From: Mike Kravetz <mike.kravetz@oracle.com>
To: Michal Hocko <mhocko@suse.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Baolin Wang <baolin.wang@linux.alibaba.com>,
Zhenguo Yao <yaozhenguo1@gmail.com>,
Liu Yuntao <liuyuntao10@huawei.com>,
Dan Carpenter <dan.carpenter@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v2] hugetlb: clean up potential spectre issue warnings
Date: Mon, 21 Feb 2022 12:24:25 -0800 [thread overview]
Message-ID: <26565cd7-01b0-197c-6ce9-af92f5bc8563@oracle.com> (raw)
In-Reply-To: <YhNQf3LUZzNRD7u0@dhcp22.suse.cz>
On 2/21/22 00:42, Michal Hocko wrote:
> On Fri 18-02-22 13:29:46, Mike Kravetz wrote:
> [...]
>> @@ -4161,7 +4162,7 @@ static int __init hugepages_setup(char *s)
>> }
>> if (tmp >= nr_online_nodes)
>> goto invalid;
>> - node = tmp;
>> + node = array_index_nospec(tmp, nr_online_nodes);
>> p += count + 1;
>> /* Parse hugepages */
>> if (sscanf(p, "%lu%n", &tmp, &count) != 1)
>> @@ -6889,9 +6890,9 @@ static int __init cmdline_parse_hugetlb_cma(char *p)
>> break;
>>
>> if (s[count] == ':') {
>> - nid = tmp;
>> - if (nid < 0 || nid >= MAX_NUMNODES)
>> + if (tmp >= MAX_NUMNODES)
>> break;
>> + nid = array_index_nospec(tmp, MAX_NUMNODES);
>>
>> s += count + 1;
>> tmp = memparse(s, &s);
>
> This is an early boot code, how is this supposed to be used as a side
> channel?
I do not have an evil hacker mind, but I can not think of a way this one time
use of a user specified index could be an issue. It does add noise to the
BUILD REGRESSION emails sent to Andrew.
--
Mike Kravetz
next prev parent reply other threads:[~2022-02-21 20:24 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-18 21:29 Mike Kravetz
2022-02-21 8:42 ` Michal Hocko
2022-02-21 20:24 ` Mike Kravetz [this message]
2022-02-22 7:47 ` Michal Hocko
2022-02-22 16:15 ` Schaufler, Casey
2022-02-22 16:36 ` Dan Carpenter
2022-02-23 8:35 ` Michal Hocko
2022-02-22 21:53 ` Mike Kravetz
2022-02-23 8:33 ` Michal Hocko
2022-02-23 18:36 ` Mike Kravetz
2022-02-24 9:31 ` Michal Hocko
2022-02-24 4:41 ` Andrew Morton
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