Re: [PATCH v2 7/8] locking/atomics, kcsan: Add KCSAN instrumentation

[Marco Elver]

On Tue, 22 Oct 2019 at 14:33, Mark Rutland <mark.rutland@xxxxxxx> wrote:
>
> On Thu, Oct 17, 2019 at 04:13:04PM +0200, Marco Elver wrote:
> > This adds KCSAN instrumentation to atomic-instrumented.h.
> >
> > Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
> > ---
> > v2:
> > * Use kcsan_check{,_atomic}_{read,write} instead of
> >   kcsan_check_{access,atomic}.
> > * Introduce __atomic_check_{read,write} [Suggested by Mark Rutland].
> > ---
> >  include/asm-generic/atomic-instrumented.h | 393 +++++++++++-----------
> >  scripts/atomic/gen-atomic-instrumented.sh |  17 +-
> >  2 files changed, 218 insertions(+), 192 deletions(-)
>
> The script changes and generated code look fine to me, so FWIW:
>
> Reviewed-by: Mark Rutland <mark.rutland@xxxxxxx>

Great, thank you Mark!

> Thanks,
> Mark.
>
> > diff --git a/scripts/atomic/gen-atomic-instrumented.sh b/scripts/atomic/gen-atomic-instrumented.sh
> > index e09812372b17..8b8b2a6f8d68 100755
> > --- a/scripts/atomic/gen-atomic-instrumented.sh
> > +++ b/scripts/atomic/gen-atomic-instrumented.sh
> > @@ -20,7 +20,7 @@ gen_param_check()
> >       # We don't write to constant parameters
> >       [ ${type#c} != ${type} ] && rw="read"
> >
> > -     printf "\tkasan_check_${rw}(${name}, sizeof(*${name}));\n"
> > +     printf "\t__atomic_check_${rw}(${name}, sizeof(*${name}));\n"
> >  }
> >
> >  #gen_param_check(arg...)
> > @@ -107,7 +107,7 @@ cat <<EOF
> >  #define ${xchg}(ptr, ...)                                            \\
> >  ({                                                                   \\
> >       typeof(ptr) __ai_ptr = (ptr);                                   \\
> > -     kasan_check_write(__ai_ptr, ${mult}sizeof(*__ai_ptr));          \\
> > +     __atomic_check_write(__ai_ptr, ${mult}sizeof(*__ai_ptr));               \\
> >       arch_${xchg}(__ai_ptr, __VA_ARGS__);                            \\
> >  })
> >  EOF
> > @@ -148,6 +148,19 @@ cat << EOF
> >
> >  #include <linux/build_bug.h>
> >  #include <linux/kasan-checks.h>
> > +#include <linux/kcsan-checks.h>
> > +
> > +static inline void __atomic_check_read(const volatile void *v, size_t size)
> > +{
> > +     kasan_check_read(v, size);
> > +     kcsan_check_atomic_read(v, size);
> > +}
> > +
> > +static inline void __atomic_check_write(const volatile void *v, size_t size)
> > +{
> > +     kasan_check_write(v, size);
> > +     kcsan_check_atomic_write(v, size);
> > +}
> >
> >  EOF
> >
> > --
> > 2.23.0.866.gb869b98d4c-goog
> >