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    SubjectRe: [PATCH] lib/sha1: use the git implementation of SHA-1
    On Sun, Aug 7, 2011 at 8:38 PM, Linus Torvalds
    <> wrote:
    > There aren't many users of that define, could you just turn it back to the proper 16, and then try changing it to 80 in each place that uses it?
    > That way we'd see exactly *which* use is the buggy one..

    Its drivers/char/random.c.

    Boots fine when forcing workspace array in extract_buf to 80.

    diff --git a/drivers/char/random.c b/drivers/char/random.c
    index c35a785..0584bb0 100644
    --- a/drivers/char/random.c
    +++ b/drivers/char/random.c
    @@ -816,7 +816,7 @@ static size_t account(struct entropy_store *r,
    size_t nbytes, int min,
    static void extract_buf(struct entropy_store *r, __u8 *out)
    int i;
    - __u32 hash[5], workspace[SHA_WORKSPACE_WORDS];
    + __u32 hash[5], workspace[80 /*SHA_WORKSPACE_WORDS*/];
    __u8 extract[64];

    /* Generate a hash across the pool, 16 words (512 bits) at a time */
    Joachim Eastwood

    >        Linus
    > Joachim  Eastwood <> wrote:
    >>On Sun, Aug 7, 2011 at 7:44 PM, Linus Torvalds
    >><> wrote:
    >>> On Sun, Aug 7, 2011 at 10:36 AM, Joachim  Eastwood
    >><> wrote:
    >>>> These printk's come from drivers/char/random.c
    >>>> So it doesn't seem like it hangs in any of the sha_* funtions.
    >>> The only other change is to SHA_WORKSPACE_WORDS - I wonder if some
    >>> code depends on the old (much bigger) workspace for some reason?
    >>> The git SHA1 routines are way smarter than the old SHA1, and will
    >>> re-use the workspace area, so they need only a fraction of the old
    >>> area.
    >>> Try changing SHA_WORKSPACE_WORDS back to 80 (in
    >>> include/linux/cryptohash.h). The git sha1 only needs 16 words, but ..
    >>yup, setting it to 80 makes my kernel boot again :-)
    >>> If that fixes it for you, then it's almost certainly some buggy user
    >>> that uses the SHA1 workspace array for its own odd case, and
    >>> incorrectly "knows" that it's that old wasteful 320 bytes. There's a
    >>> few places in networking that uses SHA_WORKSPACE_WORDS.
    >>Guess more architectures than ARM are affected by this then.
    >>Joachim Eastwood
    >>>                                     Linus
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