On Mon, Sep 27, 2021 at 2:13 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote: > > From: Arnd Bergmann <arnd@xxxxxxxx> > > There are some very old macros for doing an open-coded offsetof() and > cast between pointer and integer in ACPI headers. clang-14 now complains > about these: > > drivers/acpi/acpica/tbfadt.c:86:3: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction] > ACPI_FADT_OFFSET(pm_timer_block), > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > include/acpi/actbl.h:376:47: note: expanded from macro 'ACPI_FADT_OFFSET' > #define ACPI_FADT_OFFSET(f) (u16) ACPI_OFFSET (struct acpi_table_fadt, f) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > include/acpi/actypes.h:511:41: note: expanded from macro 'ACPI_OFFSET' > #define ACPI_OFFSET(d, f) ACPI_PTR_DIFF (&(((d *) 0)->f), (void *) 0) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > include/acpi/actypes.h:505:79: note: expanded from macro 'ACPI_PTR_DIFF' > #define ACPI_PTR_DIFF(a, b) ((acpi_size) (ACPI_CAST_PTR (u8, (a)) - ACPI_CAST_PTR (u8, (b)))) > ^ ~~~~~~~~~~~~~~~~~~~~~~~ > Convert them to the modern equivalents. > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > include/acpi/actypes.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h > index 92c71dfce0d5..285bc7b73de3 100644 > --- a/include/acpi/actypes.h > +++ b/include/acpi/actypes.h > @@ -507,8 +507,8 @@ typedef u64 acpi_integer; > /* Pointer/Integer type conversions */ > > #define ACPI_TO_POINTER(i) ACPI_CAST_PTR (void, (acpi_size) (i)) > -#define ACPI_TO_INTEGER(p) ACPI_PTR_DIFF (p, (void *) 0) > -#define ACPI_OFFSET(d, f) ACPI_PTR_DIFF (&(((d *) 0)->f), (void *) 0) > +#define ACPI_TO_INTEGER(p) ((uintptr_t)(p)) > +#define ACPI_OFFSET(d, f) offsetof(d, f) > #define ACPI_PHYSADDR_TO_PTR(i) ACPI_TO_POINTER(i) > #define ACPI_PTR_TO_PHYSADDR(i) ACPI_TO_INTEGER(i) > > -- Queued up as 5.16 material, converted into an upstream ACPICA pull request and submitted, thanks!
