On 09/18/2014 01:57 PM, Jakub Jelinek wrote:
> On Thu, Sep 18, 2014 at 01:46:21PM +0400, Yury Gribov wrote:
>> Kernel Asan patches are currently being discussed in LKML. One of
the points>> raised during review was that KAsan requires GCC 5.0 which
is presumably
>> unstable (e.g. compilation of kernel modules has been broken for two
months
>> due to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61848).
>>
>> Would it make sense to backport Kasan-related patches to 4.9 branch
to make
>> this feature more accessible to kernel developers? Quick analysis showed
>> that at the very least this would require
>> ...
>> Is it ok to backport these to 4.9? Note that I would discard patches for
>> other sanitizers (UBsan, Tsan).
>
> I'd say so, if it doesn't need any library changes
> (especially not any ABI
> visible ones, guess bugfixes could be acceptable).
Finally got time to look into this. I've successfully backported 22
patches to 4.9:
* bugfixes (12 patches)
* install Asan headers (1 patch)
* libsanitizer merge (1 patch) - this is questionable, see below for
discussion
* BUILT_IN_ASAN_REPORT_{LOAD,STORE}_N (2 patches)
* instrumentation with calls (1 patch)
* optimize strlen instrumentation (1 patch)
* move inlining to sanopt pass (2 patches)
* Kasan (2 patches)
One problem is that for BUILT_IN_ASAN_REPORT_{LOAD,STORE}_N patch I need
libsanitizer APIs (__asan_loadN, __asan_storeN) which were introduced in
a giant libsanitizer merge in 5.0. In current patchset I backport the
whole merge patch (and a bunch of cherry-picks which followed it) but it
changes libsanitizer ABI (new version of __asan_init_vXXX, etc.) which
is probably undesirable. Another option would be to backport just the
necessary minimum (__asan_loadN, __asan_storeN). How should I proceed?
Another question: Should I update patch CL dates for backported patches?
If not - should I insert them to CLs in chronological order or just
stack on top of previous contents?
-Y
