Viewing file:  uaccess.h (9.54 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ALPHA_UACCESS_H
#define __ALPHA_UACCESS_H
/*
* 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.
*
* Or at least it did once upon a time. Nowadays it is a mask that
* defines which bits of the address space are off limits. This is a
* wee bit faster than the above.
*
* For historical reasons, these macros are grossly misnamed.
*/
#define KERNEL_DS ((mm_segment_t) { 0UL })
#define USER_DS ((mm_segment_t) { -0x40000000000UL })
#define get_fs() (current_thread_info()->addr_limit)
#define set_fs(x) (current_thread_info()->addr_limit = (x))
#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
/*
* Is a address valid? This does a straightforward calculation rather
* than tests.
*
* Address valid if:
* - "addr" doesn't have any high-bits set
* - AND "size" doesn't have any high-bits set
* - AND "addr+size-(size != 0)" doesn't have any high-bits set
* - OR we are in kernel mode.
*/
#define __access_ok(addr, size) ({ \
unsigned long __ao_a = (addr), __ao_b = (size); \
unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b; \
(get_fs().seg & (__ao_a | __ao_b | __ao_end)) == 0; })
#define access_ok(addr, size) \
({ \
__chk_user_ptr(addr); \
__access_ok(((unsigned long)(addr)), (size)); \
})
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*
* As the alpha uses the same address space for kernel and user
* data, we can just do these as direct assignments. (Of course, the
* exception handling means that it's no longer "just"...)
*
* Careful to not
* (a) re-use the arguments for side effects (sizeof/typeof is ok)
* (b) require any knowledge of processes at this stage
*/
#define put_user(x, ptr) \
__put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
#define get_user(x, ptr) \
__get_user_check((x), (ptr), sizeof(*(ptr)))
/*
* The "__xxx" versions do not do address space checking, useful when
* doing multiple accesses to the same area (the programmer has to do the
* checks by hand with "access_ok()")
*/
#define __put_user(x, ptr) \
__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
#define __get_user(x, ptr) \
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
/*
* The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to
* encode the bits we need for resolving the exception. See the
* more extensive comments with fixup_inline_exception below for
* more information.
*/
#define EXC(label,cont,res,err) \
".section __ex_table,\"a\"\n" \
" .long "#label"-.\n" \
" lda "#res","#cont"-"#label"("#err")\n" \
".previous\n"
extern void __get_user_unknown(void);
#define __get_user_nocheck(x, ptr, size) \
({ \
long __gu_err = 0; \
unsigned long __gu_val; \
__chk_user_ptr(ptr); \
switch (size) { \
case 1: __get_user_8(ptr); break; \
case 2: __get_user_16(ptr); break; \
case 4: __get_user_32(ptr); break; \
case 8: __get_user_64(ptr); break; \
default: __get_user_unknown(); break; \
} \
(x) = (__force __typeof__(*(ptr))) __gu_val; \
__gu_err; \
})
#define __get_user_check(x, ptr, size) \
({ \
long __gu_err = -EFAULT; \
unsigned long __gu_val = 0; \
const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
if (__access_ok((unsigned long)__gu_addr, size)) { \
__gu_err = 0; \
switch (size) { \
case 1: __get_user_8(__gu_addr); break; \
case 2: __get_user_16(__gu_addr); break; \
case 4: __get_user_32(__gu_addr); break; \
case 8: __get_user_64(__gu_addr); break; \
default: __get_user_unknown(); break; \
} \
} \
(x) = (__force __typeof__(*(ptr))) __gu_val; \
__gu_err; \
})
struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct __user *)(x))
#define __get_user_64(addr) \
__asm__("1: ldq %0,%2\n" \
"2:\n" \
EXC(1b,2b,%0,%1) \
: "=r"(__gu_val), "=r"(__gu_err) \
: "m"(__m(addr)), "1"(__gu_err))
#define __get_user_32(addr) \
__asm__("1: ldl %0,%2\n" \
"2:\n" \
EXC(1b,2b,%0,%1) \
: "=r"(__gu_val), "=r"(__gu_err) \
: "m"(__m(addr)), "1"(__gu_err))
#ifdef __alpha_bwx__
/* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */
#define __get_user_16(addr) \
__asm__("1: ldwu %0,%2\n" \
"2:\n" \
EXC(1b,2b,%0,%1) \
: "=r"(__gu_val), "=r"(__gu_err) \
: "m"(__m(addr)), "1"(__gu_err))
#define __get_user_8(addr) \
__asm__("1: ldbu %0,%2\n" \
"2:\n" \
EXC(1b,2b,%0,%1) \
: "=r"(__gu_val), "=r"(__gu_err) \
: "m"(__m(addr)), "1"(__gu_err))
#else
/* Unfortunately, we can't get an unaligned access trap for the sub-word
