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path: root/arch/powerpc/include/asm/pte-hash64-64k.h
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2009-06-26powerpc/mm: Fix potential access to freed pages when using hugetlbfsBenjamin Herrenschmidt
When using 64k page sizes, our PTE pages are split in two halves, the second half containing the "extension" used to keep track of individual 4k pages when not using HW 64k pages. However, our page tables used for hugetlb have a slightly different format and don't carry that "second half". Our code that batched PTEs to be invalidated unconditionally reads the "second half" (to put it into the batch), which means that when called to invalidate hugetlb PTEs, it will access unrelated memory. It breaks when CONFIG_DEBUG_PAGEALLOC is enabled. This fixes it by only accessing the second half when the _PAGE_COMBO bit is set in the first half, which indicates that we are dealing with a "combo" page which represents 16x4k subpages. Anything else shouldn't have this bit set and thus not require loading from the second half. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-03-20powerpc/mm: Split the various pgtable-* headers based on MMU typeBenjamin Herrenschmidt
This patch moves the definition of the PTE format for each MMU type to separate files instead of all in one file. This improves overall maintainability and will make it easier to add new types. On 64-bit, additionally, I've separated the headers relative to the format of the page table tree (3 vs. 4 levels for 64K vs 4K pages) from the headers specific to the PTE format for hash based processors, this will make it easier to add support for Book3 "E" 64-bit implementations. There are still some type-related ifdef's in the generic headers, we might remove them in the long run, but this patch shouldn't result in any code change, -hopefully- just definitions being moved around. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>