[lld] Fix undefined behavior with misaligned SHT_GROUP section. (#180848)

read32() allows misaligned values, but a `uint32_t &` must be properly
aligned even if it isn't directly read. ubsan detects this. To fix the
issue, replace the `uint32_t &` with a value that doesn't require
alignment.

Also added an assertion to catch similar misuse of getDataAs().

(Alternatively, we could make the input validation more strict, and
reject files with a misaligned SHT_GROUP, but I don't see any obvious
reason to require that.)

GitOrigin-RevId: b7e1922ca15935342f9570ddbb7b61c8164115d5
3 files changed
tree: 36667cb299f90dc6826b94896cf742a922d2083b
  1. cmake/
  2. COFF/
  3. Common/
  4. docs/
  5. ELF/
  6. include/
  7. MachO/
  8. MinGW/
  9. test/
  10. tools/
  11. unittests/
  12. utils/
  13. wasm/
  14. .clang-format
  15. .clang-tidy
  16. .gitignore
  17. CMakeLists.txt
  18. LICENSE.TXT
  19. Maintainers.md
  20. README.md
README.md

LLVM Linker (lld)

This directory and its subdirectories contain source code for the LLVM Linker, a modular cross platform linker which is built as part of the LLVM compiler infrastructure project.

lld is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt.

Benchmarking

In order to make sure various developers can evaluate patches over the same tests, we create a collection of self contained programs.

It is hosted at https://s3-us-west-2.amazonaws.com/linker-tests/lld-speed-test.tar.xz

The current sha256 is 10eec685463d5a8bbf08d77f4ca96282161d396c65bd97dc99dbde644a31610f.