xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

x86: unify noexec handling

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

[ Impact: cleanup ]

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
[ mingo@elte.hu: build fix ]
LKML-Reference: <1240303167.771.69.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Pekka Enberg
2009-04-21 11:39:27 +03:00
committed by Ingo Molnar
parent 8ecee4620e
commit 89388913f2
4 changed files with 63 additions and 90 deletions
Download Patch File Download Diff File Expand all files Collapse all files

67
arch/x86/mm/init.c
View File

@@ -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;