On Mon, Aug 19, 2013 at 02:16:36PM -0700, Linus Torvalds wrote: > On Mon, Aug 19, 2013 at 1:29 PM, Christoph Lameter <c...@gentwo.org> wrote: > > On Mon, 19 Aug 2013, Simon Kirby wrote: > > > >> [... ] The > >> alloc/free traces are always the same -- always alloc_pipe_info and > >> free_pipe_info. This is seen on 3.10 and (now) 3.11-rc4: > >> > >> Object ffff880090f19e78: 6b 6b 6b 6b 6c 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b > >> kkkklkkkkkkkkkkk > > > > This looks like an increment after free in the second 32 bit value of the > > structure. First 32 bit value's poison is unchanged. > > Ugh. If that is "struct pipe_inode_info" and I read it right, that's > the "wait_lock" spinlock that is part of the mutex. > > Doing a "spin_lock()" could indeed cause an increment operation. But > it still sounds like a very odd case. And even for some wild pointer > I'd then expect the spin_unlock to also happen, and to then increment > the next byte (or word) too. More importantly, for a mutex, I'd expect > the *other* fields to be corrupted too (the "waiter" field etc). That > is, unless we're still spinning waiting for the mutex, but with that > value we shouldn't, as far as I can see.
Point... I would probably start with CONFIG_DEBUG_MUTEXES and see if it screams about mutex magic, etc. having been buggered. FWIW, pipe is neither a FIFO nor an internal per-task one - it's a usual pipe(2) one, which should've excluded most of the weird codepaths... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
