occur as a code base grows organically. After more than a decade of development, this codebase could use an overhaul. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/android/binder.c?h=v6.5#n2896 [2]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/android/binder.c?h=v6.5#n3658 3. Security critical: Binder is a critical part of Android's sandboxing strategy. Even Android's most de-privileged sandboxes (e.g. the Chrome renderer, or SW Codec) have direct access to Binder. More than just about any other component, it's important that Binder provide robust security, and itself be robust against security vulnerabilities. It's #1 (high complexity) that has made continuing to evolve Binder and resolving #2 (tech debt) exceptionally difficult without causing #3 (security issues). For Binder to continue to meet Android's needs, we need better ways to manage (and reduce!) complexity without increasing the risk. The biggest change is obviously the choice of programming language. We decided to use Rust because it directly addresses a number of the challenges within Binder that we have faced during the last years. It prevents mistakes with ref counting, locking, bounds checking, and also does a lot to reduce the complexity of error handling. Additionally, we've been able to use the more expressive type system to encode the ownership semantics of the various structs and pointers, which takes the complexity of managing object lifetimes out of the hands of the programmer, reducing the risk of use-after-frees and similar problems. Rust has many different pointer types that it uses to encode ownership semantics into the type system, and this is probably one of the most important aspects of how it helps in Binder. The Binder driver has a lot of different objects that have complex ownership semantics; some pointers own a refcount, some pointers have exclusive ownership, and some pointers just reference the object and it is kept alive in some other manner. With Rust, we can use