[[!meta copyright="Copyright © 2010, 2011, 2012, 2013 Free Software Foundation, Inc."]] [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable id="license" text="Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled [[GNU Free Documentation License|/fdl]]."]]"""]] In the topic of *code analysis* or *program analysis* ([[!wikipedia Program_analysis_(computer_science) desc="Wikipedia article"]]), there is static code analysis ([[!wikipedia Static_code_analysis desc="Wikipedia article"]]) and dynamic program analysis ([[!wikipedia Dynamic_program_analysis desc="Wikipedia article"]]). This topic overlaps with [[performance analysis|performance]], [[formal_verification]], as well as general [[debugging]]. [[!toc]] # Bounty There is a [[!FF_project 276]][[!tag bounty]] on some of these tasks. # Static * [[GCC]]'s warnings. Yes, really. * GCC plugins can be used for additional semantic analysis. For example, , and search for *kernel context* in the comments. * Have GCC make use of [[RPC]]/[[microkernel/mach/MIG]] *in*/*out* specifiers, and have it emit useful warnings in case these are pointing to uninitialized data (for *in* only). * [[!wikipedia List_of_tools_for_static_code_analysis]] * [Engineering zero-defect software](http://esr.ibiblio.org/?p=4340), Eric S. Raymond, 2012-05-13 * [Static Source Code Analysis Tools for C](http://spinroot.com/static/) * [Cppcheck](http://sourceforge.net/apps/mediawiki/cppcheck/) For example, [Debian's hurd_20110319-2 package](http://qa.debian.org/daca/cppcheck/sid/hurd_20110319-2.html) (Samuel Thibault, 2011-08-05: *I had a look at those, some are spurious; the realloc issues are for real*). * Coccinelle * * Has already been used for finding and fixing [[!message-id desc="double mutex unlocking issues" "1355701890-29227-1-git-send-email-tipecaml@gmail.com"]]. * [clang](http://www.google.com/search?q=clang+analysis) * [Linux' sparse](https://sparse.wiki.kernel.org/) * * * [Smatch](http://smatch.sourceforge.net/) * [Parfait](http://labs.oracle.com/projects/parfait/) * * [Saturn](http://saturn.stanford.edu/) * [Flawfinder](http://www.dwheeler.com/flawfinder/) * [sixgill](http://sixgill.org/) * [s-spider](http://code.google.com/p/s-spider/) * [CIL (C Intermediate Language)](http://kerneis.github.com/cil/) * [Frama-C](http://frama-c.com/) * [Coverity](http://www.coverity.com/) (nonfree?) * [Splint](http://www.splint.org/) * IRC, freenode, #hurd, 2011-12-04 has anyone used splint on hurd? this is tool for statically checking C programs seems I made it work ## Hurd-specific Applications * [[Port Sequence Numbers|microkernel/mach/ipc/sequence_numbering]]. If these are used, care must be taken to update them reliably, [[!message-id "1123688017.3905.22.camel@buko.sinrega.org"]]. This could be checked by a static analysis tool. * [[glibc]]'s [[glibc/critical_section]]s. # Dynamic * [[community/gsoc/project_ideas/Valgrind]] * glibc's `libmcheck` * Used by GDB, for example. * Is not thread-safe, [[!sourceware_PR 6547]], [[!sourceware_PR 9939]], [[!sourceware_PR 12751]], [[!stackoverflow_question 314931]]. * * * * * `MALLOC_CHECK_`/`MALLOC_PERTURB_` * IRC, freenode, #glibc, 2011-09-28 two things you can do -- there is an environment variable (DEBUG_MALLOC_ iirc?) that can be set to 2 to make ptmalloc (glibc's allocator) more forceful and verbose wrt error checking another is to grab a copy of Tor's source tree and copy out OpenBSD's allocator (its a clearly-identifyable file in the tree); LD_PRELOAD it or link it into your app, it is even more aggressive about detecting memory misuse. third, Red hat has a gdb python plugin that can instrument glibc's heap structure. its kinda handy, might help? MALLOC_CHECK_ was the envvar you want, sorry. * [`MALLOC_PERTURB_`](http://udrepper.livejournal.com/11429.html) * * In context of [[!message-id "1341350006-2499-1-git-send-email-rbraun@sceen.net"]]/the `alloca` issue mentioned in [[gnumach_page_cache_policy]]: IRC, freenode, #hurd, 2012-07-08: braunr: there's actually already an ifdef REDZONE in libthreads It's `RED_ZONE`. except it seems clumsy :) ah, no, the libthreads code properly sets the guard, just for grow-up stacks * GCC, LLVM/clang: [[Address Sanitizer (asan), Memory Sanitizer (msan), Thread Sanitizer (tasn), Undefined Behavor Sanitizer (ubsan), ...|_san]] * [GCC plugins](http://gcc.gnu.org/wiki/plugins) * [CTraps](https://github.com/blucia0a/CTraps-gcc) > CTraps is a gcc plugin and runtime library that inserts calls to runtime > library functions just before shared memory accesses in parallel/concurrent > code. > > The purpose of this plugin is to expose information about when and how threads > communicate with one another to programmers for the purpose of debugging and > performance tuning. The overhead of the instrumentation and runtime code is > very low -- often low enough for always-on use in production code. In a series > of initial experiments the overhead was 0-10% in many important cases. * Input fuzzing Not a new topic; has been used (and papers published?) for early [[UNIX]] tools. What about some [[RPC]] fuzzing? * * * [Jones: system call abuse](http://lwn.net/Articles/414273/), Dave Jones, 2010. * [Trinity: A Linux kernel fuzz tester (and then some)](http://www.socallinuxexpo.org/scale11x/presentations/trinity-linux-kernel-fuzz-tester-and-then-some), Dave Jones, The Eleventh Annual Southern California Linux Expo, 2013.