[PATCH -next v7 0/4]arm64: add machine check safe support
Tong Tiangen
tongtiangen at huawei.com
Wed Aug 24 16:44:09 AEST 2022
Hi Mark & Catalin & Will:
Kindly ping...
Thanks,
Tong.
在 2022/8/12 15:05, 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 scenarios, 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.
>
> Since V6:
> Resend patches that are not merged into the mainline in V6.
>
> Since V5:
> 1. Add patch2/3 to add uaccess assembly helpers.
> 2. Optimize the implementation logic of arm64_do_kernel_sea() in patch8.
> 3. Remove kernel access fixup in patch9.
> All suggestion are from Mark.
>
> Since V4:
> 1. According Michael's suggestion, add patch5.
> 2. According Mark's suggestiog, do some restructuring to arm64
> extable, then a new adaptation of machine check safe support is made based
> on this.
> 3. According Mark's suggestion, support machine check safe in do_mte() in
> cow scene.
> 4. In V4, two patches have been merged into -next, so V5 not send these
> two patches.
>
> Since V3:
> 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 V2:
> 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 V1:
> 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/
>
> Tong Tiangen (4):
> uaccess: add generic fallback version of copy_mc_to_user()
> arm64: add support for machine check error safe
> arm64: add uaccess to machine check safe
> arm64: add cow to machine check safe
>
> arch/arm64/Kconfig | 1 +
> arch/arm64/include/asm/asm-extable.h | 5 ++
> arch/arm64/include/asm/assembler.h | 4 ++
> arch/arm64/include/asm/extable.h | 1 +
> arch/arm64/include/asm/mte.h | 4 ++
> arch/arm64/include/asm/page.h | 10 ++++
> arch/arm64/lib/Makefile | 2 +
> arch/arm64/lib/copy_page_mc.S | 82 ++++++++++++++++++++++++++++
> arch/arm64/lib/mte.S | 19 +++++++
> arch/arm64/mm/copypage.c | 37 +++++++++++--
> arch/arm64/mm/extable.c | 25 +++++++++
> arch/arm64/mm/fault.c | 29 +++++++++-
> 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 +-
> 17 files changed, 233 insertions(+), 7 deletions(-)
> create mode 100644 arch/arm64/lib/copy_page_mc.S
>
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