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#include <linux/module.h>
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/kprobes.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/memory.h>
#include <asm/alternative.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
#include <asm/mce.h>
#include <asm/nmi.h>
#include <asm/vsyscall.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/io.h>
#include <asm/fixmap.h>
#define MAX_PATCH_LEN (255-1)
#ifdef CONFIG_HOTPLUG_CPU
static int smp_alt_once;
static int __init bootonly(char *str)
{
smp_alt_once = 1;
return 1;
}
__setup("smp-alt-boot", bootonly);
#else
#define smp_alt_once 1
#endif
static int debug_alternative;
static int __init debug_alt(char *str)
{
debug_alternative = 1;
return 1;
}
__setup("debug-alternative", debug_alt);
static int noreplace_smp;
static int __init setup_noreplace_smp(char *str)
{
noreplace_smp = 1;
return 1;
}
__setup("noreplace-smp", setup_noreplace_smp);
#ifdef CONFIG_PARAVIRT
static int noreplace_paravirt = 0;
static int __init setup_noreplace_paravirt(char *str)
{
noreplace_paravirt = 1;
return 1;
}
__setup("noreplace-paravirt", setup_noreplace_paravirt);
#endif
#define DPRINTK(fmt, args...) if (debug_alternative) \
printk(KERN_DEBUG fmt, args)
#ifdef GENERIC_NOP1
/* Use inline assembly to define this because the nops are defined
as inline assembly strings in the include files and we cannot
get them easily into strings. */
asm("\t.section .rodata, \"a\"\nintelnops: "
GENERIC_NOP1 GENERIC_NOP2 GENERIC_NOP3 GENERIC_NOP4 GENERIC_NOP5 GENERIC_NOP6
GENERIC_NOP7 GENERIC_NOP8
"\t.previous");
extern const unsigned char intelnops[];
static const unsigned char *const intel_nops[ASM_NOP_MAX+1] = {
NULL,
intelnops,
intelnops + 1,
intelnops + 1 + 2,
intelnops + 1 + 2 + 3,
intelnops + 1 + 2 + 3 + 4,
intelnops + 1 + 2 + 3 + 4 + 5,
intelnops + 1 + 2 + 3 + 4 + 5 + 6,
intelnops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
};
#endif
#ifdef K8_NOP1
asm("\t.section .rodata, \"a\"\nk8nops: "
K8_NOP1 K8_NOP2 K8_NOP3 K8_NOP4 K8_NOP5 K8_NOP6
K8_NOP7 K8_NOP8
"\t.previous");
extern const unsigned char k8nops[];
static const unsigned char *const k8_nops[ASM_NOP_MAX+1] = {
NULL,
k8nops,
k8nops + 1,
k8nops + 1 + 2,
k8nops + 1 + 2 + 3,
k8nops + 1 + 2 + 3 + 4,
k8nops + 1 + 2 + 3 + 4 + 5,
k8nops + 1 + 2 + 3 + 4 + 5 + 6,
k8nops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
};
#endif
#ifdef K7_NOP1
asm("\t.section .rodata, \"a\"\nk7nops: "
K7_NOP1 K7_NOP2 K7_NOP3 K7_NOP4 K7_NOP5 K7_NOP6
K7_NOP7 K7_NOP8
"\t.previous");
extern const unsigned char k7nops[];
static const unsigned char *const k7_nops[ASM_NOP_MAX+1] = {
NULL,
k7nops,
k7nops + 1,
k7nops + 1 + 2,
k7nops + 1 + 2 + 3,
k7nops + 1 + 2 + 3 + 4,
k7nops + 1 + 2 + 3 + 4 + 5,
k7nops + 1 + 2 + 3 + 4 + 5 + 6,
k7nops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
};
#endif
#ifdef P6_NOP1
asm("\t.section .rodata, \"a\"\np6nops: "
P6_NOP1 P6_NOP2 P6_NOP3 P6_NOP4 P6_NOP5 P6_NOP6
P6_NOP7 P6_NOP8
"\t.previous");
extern const unsigned char p6nops[];
static const unsigned char *const p6_nops[ASM_NOP_MAX+1] = {
NULL,
p6nops,
p6nops + 1,
p6nops + 1 + 2,
p6nops + 1 + 2 + 3,
p6nops + 1 + 2 + 3 + 4,
p6nops + 1 + 2 + 3 + 4 + 5,
p6nops + 1 + 2 + 3 + 4 + 5 + 6,
p6nops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
};
#endif
#ifdef CONFIG_X86_64
extern char __vsyscall_0;
const unsigned char *const *find_nop_table(void)
{
if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
boot_cpu_has(X86_FEATURE_NOPL))
return p6_nops;
else
return k8_nops;
}
#else /* CONFIG_X86_64 */
const unsigned char *const *find_nop_table(void)
{
if (boot_cpu_has(X86_FEATURE_K8))
return k8_nops;
else if (boot_cpu_has(X86_FEATURE_K7))
return k7_nops;
else if (boot_cpu_has(X86_FEATURE_NOPL))
return p6_nops;
else
return intel_nops;
}
#endif /* CONFIG_X86_64 */
/* Use this to add nops to a buffer, then text_poke the whole buffer. */
void add_nops(void *insns, unsigned int len)
{
const unsigned char *const *noptable = find_nop_table();
while (len > 0) {
unsigned int noplen = len;
if (noplen > ASM_NOP_MAX)
noplen = ASM_NOP_MAX;
memcpy(insns, noptable[noplen], noplen);
insns += noplen;
len -= noplen;
}
}
EXPORT_SYMBOL_GPL(add_nops);
extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
extern u8 *__smp_locks[], *__smp_locks_end[];
/* Replace instructions with better alternatives for this CPU type.
This runs before SMP is initialized to avoid SMP problems with
self modifying code. This implies that assymetric systems where
APs have less capabilities than the boot processor are not handled.
Tough. Make sure you disable such features by hand. */
void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
{
struct alt_instr *a;
char insnbuf[MAX_PATCH_LEN];
DPRINTK("%s: alt table %p -> %p\n", __func__, start, end);
for (a = start; a < end; a++) {
u8 *instr = a->instr;
BUG_ON(a->replacementlen > a->instrlen);
BUG_ON(a->instrlen > sizeof(insnbuf));
if (!boot_cpu_has(a->
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