From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marco Elver Subject: Re: [PATCH v4 00/10] Add Kernel Concurrency Sanitizer (KCSAN) Date: Thu, 14 Nov 2019 22:33:03 +0100 Message-ID: <20191114213303.GA237245@google.com> References: <20191114180303.66955-1-elver@google.com> <20191114195046.GP2865@paulmck-ThinkPad-P72> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20191114195046.GP2865@paulmck-ThinkPad-P72> Sender: linux-kernel-owner@vger.kernel.org To: "Paul E. McKenney" Cc: akiyks@gmail.com, stern@rowland.harvard.edu, glider@google.com, parri.andrea@gmail.com, andreyknvl@google.com, luto@kernel.org, ard.biesheuvel@linaro.org, arnd@arndb.de, boqun.feng@gmail.com, bp@alien8.de, dja@axtens.net, dlustig@nvidia.com, dave.hansen@linux.intel.com, dhowells@redhat.com, dvyukov@google.com, hpa@zytor.com, mingo@redhat.com, j.alglave@ucl.ac.uk, joel@joelfernandes.org, corbet@lwn.net, jpoimboe@redhat.com, luc.maranget@inria.fr, mark.rutland@arm.com, npiggin@gmail.com, peterz@infradead.org, tglx@linutronix.de, will@kernel.org, edumazet@google.com, kasan-dev@googlegroups.com, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-efi@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org List-Id: linux-arch.vger.kernel.org On Thu, 14 Nov 2019, Paul E. McKenney wrote: > On Thu, Nov 14, 2019 at 07:02:53PM +0100, Marco Elver wrote: > > This is the patch-series for the Kernel Concurrency Sanitizer (KCSAN). > > KCSAN is a sampling watchpoint-based *data race detector*. More details > > are included in **Documentation/dev-tools/kcsan.rst**. This patch-series > > only enables KCSAN for x86, but we expect adding support for other > > architectures is relatively straightforward (we are aware of > > experimental ARM64 and POWER support). > > > > To gather early feedback, we announced KCSAN back in September, and have > > integrated the feedback where possible: > > http://lkml.kernel.org/r/CANpmjNPJ_bHjfLZCAPV23AXFfiPiyXXqqu72n6TgWzb2Gnu1eA@mail.gmail.com > > > > The current list of known upstream fixes for data races found by KCSAN > > can be found here: > > https://github.com/google/ktsan/wiki/KCSAN#upstream-fixes-of-data-races-found-by-kcsan > > > > We want to point out and acknowledge the work surrounding the LKMM, > > including several articles that motivate why data races are dangerous > > [1, 2], justifying a data race detector such as KCSAN. > > > > [1] https://lwn.net/Articles/793253/ > > [2] https://lwn.net/Articles/799218/ > > I queued this and ran a quick rcutorture on it, which completed > successfully with quite a few reports. Great. Many thanks for queuing this in -rcu. And regarding merge window you mentioned, we're fine with your assumption to targeting the next (v5.6) merge window. I've just had a look at linux-next to check what a future rebase requires: - There is a change in lib/Kconfig.debug and moving KCSAN to the "Generic Kernel Debugging Instruments" section seems appropriate. - bitops-instrumented.h was removed and split into 3 files, and needs re-inserting the instrumentation into the right places. Otherwise there are no issues. Let me know what you recommend. Thanks, -- Marco