linux/arch/s390/include/asm/uaccess.h
Heiko Carstens a53c8fab3f s390/comments: unify copyright messages and remove file names
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 11:15:04 +02:00

386 lines
10 KiB
C

/*
* S390 version
* Copyright IBM Corp. 1999, 2000
* Author(s): Hartmut Penner (hp@de.ibm.com),
* Martin Schwidefsky (schwidefsky@de.ibm.com)
*
* Derived from "include/asm-i386/uaccess.h"
*/
#ifndef __S390_UACCESS_H
#define __S390_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/sched.h>
#include <linux/errno.h>
#include <asm/ctl_reg.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
/*
* The fs value determines whether argument validity checking should be
* performed or not. If get_fs() == USER_DS, checking is performed, with
* get_fs() == KERNEL_DS, checking is bypassed.
*
* For historical reasons, these macros are grossly misnamed.
*/
#define MAKE_MM_SEG(a) ((mm_segment_t) { (a) })
#define KERNEL_DS MAKE_MM_SEG(0)
#define USER_DS MAKE_MM_SEG(1)
#define get_ds() (KERNEL_DS)
#define get_fs() (current->thread.mm_segment)
#define set_fs(x) \
({ \
unsigned long __pto; \
current->thread.mm_segment = (x); \
__pto = current->thread.mm_segment.ar4 ? \
S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
__ctl_load(__pto, 7, 7); \
})
#define segment_eq(a,b) ((a).ar4 == (b).ar4)
static inline int __range_ok(unsigned long addr, unsigned long size)
{
return 1;
}
#define __access_ok(addr, size) \
({ \
__chk_user_ptr(addr); \
__range_ok((unsigned long)(addr), (size)); \
})
#define access_ok(type, addr, size) __access_ok(addr, size)
/*
* The exception table consists of pairs of addresses: the first is the
* address of an instruction that is allowed to fault, and the second is
* the address at which the program should continue. No registers are
* modified, so it is entirely up to the continuation code to figure out
* what to do.
*
* All the routines below use bits of fixup code that are out of line
* with the main instruction path. This means when everything is well,
* we don't even have to jump over them. Further, they do not intrude
* on our cache or tlb entries.
*/
struct exception_table_entry
{
unsigned long insn, fixup;
};
struct uaccess_ops {
size_t (*copy_from_user)(size_t, const void __user *, void *);
size_t (*copy_from_user_small)(size_t, const void __user *, void *);
size_t (*copy_to_user)(size_t, void __user *, const void *);
size_t (*copy_to_user_small)(size_t, void __user *, const void *);
size_t (*copy_in_user)(size_t, void __user *, const void __user *);
size_t (*clear_user)(size_t, void __user *);
size_t (*strnlen_user)(size_t, const char __user *);
size_t (*strncpy_from_user)(size_t, const char __user *, char *);
int (*futex_atomic_op)(int op, u32 __user *, int oparg, int *old);
int (*futex_atomic_cmpxchg)(u32 *, u32 __user *, u32 old, u32 new);
};
extern struct uaccess_ops uaccess;
extern struct uaccess_ops uaccess_std;
extern struct uaccess_ops uaccess_mvcos;
extern struct uaccess_ops uaccess_mvcos_switch;
extern struct uaccess_ops uaccess_pt;
extern int __handle_fault(unsigned long, unsigned long, int);
static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
{
size = uaccess.copy_to_user_small(size, ptr, x);
return size ? -EFAULT : size;
}
static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
{
size = uaccess.copy_from_user_small(size, ptr, x);
return size ? -EFAULT : size;
}
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*/
#define __put_user(x, ptr) \
({ \
__typeof__(*(ptr)) __x = (x); \
int __pu_err = -EFAULT; \
__chk_user_ptr(ptr); \
switch (sizeof (*(ptr))) { \
case 1: \
case 2: \
case 4: \
case 8: \
__pu_err = __put_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
break; \
default: \
__put_user_bad(); \
break; \
} \
__pu_err; \
})
#define put_user(x, ptr) \
({ \
might_fault(); \
__put_user(x, ptr); \
})
extern int __put_user_bad(void) __attribute__((noreturn));
#define __get_user(x, ptr) \
({ \
int __gu_err = -EFAULT; \
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: { \
unsigned char __x; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 2: { \
unsigned short __x; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 4: { \
unsigned int __x; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 8: { \
unsigned long long __x; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
default: \
__get_user_bad(); \
break; \
} \
__gu_err; \
})
#define get_user(x, ptr) \
({ \
might_fault(); \
__get_user(x, ptr); \
})
extern int __get_user_bad(void) __attribute__((noreturn));
#define __put_user_unaligned __put_user
#define __get_user_unaligned __get_user
/**
* __copy_to_user: - Copy a block of data into user space, with less checking.
