From 6ad7cbc01527223f3f92baac9b122f15651cf76b Mon Sep 17 00:00:00 2001 From: Nathan Huckleberry Date: Sat, 22 Aug 2020 23:56:18 +0900 Subject: Makefile: Add clang-tidy and static analyzer support to makefile This patch adds clang-tidy and the clang static-analyzer as make targets. The goal of this patch is to make static analysis tools usable and extendable by any developer or researcher who is familiar with basic c++. The current static analysis tools require intimate knowledge of the internal workings of the static analysis. Clang-tidy and the clang static analyzers expose an easy to use api and allow users unfamiliar with clang to write new checks with relative ease. ===Clang-tidy=== Clang-tidy is an easily extendable 'linter' that runs on the AST. Clang-tidy checks are easy to write and understand. A check consists of two parts, a matcher and a checker. The matcher is created using a domain specific language that acts on the AST (https://clang.llvm.org/docs/LibASTMatchersReference.html). When AST nodes are found by the matcher a callback is made to the checker. The checker can then execute additional checks and issue warnings. Here is an example clang-tidy check to report functions that have calls to local_irq_disable without calls to local_irq_enable and vice-versa. Functions flagged with __attribute((annotation("ignore_irq_balancing"))) are ignored for analysis. (https://reviews.llvm.org/D65828) ===Clang static analyzer=== The clang static analyzer is a more powerful static analysis tool that uses symbolic execution to find bugs. Currently there is a check that looks for potential security bugs from invalid uses of kmalloc and kfree. There are several more general purpose checks that are useful for the kernel. The clang static analyzer is well documented and designed to be extensible. (https://clang-analyzer.llvm.org/checker_dev_manual.html) (https://github.com/haoNoQ/clang-analyzer-guide/releases/download/v0.1/clang-analyzer-guide-v0.1.pdf) The main draw of the clang tools is how accessible they are. The clang documentation is very nice and these tools are built specifically to be easily extendable by any developer. They provide an accessible method of bug-finding and research to people who are not overly familiar with the kernel codebase. Signed-off-by: Nathan Huckleberry Reviewed-by: Nick Desaulniers Tested-by: Nick Desaulniers Tested-by: Lukas Bulwahn Signed-off-by: Masahiro Yamada --- MAINTAINERS | 1 + 1 file changed, 1 insertion(+) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index f0068bceeb61..05bebba204cf 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4247,6 +4247,7 @@ W: https://clangbuiltlinux.github.io/ B: https://github.com/ClangBuiltLinux/linux/issues C: irc://chat.freenode.net/clangbuiltlinux F: Documentation/kbuild/llvm.rst +F: scripts/clang-tools/ K: \b(?i:clang|llvm)\b CLEANCACHE API -- cgit v1.2.3