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    SubjectRe: [PATCH] mptsas: fix undefined behaviour of a shift of an int by more than 31 places
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    On Wed, 2019-05-08 at 14:07 +0100, Colin Ian King wrote:
    > On 05/05/2019 04:34, James Bottomley wrote:
    > > On Sat, 2019-05-04 at 17:40 +0100, Colin King wrote:
    > > > From: Colin Ian King <colin.king@canonical.com>
    > > >
    > > > Currently the shift of int value 1 by more than 31 places can
    > > > result in undefined behaviour. Fix this by making the 1 a ULL
    > > > value before the shift operation.
    > >
    > > Fusion SAS is pretty ancient. I thought the largest one ever
    > > produced had four phys, so how did you produce the overflow?
    >
    > This was an issue found by static analysis with Coverity; so I guess
    > won't happen in the wild, in which case the patch could be ignored.

    The point I was more making is that if we thought this could ever
    happen in practice, we'd need more error handling than simply this:
    we'd be setting the phy_bitmap to zero which would be every bit as bad
    as some random illegal value.

    James

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