Re: [PATCH] arm: Prevent memory aliasing on non-LPAE kernels

Arnd Bergmann
2013-05-30T22:24:50Z

On Thursday 30 May 2013 14:45:20 Stepan Moskovchenko wrote:
>
> void __init early_init_dt_add_memory_arch(u64 base, u64 size)
> {
> +#ifndef CONFIG_ARM_LPAE
> + if (base > ((phys_addr_t)~0)) {
> + pr_crit("Ignoring memory at 0x%08llx due to lack of LPAE support\n",
> + base);
> + return;
> + }
> +
> + if (size > ((phys_addr_t)~0))
> + size = ((phys_addr_t)~0);
> +
> + /* arm_add_memory() already checks for the case of base + size > 4GB */
> +#endif
> arm_add_memory(base, size);
> }

This looks wrong for the case where 'base' is between >0 and 4GB and 'size'
makes it spill over the 4GB boundary. You need to set
'size = (phys_addr_t)~0 - base' then.

Arnd