load, so we have to do a general unaligned operation. */
#define __get_user_16(addr) \
{ \
long __gu_tmp; \
__asm__("1: ldq_u %0,0(%3)\n" \
"2: ldq_u %1,1(%3)\n" \
" extwl %0,%3,%0\n" \
" extwh %1,%3,%1\n" \
" or %0,%1,%0\n" \
"3:\n" \
EXC(1b,3b,%0,%2) \
EXC(2b,3b,%0,%2) \
: "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err) \
: "r"(addr), "2"(__gu_err)); \
}
#define __get_user_8(addr) \
__asm__("1: ldq_u %0,0(%2)\n" \
" extbl %0,%2,%0\n" \
"2:\n" \
EXC(1b,2b,%0,%1) \
: "=&r"(__gu_val), "=r"(__gu_err) \
: "r"(addr), "1"(__gu_err))
#endif
extern void __put_user_unknown(void);
#define __put_user_nocheck(x, ptr, size) \
({ \
long __pu_err = 0; \
__chk_user_ptr(ptr); \
switch (size) { \
case 1: __put_user_8(x, ptr); break; \
case 2: __put_user_16(x, ptr); break; \
case 4: __put_user_32(x, ptr); break; \
case 8: __put_user_64(x, ptr); break; \
default: __put_user_unknown(); break; \
} \
__pu_err; \
})
#define __put_user_check(x, ptr, size) \
({ \
long __pu_err = -EFAULT; \
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
if (__access_ok((unsigned long)__pu_addr, size)) { \
__pu_err = 0; \
switch (size) { \
case 1: __put_user_8(x, __pu_addr); break; \
case 2: __put_user_16(x, __pu_addr); break; \
case 4: __put_user_32(x, __pu_addr); break; \
case 8: __put_user_64(x, __pu_addr); break; \
default: __put_user_unknown(); break; \
} \
} \
__pu_err; \
})
/*
* The "__put_user_xx()" macros tell gcc they read from memory
* instead of writing: this is because they do not write to
* any memory gcc knows about, so there are no aliasing issues
*/
#define __put_user_64(x, addr) \
__asm__ __volatile__("1: stq %r2,%1\n" \
"2:\n" \
EXC(1b,2b,$31,%0) \
: "=r"(__pu_err) \
: "m" (__m(addr)), "rJ" (x), "0"(__pu_err))
#define __put_user_32(x, addr) \
__asm__ __volatile__("1: stl %r2,%1\n" \
"2:\n" \
EXC(1b,2b,$31,%0) \
: "=r"(__pu_err) \
: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
#ifdef __alpha_bwx__
/* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */
#define __put_user_16(x, addr) \
__asm__ __volatile__("1: stw %r2,%1\n" \
"2:\n" \
EXC(1b,2b,$31,%0) \
: "=r"(__pu_err) \
: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
#define __put_user_8(x, addr) \
__asm__ __volatile__("1: stb %r2,%1\n" \
"2:\n" \
EXC(1b,2b,$31,%0) \
: "=r"(__pu_err) \
: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
#else
/* Unfortunately, we can't get an unaligned access trap for the sub-word
write, so we have to do a general unaligned operation. */
#define __put_user_16(x, addr) \
{ \
long __pu_tmp1, __pu_tmp2, __pu_tmp3, __pu_tmp4; \
__asm__ __volatile__( \
"1: ldq_u %2,1(%5)\n" \
"2: ldq_u %1,0(%5)\n" \
" inswh %6,%5,%4\n" \
" inswl %6,%5,%3\n" \
" mskwh %2,%5,%2\n" \
" mskwl %1,%5,%1\n" \
" or %2,%4,%2\n" \
" or %1,%3,%1\n" \
"3: stq_u %2,1(%5)\n" \
"4: stq_u %1,0(%5)\n" \
"5:\n" \
EXC(1b,5b,$31,%0) \
EXC(2b,5b,$31,%0) \
EXC(3b,5b,$31,%0) \
EXC(4b,5b,$31,%0) \
: "=r"(__pu_err), "=&r"(__pu_tmp1), \
"=&r"(__pu_tmp2), "=&r"(__pu_tmp3), \
"=&r"(__pu_tmp4) \
: "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \
}
#define __put_user_8(x, addr) \
{ \
long __pu_tmp1, __pu_tmp2; \
__asm__ __volatile__( \
"1: ldq_u %1,0(%4)\n" \
" insbl %3,%4,%2\n" \
" mskbl %1,%4,%1\n" \
" or %1,%2,%1\n" \
"2: stq_u %1,0(%4)\n" \
"3:\n" \
EXC(1b,3b,$31,%0) \
EXC(2b,3b,$31,%0) \
: "=r"(__pu_err), \
"=&r"(__pu_tmp1), "=&r"(__pu_tmp2) \
: "r"((unsigned long)(x)), "r"(addr), "0"(__pu_err)); \
}
#endif
/*
* Complex access routines
*/
extern long __copy_user(void *to, const void *from, long len);
static inline unsigned long
raw_copy_from_user(void *to, const void __user *from, unsigned long len)
{
return __copy_user(to, (__force const void *)from, len);
}
static inline unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long len)
{
return __copy_user((__force void *)to, from, len);
}
extern long __clear_user(void __user *to, long len);
extern inline long
clear_user(void __user *to, long len)
{
if (__access_ok((unsigned long)to, len))
len = __clear_user(to, len);
return len;
}
#define user_addr_max() \
(uaccess_kernel() ? ~0UL : TASK_SIZE)
extern long strncpy_from_user(char *dest, const char __user *src, long count);
extern __must_check long strnlen_user(const char __user *str, long n);
#include <asm/extable.h>
#endif /* __ALPHA_UACCESS_H */
|