lkml.org 
[lkml]   [2014]   [Nov]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v6 00/11] Kernel address sanitizer - runtime memory debugger.
    > 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.


    \
     
     \ /
      Last update: 2014-11-18 22:41    [W:4.031 / U:0.068 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site