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    Subject[regression] commit d298b03506d3 ("x86/fpu: Restore the masking out of reserved MXCSR bits")
    Hi,

    I have a 32bit installation here that stopped working. Bisected it
    to commit d298b03506d3 ("x86/fpu: Restore the masking out of reserved
    MXCSR bits").

    dhcpcd was the first thing I notice being affected on account of
    network not coming up, and after trying to look at it with gdb also
    gdb turned out to be broken.

    strace of dhcpcd shows a SIGFPE getting delivered, after which it gets
    stuck (seem to be sitting in poll but not responding to even ^C).
    And gdb seems to be stuck in a perpetual SIGFPE loop and won't even
    get to the prompt.

    The crucial bit here seems to be that most of the software is built
    with -mfpmath=sse. After rebuilding dhcpcd without that it started
    to work on the broken kernel. Rebuilding gdb didn't help so I whatever
    SSE usage is causing the issue is presumably happening in a library.
    Had to do the rebuilds on a working kernel as well because otherwise
    the build itself would die to a SIGFPE somewhere.

    Tested the same disk on on both a 64bit capable Pentium D
    and a 32bit only Pentium 4 just to rule out the specific CPU.
    Busted on both.

    --
    Ville Syrjälä
    Intel

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