On Fri, Sep 20, 2019 at 04:18:57PM +0200, Marco Elver wrote: > Hi all, > > We would like to share a new data-race detector for the Linux kernel: > Kernel Concurrency Sanitizer (KCSAN) -- > https://github.com/google/ktsan/wiki/KCSAN (Details: > https://github.com/google/ktsan/blob/kcsan/Documentation/dev-tools/kcsan.rst) > > To those of you who we mentioned at LPC that we're working on a > watchpoint-based KTSAN inspired by DataCollider [1], this is it (we > renamed it to KCSAN to avoid confusion with KTSAN). > [1] http://usenix.org/legacy/events/osdi10/tech/full_papers/Erickson.pdf > > In the coming weeks we're planning to: > * Set up a syzkaller instance. > * Share the dashboard so that you can see the races that are found. > * Attempt to send fixes for some races upstream (if you find that the > kcsan-with-fixes branch contains an important fix, please feel free to > point it out and we'll prioritize that). > > There are a few open questions: > * The big one: most of the reported races are due to unmarked > accesses; prioritization or pruning of races to focus initial efforts > to fix races might be required. Comments on how best to proceed are > welcome. We're aware that these are issues that have recently received > attention in the context of the LKMM > (https://lwn.net/Articles/793253/). > * How/when to upstream KCSAN?
Looks exciting. I think based on our discussion at LPC, you mentioned one way of pruning is if the compiler generated different code with _ONCE annotations than what would have otherwise been generated. Is that still on the table, for the purposing of pruning the reports? Also appreciate a CC on future patches as well. thanks, - Joel > > Feel free to test and send feedback. > > Thanks, > -- Marco
