[GIT pull V2] locking: Atomics and KCSAN

[Thomas Gleixner]

Linus,

the following two pull requests contain the distangled and rebased
variants of the intial locking/kcsan pull request:

  https://lore.kernel.org/159110310259.14558.3096683243532489290.tglx@xxxxxxxxxxxxxxxxxxxxxxx

Part 1 is the rebased version of Peter Zijlstra's effort to fully isolate
the INT3 text poke handling code. This has been rebased on

  b29482fde649 ("Merge branch 'work.epoll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs")

which contains the now isolated read/write_once() rework from Will Deacon.

Part 2 is the rebased version of Marco Elver's work on KCSAN which now
depends on Part 1. The rebase has preserved most of the history except for
the parts which have been squashed into the rebase merge commit.

The rebase results have been sanity checked by Marco, Will and Peter and
the interdiffs (to the extent of being possible) have not shown any
hickups. Marco's testing did not reveal any regressions.

I'm well aware that this distangling and rebasing should have happened
earlier in the development cycle, but in hindsight we're always smarter.

Thanks for your understanding and the exceptional allowance of rebasing
that late.

Thanks,

	Thomas