From: Michael Ellerman <mpe@ellerman.id.au>
To: Rui Teng <rui.teng@linux.vnet.ibm.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
Boqun Feng <boqun.feng@gmail.com>,
jia he <hejianet@linux.vnet.ibm.com>,
Rui Teng <rui.teng@linux.vnet.ibm.com>
Subject: Re: [PATCH] powerpc/mm: fix a hardcode on memory boundary checking
Date: Tue, 31 Jan 2017 20:11:41 +1100 [thread overview]
Message-ID: <877f5bvbjm.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20170112090906.17864-1-rui.teng@linux.vnet.ibm.com>
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
next prev parent reply other threads:[~2017-01-31 9:12 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-12 9:09 [PATCH] powerpc/mm: fix a hardcode on memory boundary checking Rui Teng
2017-01-31 9:11 ` Michael Ellerman [this message]
2017-02-06 2:50 ` Rui Teng
2017-07-05 4:45 ` Anshuman Khandual
2017-08-07 10:41 ` Michael Ellerman
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