From: Jason Yan <yanaijie@huawei.com>
To: Gao Xiang <hsiangkao@redhat.com>
Cc: <xiang@kernel.org>, <chao@kernel.org>,
<gregkh@linuxfoundation.org>, <linux-erofs@lists.ozlabs.org>,
<linux-kernel@vger.kernel.org>, Kees Cook <keescook@chromium.org>,
<kernel-hardening@lists.openwall.com>
Subject: Re: [PATCH] erofs: Eliminate usage of uninitialized_var() macro
Date: Mon, 15 Jun 2020 15:43:09 +0800 [thread overview]
Message-ID: <783fe4f9-fb1f-7f5e-c900-7e30d5c85222@huawei.com> (raw)
In-Reply-To: <20200615072521.GA25317@xiangao.remote.csb>
在 2020/6/15 15:25, Gao Xiang 写道:
> Hi Jason,
>
> On Mon, Jun 15, 2020 at 12:01:41PM +0800, Jason Yan wrote:
>> This is an effort to eliminate the uninitialized_var() macro[1].
>>
>> The use of this macro is the wrong solution because it forces off ANY
>> analysis by the compiler for a given variable. It even masks "unused
>> variable" warnings.
>>
>> Quoted from Linus[2]:
>>
>> "It's a horrible thing to use, in that it adds extra cruft to the
>> source code, and then shuts up a compiler warning (even the _reliable_
>> warnings from gcc)."
>>
>> The gcc option "-Wmaybe-uninitialized" has been disabled and this change
>> will not produce any warnnings even with "make W=1".
>>
>> [1] https://github.com/KSPP/linux/issues/81
>> [2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/
>>
>> Cc: Kees Cook <keescook@chromium.org>
>> Cc: Chao Yu <yuchao0@huawei.com>
>> Signed-off-by: Jason Yan <yanaijie@huawei.com>
>> ---
>
> I'm fine with the patch since "-Wmaybe-uninitialized" has been disabled and
> I've also asked Kees for it in private previously.
>
> I still remembered that Kees sent out a treewide patch. Sorry about that
> I don't catch up it... But what is wrong with the original patchset?
>
Yes, Kees has remind me of that and I will let him handle it. So you can
ignore this patch.
Thanks,
Jason
> Thanks,
> Gao Xiang
>
>
> .
>
next prev parent reply other threads:[~2020-06-15 7:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-15 4:01 [PATCH] erofs: Eliminate usage of uninitialized_var() macro Jason Yan
2020-06-15 7:25 ` Gao Xiang
2020-06-15 7:43 ` Jason Yan [this message]
2020-06-15 8:07 ` Gao Xiang
2020-06-15 8:29 ` Chao Yu
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