From: "Luck, Tony" <tony.luck@intel.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>,
Andrew Morton <akpm@linux-foundation.org>,
Tony Luck <tony.luck@gmail.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
"H. Peter Anvin" <hpa@zytor.com>,
Andy Lutomirski <luto@amacapital.net>
Subject: Re: [PATCH v14] x86, mce: Add memcpy_mcsafe()
Date: Wed, 2 Mar 2016 12:47:41 -0800 [thread overview]
Message-ID: <20160302204739.GA4728@intel.com> (raw)
In-Reply-To: <a44e1055efc2d2a9473307b22c91caa437aa3f8b.1456439214.git.tony.luck@intel.com>
On Thu, Feb 18, 2016 at 11:47:26AM -0800, Tony Luck wrote:
> Make use of the EXTABLE_FAULT exception table entries to write
> a kernel copy routine that doesn't crash the system if it
> encounters a machine check. Prime use case for this is to copy
> from large arrays of non-volatile memory used as storage.
>
> We have to use an unrolled copy loop for now because current
> hardware implementations treat a machine check in "rep mov"
> as fatal. When that is fixed we can simplify.
Ping.
Anything more needed for this? In his last message Linus
seemed OK with a *kernel* copy function that avoided death
by machine check. He said:
What a "memcpy_fault()" (or whatever it would be called) means is
that the kernel is doing its own copies, but knows that there is some
fragility involved, and wants to have a recovery mechanism that isn't
"oops, we got a machine check in the kernel, now we need to kill the
machine".
The only things left to argue are the name, and the return value.
-Tony
next prev parent reply other threads:[~2016-03-02 20:47 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-17 18:20 [PATCH v11 0/4] Machine check recovery when kernel accesses poison Tony Luck
2016-02-17 18:20 ` [PATCH v11 1/4] x86: Expand exception table to allow new handling options Tony Luck
2016-02-18 10:19 ` [tip:ras/core] x86/mm: Expand the exception table logic " tip-bot for Tony Luck
2016-02-17 18:20 ` [PATCH v11 2/4] x86, mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries Tony Luck
2016-02-18 10:19 ` [tip:ras/core] x86/mce: " tip-bot for Tony Luck
2016-02-17 18:20 ` [PATCH v11 3/4] x86, mce: Add __mcsafe_copy() Tony Luck
2016-02-18 8:21 ` Ingo Molnar
2016-02-18 9:59 ` Peter Zijlstra
2016-02-18 10:19 ` Ingo Molnar
2016-02-18 10:29 ` Borislav Petkov
2016-02-18 10:35 ` Peter Zijlstra
2016-02-18 14:59 ` Luck, Tony
2016-02-19 7:58 ` Ingo Molnar
2016-02-19 8:43 ` Peter Zijlstra
2016-02-19 9:51 ` Ingo Molnar
2016-02-18 10:29 ` Borislav Petkov
2016-02-18 10:34 ` Ingo Molnar
2016-02-18 10:36 ` Borislav Petkov
2016-02-18 18:48 ` Ingo Molnar
2016-02-18 21:14 ` [PATCH v12] x86, mce: Add memcpy_trap() Luck, Tony
2016-02-19 9:10 ` Ingo Molnar
2016-02-19 17:53 ` [PATCH v13] " Luck, Tony
2016-02-24 17:38 ` Tony Luck
2016-02-24 18:35 ` Linus Torvalds
2016-02-24 19:27 ` Tony Luck
2016-02-24 19:37 ` Linus Torvalds
2016-02-25 8:56 ` Ingo Molnar
2016-02-25 19:33 ` Luck, Tony
2016-02-25 20:39 ` Linus Torvalds
2016-02-25 22:11 ` Andy Lutomirski
2016-02-18 19:47 ` [PATCH v14] x86, mce: Add memcpy_mcsafe() Tony Luck
2016-03-02 20:47 ` Luck, Tony [this message]
2016-03-08 17:37 ` [tip:ras/core] x86/mm, x86/mce: " tip-bot for Tony Luck
2016-03-10 19:26 ` [PATCH v14] x86, mce: " Mika Penttilä
2016-03-10 19:37 ` Luck, Tony
2016-03-11 22:10 ` Tony Luck
2016-03-11 22:14 ` Dan Williams
2016-03-12 17:16 ` Ingo Molnar
2016-03-13 1:12 ` Linus Torvalds
2016-03-13 9:25 ` Ingo Molnar
2016-03-14 22:33 ` [PATCH] x86/mm, x86/mce: Fix return type/value for memcpy_mcsafe() Tony Luck
2016-03-16 8:06 ` [tip:x86/urgent] " tip-bot for Tony Luck
2016-02-26 0:58 ` [PATCH v13] x86, mce: Add memcpy_trap() Linus Torvalds
2016-02-26 1:19 ` Andy Lutomirski
2016-02-26 2:38 ` Linus Torvalds
2016-02-18 18:12 ` [PATCH v11 3/4] x86, mce: Add __mcsafe_copy() Linus Torvalds
2016-02-18 18:51 ` Ingo Molnar
2016-02-18 18:52 ` Luck, Tony
2016-02-18 20:14 ` Ingo Molnar
2016-02-18 21:33 ` Dan Williams
2016-02-17 18:20 ` [PATCH v11 4/4] x86: Create a new synthetic cpu capability for machine check recovery Tony Luck
2016-02-18 10:19 ` [tip:x86/asm] x86/cpufeature: " tip-bot for Tony Luck
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