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

From: Paul E. McKenney
Date: Wed Feb 19 2020 - 12:36:23 EST


On Wed, Feb 19, 2020 at 05:54:55PM +0100, Peter Zijlstra wrote:
> 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 :/

Fair enough!

Thanx, Paul