Re: [PATCH] powerpc/mm: fix a hardcode on memory boundary checking

From	Michael Ellerman <mpe@ellerman.id.au>
Newsgroups	linux.kernel
Subject	Re: [PATCH] powerpc/mm: fix a hardcode on memory boundary checking
Date	2017-01-31 10:20 +0100
Message-ID	<t5CLw-7mj-15@gated-at.bofh.it> (permalink)
References	<sYJI5-2bd-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Rui Teng <rui.teng@linux.vnet.ibm.com> writes:

> The offset of hugepage block will not be 16G, if the expected
> page is more than one. Calculate the totol size instead of the
> hardcode value.

I assume you found this by code inspection and not by triggering an
actual bug?

cheers

> diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
> index 8033493..b829f8e 100644
> --- a/arch/powerpc/mm/hash_utils_64.c
> +++ b/arch/powerpc/mm/hash_utils_64.c
> @@ -506,7 +506,7 @@ static int __init htab_dt_scan_hugepage_blocks(unsigned long node,
>  	printk(KERN_INFO "Huge page(16GB) memory: "
>  			"addr = 0x%lX size = 0x%lX pages = %d\n",
>  			phys_addr, block_size, expected_pages);
> -	if (phys_addr + (16 * GB) <= memblock_end_of_DRAM()) {
> +	if (phys_addr + block_size * expected_pages <= memblock_end_of_DRAM()) {
>  		memblock_reserve(phys_addr, block_size * expected_pages);
>  		add_gpage(phys_addr, block_size, expected_pages);
>  	}
> -- 
> 2.9.0

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Re: [PATCH] powerpc/mm: fix a hardcode on memory boundary checking Michael Ellerman <mpe@ellerman.id.au> - 2017-01-31 10:20 +0100
  Re: [PATCH] powerpc/mm: fix a hardcode on memory boundary checking Rui Teng <rui.teng@linux.vnet.ibm.com> - 2017-02-06 04:00 +0100

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