[sancov] Introduce optional callback for stack-depth tracking (#138323) Normally -fsanitize-coverage=stack-depth inserts inline arithmetic to update thread_local __sancov_lowest_stack. To support stack depth tracking in the Linux kernel, which does not implement traditional thread_local storage, provide the option to call a function instead. This matches the existing "stackleak" implementation that is supported in Linux via a GCC plugin. To make this coverage more performant, a minimum estimated stack depth can be chosen to enable the callback mode, skipping instrumentation of functions with smaller stacks. With -fsanitize-coverage-stack-depth-callback-min set greater than 0, the __sanitize_cov_stack_depth() callback will be injected when the estimated stack depth is greater than or equal to the given minimum.
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.
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.
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.