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Message-ID: <6b18fed1-f802-b15c-95d9-718a48edbbfc@huawei.com>
Date: Wed, 27 Apr 2022 17:09:19 +0800
From: Tong Tiangen <tongtiangen@...wei.com>
To: Mark Rutland <mark.rutland@....com>,
James Morse <james.morse@....com>,
Andrew Morton <akpm@...ux-foundation.org>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
Robin Murphy <robin.murphy@....com>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will@...nel.org>,
Alexander Viro <viro@...iv.linux.org.uk>,
Michael Ellerman <mpe@...erman.id.au>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>, <x86@...nel.org>,
"H . Peter Anvin" <hpa@...or.com>
CC: <linuxppc-dev@...ts.ozlabs.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <linux-mm@...ck.org>,
Kefeng Wang <wangkefeng.wang@...wei.com>,
Xie XiuQi <xiexiuqi@...wei.com>,
Guohanjun <guohanjun@...wei.com>
Subject: Re: [PATCH -next v4 0/7]arm64: add machine check safe support
Hi Mark, James, Robin, kindly ping...
Thanks.
在 2022/4/20 11:04, Tong Tiangen 写道:
> With the increase of memory capacity and density, the probability of
> memory error increases. The increasing size and density of server RAM
> in the data center and cloud have shown increased uncorrectable memory
> errors.
>
> Currently, the kernel has a mechanism to recover from hardware memory
> errors. This patchset provides an new recovery mechanism.
>
> For arm64, the hardware memory error handling is do_sea() which divided
> into two cases:
> 1. The user state consumed the memory errors, the solution is kill the
> user process and isolate the error page.
> 2. The kernel state consumed the memory errors, the solution is panic.
>
> For case 2, Undifferentiated panic maybe not the optimal choice, it can be
> handled better, in some scenes, we can avoid panic, such as uaccess, if the
> uaccess fails due to memory error, only the user process will be affected,
> kill the user process and isolate the user page with hardware memory errors
> is a better choice.
>
> This patchset can be divided into three parts:
> 1. Patch 0/1/4 - make some minor fixes to the associated code.
> 2. Patch 3 - arm64 add support for machine check safe framework.
> 3. Pathc 5/6/7 - arm64 add uaccess and cow to machine check safe.
>
> Since V4:
> 1. According to Robin's suggestion, direct modify user_ldst and
> user_ldp in asm-uaccess.h and modify mte.S.
> 2. Add new macro USER_MC in asm-uaccess.h, used in copy_from_user.S
> and copy_to_user.S.
> 3. According to Robin's suggestion, using micro in copy_page_mc.S to
> simplify code.
> 4. According to KeFeng's suggestion, modify powerpc code in patch1.
> 5. According to KeFeng's suggestion, modify mm/extable.c and some code
> optimization.
>
> Since V3:
> 1. According to Mark's suggestion, all uaccess can be recovered due to
> memory error.
> 2. Scenario pagecache reading is also supported as part of uaccess
> (copy_to_user()) and duplication code problem is also solved.
> Thanks for Robin's suggestion.
> 3. According Mark's suggestion, update commit message of patch 2/5.
> 4. According Borisllav's suggestion, update commit message of patch 1/5.
>
> Since V2:
> 1.Consistent with PPC/x86, Using CONFIG_ARCH_HAS_COPY_MC instead of
> ARM64_UCE_KERNEL_RECOVERY.
> 2.Add two new scenes, cow and pagecache reading.
> 3.Fix two small bug(the first two patch).
>
> V1 in here:
> https://lore.kernel.org/lkml/20220323033705.3966643-1-tongtiangen@huawei.com/
>
> Robin Murphy (1):
> arm64: mte: Clean up user tag accessors
>
> Tong Tiangen (6):
> x86, powerpc: fix function define in copy_mc_to_user
> arm64: fix types in copy_highpage()
> arm64: add support for machine check error safe
> arm64: add copy_{to, from}_user to machine check safe
> arm64: add {get, put}_user to machine check safe
> arm64: add cow to machine check safe
>
> arch/arm64/Kconfig | 1 +
> arch/arm64/include/asm/asm-extable.h | 33 +++++++++++
> arch/arm64/include/asm/asm-uaccess.h | 15 +++--
> arch/arm64/include/asm/extable.h | 1 +
> arch/arm64/include/asm/page.h | 10 ++++
> arch/arm64/include/asm/uaccess.h | 4 +-
> arch/arm64/lib/Makefile | 2 +
> arch/arm64/lib/copy_from_user.S | 18 +++---
> arch/arm64/lib/copy_page_mc.S | 86 ++++++++++++++++++++++++++++
> arch/arm64/lib/copy_to_user.S | 18 +++---
> arch/arm64/lib/mte.S | 4 +-
> arch/arm64/mm/copypage.c | 36 ++++++++++--
> arch/arm64/mm/extable.c | 33 +++++++++++
> arch/arm64/mm/fault.c | 27 ++++++++-
> arch/powerpc/include/asm/uaccess.h | 1 +
> arch/x86/include/asm/uaccess.h | 1 +
> include/linux/highmem.h | 8 +++
> include/linux/uaccess.h | 9 +++
> mm/memory.c | 2 +-
> 19 files changed, 278 insertions(+), 31 deletions(-)
> create mode 100644 arch/arm64/lib/copy_page_mc.S
>
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