linux-kernel - Re: [PATCH -next v4 1/7] x86, powerpc: fix function define in copy_mc_to

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 5 May 2022 09:21:11 +0800
From:   Kefeng Wang <wangkefeng.wang@...wei.com>
To:     Tong Tiangen <tongtiangen@...wei.com>,
        Christophe Leroy <christophe.leroy@...roup.eu>,
        Mark Rutland <mark.rutland@....com>,
        "James Morse" <james.morse@....com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Robin Murphy <robin.murphy@....com>,
        "Dave Hansen" <dave.hansen@...ux.intel.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Michael Ellerman <mpe@...erman.id.au>,
        "Benjamin Herrenschmidt" <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        "x86@...nel.org" <x86@...nel.org>,
        "H . Peter Anvin" <hpa@...or.com>
CC:     Xie XiuQi <xiexiuqi@...wei.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        Guohanjun <guohanjun@...wei.com>,
        "linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH -next v4 1/7] x86, powerpc: fix function define in
 copy_mc_to_user


On 2022/5/3 9:06, Tong Tiangen wrote:
>
>
> 在 2022/5/2 22:24, Christophe Leroy 写道:
>>
>>
>> Le 20/04/2022 à 05:04, Tong Tiangen a écrit :
>>> x86/powerpc has it's implementation of copy_mc_to_user but not use 
>>> #define
>>> to declare.
>>>
>>> This may cause problems, for example, if other architectures open
>>> CONFIG_ARCH_HAS_COPY_MC, but want to use copy_mc_to_user() outside the
>>> architecture, the code add to include/linux/uaddess.h is as follows:
>>>
>>>       #ifndef copy_mc_to_user
>>>       static inline unsigned long __must_check
>>>       copy_mc_to_user(void *dst, const void *src, size_t cnt)
>>>       {
>>>         ...
>>>       }
>>>       #endif
>>>
>>> Then this definition will conflict with the implementation of 
>>> x86/powerpc
>>> and cause compilation errors as follow:
>>>
>>> Fixes: ec6347bb4339 ("x86, powerpc: Rename memcpy_mcsafe() to 
>>> copy_mc_to_{user, kernel}()")
>>
>> I don't understand, what does it fix really ? What was the
>> (existing/real) bug introduced by that patch and that your are fixing ?
>>
>> If those defined had been expected and missing, we would have had a
>> build failure. If you have one, can you describe it ?
>
It could prevent future problems when patch3 is introduced， and yes，for 
now，

this patch won't fix any issue，we could drop the fix tag, and update the 
changelog.


> There will be build failure after patch 3 is added, there is a little
> confusing for a reader of this commit in isolation.
> In the next version, I will put this patch after patch 3.
This is an alternative.
>
> Thanks,
> Tong.
> .