Re: [PATCH v3 16/22] locking/atomics, kcsan: Add KCSAN instrumentation

[Peter Zijlstra]

On Wed, Feb 19, 2020 at 08:50:20AM -0800, Paul E. McKenney wrote:
> On Wed, Feb 19, 2020 at 05:03:18PM +0100, Peter Zijlstra wrote:
> > On Wed, Feb 19, 2020 at 10:46:26AM -0500, Steven Rostedt wrote:
> > > On Wed, 19 Feb 2020 15:47:40 +0100
> > > Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> > > 
> > > > From: Marco Elver <elver@xxxxxxxxxx>
> > > > 
> > > > This adds KCSAN instrumentation to atomic-instrumented.h.
> > > > 
> > > > Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
> > > > Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
> > > > [peterz: removed the actual kcsan hooks]
> > > > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> > > > Reviewed-by: Mark Rutland <mark.rutland@xxxxxxx>
> > > > ---
> > > >  include/asm-generic/atomic-instrumented.h |  390 +++++++++++++++---------------
> > > >  scripts/atomic/gen-atomic-instrumented.sh |   14 -
> > > >  2 files changed, 212 insertions(+), 192 deletions(-)
> > > > 
> > > 
> > > 
> > > Does this and the rest of the series depend on the previous patches in
> > > the series? Or can this be a series on to itself (patches 16-22)?
> > 
> > It can probably stand on its own, but it very much is related in so far
> > that it's fallout from staring at all this nonsense.
> > 
> > Without these the do_int3() can actually have accidental tracing before
> > reaching it's nmi_enter().
> 
> The original is already in -tip, so some merge magic will be required.

Yes, So I don't strictly need this one, but I do need the two next
patches adding __always_inline to everything. I figured it was easier to
also pick this one (and butcher it) than to rebase everything.

I didn't want to depend on the locking/kcsan tree, and if this goes in,
we do have to do something 'funny' there. Maybe rebase, maybe put in a
few kcsan stubs so the original patch at least compiles. We'll see :/