1 #ifndef __PARISC_UACCESS_H
2 #define __PARISC_UACCESS_H
5 * User space memory access functions
10 #include <asm-generic/uaccess-unaligned.h>
12 #include <linux/bug.h>
13 #include <linux/string.h>
16 #define VERIFY_WRITE 1
18 #define KERNEL_DS ((mm_segment_t){0})
19 #define USER_DS ((mm_segment_t){1})
21 #define segment_eq(a, b) ((a).seg == (b).seg)
23 #define get_ds() (KERNEL_DS)
24 #define get_fs() (current_thread_info()->addr_limit)
25 #define set_fs(x) (current_thread_info()->addr_limit = (x))
28 * Note that since kernel addresses are in a separate address space on
29 * parisc, we don't need to do anything for access_ok().
30 * We just let the page fault handler do the right thing. This also means
31 * that put_user is the same as __put_user, etc.
34 static inline long access_ok(int type, const void __user * addr,
40 #define put_user __put_user
41 #define get_user __get_user
43 #if !defined(CONFIG_64BIT)
44 #define LDD_USER(ptr) __get_user_asm64(ptr)
45 #define STD_USER(x, ptr) __put_user_asm64(x, ptr)
47 #define LDD_USER(ptr) __get_user_asm("ldd", ptr)
48 #define STD_USER(x, ptr) __put_user_asm("std", x, ptr)
52 * The exception table contains two values: the first is the relative offset to
53 * the address of the instruction that is allowed to fault, and the second is
54 * the relative offset to the address of the fixup routine. Since relative
55 * addresses are used, 32bit values are sufficient even on 64bit kernel.
58 #define ARCH_HAS_RELATIVE_EXTABLE
59 struct exception_table_entry {
60 int insn; /* relative address of insn that is allowed to fault. */
61 int fixup; /* relative address of fixup routine */
64 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
65 ".section __ex_table,\"aw\"\n" \
66 ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \
70 * The page fault handler stores, in a per-cpu area, the following information
71 * if a fixup routine is available.
73 struct exception_data {
74 unsigned long fault_ip;
75 unsigned long fault_gp;
76 unsigned long fault_space;
77 unsigned long fault_addr;
81 * load_sr2() preloads the space register %%sr2 - based on the value of
82 * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
83 * is 0), or with the current value of %%sr3 to access user space (USER_DS)
84 * memory. The following __get_user_asm() and __put_user_asm() functions have
85 * %%sr2 hard-coded to access the requested memory.
88 __asm__(" or,= %0,%%r0,%%r0\n\t" \
89 " mfsp %%sr3,%0\n\t" \
90 " mtsp %0,%%sr2\n\t" \
93 #define __get_user(x, ptr) \
95 register long __gu_err __asm__ ("r8") = 0; \
96 register long __gu_val __asm__ ("r9") = 0; \
99 switch (sizeof(*(ptr))) { \
100 case 1: __get_user_asm("ldb", ptr); break; \
101 case 2: __get_user_asm("ldh", ptr); break; \
102 case 4: __get_user_asm("ldw", ptr); break; \
103 case 8: LDD_USER(ptr); break; \
104 default: BUILD_BUG(); break; \
107 (x) = (__force __typeof__(*(ptr))) __gu_val; \
111 #define __get_user_asm(ldx, ptr) \
112 __asm__("\n1:\t" ldx "\t0(%%sr2,%2),%0\n\t" \
113 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
114 : "=r"(__gu_val), "=r"(__gu_err) \
115 : "r"(ptr), "1"(__gu_err) \
118 #if !defined(CONFIG_64BIT)
120 #define __get_user_asm64(ptr) \
121 __asm__("\n1:\tldw 0(%%sr2,%2),%0" \
122 "\n2:\tldw 4(%%sr2,%2),%R0\n\t" \
123 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_2)\
124 ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_get_user_skip_1)\
125 : "=r"(__gu_val), "=r"(__gu_err) \
126 : "r"(ptr), "1"(__gu_err) \
129 #endif /* !defined(CONFIG_64BIT) */
132 #define __put_user(x, ptr) \
134 register long __pu_err __asm__ ("r8") = 0; \
135 __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \
138 switch (sizeof(*(ptr))) { \
139 case 1: __put_user_asm("stb", __x, ptr); break; \
140 case 2: __put_user_asm("sth", __x, ptr); break; \
141 case 4: __put_user_asm("stw", __x, ptr); break; \
142 case 8: STD_USER(__x, ptr); break; \
143 default: BUILD_BUG(); break; \
150 * The "__put_user/kernel_asm()" macros tell gcc they read from memory
151 * instead of writing. This is because they do not write to any memory
152 * gcc knows about, so there are no aliasing issues. These macros must
153 * also be aware that "fixup_put_user_skip_[12]" are executed in the
154 * context of the fault, and any registers used there must be listed
155 * as clobbers. In this case only "r1" is used by the current routines.
156 * r8/r9 are already listed as err/val.
159 #define __put_user_asm(stx, x, ptr) \
160 __asm__ __volatile__ ( \
161 "\n1:\t" stx "\t%2,0(%%sr2,%1)\n\t" \
162 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\
164 : "r"(ptr), "r"(x), "0"(__pu_err) \
168 #if !defined(CONFIG_64BIT)
170 #define __put_user_asm64(__val, ptr) do { \
171 __asm__ __volatile__ ( \
172 "\n1:\tstw %2,0(%%sr2,%1)" \
173 "\n2:\tstw %R2,4(%%sr2,%1)\n\t" \
174 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\
175 ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\
177 : "r"(ptr), "r"(__val), "0"(__pu_err) \
181 #endif /* !defined(CONFIG_64BIT) */
185 * Complex access routines -- external declarations
188 extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long);
189 extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long);
190 extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long);
191 extern long strncpy_from_user(char *, const char __user *, long);
192 extern unsigned lclear_user(void __user *, unsigned long);
193 extern long lstrnlen_user(const char __user *, long);
195 * Complex access routines -- macros
197 #define user_addr_max() (~0UL)
199 #define strnlen_user lstrnlen_user
200 #define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
201 #define clear_user lclear_user
202 #define __clear_user lclear_user
204 unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len);
205 #define __copy_to_user copy_to_user
206 unsigned long __copy_from_user(void *dst, const void __user *src, unsigned long len);
207 unsigned long copy_in_user(void __user *dst, const void __user *src, unsigned long len);
208 #define __copy_in_user copy_in_user
209 #define __copy_to_user_inatomic __copy_to_user
210 #define __copy_from_user_inatomic __copy_from_user
212 extern void __compiletime_error("usercopy buffer size is too small")
213 __bad_copy_user(void);
215 static inline void copy_user_overflow(int size, unsigned long count)
217 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
220 static inline unsigned long __must_check copy_from_user(void *to,
221 const void __user *from,
224 int sz = __compiletime_object_size(to);
225 unsigned long ret = n;
227 if (likely(sz == -1 || sz >= n))
228 ret = __copy_from_user(to, from, n);
229 else if (!__builtin_constant_p(n))
230 copy_user_overflow(sz, n);
235 memset(to + (n - ret), 0, ret);
240 int fixup_exception(struct pt_regs *regs);
242 #endif /* __PARISC_UACCESS_H */