Re: [PATCH v2] srcu: avoid escaped section names

From: Paul E. McKenney
Date: Fri Oct 02 2020 - 16:51:34 EST


On Wed, Sep 30, 2020 at 01:55:48PM -0700, Nick Desaulniers wrote:
> On Wed, Sep 30, 2020 at 1:40 PM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote:
> >
> > On Tue, Sep 29, 2020 at 12:25:49PM -0700, Nick Desaulniers wrote:
> > > The stringification operator, `#`, in the preprocessor escapes strings.
> > > For example, `# "foo"` becomes `"\"foo\""`. GCC and Clang differ in how
> > > they treat section names that contain \".
> > >
> > > The portable solution is to not use a string literal with the
> > > preprocessor stringification operator.
> > >
> > > Link: https://bugs.llvm.org/show_bug.cgi?id=42950
> > > Fixes: commit fe15b50cdeee ("srcu: Allocate per-CPU data for DEFINE_SRCU() in modules")
> > > Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> >
> > I am guessing that this needs to go up with other patches. If so:
> >
> > Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
> >
> > If not, let me know and I will queue it.
>
> I could have bundled them up as a series. I think you can pick it up,
> and I'll owe you a beer?

It is queued, thank you!

When does it need to hit mainline? (Your default is the v5.11 merge
window, that is, the one following the upcoming merge window.)


Thanx, Paul

> > > ---
> > > Changes V1->V2:
> > > * drop unrelated Kconfig changes accidentally committed in v1.
> > >
> > > include/linux/srcutree.h | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h
> > > index 9cfcc8a756ae..9de652f4e1bd 100644
> > > --- a/include/linux/srcutree.h
> > > +++ b/include/linux/srcutree.h
> > > @@ -124,7 +124,7 @@ struct srcu_struct {
> > > # define __DEFINE_SRCU(name, is_static) \
> > > is_static struct srcu_struct name; \
> > > struct srcu_struct * const __srcu_struct_##name \
> > > - __section("___srcu_struct_ptrs") = &name
> > > + __section(___srcu_struct_ptrs) = &name
> > > #else
> > > # define __DEFINE_SRCU(name, is_static) \
> > > static DEFINE_PER_CPU(struct srcu_data, name##_srcu_data); \
> > > --
> > > 2.28.0.709.gb0816b6eb0-goog
> > >
>
>
>
> --
> Thanks,
> ~Nick Desaulniers