On Thu, Jul 23, 2015 at 01:59:11PM -0700, Andrew Morton wrote: > On Fri, 17 Jul 2015 14:53:09 +0300 "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> 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. Ingo has applied an updated version to x86/urgent: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?h=x86/urgent&id=a89652769470d12cd484ee3d3f7bde0742be8d96 -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>