linux/arch/sparc/include/asm/uaccess_64.h
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   1#ifndef _ASM_UACCESS_H
   2#define _ASM_UACCESS_H
   3
   4/*
   5 * User space memory access functions
   6 */
   7
   8#ifdef __KERNEL__
   9#include <linux/compiler.h>
  10#include <linux/sched.h>
  11#include <linux/string.h>
  12#include <asm/asi.h>
  13#include <asm/system.h>
  14#include <asm/spitfire.h>
  15#include <asm-generic/uaccess.h>
  16#endif
  17
  18#ifndef __ASSEMBLY__
  19
  20/*
  21 * Sparc64 is segmented, though more like the M68K than the I386.
  22 * We use the secondary ASI to address user memory, which references a
  23 * completely different VM map, thus there is zero chance of the user
  24 * doing something queer and tricking us into poking kernel memory.
  25 *
  26 * What is left here is basically what is needed for the other parts of
  27 * the kernel that expect to be able to manipulate, erum, "segments".
  28 * Or perhaps more properly, permissions.
  29 *
  30 * "For historical reasons, these macros are grossly misnamed." -Linus
  31 */
  32
  33#define KERNEL_DS   ((mm_segment_t) { ASI_P })
  34#define USER_DS     ((mm_segment_t) { ASI_AIUS })       /* har har har */
  35
  36#define VERIFY_READ     0
  37#define VERIFY_WRITE    1
  38
  39#define get_fs() ((mm_segment_t) { get_thread_current_ds() })
  40#define get_ds() (KERNEL_DS)
  41
  42#define segment_eq(a,b)  ((a).seg == (b).seg)
  43
  44#define set_fs(val)                                                             \
  45do {                                                                            \
  46        set_thread_current_ds((val).seg);                                       \
  47        __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
  48} while(0)
  49
  50static inline int __access_ok(const void __user * addr, unsigned long size)
  51{
  52        return 1;
  53}
  54
  55static inline int access_ok(int type, const void __user * addr, unsigned long size)
  56{
  57        return 1;
  58}
  59
  60/*
  61 * The exception table consists of pairs of addresses: the first is the
  62 * address of an instruction that is allowed to fault, and the second is
  63 * the address at which the program should continue.  No registers are
  64 * modified, so it is entirely up to the continuation code to figure out
  65 * what to do.
  66 *
  67 * All the routines below use bits of fixup code that are out of line
  68 * with the main instruction path.  This means when everything is well,
  69 * we don't even have to jump over them.  Further, they do not intrude
  70 * on our cache or tlb entries.
  71 */
  72
  73struct exception_table_entry {
  74        unsigned int insn, fixup;
  75};
  76
  77extern void __ret_efault(void);
  78extern void __retl_efault(void);
  79
  80/* Uh, these should become the main single-value transfer routines..
  81 * They automatically use the right size if we just have the right
  82 * pointer type..
  83 *
  84 * This gets kind of ugly. We want to return _two_ values in "get_user()"
  85 * and yet we don't want to do any pointers, because that is too much
  86 * of a performance impact. Thus we have a few rather ugly macros here,
  87 * and hide all the ugliness from the user.
