On Fri, Oct 2, 2026 at 6:52 AM Ard Biesheuvel <[email protected]> wrote: > On Fri, 2 Oct 2026, at 14:44, Bill Wendling wrote: > > On Fri, Oct 2, 2026 at 12:38 AM Ard Biesheuvel <[email protected]> wrote: > >> On Thu, 1 Oct 2026, at 23:24, Linus Walleij wrote: > >> > On Thu, Oct 1, 2026 at 10:05 PM Bill Wendling <[email protected]> wrote: > >> >> On Thu, Oct 1, 2026 at 12:56 PM Linus Walleij <[email protected]> wrote: > >> >> > On Mon, Sep 28, 2026 at 9:22 AM Bill Wendling <[email protected]> > >> >> > wrote: > >> >> > > On Sun, Sep 27, 2026 at 11:38 PM Bill Wendling <[email protected]> > >> >> > > wrote: > >> >> > > > > >> >> > > > The 'data' pointer field in 'struct acpi_gpio_mapping' is > >> >> > > > associated > >> >> > > > with the 'size' field, which represents the number of elements of > >> >> > > > type 'struct acpi_gpio_params' allocated for 'data'. > >> >> > > > > >> >> > > > To improve bounds checking via CONFIG_UBSAN_BOUNDS and > >> >> > > > CONFIG_FORTIFY_SOURCE, annotate 'data' with the __counted_by_ptr > >> >> > > > attribute. > >> >> > > > > >> >> > > > Analysis of allocation, assignment, and access points shows that > >> >> > > > the > >> >> > > > pointer is never accessed before the count is set, which > >> >> > > > guarantees that > >> >> > > > this annotation is safe and will not cause runtime panics or > >> >> > > > false-positive bounds checks. > >> >> > > > > >> >> > > > Cc: [email protected] > >> >> > > > Assisted-by: LLM > >> >> > > > Signed-off-by: Bill Wendling <[email protected]> > >> >> > > > --- > >> >> > > > include/linux/gpio/consumer.h | 2 +- > >> >> > > > 1 file changed, 1 insertion(+), 1 deletion(-) > >> >> > > > > >> >> > > > diff --git a/include/linux/gpio/consumer.h > >> >> > > > b/include/linux/gpio/consumer.h > >> >> > > > index fceeefd5f893..2b80cf7aa7e7 100644 > >> >> > > > --- a/include/linux/gpio/consumer.h > >> >> > > > +++ b/include/linux/gpio/consumer.h > >> >> > > > @@ -667,7 +667,7 @@ struct acpi_gpio_params { > >> >> > > > > >> >> > > > struct acpi_gpio_mapping { > >> >> > > > const char *name; > >> >> > > > - const struct acpi_gpio_params *data; > >> >> > > > + const struct acpi_gpio_params *data > >> >> > > > __counted_by_ptr(size); > >> >> > > > unsigned int size; > >> >> > > > > >> >> > > > /* Ignore IoRestriction field */ > >> >> > > > >> >> > > There's a problem with 'drivers/firmware/efi/libstub/Makefile'. > >> >> > > Clang > >> >> > > needs a compiler flag to support the "__counted_by_ptr" attribute > >> >> > > referencing a field *after* the pointer, like in this patch. > >> >> > > However, > >> >> > > the Makefile blasts the flag away for x86 platforms. Below is a hack > >> >> > > that copies the part of the top-level Makefile that adds the flag. I > >> >> > > don't think that's a good solution. The comment in the driver's > >> >> > > Makefile says that the stub code executes before the kernel does, > >> >> > > which I assume is why a lot of the flags are blown away... In any > >> >> > > event, I'm not sure how best to address this. > >> >> > > >> >> > But is this a problem with the current patch? > >> >> > > >> >> > Does libefistub use <linux/gpio/consumer.h> in any way, shape > >> >> > or form? > >> >> > > >> >> It's being #included transitively: > >> >> > >> >> In file included from drivers/firmware/efi/libstub/efi-stub-helper.c:12: > >> >> In file included from ./include/linux/efi.h:20: > >> >> In file included from ./include/linux/rtc.h:18: > >> >> In file included from ./include/linux/nvmem-provider.h:16: > >> >> ./include/linux/gpio/consumer.h:670:55: error: use of undeclared > >> >> identifier 'size'; did you > >> >> mean 'ksize'? > >> >> 670 | const struct acpi_gpio_params *data > >> >> __counted_by_ptr(size); > >> >> | > >> >> ^~~~ > >> >> | > >> >> ksize > >> >> ././include/linux/compiler_types.h:392:64: note: expanded from macro > >> >> '__counted_by_ptr' > >> >> 392 | #define __counted_by_ptr(member) > >> >> __attribute__((__counted_by__(member))) > >> >> | > >> >> ^~~~~~ > >> >> ./include/linux/slab.h:602:8: note: 'ksize' declared here > >> >> 602 | size_t ksize(const void *objp); > >> >> | ^ > >> > > >> > Hm I see. > >> > > >> > Certainly Jeremy or Ard will have an idea about how to solve this, > >> > so paging them in. > >> > > >> > >> libstub code never executes in the context of the kernel, but only in > >> the context of the boot firmware. Generally, we disable instrumentation > >> there that has a significant runtime component, basically because we > >> cannot crash or panic the kernel before we have even booted it. > >> > >> Can we just #define __counted_by_ptr(...) to nothing when building > >> from that Makefile? > >> > > Doing it in the Makefile is tricky, because of how the "c_flags" > > variable is defined and used. I couldn't find a good way to do it. > > Instead, I inserted "#undef __counted_by{_ptr}" at the top of the > > affected files. It's gross. If there's a way I'm missing, please let > > me know. > > > > Does that even build?
It did for me... Let me look into Sashiko's comments. -bw
