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llvm / llvm-project / 691ca556e04dafa3d755e975ea3432fbfd4ca9ad
commit691ca556e04dafa3d755e975ea3432fbfd4ca9ad[log] [tgz]
authorMing-Yi Lai <ming-yi.lai@mediatek.com>Wed May 14 11:48:59 2025 +0800
committerGitHub <noreply@github.com>Wed May 14 11:48:59 2025 +0800
tree7644a49475354c617440d116c6c9815180a6b84f
parent866f1cd6a9146b3ee6ed012c0d90e02bc96d4e16 [diff]
[RISCV] Emit .note.gnu.property section when Zicfiss-based shadow stack is enabled (#127036)

RISC-V Zicfiss-based shadow stack needs to let the linker/loader know if
the binary is built with the mechanism enabled to support proper
link-time/load-time management of this feature. The information is
encoded as a bit in the `.note.gnu.property` section. This patch
implements emitting the section for RISC-V targets when Zicfiss-based
shadow stack is enabled.

When Clang receives the `-fcf-protection=return` flag, it adds the
`hw-shadow-stack` attribute to LLVM functions, and adds a non-zero
valued attribute named `cf-protection-return` to the LLVM module it
generates. The backend depends on the `hw-shadow-stack` attributes to
generate Zicfiss-based shadow stack instructions for each function, but
at the module scope, the `cf-protection-return` attribute is a better
indication of whether the translation unit is built with Zicfiss-based
shadow stack enabled, so this patch emits the `.note.gnu.property`
section with the "Zicfiss-based shadow stack" bit toggled on when it
sees the `cf-protection-return` attribute.
4 files changed
tree: 7644a49475354c617440d116c6c9815180a6b84f
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. flang-rt/
  11. libc/
  12. libclc/
  13. libcxx/
  14. libcxxabi/
  15. libunwind/
  16. lld/
  17. lldb/
  18. llvm/
  19. llvm-libgcc/
  20. mlir/
  21. offload/
  22. openmp/
  23. polly/
  24. pstl/
  25. runtimes/
  26. third-party/
  27. utils/
  28. .clang-format
  29. .clang-format-ignore
  30. .clang-tidy
  31. .git-blame-ignore-revs
  32. .gitattributes
  33. .gitignore
  34. .mailmap
  35. CODE_OF_CONDUCT.md
  36. CONTRIBUTING.md
  37. LICENSE.TXT
  38. pyproject.toml
  39. README.md
  40. SECURITY.md
README.md

The LLVM Compiler Infrastructure

OpenSSF Scorecard OpenSSF Best Practices libc++

Welcome to the LLVM project!

This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.

The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.

C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.

Other components include: the libc++ C++ standard library, the LLD linker, and more.

Getting the Source Code and Building LLVM

Consult the Getting Started with LLVM page for information on building and running LLVM.

For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.

Getting in touch

Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.

The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.