"With a lot of help from Ingo Molnar and Pekka Enberg over the last couple of weeks, we've been able to produce a new version of kmemcheck!" announced Vegard Nossum, adding, "the current version of the patch boots on real hardware, but we've seen freezes on some machines, so it's not perfect yet. (In other words, this patch is HIGHLY experimental, and run at your own risk, etc.)". He also offered a high level summary of the patch:
"kmemcheck is a patch to the linux kernel that detects use of uninitialized memory. It does this by trapping every read and write to memory that was allocated dynamically (e.g. using kmalloc()). If a memory address is read that has not previously been written to, a message is printed to the kernel log."
Ingo Molnar credited the new patch with already finding 4 kernel bugs, and offered some more insights into how the patch works, and why it's useful, "it should also be made clear that not only does kmemcheck consume half of the RAM to do byte granular tracking of the other half of RAM, it's also slow, very slow, because almost every kernel-space instruction will generate a pagefault and then it will be single-stepped and it takes a debug fault as well. That's of course totally crazy, but that's also OK and it's what makes the feature so interesting and powerful."