From: Zhao Liu <zhao1.liu@linux.intel.com>
To: Wei Liu <wei.liu@kernel.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>,
"Haiyang Zhang" <haiyangz@microsoft.com>,
"Stephen Hemminger" <sthemmin@microsoft.com>,
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: Thu, 27 Oct 2022 18:05:48 +0800 [thread overview]
Message-ID: <Y1pX/BGRgceJcEE9@liuzhao-OptiPlex-7080> (raw)
In-Reply-To: <Y1lPfphHVRn2e4I5@liuwe-devbox-debian-v2>
On Wed, Oct 26, 2022 at 03:17:18PM +0000, Wei Liu wrote:
> Date: Wed, 26 Oct 2022 15:17:18 +0000
> From: Wei Liu <wei.liu@kernel.org>
> Subject: Re: [PATCH v2] x86/hyperv: Remove BUG_ON() for kmap_local_page()
>
> 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.
Sorry Wei, I appology for not deleting unused variables, which caused
the next tree break. Do I need to send another v3 to make up for my
carelessness?
Zhao
next prev parent reply other threads:[~2022-10-27 10:01 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
2022-10-27 10:05 ` Zhao Liu [this message]
2022-10-27 11:19 ` Wei Liu
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