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dawn/dawn/2e555f2aee3c002b9b95a9c78b02cff1d877b2e7
commit
2e555f2aee3c002b9b95a9c78b02cff1d877b2e7
[log]
author
Antonio Maiorano <amaiorano@google.com>
Thu Sep 03 13:56:03 2026 -0700
committer
dawn-scoped@luci-project-accounts.iam.gserviceaccount.com <dawn-scoped@luci-project-accounts.iam.gserviceaccount.com>
Thu Sep 03 13:56:03 2026 -0700
tree
8d9b354b9a718e0d78d17b22d709fce2ef118dcc
parent
b011e782826a391813ff229b321911e00e4cd84f [diff]
[dawn][native] Trim mappedData in DynamicUploader large reservation path

In commit c3845d0d9626, UploadReservation was spanified, but the large
allocation path (>4MiB) in DynamicUploader::Reserve left mappedData set
to the full staging buffer range of size Align(allocationSize, 8).

When allocationSize is not a multiple of 8, Span::CopyFrom triggers an
assertion failure in BufferBase::UploadData (DAWN_CHECK(other.size() ==
size())), causing the process to abort on writeBuffer calls >4MiB whose
size is not a multiple of 8.

Fix this by trimming mappedData with .first(allocationSize), matching
the ring buffer path.

Fixed: 556738097
Bug: 534203108
Change-Id: I52caec20e3dfac18723db126880f84cf0e731aac
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/339375
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Antonio Maiorano <amaiorano@google.com>
2 files changed
tree: 8d9b354b9a718e0d78d17b22d709fce2ef118dcc
  1. .github/
  2. .vscode/
  3. agents/
  4. build_overrides/
  5. docs/
  6. generator/
  7. include/
  8. infra/
  9. scripts/
  10. src/
  11. test/
  12. third_party/
  13. tools/
  14. webgpu-cts/
  15. build
  16. buildtools
  17. testing
  18. .bazelignore
  19. .bazelrc
  20. .bazelversion
  21. .clang-format
  22. .clang-format-ignore
  23. .clang-tidy
  24. .git-blame-ignore-revs
  25. .gitattributes
  26. .gitignore
  27. .gitmodules
  28. .gn
  29. .style.yapf
  30. .vpython3
  31. AUTHORS
  32. BUILD.bazel
  33. BUILD.gn
  34. CMakeLists.txt
  35. CMakeSettings.json
  36. CODE_OF_CONDUCT.md
  37. codereview.settings
  38. CONTRIBUTING.md
  39. CPPLINT.cfg
  40. DEPS
  41. DIR_METADATA
  42. go.mod
  43. go.sum
  44. go_presubmit_support.py
  45. LICENSE
  46. MODULE.bazel
  47. MODULE.bazel.lock
  48. OWNERS
  49. PRESUBMIT.py
  50. PRESUBMIT_test.py
  51. README.chromium
  52. README.md
  53. unsafe_buffers_paths.txt
  54. WATCHLISTS
  55. WORKSPACE.bazel
README.md

Build Status Matrix Space

Dawn, a WebGPU implementation

Dawn is an open-source and cross-platform implementation of the WebGPU standard. More precisely it implements webgpu.h that is a one-to-one mapping with the WebGPU IDL. Dawn is meant to be integrated as part of a larger system and is the underlying implementation of WebGPU in Chromium.

Dawn provides several WebGPU building blocks:

  • WebGPU C/C++ headers that applications and other building blocks use.
    • The webgpu.h version that Dawn implements.
    • A C++ wrapper for the webgpu.h.
  • A “native” implementation of WebGPU using platforms' GPU APIs: D3D12, Metal, Vulkan and OpenGL. See per API support for more details.
  • A client-server implementation of WebGPU for applications that are in a sandbox without access to native drivers
  • Tint is a compiler for the WebGPU Shader Language (WGSL) that can be used in standalone to convert shaders from and to WGSL.

Helpful links:

Documentation table of content

Developer documentation:

User documentation: (TODO, figure out what overlaps with the webgpu.h docs)

License

BSD 3-Clause License, please see LICENSE.

Disclaimer

This is not an officially supported Google product.