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    SubjectRe: usercopy whitelist woe in scsi_sense_cache
    Hi.

    10.04.2018 08:35, Oleksandr Natalenko wrote:
    >> - does it reproduce _without_ hardened usercopy? (I would assume yes,
    >> but you'd just not get any warning until the hangs started.) If it
    >> does reproduce without hardened usercopy, then a new bisect run could
    >> narrow the search even more.
    >
    > Looks like it cannot be disabled via kernel cmdline, so I have to
    > re-compile the kernel, right? I can certainly do that anyway.

    Okay, I've recompiled the kernel without hardened usercopy:

    [root@archlinux ~]# zgrep USERCOPY /proc/config.gz
    CONFIG_X86_INTEL_USERCOPY=y
    CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR=y
    # CONFIG_HARDENED_USERCOPY is not set

    and I cannot reproduce the issue anymore. I/O doesn't hang regardless of
    how long I hammer it.

    Eeeh? Maybe, this is a matter of some cleanup code path once the
    warn/bug condition is hit with hardening enabled? I'm just guessing here
    again.

    Will work towards checking Linus' master branch now…

    Regards,
    Oleksandr

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