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From: Michal Hocko <mhocko@kernel.org>
To: Wei Yang <richard.weiyang@gmail.com>
Cc: trivial@kernel.org, akpm@linux-foundation.org,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH V2 2/2] mm/memblock.c: check return value of memblock_reserve() in memblock_virt_alloc_internal()
Date: Mon, 19 Dec 2016 16:21:57 +0100	[thread overview]
Message-ID: <20161219152156.GC5175@dhcp22.suse.cz> (raw)
In-Reply-To: <1482072470-26151-3-git-send-email-richard.weiyang@gmail.com>

On Sun 18-12-16 14:47:50, Wei Yang wrote:
> memblock_reserve() may fail in case there is not enough regions.

Have you seen this happenning in the real setups or this is a by-review
driven change?
[...]
>  again:
>  	alloc = memblock_find_in_range_node(size, align, min_addr, max_addr,
>  					    nid, flags);
> -	if (alloc)
> +	if (alloc && !memblock_reserve(alloc, size))
>  		goto done;
>  
>  	if (nid != NUMA_NO_NODE) {
>  		alloc = memblock_find_in_range_node(size, align, min_addr,
>  						    max_addr, NUMA_NO_NODE,
>  						    flags);
> -		if (alloc)
> +		if (alloc && !memblock_reserve(alloc, size))
>  			goto done;
>  	}

This doesn't look right. You can end up leaking the first allocated
range.

>  
> @@ -1303,7 +1302,6 @@ static void * __init memblock_virt_alloc_internal(
>  
>  	return NULL;
>  done:
> -	memblock_reserve(alloc, size);
>  	ptr = phys_to_virt(alloc);
>  	memset(ptr, 0, size);


>  
> -- 
> 2.5.0
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

-- 
Michal Hocko
SUSE Labs

  reply	other threads:[~2016-12-19 15:22 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-18 14:47 [PATCH V2 0/2] mm/memblock.c: fix potential bug and code refine Wei Yang
2016-12-18 14:47 ` [PATCH V2 1/2] mm/memblock.c: trivial code refine in memblock_is_region_memory() Wei Yang
2016-12-19 15:15   ` Michal Hocko
2016-12-20 16:35     ` Wei Yang
2016-12-21  7:48       ` Michal Hocko
2016-12-21 12:43         ` Wei Yang
2016-12-21 12:48           ` Michal Hocko
2016-12-21 13:15             ` Wei Yang
2016-12-18 14:47 ` [PATCH V2 2/2] mm/memblock.c: check return value of memblock_reserve() in memblock_virt_alloc_internal() Wei Yang
2016-12-19 15:21   ` Michal Hocko [this message]
2016-12-20 16:48     ` Wei Yang
2016-12-21  7:51       ` Michal Hocko
2016-12-21 13:13         ` Wei Yang
2016-12-21 13:22           ` Michal Hocko
2016-12-21 14:39             ` Wei Yang
2016-12-21 14:52               ` Michal Hocko

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