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/* SPDX-License-Identifier: GPL-2.0 */
/*
* uaccess.h: User space memore access functions.
*
* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
* Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#ifndef _ASM_UACCESS_H
#define _ASM_UACCESS_H
#include <linux/compiler.h>
#include <linux/string.h>
#include <asm/processor.h>
#define ARCH_HAS_SORT_EXTABLE
#define ARCH_HAS_SEARCH_EXTABLE
/* Sparc is not segmented, however we need to be able to fool access_ok()
* when doing system calls from kernel mode legitimately.
*
* "For historical reasons, these macros are grossly misnamed." -Linus
*/
#define KERNEL_DS ((mm_segment_t) { 0 })
#define USER_DS ((mm_segment_t) { -1 })
#define get_fs() (current->thread.current_ds)
#define set_fs(val) ((current->thread.current_ds) = (val))
#define segment_eq(a, b) ((a).seg == (b).seg)
/* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test
* can be fairly lightweight.
* No one can read/write anything from userland in the kernel space by setting
* large size and address near to PAGE_OFFSET - a fault will break his intentions.
*/
#define __user_ok(addr, size) ({ (void)(size); (addr) < STACK_TOP; })
#define __kernel_ok (uaccess_kernel())
#define __access_ok(addr, size) (__user_ok((addr) & get_fs().seg, (size)))
#define access_ok(addr, size) __access_ok((unsigned long)(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.
*
* There is a special way how to put a range of potentially faulting
* insns (like twenty ldd/std's with now intervening other instructions)
* You specify address of first in insn and 0 in fixup and in the next
* exception_table_entry you specify last potentially faulting insn + 1
* and in fixup the routine which should handle the fault.
* That fixup code will get
* (faulting_insn_address - first_insn_in_the_range_address)/4
* in %g2 (ie. index of the faulting instruction in the range).
*/
struct exception_table_entry
{
unsigned long insn, fixup;
};
/* Returns 0 if exception not found and fixup otherwise. */
unsigned long search_extables_range(unsigned long addr, unsigned long *g2);
/* Uh, these should become the main single-value transfer routines..
* They automatically use the right size if we just have the right
* pointer type..
*
* This gets kind of ugly. We want to return _two_ values in "get_user()"
* and yet we don't want to do any pointers, because that is too much
* of a performance impact. Thus we have a few rather ugly macros here,
* and hide all the ugliness from the user.
*/
#define put_user(x, ptr) ({ \
unsigned long __pu_addr = (unsigned long)(ptr); \
__chk_user_ptr(ptr); \
__put_user_check((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr))); \
})
#define get_user(x, ptr) ({ \
unsigned long __gu_addr = (unsigned long)(ptr); \
__chk_user_ptr(ptr); \
__get_user_check((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr))); \
})
/*
* The "__xxx" versions do not do address space checking, useful when
* doing multiple accesses to the same area (the user 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)), __typeof__(*(ptr)))
struct __large_struct { unsigned long buf[100]; };
#define __m(x) ((struct __large_struct __user *)(x))
#define __put_user_check(x, addr, size) ({ \
register int __pu_ret; \
if (__access_ok(addr, size)) { \
switch (size) { \
case 1: \
__put_user_asm(x, b, addr, __pu_ret); \
break; \
case 2: \
__put_user_asm(x, h, addr, __pu_ret); \
break; \
case 4: \
__put_user_asm(x, , addr, __pu_ret); \
break; \
case 8: \
__put_user_asm(x, d, addr, __pu_ret); \
break; \
