[dpdk-dev] [PATCH] ivshmem: fix overlap detection code

Burakov, Anatoly anatoly.burakov at intel.com
Tue May 24 14:52:59 CEST 2016


> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Anatoly Burakov
> Sent: Tuesday, May 24, 2016 1:50 PM
> To: dev at dpdk.org
> Subject: [dpdk-dev] [PATCH] ivshmem: fix overlap detection code
> 
> Partial revert of an earlier ill-conceived "fix".
> Adjacent segments can never be considered overlapping because we
> are not comparing ends to starts, but rather starts to starts.
> Therefore the earlier fix was wrong (plus it also had a typo).
> 
> Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
> ---
>  lib/librte_eal/linuxapp/eal/eal_ivshmem.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/librte_eal/linuxapp/eal/eal_ivshmem.c
> b/lib/librte_eal/linuxapp/eal/eal_ivshmem.c
> index 07aec69..eea0314 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_ivshmem.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_ivshmem.c
> @@ -184,21 +184,21 @@ overlap(const struct rte_memzone * mz1, const
> struct rte_memzone * mz2)
>  	i_end2 = mz2->ioremap_addr + mz2->len;
> 
>  	/* check for overlap in virtual addresses */
> -	if (start1 > start2 && start1 < end2)
> +	if (start1 >= start2 && start1 < end2)
>  		result |= VIRT;
>  	if (start2 >= start1 && start2 < end1)
>  		result |= VIRT;
> 
>  	/* check for overlap in physical addresses */
> -	if (p_start1 > p_start2 && p_start1 < p_end2)
> +	if (p_start1 >= p_start2 && p_start1 < p_end2)
>  		result |= PHYS;
> -	if (p_start2 > p_start1 && p_start2 < p_end1)
> +	if (p_start2 >= p_start1 && p_start2 < p_end1)
>  		result |= PHYS;
> 
>  	/* check for overlap in ioremap addresses */
> -	if (i_start1 > i_start2 && i_start1 < i_end2)
> +	if (i_start1 >= i_start2 && i_start1 < i_end2)
>  		result |= IOREMAP;
> -	if (i_start2 > i_start1 && i_start2 < i_end1)
> +	if (i_start2 >= i_start1 && i_start2 < i_end1)
>  		result |= IOREMAP;
> 
>  	return result;
> --
> 2.5.5

Apologies, forgot to add:

Tested-by: Ferruh Yigit <ferruh.yigit at intel.com>
Fixes: d6cf31419e51 ("ivshmem: avoid infinite loop when concatenating segments")

Thanks,
Anatoly


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