Re: [GIT PULL] gcc-plugins updates for v4.13-rc1

From: Andrey Ryabinin
Date: Wed Jul 05 2017 - 18:41:58 EST

2017-07-06 0:56 GMT+03:00 Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>:
> On Wed, Jul 5, 2017 at 2:48 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>> This particular example should be handled by
>> scripts/gcc-plugins/structleak_plugin.c, right?
> .. probably. But we have a ton of other uses that just pass in
> "result" pointers (not structs), which admittedly don't have the
> padding issue, but do have the exact same issue otherwise.
> We have those random "initialize to zero by hand", and I wouldn't
> actually worry about most of the common cases. KASAN will find them
> anyway.

KASAN doesn't find "use-of-unitialized memory" bugs. It can find only
and out-of-bounds accesses.

MemorySanitizer (aka KMSAN) is supposed to detect uses of unitialized memory.
It's still in WIP stage, but have some trophies already (just grep for
KMSAN in git log)

> It tends to be the random odd ioctl-like things that nobody finds
> because it's only uninitialized for some silly error case that never
> triggers (or some unusual driver that needs to be loaded).
> Linus