Andrey Ryabinin [off-list ref] writes:

2015-08-26 11:26 GMT+03:00 Aneesh Kumar K.V [off-list ref]:

quoted

We we end up calling kasan_report in real mode, our shadow mapping
for even spinlock variable will show poisoned.

Generally I agree with this patch. We should disable reports when we
print report as early
as possible to prevent recursion in case of bug in spinlock or printk etc.

But I don't understand what is the problem that you observing.
How we ended up with shadow poisoned for a valid spinlock struct?
And since  shadow poisoned for some valid memory we should get
enormous amount of false positive reports.

I still haven't fully isolated all the .c files which should not be
kasan instrumented. That means in case of ppc64 i ended up calling
kasan _load/_store in real mode. That will result in failure w.r.t
to the above spin_lock code.

-aneesh