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x86: keep the BIOS area executable

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keep the BIOS area executable.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Ingo Molnar 2008-01-30 13:34:04 +01:00
parent 30551bb3ce
commit 687c4825b6
1 changed files with 22 additions and 7 deletions
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29
arch/x86/mm/pageattr.c
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@ -22,6 +22,27 @@ void clflush_cache_range(void *addr, int size)
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
/*
* We allow the BIOS range to be executable:
*/
#define BIOS_BEGIN 0x000a0000
#define BIOS_END 0x00100000
static inline pgprot_t check_exec(pgprot_t prot, unsigned long address)
{
if (__pa(address) >= BIOS_BEGIN && __pa(address) < BIOS_END)
pgprot_val(prot) &= ~_PAGE_NX;
/*
* Better fail early if someone sets the kernel text to NX.
* Does not cover __inittext
*/
BUG_ON(address >= (unsigned long)&_text &&
address < (unsigned long)&_etext &&
(pgprot_val(prot) & _PAGE_NX));
return prot;
}
pte_t *lookup_address(unsigned long address, int *level)
{
pgd_t *pgd = pgd_offset_k(address);
@ -140,13 +161,7 @@ __change_page_attr(unsigned long address, struct page *page, pgprot_t prot)
BUG_ON(PageLRU(kpte_page));
BUG_ON(PageCompound(kpte_page));
/*
* Better fail early if someone sets the kernel text to NX.
* Does not cover __inittext
*/
BUG_ON(address >= (unsigned long)&_text &&
address < (unsigned long)&_etext &&
(pgprot_val(prot) & _PAGE_NX));
prot = check_exec(prot, address);
if (level == PG_LEVEL_4K) {
set_pte_atomic(kpte, mk_pte(page, canon_pgprot(prot)));