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Date:   Mon, 20 Jul 2020 21:14:03 +0200
From:   "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
To:     Atish Patra <Atish.Patra@wdc.com>
Cc:     "naresh.kamboju@linaro.org" <naresh.kamboju@linaro.org>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "walken@google.com" <walken@google.com>,
        "palmerdabbelt@google.com" <palmerdabbelt@google.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "zong.li@sifive.com" <zong.li@sifive.com>,
        "lkft-triage@lists.linaro.org" <lkft-triage@lists.linaro.org>
Subject: Re: [PATCH 5.7 233/244] RISC-V: Acquire mmap lock before invoking
 walk_page_range
Message-ID: <20200720191403.GB1529125@kroah.com>
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On Mon, Jul 20, 2020 at 06:50:10PM +0000, Atish Patra wrote:
> On Mon, 2020-07-20 at 23:11 +0530, Naresh Kamboju wrote:
> > RISC-V build breaks on stable-rc 5.7 branch.
> > build failed with gcc-8, gcc-9 and gcc-9.
> > 
> 
> Sorry for the compilation issue.
> 
> mmap_read_lock was intrdouced in the following commit.
> 
> commit 9740ca4e95b4
> Author: Michel Lespinasse <walken@google.com>
> Date:   Mon Jun 8 21:33:14 2020 -0700
> 
>     mmap locking API: initial implementation as rwsem wrappers
> 
> The following two commits replaced the usage of mmap_sem rwsem calls
> with mmap_lock.
> 
> d8ed45c5dcd4 (mmap locking API: use coccinelle to convert mmap_sem
> rwsem call sites)
> 89154dd5313f (mmap locking API: convert mmap_sem call sites missed by
> coccinelle)
> 
> The first commit is not present in stale 5.7-y for obvious reasons.
> 
> Do we need to send a separate patch only for stable branch with
> mmap_sem ? I am not sure if that will cause a conflict again in future.

I do not like taking odd backports, and would rather take the real patch
that is upstream.

I will drop this patch from the tree now, so everyone can figure out
what they want to do in the future :)

thanks,

greg k-h