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Commit 687c4825 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86: keep the BIOS area executable 



keep the BIOS area executable.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 30551bb3

arch/x86/mm/pageattr.c

+22 −7
Original line number Diff line number Diff line
@@ -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)));