android_kernel_xiaomi_sm8350/arch/x86/include/asm/uaccess_64.h
Frederic Weisbecker 3c93ca00ee x86: Add missing might_fault() checks to copy_{to,from}_user()
On x86-64, copy_[to|from]_user() rely on assembly routines that
never call might_fault(), making us missing various lockdep
checks.

This doesn't apply to __copy_from,to_user() that explicitly
handle these calls, neither is it a problem in x86-32 where
copy_to,from_user() rely on the "__" prefixed versions that
also call might_fault().

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1258382538-30979-1-git-send-email-fweisbec@gmail.com>
[ v2: fix module export ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-16 16:09:52 +01:00

237 lines
6.3 KiB
C

#ifndef _ASM_X86_UACCESS_64_H
#define _ASM_X86_UACCESS_64_H
/*
* User space memory access functions
*/
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/prefetch.h>
#include <linux/lockdep.h>
#include <asm/page.h>
/*
* Copy To/From Userspace
*/
/* Handles exceptions in both to and from, but doesn't do access_ok */
__must_check unsigned long
copy_user_generic(void *to, const void *from, unsigned len);
__must_check unsigned long
_copy_to_user(void __user *to, const void *from, unsigned len);
__must_check unsigned long
_copy_from_user(void *to, const void __user *from, unsigned len);
__must_check unsigned long
copy_in_user(void __user *to, const void __user *from, unsigned len);
static inline unsigned long __must_check copy_from_user(void *to,
const void __user *from,
unsigned long n)
{
int sz = __compiletime_object_size(to);
int ret = -EFAULT;
might_fault();
if (likely(sz == -1 || sz >= n))
ret = _copy_from_user(to, from, n);
#ifdef CONFIG_DEBUG_VM
else
WARN(1, "Buffer overflow detected!\n");
#endif
return ret;
}
static __always_inline __must_check
int copy_to_user(void __user *dst, const void *src, unsigned size)
{
might_fault();
return _copy_to_user(dst, src, size);
}
static __always_inline __must_check
int __copy_from_user(void *dst, const void __user *src, unsigned size)
{
int ret = 0;
might_fault();
if (!__builtin_constant_p(size))
return copy_user_generic(dst, (__force void *)src, size);
switch (size) {
case 1:__get_user_asm(*(u8 *)dst, (u8 __user *)src,
ret, "b", "b", "=q", 1);
return ret;
case 2:__get_user_asm(*(u16 *)dst, (u16 __user *)src,
ret, "w", "w", "=r", 2);
return ret;
case 4:__get_user_asm(*(u32 *)dst, (u32 __user *)src,
ret, "l", "k", "=r", 4);
return ret;
case 8:__get_user_asm(*(u64 *)dst, (u64 __user *)src,
ret, "q", "", "=r", 8);
return ret;
case 10:
__get_user_asm(*(u64 *)dst, (u64 __user *)src,
ret, "q", "", "=r", 10);
if (unlikely(ret))
return ret;
__get_user_asm(*(u16 *)(8 + (char *)dst),
(u16 __user *)(8 + (char __user *)src),
ret, "w", "w", "=r", 2);
return ret;
case 16:
__get_user_asm(*(u64 *)dst, (u64 __user *)src,
ret, "q", "", "=r", 16);
if (unlikely(ret))
return ret;
__get_user_asm(*(u64 *)(8 + (char *)dst),
(u64 __user *)(8 + (char __user *)src),
ret, "q", "", "=r", 8);
return ret;
default:
return copy_user_generic(dst, (__force void *)src, size);
}
}
static __always_inline __must_check
int __copy_to_user(void __user *dst, const void *src, unsigned size)
{
int ret = 0;
might_fault();
if (!__builtin_constant_p(size))
return copy_user_generic((__force void *)dst, src, size);
switch (size) {
case 1:__put_user_asm(*(u8 *)src, (u8 __user *)dst,
ret, "b", "b", "iq", 1);
return ret;
case 2:__put_user_asm(*(u16 *)src, (u16 __user *)dst,
ret, "w", "w", "ir", 2);
return ret;
case 4:__put_user_asm(*(u32 *)src, (u32 __user *)dst,
ret, "l", "k", "ir", 4);
return ret;
case 8:__put_user_asm(*(u64 *)src, (u64 __user *)dst,
ret, "q", "", "er", 8);
return ret;
case 10:
__put_user_asm(*(u64 *)src, (u64 __user *)dst,
ret, "q", "", "er", 10);
if (unlikely(ret))
return ret;
asm("":::"memory");
__put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
ret, "w", "w", "ir", 2);
return ret;
case 16:
__put_user_asm(*(u64 *)src, (u64 __user *)dst,
ret, "q", "", "er", 16);
if (unlikely(ret))
return ret;
asm("":::"memory");
__put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
ret, "q", "", "er", 8);
return ret;
default:
return copy_user_generic((__force void *)dst, src, size);
}
}
static __always_inline __must_check
int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
{
int ret = 0;
might_fault();
if (!__builtin_constant_p(size))
return copy_user_generic((__force void *)dst,
(__force void *)src, size);
switch (size) {
case 1: {
u8 tmp;
__get_user_asm(tmp, (u8 __user *)src,
ret, "b", "b", "=q", 1);
if (likely(!ret))
__put_user_asm(tmp, (u8 __user *)dst,
ret, "b", "b", "iq", 1);
return ret;
}
case 2: {
u16 tmp;
__get_user_asm(tmp, (u16 __user *)src,
ret, "w", "w", "=r", 2);
if (likely(!ret))
__put_user_asm(tmp, (u16 __user *)dst,
ret, "w", "w", "ir", 2);
return ret;
}
case 4: {
u32 tmp;
__get_user_asm(tmp, (u32 __user *)src,
ret, "l", "k", "=r", 4);
if (likely(!ret))
__put_user_asm(tmp, (u32 __user *)dst,
ret, "l", "k", "ir", 4);
return ret;
}
case 8: {
u64 tmp;
__get_user_asm(tmp, (u64 __user *)src,
ret, "q", "", "=r", 8);
if (likely(!ret))
__put_user_asm(tmp, (u64 __user *)dst,
ret, "q", "", "er", 8);
return ret;
}
default:
return copy_user_generic((__force void *)dst,
(__force void *)src, size);
}
}
__must_check long
strncpy_from_user(char *dst, const char __user *src, long count);
__must_check long
__strncpy_from_user(char *dst, const char __user *src, long count);
__must_check long strnlen_user(const char __user *str, long n);
__must_check long __strnlen_user(const char __user *str, long n);
__must_check long strlen_user(const char __user *str);
__must_check unsigned long clear_user(void __user *mem, unsigned long len);
__must_check unsigned long __clear_user(void __user *mem, unsigned long len);
static __must_check __always_inline int
__copy_from_user_inatomic(void *dst, const void __user *src, unsigned size)
{
return copy_user_generic(dst, (__force const void *)src, size);
}
static __must_check __always_inline int
__copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
{
return copy_user_generic((__force void *)dst, src, size);
}
extern long __copy_user_nocache(void *dst, const void __user *src,
unsigned size, int zerorest);
static inline int
__copy_from_user_nocache(void *dst, const void __user *src, unsigned size)
{
might_sleep();
return __copy_user_nocache(dst, src, size, 1);
}
static inline int
__copy_from_user_inatomic_nocache(void *dst, const void __user *src,
unsigned size)
{
return __copy_user_nocache(dst, src, size, 0);
}
unsigned long
copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest);
#endif /* _ASM_X86_UACCESS_64_H */