Re: [PATCHV3 3/3] x86, ras: Add mcsafe_memcpy() function to recover from machine checks

From: Tony Luck <tony.luck@gmail.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andy Lutomirski <luto@kernel.org>,
	Elliott@pd.tnic, Robert <elliott@hpe.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	linux-nvdimm <linux-nvdimm@ml01.01.org>, X86-ML <x86@kernel.org>
Subject: Re: [PATCHV3 3/3] x86, ras: Add mcsafe_memcpy() function to recover from machine checks
Date: Wed, 23 Dec 2015 12:46:20 -0800	[thread overview]
Message-ID: <CA+8MBbJX+3SW7CxqWT1ghzzbdV9pgVxXNejg4XC1=sDFY3Xgpw@mail.gmail.com> (raw)
In-Reply-To: <CAPcyv4gXDHGgiqfve_fP1RLXBGfyWarjWgUU3QPMhnFn_BbshA@mail.gmail.com>

> I know, memcpy returns the ptr to @dest like a parrot

Maybe I need to change the name to remove the
"memcpy" substring to avoid this confusion. How
about "mcsafe_copy()"? Perhaps with a "__" prefix
to point out it is a building block that will get various
wrappers around it??

Dan wants a copy_from_nvdimm() that either completes
the copy, or indicates where a machine check occurred.

I'm going to want a copy_from_user() that has two fault
options (user gave a bad address -> -EFAULT, or the
source address had an uncorrected error -> SIGBUS).

-Tony