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Commit 89388913 authored by Pekka Enberg's avatar Pekka Enberg Committed by Ingo Molnar
Browse files

x86: unify noexec handling 



This patch unifies noexec handling on 32-bit and 64-bit.

[ Impact: cleanup ]

Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
[ mingo@elte.hu: build fix ]
LKML-Reference: <1240303167.771.69.camel@penberg-laptop>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 8ecee462

arch/x86/include/asm/pgtable_types.h

+0 −1
Original line number Diff line number Diff line
@@ -273,7 +273,6 @@ typedef struct page *pgtable_t; 


extern pteval_t __supported_pte_mask;

extern int nx_enabled;

extern void set_nx(void);



#define pgprot_writecombine	pgprot_writecombine

extern pgprot_t pgprot_writecombine(pgprot_t prot);

arch/x86/mm/init.c

+63 −4
Original line number Diff line number Diff line
@@ -22,6 +22,69 @@ int direct_gbpages 
#endif

;



int nx_enabled;



#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)

static int disable_nx __cpuinitdata;



/*

 * noexec = on|off

 *

 * Control non-executable mappings for processes.

 *

 * on      Enable

 * off     Disable

 */

static int __init noexec_setup(char *str)

{

	if (!str)

		return -EINVAL;

	if (!strncmp(str, "on", 2)) {

		__supported_pte_mask |= _PAGE_NX;

		disable_nx = 0;

	} else if (!strncmp(str, "off", 3)) {

		disable_nx = 1;

		__supported_pte_mask &= ~_PAGE_NX;

	}

	return 0;

}

early_param("noexec", noexec_setup);

#endif



#ifdef CONFIG_X86_PAE

static void __init set_nx(void)

{

	unsigned int v[4], l, h;



	if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {

		cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);



		if ((v[3] & (1 << 20)) && !disable_nx) {

			rdmsr(MSR_EFER, l, h);

			l |= EFER_NX;

			wrmsr(MSR_EFER, l, h);

			nx_enabled = 1;

			__supported_pte_mask |= _PAGE_NX;

		}

	}

}

#else

static inline void set_nx(void)

{

}

#endif



#ifdef CONFIG_X86_64

void __cpuinit check_efer(void)

{

	unsigned long efer;



	rdmsrl(MSR_EFER, efer);

	if (!(efer & EFER_NX) || disable_nx)

		__supported_pte_mask &= ~_PAGE_NX;

}

#endif



static void __init find_early_table_space(unsigned long end, int use_pse,

					  int use_gbpages)

{
@@ -158,12 +221,9 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, 
	use_gbpages = direct_gbpages;

#endif



#ifdef CONFIG_X86_32

#ifdef CONFIG_X86_PAE

	set_nx();

	if (nx_enabled)

		printk(KERN_INFO "NX (Execute Disable) protection: active\n");

#endif



	/* Enable PSE if available */

	if (cpu_has_pse)
@@ -174,7 +234,6 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, 
		set_in_cr4(X86_CR4_PGE);

		__supported_pte_mask |= _PAGE_GLOBAL;

	}

#endif



	if (use_gbpages)

		page_size_mask |= 1 << PG_LEVEL_1G;

arch/x86/mm/init_32.c

+0 −52
Original line number Diff line number Diff line
@@ -587,61 +587,9 @@ void zap_low_mappings(void) 
	flush_tlb_all();

}



int nx_enabled;



pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);

EXPORT_SYMBOL_GPL(__supported_pte_mask);



#ifdef CONFIG_X86_PAE



static int disable_nx __initdata;



/*

 * noexec = on|off

 *

 * Control non executable mappings.

 *

 * on      Enable

 * off     Disable

 */

static int __init noexec_setup(char *str)

{

	if (!str || !strcmp(str, "on")) {

		if (cpu_has_nx) {

			__supported_pte_mask |= _PAGE_NX;

			disable_nx = 0;

		}

	} else {

		if (!strcmp(str, "off")) {

			disable_nx = 1;

			__supported_pte_mask &= ~_PAGE_NX;

		} else {

			return -EINVAL;

		}

	}



	return 0;

}

early_param("noexec", noexec_setup);



void __init set_nx(void)

{

	unsigned int v[4], l, h;



	if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {

		cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);



		if ((v[3] & (1 << 20)) && !disable_nx) {

			rdmsr(MSR_EFER, l, h);

			l |= EFER_NX;

			wrmsr(MSR_EFER, l, h);

			nx_enabled = 1;

			__supported_pte_mask |= _PAGE_NX;

		}

	}

}

#endif



/* user-defined highmem size */

static unsigned int highmem_pages = -1;

arch/x86/mm/init_64.c

+0 −33
Original line number Diff line number Diff line
@@ -85,39 +85,6 @@ early_param("gbpages", parse_direct_gbpages_on); 
pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;

EXPORT_SYMBOL_GPL(__supported_pte_mask);



static int disable_nx __cpuinitdata;



/*

 * noexec=on|off

 * Control non-executable mappings for 64-bit processes.

 *

 * on	Enable (default)

 * off	Disable

 */

static int __init nonx_setup(char *str)

{

	if (!str)

		return -EINVAL;

	if (!strncmp(str, "on", 2)) {

		__supported_pte_mask |= _PAGE_NX;

		disable_nx = 0;

	} else if (!strncmp(str, "off", 3)) {

		disable_nx = 1;

		__supported_pte_mask &= ~_PAGE_NX;

	}

	return 0;

}

early_param("noexec", nonx_setup);



void __cpuinit check_efer(void)

{

	unsigned long efer;



	rdmsrl(MSR_EFER, efer);

	if (!(efer & EFER_NX) || disable_nx)

		__supported_pte_mask &= ~_PAGE_NX;

}



int force_personality32;



/*