unimore/kernel-hacking-2024-linux-steffo
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x86, cpa: remove USER permission from the very early identity mapping attribute

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remove USER from the PTE/PDE attributes for the very early identity
mapping. We overwrite these mappings with KERNEL attribute later
in the boot. Just being paranoid here as there is no need for USER bit
to be set.

If this breaks something(don't know the history), then we can simply drop
this change.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: arjan@linux.intel.com
Cc: venkatesh.pallipadi@intel.com
Cc: jeremy@goop.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Suresh Siddha 2008-09-23 14:00:37 -07:00 committed by Ingo Molnar
parent b2bc273146
commit 3a85e770aa
1 changed files with 2 additions and 2 deletions
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4
include/asm-x86/pgtable.h
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@ -138,8 +138,8 @@
#ifdef CONFIG_X86_64
#define __PAGE_KERNEL_IDENT_LARGE_EXEC __PAGE_KERNEL_LARGE_EXEC
#else
#define PTE_IDENT_ATTR 0x007 /* PRESENT+RW+USER */
#define PDE_IDENT_ATTR 0x067 /* PRESENT+RW+USER+DIRTY+ACCESSED */
#define PTE_IDENT_ATTR 0x003 /* PRESENT+RW */
#define PDE_IDENT_ATTR 0x063 /* PRESENT+RW+DIRTY+ACCESSED */
#define PGD_IDENT_ATTR 0x001 /* PRESENT (no other attributes) */
#endif