  88 */
  89#define put_user(x,ptr) ({ \
  90unsigned long __pu_addr = (unsigned long)(ptr); \
  91__chk_user_ptr(ptr); \
  92__put_user_nocheck((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
  93
  94#define get_user(x,ptr) ({ \
  95unsigned long __gu_addr = (unsigned long)(ptr); \
  96__chk_user_ptr(ptr); \
  97__get_user_nocheck((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
  98
  99#define __put_user(x,ptr) put_user(x,ptr)
 100#define __get_user(x,ptr) get_user(x,ptr)
 101
 102struct __large_struct { unsigned long buf[100]; };
 103#define __m(x) ((struct __large_struct *)(x))
 104
 105#define __put_user_nocheck(data,addr,size) ({ \
 106register int __pu_ret; \
 107switch (size) { \
 108case 1: __put_user_asm(data,b,addr,__pu_ret); break; \
 109case 2: __put_user_asm(data,h,addr,__pu_ret); break; \
 110case 4: __put_user_asm(data,w,addr,__pu_ret); break; \
 111case 8: __put_user_asm(data,x,addr,__pu_ret); break; \
 112default: __pu_ret = __put_user_bad(); break; \
 113} __pu_ret; })
 114
 115#define __put_user_asm(x,size,addr,ret)                                 \
 116__asm__ __volatile__(                                                   \
 117        "/* Put user asm, inline. */\n"                                 \
 118"1:\t"  "st"#size "a %1, [%2] %%asi\n\t"                                \
 119        "clr    %0\n"                                                   \
 120"2:\n\n\t"                                                              \
 121        ".section .fixup,#alloc,#execinstr\n\t"                         \
 122        ".align 4\n"                                                    \
 123"3:\n\t"                                                                \
 124        "sethi  %%hi(2b), %0\n\t"                                       \
 125        "jmpl   %0 + %%lo(2b), %%g0\n\t"                                \
 126        " mov   %3, %0\n\n\t"                                           \
 127        ".previous\n\t"                                                 \
 128        ".section __ex_table,\"a\"\n\t"                                 \
 129        ".align 4\n\t"                                                  \
 130        ".word  1b, 3b\n\t"                                             \
 131        ".previous\n\n\t"                                               \
 132       : "=r" (ret) : "r" (x), "r" (__m(addr)),                         \
 133         "i" (-EFAULT))
 134
 135extern int __put_user_bad(void);
 136
 137#define __get_user_nocheck(data,addr,size,type) ({ \
 138register int __gu_ret; \
 139register unsigned long __gu_val; \
 140switch (size) { \
 141case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 142case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 143case 4: __get_user_asm(__gu_val,uw,addr,__gu_ret); break; \
 144case 8: __get_user_asm(__gu_val,x,addr,__gu_ret); break; \
 145default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 146} data = (type) __gu_val; __gu_ret; })
 147
 148#define __get_user_nocheck_ret(data,addr,size,type,retval) ({ \
 149register unsigned long __gu_val __asm__ ("l1"); \
 150switch (size) { \
 151case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 152case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 153case 4: __get_user_asm_ret(__gu_val,uw,addr,retval); break; \
 154case 8: __get_user_asm_ret(__gu_val,x,addr,retval); break; \
 155default: if (__get_user_bad()) return retval; \
 156} data = (type) __gu_val; })
 157
 158#define __get_user_asm(x,size,addr,ret)                                 \
 159__asm__ __volatile__(                                                   \
 160        "/* Get user asm, inline. */\n"                                 \
 161"1:\t"  "ld"#size "a [%2] %%asi, %1\n\t"                                \
 162        "clr    %0\n"                                                   \
 163"2:\n\n\t"                                                              \
 164        ".section .fixup,#alloc,#execinstr\n\t"                         \
 165        ".align 4\n"                                                    \
 166"3:\n\t"                                                                \
 167        "sethi  %%hi(2b), %0\n\t"                                       \
 168        "clr    %1\n\t"                                                 \
 169        "jmpl   %0 + %%lo(2b), %%g0\n\t"                                \
 170        " mov   %3, %0\n\n\t"                                           \
 171        ".previous\n\t"                                                 \
 172        ".section __ex_table,\"a\"\n\t"                                 \
 173        ".align 4\n\t"                                                  \
 174        ".word  1b, 3b\n\n\t"                                           \
 175        ".previous\n\t"                                                 \