default: \
__pu_ret = __put_user_bad(); \
break; \
} \
} else { \
__pu_ret = -EFAULT; \
} \
__pu_ret; \
})
#define __put_user_nocheck(x, addr, size) ({ \
register int __pu_ret; \
switch (size) { \
case 1: __put_user_asm(x, b, addr, __pu_ret); break; \
case 2: __put_user_asm(x, h, addr, __pu_ret); break; \
case 4: __put_user_asm(x, , addr, __pu_ret); break; \
case 8: __put_user_asm(x, d, addr, __pu_ret); break; \
default: __pu_ret = __put_user_bad(); break; \
} \
__pu_ret; \
})
#define __put_user_asm(x, size, addr, ret) \
__asm__ __volatile__( \
"/* Put user asm, inline. */\n" \
"1:\t" "st"#size " %1, %2\n\t" \
"clr %0\n" \
"2:\n\n\t" \
".section .fixup,#alloc,#execinstr\n\t" \
".align 4\n" \
"3:\n\t" \
"b 2b\n\t" \
" mov %3, %0\n\t" \
".previous\n\n\t" \
".section __ex_table,#alloc\n\t" \
".align 4\n\t" \
".word 1b, 3b\n\t" \
".previous\n\n\t" \
: "=&r" (ret) : "r" (x), "m" (*__m(addr)), \
"i" (-EFAULT))
int __put_user_bad(void);
#define __get_user_check(x, addr, size, type) ({ \
register int __gu_ret; \
register unsigned long __gu_val; \
if (__access_ok(addr, size)) { \
switch (size) { \
case 1: \
__get_user_asm(__gu_val, ub, addr, __gu_ret); \
break; \
case 2: \
__get_user_asm(__gu_val, uh, addr, __gu_ret); \
break; \
case 4: \
__get_user_asm(__gu_val, , addr, __gu_ret); \
break; \
case 8: \
__get_user_asm(__gu_val, d, addr, __gu_ret); \
break; \
default: \
__gu_val = 0; \
__gu_ret = __get_user_bad(); \
break; \
} \
} else { \
__gu_val = 0; \
__gu_ret = -EFAULT; \
} \
x = (__force type) __gu_val; \
__gu_ret; \
})
#define __get_user_nocheck(x, addr, size, type) ({ \
register int __gu_ret; \
register unsigned long __gu_val; \
switch (size) { \
case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
case 4: __get_user_asm(__gu_val, , addr, __gu_ret); break; \
case 8: __get_user_asm(__gu_val, d, addr, __gu_ret); break; \
default: \
__gu_val = 0; \
__gu_ret = __get_user_bad(); \
break; \
} \
x = (__force type) __gu_val; \
__gu_ret; \
})
#define __get_user_asm(x, size, addr, ret) \
__asm__ __volatile__( \
"/* Get user asm, inline. */\n" \
"1:\t" "ld"#size " %2, %1\n\t" \
"clr %0\n" \
"2:\n\n\t" \
".section .fixup,#alloc,#execinstr\n\t" \
".align 4\n" \
"3:\n\t" \
"clr %1\n\t" \
"b 2b\n\t" \
" mov %3, %0\n\n\t" \
".previous\n\t" \
".section __ex_table,#alloc\n\t" \
".align 4\n\t" \
".word 1b, 3b\n\n\t" \
".previous\n\t" \
: "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \
"i" (-EFAULT))
int __get_user_bad(void);
unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size);
static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
return __copy_user(to, (__force void __user *) from, n);
}
static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
{
return __copy_user((__force void __user *) to, from, n);
}
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
static inline unsigned long __clear_user(void __user *addr, unsigned long size)
{
unsigned long ret;
__asm__ __volatile__ (
".section __ex_table,#alloc\n\t"
".align 4\n\t"
".word 1f,3\n\t"
".previous\n\t"
"mov %2, %%o1\n"
"1:\n\t"
"call __bzero\n\t"
" mov %1, %%o0\n\t"
"mov %%o0, %0\n"
: "=r" (ret) : "r" (addr), "r" (size) :
"o0", "o1", "o2", "o3", "o4", "o5", "o7",
"g1", "g2", "g3", "g4", "g5", "g7", "cc");
return ret;
}
static inline unsigned long clear_user(void __user *addr, unsigned long n)
{
if (n && __access_ok((unsigned long) addr, n))
return __clear_user(addr, n);
else
return n;
}
__must_check long strnlen_user(const char __user *str, long n);
#endif /* _ASM_UACCESS_H */
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