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From: Stephen Hemminger <stephen@networkplumber.org>
To: Michal Kobylinski <michalx.kobylinski@intel.com>
Cc: thomas.monjalon@6wind.com, dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH] mem: fix overflowed return value
Date: Fri, 22 Apr 2016 09:24:34 -0700	[thread overview]
Message-ID: <20160422092434.00bc0c46@xeon-e3> (raw)
In-Reply-To: <1461321858-30339-1-git-send-email-michalx.kobylinski@intel.com>

On Fri, 22 Apr 2016 12:44:18 +0200
Michal Kobylinski <michalx.kobylinski@intel.com> wrote:

> Fix issue reported by Coverity.
> 
> Coverity ID 13255: Overflowed return value: The return value will be too
> small or even negative, likely resulting in unexpected behavior in a
> caller that uses the return value. In rte_mem_virt2phy: An integer
> overflow occurs, with the overflowed value used as the return value of
> the function
> 
> Fixes: 3097de6e6bfb ("mem: get physical address of any pointer")
> 
> Signed-off-by: Michal Kobylinski <michalx.kobylinski@intel.com>
> ---
>  lib/librte_eal/linuxapp/eal/eal_memory.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
> index 5b9132c..6ceca5b 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_memory.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
> @@ -195,7 +195,7 @@ rte_mem_virt2phy(const void *virtaddr)
>  	 * the pfn (page frame number) are bits 0-54 (see
>  	 * pagemap.txt in linux Documentation)
>  	 */
> -	physaddr = ((page & 0x7fffffffffffffULL) * page_size)
> +	physaddr = (uint64_t)((page & 0x7fffffffffffffULL) * page_size)
>  		+ ((unsigned long)virtaddr % page_size);
>  	close(fd);
>  	return physaddr;

I am not trusting any of these Coverity patches you are sending.
It seems you think wraparound can be just fixed by casting, it can't

  reply	other threads:[~2016-04-22 16:24 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-22 10:44 Michal Kobylinski
2016-04-22 16:24 ` Stephen Hemminger [this message]
2016-06-08 11:40   ` Mrzyglod, DanielX T
2016-06-28  8:06     ` Jastrzebski, MichalX K

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