 176       : "=r" (ret), "=r" (x) : "r" (__m(addr)),                        \
 177         "i" (-EFAULT))
 178
 179#define __get_user_asm_ret(x,size,addr,retval)                          \
 180if (__builtin_constant_p(retval) && retval == -EFAULT)                  \
 181__asm__ __volatile__(                                                   \
 182        "/* Get user asm ret, inline. */\n"                             \
 183"1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
 184        ".section __ex_table,\"a\"\n\t"                                 \
 185        ".align 4\n\t"                                                  \
 186        ".word  1b,__ret_efault\n\n\t"                                  \
 187        ".previous\n\t"                                                 \
 188       : "=r" (x) : "r" (__m(addr)));                                   \
 189else                                                                    \
 190__asm__ __volatile__(                                                   \
 191        "/* Get user asm ret, inline. */\n"                             \
 192"1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
 193        ".section .fixup,#alloc,#execinstr\n\t"                         \
 194        ".align 4\n"                                                    \
 195"3:\n\t"                                                                \
 196        "ret\n\t"                                                       \
 197        " restore %%g0, %2, %%o0\n\n\t"                                 \
 198        ".previous\n\t"                                                 \
 199        ".section __ex_table,\"a\"\n\t"                                 \
 200        ".align 4\n\t"                                                  \
 201        ".word  1b, 3b\n\n\t"                                           \
 202        ".previous\n\t"                                                 \
 203       : "=r" (x) : "r" (__m(addr)), "i" (retval))
 204
 205extern int __get_user_bad(void);
 206
 207extern unsigned long __must_check ___copy_from_user(void *to,
 208                                                    const void __user *from,
 209                                                    unsigned long size);
 210extern unsigned long copy_from_user_fixup(void *to, const void __user *from,
 211                                          unsigned long size);
 212static inline unsigned long __must_check
 213copy_from_user(void *to, const void __user *from, unsigned long size)
 214{
 215        unsigned long ret = ___copy_from_user(to, from, size);
 216
 217        if (unlikely(ret))
 218                ret = copy_from_user_fixup(to, from, size);
 219        return ret;
 220}
 221#define __copy_from_user copy_from_user
 222
 223extern unsigned long __must_check ___copy_to_user(void __user *to,
 224                                                  const void *from,
 225                                                  unsigned long size);
 226extern unsigned long copy_to_user_fixup(void __user *to, const void *from,
 227                                        unsigned long size);
 228static inline unsigned long __must_check
 229copy_to_user(void __user *to, const void *from, unsigned long size)
 230{
 231        unsigned long ret = ___copy_to_user(to, from, size);
 232
 233        if (unlikely(ret))
 234                ret = copy_to_user_fixup(to, from, size);
 235        return ret;
 236}
 237#define __copy_to_user copy_to_user
 238
 239extern unsigned long __must_check ___copy_in_user(void __user *to,
 240                                                  const void __user *from,
 241                                                  unsigned long size);
 242extern unsigned long copy_in_user_fixup(void __user *to, void __user *from,
 243                                        unsigned long size);
 244static inline unsigned long __must_check
 245copy_in_user(void __user *to, void __user *from, unsigned long size)
 246{
 247        unsigned long ret = ___copy_in_user(to, from, size);
 248
 249        if (unlikely(ret))
 250                ret = copy_in_user_fixup(to, from, size);
 251        return ret;
 252}
 253#define __copy_in_user copy_in_user
 254
 255extern unsigned long __must_check __clear_user(void __user *, unsigned long);
 256
 257#define clear_user __clear_user
 258
 259extern long __must_check __strncpy_from_user(char *dest, const char __user *src, long count);
 260
 261#define strncpy_from_user __strncpy_from_user
 262
 263extern long __strlen_user(const char __user *);
 264extern long __strnlen_user(const char __user *, long len);
 265
 266#define strlen_user __strlen_user
 267#define strnlen_user __strnlen_user
 268#define __copy_to_user_inatomic ___copy_to_user
 269#define __copy_from_user_inatomic ___copy_from_user
 270
 271#endif  /* __ASSEMBLY__ */
 272
 273#endif /* _ASM_UACCESS_H */
 274
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