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Commit 3ee1afa3 authored by Nick Piggin's avatar Nick Piggin Committed by Ingo Molnar
Browse files

x86: some lock annotations for user copy paths, v2 



 - introduce might_fault()
 - handle the atomic user copy paths correctly

[ mingo@elte.hu: move might_sleep() outside of in_atomic(). ]
Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent c10d38dd

arch/x86/lib/usercopy_32.c

+3 −9
Original line number Diff line number Diff line
@@ -32,9 +32,7 @@ static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned lon 
#define __do_strncpy_from_user(dst, src, count, res)			   \

do {									   \

	int __d0, __d1, __d2;						   \

	might_sleep();							   \

	if (current->mm)						   \

		might_lock_read(&current->mm->mmap_sem);		   \

	might_fault();							   \

	__asm__ __volatile__(						   \

		"	testl %1,%1\n"					   \

		"	jz 2f\n"					   \
@@ -121,9 +119,7 @@ EXPORT_SYMBOL(strncpy_from_user); 
#define __do_clear_user(addr,size)					\

do {									\

	int __d0;							\

	might_sleep();							\

	if (current->mm)						\

		might_lock_read(&current->mm->mmap_sem);		\

	might_fault();							\

	__asm__ __volatile__(						\

		"0:	rep; stosl\n"					\

		"	movl %2,%0\n"					\
@@ -193,9 +189,7 @@ long strnlen_user(const char __user *s, long n) 
	unsigned long mask = -__addr_ok(s);

	unsigned long res, tmp;



	might_sleep();

	if (current->mm)

		might_lock_read(&current->mm->mmap_sem);

	might_fault();



	__asm__ __volatile__(

		"	testl %0, %0\n"

arch/x86/lib/usercopy_64.c

+2 −6
Original line number Diff line number Diff line
@@ -15,9 +15,7 @@ 
#define __do_strncpy_from_user(dst,src,count,res)			   \

do {									   \

	long __d0, __d1, __d2;						   \

	might_sleep();							   \

	if (current->mm)						   \

		might_lock_read(&current->mm->mmap_sem);		   \

	might_fault();							   \

	__asm__ __volatile__(						   \

		"	testq %1,%1\n"					   \

		"	jz 2f\n"					   \
@@ -66,9 +64,7 @@ EXPORT_SYMBOL(strncpy_from_user); 
unsigned long __clear_user(void __user *addr, unsigned long size)

{

	long __d0;

	might_sleep();

	if (current->mm)

		might_lock_read(&current->mm->mmap_sem);

	might_fault();

	/* no memory constraint because it doesn't change any memory gcc knows

	   about */

	asm volatile(

include/asm-x86/uaccess.h

+4 −14
Original line number Diff line number Diff line
@@ -8,8 +8,6 @@ 
#include <linux/thread_info.h>

#include <linux/prefetch.h>

#include <linux/string.h>

#include <linux/lockdep.h>

#include <linux/sched.h>

#include <asm/asm.h>

#include <asm/page.h>
@@ -159,9 +157,7 @@ extern int __get_user_bad(void); 
	int __ret_gu;							\

	unsigned long __val_gu;						\

	__chk_user_ptr(ptr);						\

	might_sleep();							\

	if (current->mm)						\

		might_lock_read(&current->mm->mmap_sem);		\

	might_fault();							\

	switch (sizeof(*(ptr))) {					\

	case 1:								\

		__get_user_x(1, __ret_gu, __val_gu, ptr);		\
@@ -246,9 +242,7 @@ extern void __put_user_8(void); 
	int __ret_pu;						\

	__typeof__(*(ptr)) __pu_val;				\

	__chk_user_ptr(ptr);					\

	might_sleep();						\

	if (current->mm)					\

		might_lock_read(&current->mm->mmap_sem);	\

	might_fault();						\

	__pu_val = x;						\

	switch (sizeof(*(ptr))) {				\

	case 1:							\
@@ -273,9 +267,7 @@ extern void __put_user_8(void); 
#define __put_user_size(x, ptr, size, retval, errret)			\

do {									\

	retval = 0;							\

	might_sleep();							\

	if (current->mm)						\

		might_lock_read(&current->mm->mmap_sem);		\

	might_fault();							\

	__chk_user_ptr(ptr);						\

	switch (size) {							\

	case 1:								\
@@ -328,9 +320,7 @@ do { \ 
#define __get_user_size(x, ptr, size, retval, errret)			\

do {									\

	retval = 0;							\

	might_sleep();							\

	if (current->mm)						\

		might_lock_read(&current->mm->mmap_sem);		\

	might_fault();							\

	__chk_user_ptr(ptr);						\

	switch (size) {							\

	case 1:								\

include/asm-x86/uaccess_32.h

+3 −9
Original line number Diff line number Diff line
@@ -82,9 +82,7 @@ __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) 
static __always_inline unsigned long __must_check

__copy_to_user(void __user *to, const void *from, unsigned long n)

{

	might_sleep();

	if (current->mm)

		might_lock_read(&current->mm->mmap_sem);

	might_fault();

	return __copy_to_user_inatomic(to, from, n);

}
@@ -139,9 +137,7 @@ __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) 
static __always_inline unsigned long

__copy_from_user(void *to, const void __user *from, unsigned long n)

{

	might_sleep();

	if (current->mm)

		might_lock_read(&current->mm->mmap_sem);

	might_fault();

	if (__builtin_constant_p(n)) {

		unsigned long ret;
@@ -163,9 +159,7 @@ __copy_from_user(void *to, const void __user *from, unsigned long n) 
static __always_inline unsigned long __copy_from_user_nocache(void *to,

				const void __user *from, unsigned long n)

{

	might_sleep();

	if (current->mm)

		might_lock_read(&current->mm->mmap_sem);

	might_fault();

	if (__builtin_constant_p(n)) {

		unsigned long ret;

include/asm-x86/uaccess_64.h

+3 −9
Original line number Diff line number Diff line
@@ -29,9 +29,7 @@ int __copy_from_user(void *dst, const void __user *src, unsigned size) 
{

	int ret = 0;



	might_sleep();

	if (current->mm)

		might_lock_read(&current->mm->mmap_sem);

	might_fault();

	if (!__builtin_constant_p(size))

		return copy_user_generic(dst, (__force void *)src, size);

	switch (size) {
@@ -75,9 +73,7 @@ int __copy_to_user(void __user *dst, const void *src, unsigned size) 
{

	int ret = 0;



	might_sleep();

	if (current->mm)

		might_lock_read(&current->mm->mmap_sem);

	might_fault();

	if (!__builtin_constant_p(size))

		return copy_user_generic((__force void *)dst, src, size);

	switch (size) {
@@ -121,9 +117,7 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size) 
{

	int ret = 0;



	might_sleep();

	if (current->mm)

		might_lock_read(&current->mm->mmap_sem);

	might_fault();

	if (!__builtin_constant_p(size))

		return copy_user_generic((__force void *)dst,

					 (__force void *)src, size);