Messages in this thread | | | Date | Tue, 18 Nov 2014 22:15:31 +0100 | From | Andi Kleen <> | Subject | Re: [PATCH v6 00/11] Kernel address sanitizer - runtime memory debugger. |
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> It's a huge pile of tricky code we'll need to maintain. To justify its > inclusion I think we need to be confident that kasan will find a > significant number of significant bugs that > kmemcheck/debug_pagealloc/slub_debug failed to detect.
I would put it differently. kmemcheck is effectively too slow to run regularly. kasan is much faster and covers most of kmemcheck.
So I would rather see it as a more practical replacement to kmemcheck, not an addition.
> How do we get that confidence? I've seen a small number of > minorish-looking kasan-detected bug reports go past, maybe six or so. > That's in a 20-year-old code base, so one new minor bug discovered per > three years? Not worth it! > > Presumably more bugs will be exposed as more people use kasan on > different kernel configs, but will their number and seriousness justify > the maintenance effort?
I would expect so. It's also about saving developer time.
IMHO getting better tools like this is the only way to keep up with growing complexity.
> If kasan will permit us to remove kmemcheck/debug_pagealloc/slub_debug > then that tips the balance a little. What's the feasibility of that?
Maybe removing kmemcheck. slub_debug/debug_pagealloc are simple, and are in different niches (lower overhead debugging)
-Andi
-- ak@linux.intel.com -- Speaking for myself only.
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