Messages in this thread | | | Date | Wed, 6 Aug 2014 13:21:18 -0400 (EDT) | From | Nicolas Pitre <> | Subject | Re: [PATCH v3 2/2] ARM : change fixmap mapping region to support 32 CPUs |
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On Wed, 6 Aug 2014, Kees Cook wrote:
> With the original code, there is (I think) a page table entry for the > fixmap range. For the latter, there isn't. I see a NULL pgd entry > fault when trying to use it, and noticed that this only exists under > highmem: > > static void __init kmap_init(void) > { > #ifdef CONFIG_HIGHMEM > pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE), > PKMAP_BASE, _PAGE_KERNEL_TABLE); > > fixmap_page_table = early_pte_alloc(pmd_off_k(FIXADDR_START), > FIXADDR_START, _PAGE_KERNEL_TABLE); > #endif > }
The above is wrong. The fixmap PTEs must be allocated unconditionally irrespective of highmem. So the #endif should be moved up by 3 lines.
Nicolas
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