From: Vasileios Karakasis <bkk@cslab.ece.ntua.gr>
To: Andi Kleen <andi@firstfloor.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-numa@vger.kernel.org
Subject: Re: [BUG] Invalid return address of mmap() followed by mbind() in multithreaded context
Date: Sat, 18 Jun 2011 21:41:03 +0300 [thread overview]
Message-ID: <4DFCF13F.50401@cslab.ece.ntua.gr> (raw)
In-Reply-To: <20110618181232.GI16236@one.firstfloor.org>
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That's right, but what I want to demonstrate is that the address
returned by mmap() is invalid and the dereference crashes the program,
while it shouldn't. I could equally omit this statement, in which case
mbind() would fail with EFAULT.
On 06/18/2011 09:12 PM, Andi Kleen wrote:
>> for (i = 0; i < NR_ITER; i++) {
>> addr = mmap(0, PAGE_SIZE, PROT_READ | PROT_WRITE,
>> MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
>> if (addr == (void *) -1) {
>> assert(0 && "mmap failed");
>> }
>> *addr = 0;
>>
>> err = mbind(addr, PAGE_SIZE, MPOL_BIND, &node, sizeof(node), 0);
>
> mbind() can be only done before the first touch. you're not actually testing
> numa policy.
>
> -andi
--
V.K.
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next prev parent reply other threads:[~2011-06-18 18:41 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-17 15:21 [BUG] Invalid return address of mmap() followed by mbind() in multithreaded context Vasileios Karakasis
2011-06-18 18:12 ` Andi Kleen
2011-06-18 18:41 ` Vasileios Karakasis [this message]
2011-06-19 23:42 ` Vasileios Karakasis
2011-06-27 17:18 ` Kornilios Kourtis
2011-06-28 2:06 ` KOSAKI Motohiro
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