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    SubjectRe: [patch 2/2] gru: cleanup gru_dump_context() a little
    Acked-by: Dimitri Sivanich <sivanich@sgi.com>

    On Thu, Jan 30, 2014 at 03:10:48PM +0300, Dan Carpenter wrote:
    > "ret" is zero here so we can remove the "!ret" part of the condition.
    > "uhdr" is alread a __user pointer so we can remove the cast.
    >
    > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
    > ---
    > Btw, speaking of __user pointers there are some places where we
    > dereference them in this file. It's not a security problem because we
    > have already used copy_to_user() to successfully write to the pointer at
    > point. But if you have something like PAX which puts user pointers and
    > kernel pointers in a separate address space then this will cause
    > problems.
    >
    > Run sparse to see the issue.
    >
    > diff --git a/drivers/misc/sgi-gru/grukdump.c b/drivers/misc/sgi-gru/grukdump.c
    > index 2bef3f76032a..a3700a56b8ff 100644
    > --- a/drivers/misc/sgi-gru/grukdump.c
    > +++ b/drivers/misc/sgi-gru/grukdump.c
    > @@ -178,10 +178,10 @@ static int gru_dump_context(struct gru_state *gru, int ctxnum,
    > hdr.cbrcnt = cbrcnt;
    > hdr.dsrcnt = dsrcnt;
    > hdr.cch_locked = cch_locked;
    > - if (!ret && copy_to_user((void __user *)uhdr, &hdr, sizeof(hdr)))
    > - ret = -EFAULT;
    > + if (copy_to_user(uhdr, &hdr, sizeof(hdr)))
    > + return -EFAULT;
    >
    > - return ret ? ret : bytes;
    > + return bytes;
    > }
    >
    > int gru_dump_chiplet_request(unsigned long arg)


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