• Andi Kleen's avatar
    Encode huge page size for VM_FAULT_HWPOISON errors · aa50d3a7
    Andi Kleen authored
    
    
    This fixes a problem introduced with the hugetlb hwpoison handling
    
    The user space SIGBUS signalling wants to know the size of the hugepage
    that caused a HWPOISON fault.
    
    Unfortunately the architecture page fault handlers do not have easy
    access to the struct page.
    
    Pass the information out in the fault error code instead.
    
    I added a separate VM_FAULT_HWPOISON_LARGE bit for this case and encode
    the hpage index in some free upper bits of the fault code. The small
    page hwpoison keeps stays with the VM_FAULT_HWPOISON name to minimize
    changes.
    
    Also add code to hugetlb.h to convert that index into a page shift.
    
    Will be used in a further patch.
    
    Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
    Cc: fengguang.wu@intel.com
    Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
    aa50d3a7
memory.c 97.1 KB