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authorJan Beulich <jbeulich@novell.com>2007-05-02 19:27:10 +0200
committerAndi Kleen <andi@basil.nowhere.org>2007-05-02 19:27:10 +0200
commit6fb14755a676282a4e6caa05a08c92db8e45cfff (patch)
tree71a862edf87cafe61986c0aff90db72045cf14c3 /include/linux
parentd01ad8dd56527be72947b4b9997bb2c05783c3ed (diff)
[PATCH] x86: tighten kernel image page access rights
On x86-64, kernel memory freed after init can be entirely unmapped instead of just getting 'poisoned' by overwriting with a debug pattern. On i386 and x86-64 (under CONFIG_DEBUG_RODATA), kernel text and bug table can also be write-protected. Compared to the first version, this one prevents re-creating deleted mappings in the kernel image range on x86-64, if those got removed previously. This, together with the original changes, prevents temporarily having inconsistent mappings when cacheability attributes are being changed on such pages (e.g. from AGP code). While on i386 such duplicate mappings don't exist, the same change is done there, too, both for consistency and because checking pte_present() before using various other pte_XXX functions is a requirement anyway. At once, i386 code gets adjusted to use pte_huge() instead of open coding this. AK: split out cpa() changes Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/poison.h3
1 files changed, 0 insertions, 3 deletions
diff --git a/include/linux/poison.h b/include/linux/poison.h
index 3e628f990fd..89580b76495 100644
--- a/include/linux/poison.h
+++ b/include/linux/poison.h
@@ -26,9 +26,6 @@
/********** arch/$ARCH/mm/init.c **********/
#define POISON_FREE_INITMEM 0xcc
-/********** arch/x86_64/mm/init.c **********/
-#define POISON_FREE_INITDATA 0xba
-
/********** arch/ia64/hp/common/sba_iommu.c **********/
/*
* arch/ia64/hp/common/sba_iommu.c uses a 16-byte poison string with a