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x86: properly annotate alternatives.c 

Some of the NOPs tables aren't used on 64-bits, quite some code and
data is needed post-init for module loading only, and a couple of
functions aren't used outside that file (i.e. can be static, and don't
need to be exported).

The change to __INITDATA/__INITRODATA is needed to avoid an assembler
warning.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4A8BC8A00200007800010823@vpn.id2.novell.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
Jan Beulich 2009-08-19 08:40:48 +01:00 committed by H. Peter Anvin
parent c7425314c7
commit 8b5a10fc6f
3 changed files with 42 additions and 33 deletions
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7
arch/x86/include/asm/alternative.h
View File

@ -73,8 +73,6 @@ static inline void alternatives_smp_module_del(struct module *mod) {}
static inline void alternatives_smp_switch(int smp) {}
#endif /* CONFIG_SMP */
const unsigned char *const *find_nop_table(void);
/* alternative assembly primitive: */
#define ALTERNATIVE(oldinstr, newinstr, feature) \
\
@ -144,8 +142,6 @@ static inline void apply_paravirt(struct paravirt_patch_site *start,
#define __parainstructions_end NULL
#endif
extern void add_nops(void *insns, unsigned int len);
/*
* Clear and restore the kernel write-protection flag on the local CPU.
* Allows the kernel to edit read-only pages.
@ -161,10 +157,7 @@ extern void add_nops(void *insns, unsigned int len);
* Intel's errata.
* On the local CPU you need to be protected again NMI or MCE handlers seeing an
* inconsistent instruction while you patch.
* The _early version expects the memory to already be RW.
*/
extern void *text_poke(void *addr, const void *opcode, size_t len);
extern void *text_poke_early(void *addr, const void *opcode, size_t len);
#endif /* _ASM_X86_ALTERNATIVE_H */

