Messages in this thread | | | From | Tony Luck <> | Date | Fri, 11 Dec 2015 11:13:23 -0800 | Subject | [PATCHV2 0/3] Machine check recovery when kernel accesses poison |
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This series is initially targeted at the folks doing filesystems on top of NVDIMMs. They really want to be able to return -EIO when there is a h/w error (just like spinning rust, and SSD does).
I plan to use the same infrastructure in parts 1&2 to write a machine check aware "copy_from_user()" that will SIGBUS the calling application when a syscall touches poison in user space (just like we do when the application touches the poison itself).
Changes V1->V2:
0-day: Reported build errors and warnings on 32-bit systems. Fixed 0-day: Reported bloat to tinyconfig. Fixed Boris: Suggestions to use extra macros to reduce code duplication in _ASM_*EXTABLE. Done Boris: Re-write "tolerant==3" check to reduce indentation level. See below. Andy: Check IP is valid before searching kernel exception tables. Done. Andy: Explain use of BIT(63) on return value from mcsafe_memcpy(). Done (added decode macros). Andy: Untangle mess of code in tail of do_machine_check() to make it clear what is going on (e.g. that we only enter the ist_begin_non_atomic() if we were called from user code, not from kernel!). Done
Tony Luck (3): x86, ras: Add new infrastructure for machine check fixup tables 2/6] x86, ras: Extend machine check recovery code to annotated ring0 areas 3/6] x86, ras: Add mcsafe_memcpy() function to recover from machine checks
arch/x86/Kconfig | 4 ++ arch/x86/include/asm/asm.h | 10 +++- arch/x86/include/asm/uaccess.h | 8 +++ arch/x86/include/asm/uaccess_64.h | 5 ++ arch/x86/kernel/cpu/mcheck/mce-severity.c | 22 +++++++- arch/x86/kernel/cpu/mcheck/mce.c | 69 +++++++++++------------ arch/x86/kernel/x8664_ksyms_64.c | 2 + arch/x86/lib/copy_user_64.S | 91 +++++++++++++++++++++++++++++++ arch/x86/mm/extable.c | 19 +++++++ include/asm-generic/vmlinux.lds.h | 6 ++ include/linux/module.h | 1 + kernel/extable.c | 20 +++++++ 12 files changed, 219 insertions(+), 38 deletions(-)
-- 2.1.4
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