https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61538
--- Comment #15 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Joshua Kinard from comment #14) > (In reply to Andrew Pinski from comment #13) > > What is the kernel version? There has been some recent (this year) fixes > > inside the kernel for futex. > > > > Though I admit I have seen this just recently when debugging a program where > > I did next over a pthread_mutex_unlock call. > > Was under 3.14.x. I already tried going back to 3.14.0, due to the recent > futex security flaws covered in CVE-2014-3153. Now on 3.15.5 on the Octane, > and my test binaries still hang, so I've pretty much ruled out it being the > kernel. > > I've been doing a git bisect of gcc the last few days, and I've pinned the > problem commit down to somewhere between Jun 12 2012 and June 26 2012. > anything prior to the 26th works so far, anything after doesn't. My current > bisect build is going to test June 19 2012 next. Averages about ~7.5hrs for > gcc and 3.5hrs for glibc to build, so I can cram in roughly, 2 tests a day. I would try the daily date update right before 30c3c4427521f96fb58b6e1debb86da4f113f06f commit and then bispect from there because there are a few changes between the daily date update which could have caused this issue. > > So far, I am leaning towards commit 30c3c4427521f96fb58b6e1debb86da4f113f06f > as the culprit. That was added on June 20th, and I *think* the refactoring > of the case statement is wrong for MIPS. The logic just doesn't seem to > work out to be the same as the old code it replaced, and maybe this only is > a problem on the R10000 processors. I am also running into a similar issue (though not exactly the same) with a based GCC 4.7 toolchain with this change in too on Octeon. I am still trying to debug it and reproduce it.
