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    SubjectRe: [PATCH 0/5] i387: stable kernel backport
    On Thu, Feb 23, 2012 at 02:38:42PM -0800, Linus Torvalds wrote:
    > On Thu, Feb 23, 2012 at 2:27 PM, Willy Tarreau <w@1wt.eu> wrote:
    > >
    > > OK so indeed I will only be able to check that it boots :-/
    >
    > Well, we could do some trivial test-harness that just forces the issue
    > with regular timer interrupts (and even without AES-NI). I think Peter
    > talked about that when we were trying to hunt it down - but I think he
    > was then able to reproduce the problem without anything special and we
    > dropped it.
    >
    > Essentially, just doing something like
    >
    > if (irq_fpu_usable()) {
    > kernel_fpu_begin();
    > kernel_fpu_end();
    > }
    >
    > in do_irq() and do_softirq() would stress-test things even without
    > wireless, and even without AES-NI.
    >
    > You'd still need an x86-32 machine to test on, because x86-64 was
    > immune to this issue.
    >
    > But yeah, the impact of this seems to be small enough that for older
    > kernels (which are likely used on older systems for maintenance
    > anyway) disabling AES-NI on x86-32 really might be the way to go.

    I think that's already the case, 2.6.32 has the following depends for
    CRYPTO_AES_NI_INTEL:
    depends on (X86 || UML_X86) && 64BIT
    It was this way until commit 0d258efb (crypto: aesni-intel - Ported
    implementation to x86-32) which showed up in 2.6.38.

    So we should be safe for 2.6.32 no changes needed, right?

    greg k-h


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