From: Wei Liu <wei.liu@kernel.org>
To: Zhao Liu <zhao1.liu@linux.intel.com>
Cc: "K . Y . Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
Ira Weiny <ira.weiny@intel.com>,
"Fabio M . De Francesco" <fmdefrancesco@gmail.com>,
Zhenyu Wang <zhenyu.z.wang@intel.com>,
Zhao Liu <zhao1.liu@intel.com>
Subject: Re: [PATCH v2] x86/hyperv: Remove BUG_ON() for kmap_local_page()
Date: Wed, 26 Oct 2022 15:17:18 +0000 [thread overview]
Message-ID: <Y1lPfphHVRn2e4I5@liuwe-devbox-debian-v2> (raw)
In-Reply-To: <20221020083820.2341088-1-zhao1.liu@linux.intel.com>
On Thu, Oct 20, 2022 at 04:38:20PM +0800, Zhao Liu wrote:
> From: Zhao Liu <zhao1.liu@intel.com>
>
> The commit 154fb14df7a3c ("x86/hyperv: Replace kmap() with
> kmap_local_page()") keeps the BUG_ON() to check if kmap_local_page()
> fails.
>
> But in fact, kmap_local_page() always returns a valid kernel address
> and won't return NULL here. It will BUG on its own if it fails. [1]
>
> So directly use memcpy_to_page() which creates local mapping to copy.
>
> [1]: https://lore.kernel.org/lkml/YztFEyUA48et0yTt@iweiny-mobl/
>
> Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
> Suggested-by: Ira Weiny <ira.weiny@intel.com>
> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Applied to hyperv-fixes. Thanks.
next prev parent reply other threads:[~2022-10-26 15:17 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-20 8:38 [PATCH v2] x86/hyperv: Remove BUG_ON() for kmap_local_page() Zhao Liu
2022-10-26 15:17 ` Wei Liu [this message]
2022-10-27 10:05 ` Zhao Liu
2022-10-27 11:19 ` Wei Liu
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