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Date: Tue, 31 Aug 2010 21:53:29 -0600
Message-ID: <AANLkTikJu_oEpwP16UVRafO2p0SXwKC_3sSaei3ha-iQ@mail.gmail.com>
From: Cam Macdonell <cam@cs.ualberta.ca>
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Subject: [Qemu-devel] Re: [PATCH] hw/ivshmem.c don't check for negative
 values on unsigned data types
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To: Jes.Sorensen@redhat.com
Cc: xudong.hao@intel.com, qemu-devel@nongnu.org

On Mon, Aug 30, 2010 at 4:31 AM,  <Jes.Sorensen@redhat.com> wrote:
> From: Jes Sorensen <Jes.Sorensen@redhat.com>
>
> There is no need to check for dest < 0 or vector >=3D 0 as both are
> uint16_t.
>
> This should fix problems with broken build with aggressive compiler
> flags. Reported by Xudong Hao <xudong.hao@intel.com>
>
> Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
> ---
> =A0hw/ivshmem.c | =A0 =A04 ++--
> =A01 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/ivshmem.c b/hw/ivshmem.c
> index bbb5cba..afebbc3 100644
> --- a/hw/ivshmem.c
> +++ b/hw/ivshmem.c
> @@ -199,13 +199,13 @@ static void ivshmem_io_writel(void *opaque, target_=
phys_addr_t addr,
>
> =A0 =A0 =A0 =A0 case DOORBELL:
> =A0 =A0 =A0 =A0 =A0 =A0 /* check that dest VM ID is reasonable */
> - =A0 =A0 =A0 =A0 =A0 =A0if ((dest < 0) || (dest > s->max_peer)) {
> + =A0 =A0 =A0 =A0 =A0 =A0if (dest > s->max_peer) {
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 IVSHMEM_DPRINTF("Invalid destination VM I=
D (%d)\n", dest);
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 break;
> =A0 =A0 =A0 =A0 =A0 =A0 }
>
> =A0 =A0 =A0 =A0 =A0 =A0 /* check doorbell range */
> - =A0 =A0 =A0 =A0 =A0 =A0if ((vector >=3D 0) && (vector < s->peers[dest].=
nb_eventfds)) {
> + =A0 =A0 =A0 =A0 =A0 =A0if (vector < s->peers[dest].nb_eventfds) {
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 IVSHMEM_DPRINTF("Writing %" PRId64 " to V=
M %d on vector %d\n",
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 write_one, dest, vector);
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (write(s->peers[dest].eventfds[vector]=
,
> --
> 1.7.2.2
>
>

Acked-by: Cam Macdonell <cam@cs.ualberta.ca>

I sent a patch yesterday that addressed it, but it is probably better
to remove the tests that switched to signed 16-bit ints.

Anthony, please apply this one.

Cam