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List:       linux-kernel
Subject:    Re: To all architecture maintainers: RFC: mmap2()
From:       Jakub Jelinek <jakub () redhat ! com>
Date:       2000-01-09 5:37:03
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On Sat, Jan 08, 2000 at 08:46:52PM +0000, Russell King wrote:
> Hi,
> 
> Looking through the various implementations of mmap2(), it occurs that
> at least the sparc implementation is byggy.
> 
> Sparc's mmap2() consists of:
> 
>         /* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
>            we have. */
>         return do_mmap2(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT - 12));
> 
> What happens if you have an 8K page size (PAGE_SHIFT == 13), and the
> user supplies an odd number in pgoff?
> 
> You are unable to represent the requested offset into the do_mmap2()
> call.  Surely, in this case, mmap2() should return EINVAL.

Agreed completely. Will add checks for that both in sys_mmap2 and sys_mmap2
on sparc32.

Cheers,
    Jakub
___________________________________________________________________
Jakub Jelinek | jakub@redhat.com | http://sunsite.mff.cuni.cz/~jj
Linux version 2.3.36 on a sparc64 machine (1343.49 BogoMips)
___________________________________________________________________

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