فهرست منبع

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@linux.intel.com>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Yinghai Lu <yinghai@kernel.org>
H. Peter Anvin 16 سال پیش
والد
کامیت
60ac982139
1فایلهای تغییر یافته به همراه2 افزوده شده و 1 حذف شده
  1. 2 1
      arch/x86/kernel/head_32.S

+ 2 - 1
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: