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Groups > linux.kernel > #1702552
| From | Nick Desaulniers <ndesaulniers@google.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 2/2] arm64: Define PAGE_OFFSET using GENMASK_ULL |
| Date | 2017-08-03 01:20 +0200 |
| Message-ID | <uab5M-8f2-9@gated-at.bofh.it> (permalink) |
| References | <uaaMq-7QI-5@gated-at.bofh.it> <uaaMq-7QI-17@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
don't forget to include linux/bitops.h now in memory.h
/usr/local/google/home/ndesaulniers/android/kernel-wahoo/private/msm-google/arch/arm64/kernel/head.S:47:8:
error:
function-like macro 'GENMASK_ULL' is not defined
#elif (PAGE_OFFSET & 0x1fffff) != 0
^
/usr/local/google/home/ndesaulniers/android/kernel-wahoo/private/msm-google/arch/arm64/include/asm/memory.h:52:22:
note:
expanded from macro 'PAGE_OFFSET'
#define PAGE_OFFSET GENMASK_ULL(BITS_PER_LONG_LONG - 1, VA_BITS - 1)
^
1 error generated.
On Wed, Aug 2, 2017 at 3:51 PM, Matthias Kaehlcke <mka@chromium.org> wrote:
> As is the definition causes an integer overflow, which is expected,
> however clang raises the following warning:
>
> arch/arm64/kernel/head.S:47:8: warning:
> integer overflow in preprocessor expression
> #elif (PAGE_OFFSET & 0x1fffff) != 0
> ^~~~~~~~~~~
> arch/arm64/include/asm/memory.h:52:46: note:
> expanded from macro 'PAGE_OFFSET'
> #define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1))
> ~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~
>
> Use GENMASK_ULL() instead of shifting explicitly, the macro takes care
> of avoiding the overflow.
>
> Reported-by: Nick Desaulniers <ndesaulniers@google.com>
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
> arch/arm64/include/asm/memory.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> index 32f82723338a..732d4eed8edd 100644
> --- a/arch/arm64/include/asm/memory.h
> +++ b/arch/arm64/include/asm/memory.h
> @@ -65,7 +65,7 @@
> */
> #define VA_BITS (CONFIG_ARM64_VA_BITS)
> #define VA_START (UL(0xffffffffffffffff) << VA_BITS)
> -#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1))
> +#define PAGE_OFFSET GENMASK_ULL(BITS_PER_LONG_LONG - 1, VA_BITS - 1)
> #define KIMAGE_VADDR (MODULES_END)
> #define MODULES_END (MODULES_VADDR + MODULES_VSIZE)
> #define MODULES_VADDR (VA_START + KASAN_SHADOW_SIZE)
> --
> 2.14.0.rc1.383.gd1ce394fe2-goog
>
--
Thanks,
~Nick Desaulniers
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[PATCH 1/2] bitops: Avoid integer overflow warning in GENMASK_ULL Matthias Kaehlcke <mka@chromium.org> - 2017-08-03 01:00 +0200
[PATCH 2/2] arm64: Define PAGE_OFFSET using GENMASK_ULL Matthias Kaehlcke <mka@chromium.org> - 2017-08-03 01:00 +0200
Re: [PATCH 2/2] arm64: Define PAGE_OFFSET using GENMASK_ULL Nick Desaulniers <ndesaulniers@google.com> - 2017-08-03 01:20 +0200
Re: [PATCH 2/2] arm64: Define PAGE_OFFSET using GENMASK_ULL Matthias Kaehlcke <mka@chromium.org> - 2017-08-03 01:50 +0200
Re: [PATCH 2/2] arm64: Define PAGE_OFFSET using GENMASK_ULL Nick Desaulniers <ndesaulniers@google.com> - 2017-08-03 01:20 +0200
Re: [PATCH 1/2] bitops: Avoid integer overflow warning in GENMASK_ULL Matthias Kaehlcke <mka@chromium.org> - 2017-08-03 19:10 +0200
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