Messages in this thread | | | Date | Thu, 23 Jul 2015 13:59:11 -0700 | From | Andrew Morton <> | Subject | Re: [PATCHv2 2/6] x86, mpx: do not set ->vm_ops on mpx VMAs |
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On Fri, 17 Jul 2015 14:53:09 +0300 "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> wrote:
> MPX setups private anonymous mapping, but uses vma->vm_ops too. > This can confuse core VM, as it relies on vm->vm_ops to distinguish > file VMAs from anonymous. > > As result we will get SIGBUS, because handle_pte_fault() thinks it's > file VMA without vm_ops->fault and it doesn't know how to handle the > situation properly. > > Let's fix that by not setting ->vm_ops. > > We don't really need ->vm_ops here: MPX VMA can be detected with VM_MPX > flag. And vma_merge() will not merge MPX VMA with non-MPX VMA, because > ->vm_flags won't match. > > The only thing left is name of VMA. I'm not sure if it's part of ABI, or > we can just drop it. The patch keep it by providing arch_vma_name() on x86. > > Build tested only.
mpx.c has changed.
arch/x86/mm/mpx.c: In function 'try_unmap_single_bt': arch/x86/mm/mpx.c:930: error: implicit declaration of function 'is_mpx_vma'
I'll drop this patch and see what happens.
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