Commit-ID: 60ac98213914cc615c67e84bfb964aa95a080d13 Gitweb: http://git.kernel.org/tip/60ac98213914cc615c67e84bfb964aa95a080d13 Author: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> AuthorDate: Tue, 17 Mar 2009 11:38:23 -0700 Commit: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> CommitDate: Tue, 17 Mar 2009 11:52:10 -0700 x86-32: tighten the bound on additional memory to map Impact: Tighten bound to avoid masking errors The definition of MAPPING_BEYOND_END was excessive; this has a nasty tendency to mask bugs. We have learned over time that this kind of bug hiding can cause some very strange errors. Therefore, tighten the bound to only need to map the actual kernel area. Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx> Cc: Yinghai Lu <yinghai@xxxxxxxxxx> --- arch/x86/kernel/head_32.S | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index fc884b9..3068388 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -60,7 +60,8 @@ #endif /* Enough space to fit pagetables for the low memory linear map */ -MAPPING_BEYOND_END = (PAGE_TABLE_SIZE(1 << (32 - PAGE_SHIFT)) * PAGE_SIZE) +MAPPING_BEYOND_END = \ + PAGE_TABLE_SIZE(((1<<32) - __PAGE_OFFSET) >> PAGE_SHIFT) << PAGE_SHIFT /* * Worst-case size of the kernel mapping we need to make: -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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