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>
14 #include <linux/thread_info.h>
17 #define VERIFY_WRITE 1
19 #define KERNEL_DS ((mm_segment_t){0})
20 #define USER_DS ((mm_segment_t){1})
22 #define segment_eq(a, b) ((a).seg == (b).seg)
24 #define get_ds() (KERNEL_DS)
25 #define get_fs() (current_thread_info()->addr_limit)
26 #define set_fs(x) (current_thread_info()->addr_limit = (x))
29 * Note that since kernel addresses are in a separate address space on
30 * parisc, we don't need to do anything for access_ok().
31 * We just let the page fault handler do the right thing. This also means
32 * that put_user is the same as __put_user, etc.
35 static inline long access_ok(int type, const void __user * addr,
41 #define put_user __put_user
42 #define get_user __get_user
44 #if !defined(CONFIG_64BIT)
45 #define LDD_USER(ptr) __get_user_asm64(ptr)
46 #define STD_USER(x, ptr) __put_user_asm64(x, ptr)
48 #define LDD_USER(ptr) __get_user_asm("ldd", ptr)
49 #define STD_USER(x, ptr) __put_user_asm("std", x, ptr)
53 * The exception table contains two values: the first is the relative offset to
54 * the address of the instruction that is allowed to fault, and the second is
55 * the relative offset to the address of the fixup routine. Since relative
56 * addresses are used, 32bit values are sufficient even on 64bit kernel.
59 #define ARCH_HAS_RELATIVE_EXTABLE
60 struct exception_table_entry {
61 int insn; /* relative address of insn that is allowed to fault. */
62 int fixup; /* relative address of fixup routine */
65 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
66 ".section __ex_table,\"aw\"\n" \
67 ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \
71 * The page fault handler stores, in a per-cpu area, the following information
72 * if a fixup routine is available.
74 struct exception_data {
75 unsigned long fault_ip;
76 unsigned long fault_gp;
77 unsigned long fault_space;
78 unsigned long fault_addr;
82 * load_sr2() preloads the space register %%sr2 - based on the value of
83 * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
84 * is 0), or with the current value of %%sr3 to access user space (USER_DS)
85 * memory. The following __get_user_asm() and __put_user_asm() functions have
86 * %%sr2 hard-coded to access the requested memory.
89 __asm__(" or,= %0,%%r0,%%r0\n\t" \
90 " mfsp %%sr3,%0\n\t" \
91 " mtsp %0,%%sr2\n\t" \
94 #define __get_user(x, ptr) \
96 register long __gu_err __asm__ ("r8") = 0; \
97 register long __gu_val __asm__ ("r9") = 0; \
100 switch (sizeof(*(ptr))) { \
101 case 1: __get_user_asm("ldb", ptr); break; \
102 case 2: __get_user_asm("ldh", ptr); break; \
103 case 4: __get_user_asm("ldw", ptr); break; \
104 case 8: LDD_USER(ptr); break; \
105 default: BUILD_BUG(); break; \
108 (x) = (__force __typeof__(*(ptr))) __gu_val; \
112 #define __get_user_asm(ldx, ptr) \
113 __asm__("\n1:\t" ldx "\t0(%%sr2,%2),%0\n\t" \
114 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
115 : "=r"(__gu_val), "=r"(__gu_err) \
116 : "r"(ptr), "1"(__gu_err) \
119 #if !defined(CONFIG_64BIT)
121 #define __get_user_asm64(ptr) \
122 __asm__("\n1:\tldw 0(%%sr2,%2),%0" \
123 "\n2:\tldw 4(%%sr2,%2),%R0\n\t" \
124 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_2)\
125 ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_get_user_skip_1)\
126 : "=r"(__gu_val), "=r"(__gu_err) \
127 : "r"(ptr), "1"(__gu_err) \
130 #endif /* !defined(CONFIG_64BIT) */
133 #define __put_user(x, ptr) \
135 register long __pu_err __asm__ ("r8") = 0; \
136 __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \
139 switch (sizeof(*(ptr))) { \
140 case 1: __put_user_asm("stb", __x, ptr); break; \
141 case 2: __put_user_asm("sth", __x, ptr); break; \
142 case 4: __put_user_asm("stw", __x, ptr); break; \
143 case 8: STD_USER(__x, ptr); break; \
144 default: BUILD_BUG(); break; \
151 * The "__put_user/kernel_asm()" macros tell gcc they read from memory
152 * instead of writing. This is because they do not write to any memory
153 * gcc knows about, so there are no aliasing issues. These macros must
154 * also be aware that "fixup_put_user_skip_[12]" are executed in the
155 * context of the fault, and any registers used there must be listed
156 * as clobbers. In this case only "r1" is used by the current routines.
157 * r8/r9 are already listed as err/val.
160 #define __put_user_asm(stx, x, ptr) \
161 __asm__ __volatile__ ( \
162 "\n1:\t" stx "\t%2,0(%%sr2,%1)\n\t" \
163 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\
165 : "r"(ptr), "r"(x), "0"(__pu_err) \
169 #if !defined(CONFIG_64BIT)
171 #define __put_user_asm64(__val, ptr) do { \
172 __asm__ __volatile__ ( \
173 "\n1:\tstw %2,0(%%sr2,%1)" \
174 "\n2:\tstw %R2,4(%%sr2,%1)\n\t" \
175 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\
176 ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\
178 : "r"(ptr), "r"(__val), "0"(__pu_err) \
182 #endif /* !defined(CONFIG_64BIT) */
186 * Complex access routines -- external declarations
189 extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long);
190 extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long);
191 extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long);
192 extern long strncpy_from_user(char *, const char __user *, long);
193 extern unsigned lclear_user(void __user *, unsigned long);
194 extern long lstrnlen_user(const char __user *, long);
196 * Complex access routines -- macros
198 #define user_addr_max() (~0UL)
200 #define strnlen_user lstrnlen_user
201 #define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
202 #define clear_user lclear_user
203 #define __clear_user lclear_user
205 unsigned long __must_check __copy_to_user(void __user *dst, const void *src,
207 unsigned long __must_check __copy_from_user(void *dst, const void __user *src,
209 unsigned long copy_in_user(void __user *dst, const void __user *src,
211 #define __copy_in_user copy_in_user
212 #define __copy_to_user_inatomic __copy_to_user
213 #define __copy_from_user_inatomic __copy_from_user
215 extern void __compiletime_error("usercopy buffer size is too small")
216 __bad_copy_user(void);
218 static inline void copy_user_overflow(int size, unsigned long count)
220 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
223 static __always_inline unsigned long __must_check
224 copy_from_user(void *to, const void __user *from, unsigned long n)
226 int sz = __compiletime_object_size(to);
227 unsigned long ret = n;
229 if (likely(sz < 0 || sz >= n)) {
230 check_object_size(to, n, false);
231 ret = __copy_from_user(to, from, n);
232 } else if (!__builtin_constant_p(n))
233 copy_user_overflow(sz, n);
238 memset(to + (n - ret), 0, ret);
243 static __always_inline unsigned long __must_check
244 copy_to_user(void __user *to, const void *from, unsigned long n)
246 int sz = __compiletime_object_size(from);
248 if (likely(sz < 0 || sz >= n)) {
249 check_object_size(from, n, true);
250 n = __copy_to_user(to, from, n);
251 } else if (!__builtin_constant_p(n))
252 copy_user_overflow(sz, n);
260 int fixup_exception(struct pt_regs *regs);
262 #endif /* __PARISC_UACCESS_H */