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Commit 4c3c4b45 authored by Andi Kleen's avatar Andi Kleen Committed by Ingo Molnar
Browse files

x86: clean up pte_exec 



- Rename it to pte_exec() from pte_exec_kernel(). There is nothing
kernel specific in there.
- Move it into the common file because _PAGE_NX is 0 on !PAE and then
pte_exec() will be always evaluate to true.

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent e66a9512

arch/x86/mm/fault_32.c

+1 −1
Original line number Diff line number Diff line
@@ -615,7 +615,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) 
		if (error_code & PF_INSTR) {

			pte_t *pte = lookup_address(address);



			if (pte && pte_present(*pte) && !pte_exec_kernel(*pte))

			if (pte && pte_present(*pte) && !pte_exec(*pte))

				printk(KERN_CRIT "kernel tried to execute "

					"NX-protected page - exploit attempt? "

					"(uid: %d)\n", current->uid);

arch/x86/mm/init_32.c

+1 −1
Original line number Diff line number Diff line
@@ -542,7 +542,7 @@ int __init set_kernel_exec(unsigned long vaddr, int enable) 
	pte = lookup_address(vaddr);

	BUG_ON(!pte);



	if (!pte_exec_kernel(*pte))

	if (!pte_exec(*pte))

		ret = 0;



	if (enable)

include/asm-x86/pgtable-2level.h

+0 −8
Original line number Diff line number Diff line
@@ -55,14 +55,6 @@ static inline pte_t native_ptep_get_and_clear(pte_t *xp) 
#define pte_none(x)		(!(x).pte_low)

#define pte_pfn(x)		(pte_val(x) >> PAGE_SHIFT)



/*

 * All present pages are kernel-executable:

 */

static inline int pte_exec_kernel(pte_t pte)

{

	return 1;

}



/*

 * Bits 0, 6 and 7 are taken, split up the 29 bits of offset

 * into this range:

include/asm-x86/pgtable-3level.h

+0 −8
Original line number Diff line number Diff line
@@ -19,14 +19,6 @@ 
#define pud_bad(pud)				0

#define pud_present(pud)			1



/*

 * All present pages with !NX bit are kernel-executable:

 */

static inline int pte_exec_kernel(pte_t pte)

{

	return !(pte_val(pte) & _PAGE_NX);

}



/* Rules for using set_pte: the pte being assigned *must* be

 * either not present or in a state where the hardware will

 * not attempt to update the pte.  In places where this is

include/asm-x86/pgtable.h

+1 −0
Original line number Diff line number Diff line
@@ -139,6 +139,7 @@ static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; 
static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_RW; }

static inline int pte_file(pte_t pte)		{ return pte_val(pte) & _PAGE_FILE; }

static inline int pte_huge(pte_t pte)		{ return pte_val(pte) & _PAGE_PSE; }

static inline int pte_exec(pte_t pte)		{ return !(pte_val(pte) & _PAGE_NX); }



static inline int pmd_large(pmd_t pte) {

	return (pmd_val(pte) & (_PAGE_PSE|_PAGE_PRESENT)) ==