Re: [BUG] Invalid return address of mmap() followed by mbind() in multithreaded context
Vasileios Karakasis <[email protected]> Sat, 18 Jun 2011 21:41:03 +0300
| Newsgroups | org.kernel.vger.linux-numa,org.kernel.vger.linux-kernel,org.kvack.linux-mm |
|---|---|
| Message-ID | <[email protected]> |
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
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