[PATCH 1/2] arm64: mm: dump: fix shift warning

Steve Capper steve.capper at linaro.org
Fri Dec 5 05:39:56 PST 2014

On 5 December 2014 at 12:34, Mark Rutland <mark.rutland at arm.com> wrote:
> When building with 48-bit VAs, it's possible to get the following
> warning when building the arm64 page table dumping code:
> arch/arm64/mm/dump.c: In function ‘walk_pgd’:
> arch/arm64/mm/dump.c:266:2: warning: right shift count >= width of type
>   pgd_t *pgd = pgd_offset(mm, 0);
>   ^
> As pgd_offset is a macro and the second argument is not cast to any
> particular type, the zero will be given integer type by the compiler.
> As pgd_offset passes the pargument to pgd_index, we then try to shift
> the 32-bit integer by at least 39 bits (for 4k pages).
> Elsewhere the pgd_offset is passed a second argument of unsigned long
> type, so let's do the same here by passing '0UL' rather than '0'.

Hi Mark,
Thanks, I must not have spotted that warning earlier.

Acked-by: Steve Capper <steve.capper at linaro.org>

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