From: zhong jiang <zhongjiang@huawei.com>
To: "Michal Suchánek" <msuchanek@suse.de>
Cc: <paulus@samba.org>, <benh@kernel.crashing.org>,
<mpe@ellerman.id.au>, <linuxppc-dev@lists.ozlabs.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] powerpc: Move a dereference below a NULL test
Date: Wed, 26 Sep 2018 22:42:23 +0800 [thread overview]
Message-ID: <5BAB9ACF.6040102@huawei.com> (raw)
In-Reply-To: <20180926162232.250c0090@naga>
On 2018/9/26 22:22, Michal Suchánek wrote:
> On Wed, 26 Sep 2018 19:46:08 +0800
> zhong jiang <zhongjiang@huawei.com> wrote:
>
>> It is safe to move dereference below a NULL test.
>>
>> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
>> ---
>> arch/powerpc/kernel/cacheinfo.c | 5 ++---
>> 1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/cacheinfo.c
>> b/arch/powerpc/kernel/cacheinfo.c index a8f20e5..7f19714 100644
>> --- a/arch/powerpc/kernel/cacheinfo.c
>> +++ b/arch/powerpc/kernel/cacheinfo.c
>> @@ -401,14 +401,13 @@ static struct cache
>> *cache_lookup_or_instantiate(struct device_node *node, struct cache
>> *cache;
>> cache = cache_lookup_by_node(node);
>> + if (!cache)
>> + cache = cache_do_one_devnode(node, level);
>>
>> WARN_ONCE(cache && cache->level != level,
> This has also null test so cache should be dereferenced only when
> non-null here.
:-[ , you're right. I forget WARN_ONCE. please ignore the patch.
Sincerely,
zhong jiang
> Thanks
>
> Michal
>
> .
>
prev parent reply other threads:[~2018-09-26 14:42 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-26 11:46 [PATCH] powerpc: Move a dereference below a NULL test zhong jiang
2018-09-26 13:58 ` Christophe LEROY
2018-09-26 14:06 ` zhong jiang
2018-09-26 14:22 ` Michal Suchánek
2018-09-26 14:42 ` zhong jiang [this message]
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