* @to: Destination address, in user space.
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from kernel space to user space. Caller must check
* the specified block with access_ok() before calling this function.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*/
static inline unsigned long __must_check
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
if (__builtin_constant_p(n) && (n <= 256))
return uaccess.copy_to_user_small(n, to, from);
else
return uaccess.copy_to_user(n, to, from);
}
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user
/**
* copy_to_user: - Copy a block of data into user space.
* @to: Destination address, in user space.
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from kernel space to user space.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*/
static inline unsigned long __must_check
copy_to_user(void __user *to, const void *from, unsigned long n)
{
might_fault();
if (access_ok(VERIFY_WRITE, to, n))
n = __copy_to_user(to, from, n);
return n;
}
/**
* __copy_from_user: - Copy a block of data from user space, with less checking.
* @to: Destination address, in kernel space.
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from user space to kernel space. Caller must check
* the specified block with access_ok() before calling this function.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*
* If some data could not be copied, this function will pad the copied
* data to the requested size using zero bytes.
*/
static inline unsigned long __must_check
__copy_from_user(void *to, const void __user *from, unsigned long n)
{
if (__builtin_constant_p(n) && (n <= 256))
return uaccess.copy_from_user_small(n, from, to);
else
return uaccess.copy_from_user(n, from, to);
}
extern void copy_from_user_overflow(void)
#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
__compiletime_warning("copy_from_user() buffer size is not provably correct")
#endif
;
/**
* copy_from_user: - Copy a block of data from user space.
* @to: Destination address, in kernel space.
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from user space to kernel space.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*
* If some data could not be copied, this function will pad the copied
* data to the requested size using zero bytes.
*/
static inline unsigned long __must_check
copy_from_user(void *to, const void __user *from, unsigned long n)
{
unsigned int sz = __compiletime_object_size(to);
might_fault();
if (unlikely(sz != -1 && sz < n)) {
copy_from_user_overflow();
return n;
}
if (access_ok(VERIFY_READ, from, n))
n = __copy_from_user(to, from, n);
else
memset(to, 0, n);
return n;
}
static inline unsigned long __must_check
__copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
return uaccess.copy_in_user(n, to, from);
}
static inline unsigned long __must_check
copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
might_fault();
if (__access_ok(from,n) && __access_ok(to,n))
n = __copy_in_user(to, from, n);
return n;
}
/*
* Copy a null terminated string from userspace.
*/
static inline long __must_check
strncpy_from_user(char *dst, const char __user *src, long count)
{
long res = -EFAULT;
might_fault();
if (access_ok(VERIFY_READ, src, 1))
res = uaccess.strncpy_from_user(count, src, dst);
return res;
}
static inline unsigned long
strnlen_user(const char __user * src, unsigned long n)
{
might_fault();
return uaccess.strnlen_user(n, src);
}
/**
* strlen_user: - Get the size of a string in user space.
* @str: The string to measure.
*
* Context: User context only. This function may sleep.
*
* Get the size of a NUL-terminated string in user space.
*
* Returns the size of the string INCLUDING the terminating NUL.
* On exception, returns 0.
*
* If there is a limit on the length of a valid string, you may wish to
* consider using strnlen_user() instead.
*/
#define strlen_user(str) strnlen_user(str, ~0UL)
/*
* Zero Userspace
*/
static inline unsigned long __must_check
__clear_user(void __user *to, unsigned long n)
{
return uaccess.clear_user(n, to);
}
static inline unsigned long __must_check
clear_user(void __user *to, unsigned long n)
{
might_fault();
if (access_ok(VERIFY_WRITE, to, n))
n = uaccess.clear_user(n, to);
return n;
}
extern int copy_to_user_real(void __user *dest, void *src, size_t count);
extern int copy_from_user_real(void *dest, void __user *src, size_t count);
#endif /* __S390_UACCESS_H */