On 02/10/2016 06:33 PM, Alfredo Alvarez Fernandez wrote: > This patch series prevents possible collisions in the chain_key > hashing macro iterate_chain_key(key1, key2) that can lead to lockdep > not detecting very simple deadlocks such as AA or ABBA. > > The problem only affects the first allocated lock classes. That could > explain why it was not seen while running lockdep's test suite, since > by the time the test suite runs there are already registered lock > classes and the indexes allocated for the lock classes under test are > high enough to avoid collisions. > > The patch series also extends the tools/liblockdep test suite with > tests covering the offending cases. > > I came across the problem while testing a simple AA deadlock scenario > in userspace using a pthread_mutex and tools/liblockdep. In that > context it is fairly easy to have a clean and deterministic initial > state where the problem can be reproduced. > > The proposed solution was tested with the newly introduced tests and > also with lockdep's test suite: > [ 0.000000] Good, all 253 testcases passed! |
Thanks Alfredo, I'll grab the first two. Peter/Ingo, will you take the lockdep one or do you want it to go through my tree? Thanks, Sasha
