Re: [BUGFIX PATCH 1/5] selftests: proc: Make va_max 3GB on 32bit arch

From: Alexey Dobriyan
Date: Tue Oct 08 2019 - 13:59:23 EST


On Tue, Oct 08, 2019 at 12:10:26AM +0900, Masami Hiramatsu wrote:
> Currently proc-self-map-files-002.c sets va_max (max test address
> of user virtual address) to 4GB, but it is too big for 32bit
> arch and 1UL << 32 is overflow on 32bit long.
>
> Make va_max 3GB on 32bit arch like i386 and arm.

IIRC i386 had 1G/3G split, so 3GB would be too much still.

> --- a/tools/testing/selftests/proc/proc-self-map-files-002.c
> +++ b/tools/testing/selftests/proc/proc-self-map-files-002.c

> +#if __BITS_PER_LONG == 32
> +# define VA_MAX (3UL << 30)
> +#elif __BITS_PER_LONG == 64
> +# define VA_MAX (1UL << 32)
> +#else
> +# define VA_MAX 0
> +#endif
> +
> int main(void)
> {
> const int PAGE_SIZE = sysconf(_SC_PAGESIZE);
> - const unsigned long va_max = 1UL << 32;
> + const unsigned long va_max = VA_MAX;

This limit doesn't need to be precise, 1GB is "big enough".