56
arch/x86/kernel/alternative.c
View File

@ -2,6 +2,7 @@
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/stringify.h>
#include <linux/kprobes.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
@ -32,7 +33,7 @@ __setup("smp-alt-boot", bootonly);
#define smp_alt_once 1
#endif
static int debug_alternative;
static int __initdata_or_module debug_alternative;
static int __init debug_alt(char *str)
{
@ -51,7 +52,7 @@ static int __init setup_noreplace_smp(char *str)
__setup("noreplace-smp", setup_noreplace_smp);
#ifdef CONFIG_PARAVIRT
static int noreplace_paravirt = 0;
static int __initdata_or_module noreplace_paravirt = 0;
static int __init setup_noreplace_paravirt(char *str)
{
@ -64,16 +65,17 @@ __setup("noreplace-paravirt", setup_noreplace_paravirt);
#define DPRINTK(fmt, args...) if (debug_alternative) \
printk(KERN_DEBUG fmt, args)
#ifdef GENERIC_NOP1
#if defined(GENERIC_NOP1) && !defined(CONFIG_X86_64)
/* 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: "
asm("\t" __stringify(__INITRODATA_OR_MODULE) "\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] = {
static const unsigned char *const __initconst_or_module
intel_nops[ASM_NOP_MAX+1] = {
NULL,
intelnops,
intelnops + 1,
@ -87,12 +89,13 @@ static const unsigned char *const intel_nops[ASM_NOP_MAX+1] = {
#endif
#ifdef K8_NOP1
asm("\t.section .rodata, \"a\"\nk8nops: "
asm("\t" __stringify(__INITRODATA_OR_MODULE) "\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] = {
static const unsigned char *const __initconst_or_module
k8_nops[ASM_NOP_MAX+1] = {
NULL,
k8nops,
k8nops + 1,
@ -105,13 +108,14 @@ static const unsigned char *const k8_nops[ASM_NOP_MAX+1] = {
};
#endif
#ifdef K7_NOP1
asm("\t.section .rodata, \"a\"\nk7nops: "
#if defined(K7_NOP1) && !defined(CONFIG_X86_64)
asm("\t" __stringify(__INITRODATA_OR_MODULE) "\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] = {
static const unsigned char *const __initconst_or_module
k7_nops[ASM_NOP_MAX+1] = {
NULL,
k7nops,
k7nops + 1,
@ -125,12 +129,13 @@ static const unsigned char *const k7_nops[ASM_NOP_MAX+1] = {
#endif
#ifdef P6_NOP1
asm("\t.section .rodata, \"a\"\np6nops: "
asm("\t" __stringify(__INITRODATA_OR_MODULE) "\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] = {
static const unsigned char *const __initconst_or_module
p6_nops[ASM_NOP_MAX+1] = {
NULL,
p6nops,
p6nops + 1,
@ -146,7 +151,7 @@ static const unsigned char *const p6_nops[ASM_NOP_MAX+1] = {
#ifdef CONFIG_X86_64
extern char __vsyscall_0;
const unsigned char *const *find_nop_table(void)
static const unsigned char *const *__init_or_module find_nop_table(void)
{
if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
boot_cpu_has(X86_FEATURE_NOPL))
@ -157,7 +162,7 @@ const unsigned char *const *find_nop_table(void)
#else /* CONFIG_X86_64 */
const unsigned char *const *find_nop_table(void)
static const unsigned char *const *__init_or_module find_nop_table(void)
{
if (boot_cpu_has(X86_FEATURE_K8))
return k8_nops;
@ -172,7 +177,7 @@ const unsigned char *const *find_nop_table(void)
#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)
static void __init_or_module add_nops(void *insns, unsigned int len)
{
const unsigned char *const *noptable = find_nop_table();
@ -185,10 +190,10 @@ void add_nops(void *insns, unsigned int len)
len -= noplen;
}
}
EXPORT_SYMBOL_GPL(add_nops);
extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
extern u8 *__smp_locks[], *__smp_locks_end[];
static void *text_poke_early(void *addr, const void *opcode, size_t len);
/* Replace instructions with better alternatives for this CPU type.
This runs before SMP is initialized to avoid SMP problems with
@ -196,7 +201,8 @@ extern u8 *__smp_locks[], *__smp_locks_end[];
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)
void __init_or_module apply_alternatives(struct alt_instr *start,
struct alt_instr *end)
{
struct alt_instr *a;
char insnbuf[MAX_PATCH_LEN];
@ -279,9 +285,10 @@ static LIST_HEAD(smp_alt_modules);
static DEFINE_MUTEX(smp_alt);
static int smp_mode = 1; /* protected by smp_alt */
void alternatives_smp_module_add(struct module *mod, char *name,
void *locks, void *locks_end,
void *text, void *text_end)
void __init_or_module alternatives_smp_module_add(struct module *mod,
char *name,
void *locks, void *locks_end,
void *text, void *text_end)
{
struct smp_alt_module *smp;
@ -317,7 +324,7 @@ void alternatives_smp_module_add(struct module *mod, char *name,
mutex_unlock(&smp_alt);
}
void alternatives_smp_module_del(struct module *mod)
void __init_or_module alternatives_smp_module_del(struct module *mod)
{
struct smp_alt_module *item;
@ -386,8 +393,8 @@ void alternatives_smp_switch(int smp)
#endif
#ifdef CONFIG_PARAVIRT
void apply_paravirt(struct paravirt_patch_site *start,
struct paravirt_patch_site *end)
void __init_or_module apply_paravirt(struct paravirt_patch_site *start,
struct paravirt_patch_site *end)
{
struct paravirt_patch_site *p;
char insnbuf[MAX_PATCH_LEN];
@ -485,7 +492,8 @@ void __init alternative_instructions(void)
* instructions. And on the local CPU you need to be protected again NMI or MCE
* handlers seeing an inconsistent instruction while you patch.
*/
void *text_poke_early(void *addr, const void *opcode, size_t len)
static void *__init_or_module text_poke_early(void *addr, const void *opcode,
size_t len)
{
unsigned long flags;
local_irq_save(flags);

12
include/linux/init.h
View File

@ -103,8 +103,8 @@
#define __INIT .section ".init.text","ax"
#define __FINIT .previous
#define __INITDATA .section ".init.data","aw"
#define __INITRODATA .section ".init.rodata","a"
#define __INITDATA .section ".init.data","aw",%progbits
#define __INITRODATA .section ".init.rodata","a",%progbits
#define __FINITDATA .previous
#define __DEVINIT .section ".devinit.text", "ax"
@ -305,9 +305,17 @@ void __init parse_early_options(char *cmdline);
#ifdef CONFIG_MODULES
#define __init_or_module
#define __initdata_or_module
#define __initconst_or_module
#define __INIT_OR_MODULE .text
#define __INITDATA_OR_MODULE .data
#define __INITRODATA_OR_MODULE .section ".rodata","a",%progbits
#else
#define __init_or_module __init
#define __initdata_or_module __initdata
#define __initconst_or_module __initconst
#define __INIT_OR_MODULE __INIT
#define __INITDATA_OR_MODULE __INITDATA
#define __INITRODATA_OR_MODULE __INITRODATA
#endif /*CONFIG_MODULES*/
/* Functions marked as __devexit may be discarded at kernel link time, depending