LXR linux/arch/sparc/include/asm/uaccess

   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/errno.h>
  10#include <linux/compiler.h>
  11#include <linux/string.h>
  12#include <linux/thread_info.h>
  13#include <asm/asi.h>
  14#include <asm/spitfire.h>
  15#include <asm-generic/uaccess-unaligned.h>
  16#endif
  17
  18#ifndef __ASSEMBLY__
  19
  20#include <asm/processor.h>
  21
  22/*
  23 * Sparc64 is segmented, though more like the M68K than the I386.
  24 * We use the secondary ASI to address user memory, which references a
  25 * completely different VM map, thus there is zero chance of the user
  26 * doing something queer and tricking us into poking kernel memory.
  27 *
  28 * What is left here is basically what is needed for the other parts of
  29 * the kernel that expect to be able to manipulate, erum, "segments".
  30 * Or perhaps more properly, permissions.
  31 *
  32 * "For historical reasons, these macros are grossly misnamed." -Linus
  33 */
  34
  35#define KERNEL_DS   ((mm_segment_t) { ASI_P })
  36#define USER_DS     ((mm_segment_t) { ASI_AIUS })       /* har har har */
  37
  38#define VERIFY_READ     0
  39#define VERIFY_WRITE    1
  40
  41#define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)})
  42#define get_ds() (KERNEL_DS)
  43
  44#define segment_eq(a,b)  ((a).seg == (b).seg)
  45
  46#define set_fs(val)                                                             \
  47do {                                                                            \
  48        current_thread_info()->current_ds =(val).seg;                           \
  49        __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
  50} while(0)
  51
  52static inline int __access_ok(const void __user * addr, unsigned long size)
  53{
  54        return 1;
  55}
  56
  57static inline int access_ok(int type, const void __user * addr, unsigned long size)
  58{
  59        return 1;
  60}
  61
  62/*
  63 * The exception table consists of pairs of addresses: the first is the
  64 * address of an instruction that is allowed to fault, and the second is
  65 * the address at which the program should continue.  No registers are
  66 * modified, so it is entirely up to the continuation code to figure out
  67 * what to do.
  68 *
  69 * All the routines below use bits of fixup code that are out of line
  70 * with the main instruction path.  This means when everything is well,
  71 * we don't even have to jump over them.  Further, they do not intrude
  72 * on our cache or tlb entries.
  73 */
  74
  75struct exception_table_entry {
  76        unsigned int insn, fixup;
  77};
  78
  79extern void __ret_efault(void);
  80extern void __retl_efault(void);
  81
  82/* Uh, these should become the main single-value transfer routines..
  83 * They automatically use the right size if we just have the right
  84 * pointer type..
  85 *
  86 * This gets kind of ugly. We want to return _two_ values in "get_user()"
  87 * and yet we don't want to do any pointers, because that is too much
  88 * of a performance impact. Thus we have a few rather ugly macros here,
  89 * and hide all the ugliness from the user.
  90 */
  91#define put_user(x,ptr) ({ \
  92unsigned long __pu_addr = (unsigned long)(ptr); \
  93__chk_user_ptr(ptr); \
  94__put_user_nocheck((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
  95
  96#define get_user(x,ptr) ({ \
  97unsigned long __gu_addr = (unsigned long)(ptr); \
  98__chk_user_ptr(ptr); \
  99__get_user_nocheck((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
 100
 101#define __put_user(x,ptr) put_user(x,ptr)
 102#define __get_user(x,ptr) get_user(x,ptr)
 103
 104struct __large_struct { unsigned long buf[100]; };
 105#define __m(x) ((struct __large_struct *)(x))
 106
 107#define __put_user_nocheck(data,addr,size) ({ \
 108register int __pu_ret; \
 109switch (size) { \
 110case 1: __put_user_asm(data,b,addr,__pu_ret); break; \
 111case 2: __put_user_asm(data,h,addr,__pu_ret); break; \
 112case 4: __put_user_asm(data,w,addr,__pu_ret); break; \
 113case 8: __put_user_asm(data,x,addr,__pu_ret); break; \
 114default: __pu_ret = __put_user_bad(); break; \
 115} __pu_ret; })
 116
 117#define __put_user_asm(x,size,addr,ret)                                 \
 118__asm__ __volatile__(                                                   \
 119        "/* Put user asm, inline. */\n"                                 \
 120"1:\t"  "st"#size "a %1, [%2] %%asi\n\t"                                \
 121        "clr    %0\n"                                                   \
 122"2:\n\n\t"                                                              \
 123        ".section .fixup,#alloc,#execinstr\n\t"                         \
 124        ".align 4\n"                                                    \
 125"3:\n\t"                                                                \
 126        "sethi  %%hi(2b), %0\n\t"                                       \
 127        "jmpl   %0 + %%lo(2b), %%g0\n\t"                                \
 128        " mov   %3, %0\n\n\t"                                           \
 129        ".previous\n\t"                                                 \
 130        ".section __ex_table,\"a\"\n\t"                                 \
 131        ".align 4\n\t"                                                  \
 132        ".word  1b, 3b\n\t"                                             \
 133        ".previous\n\n\t"                                               \
 134       : "=r" (ret) : "r" (x), "r" (__m(addr)),                         \
 135         "i" (-EFAULT))
 136
 137extern int __put_user_bad(void);
 138
 139#define __get_user_nocheck(data,addr,size,type) ({ \
 140register int __gu_ret; \
 141register unsigned long __gu_val; \
 142switch (size) { \
 143case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 144case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 145case 4: __get_user_asm(__gu_val,uw,addr,__gu_ret); break; \
 146case 8: __get_user_asm(__gu_val,x,addr,__gu_ret); break; \
 147default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 148} data = (type) __gu_val; __gu_ret; })
 149
 150#define __get_user_nocheck_ret(data,addr,size,type,retval) ({ \
 151register unsigned long __gu_val __asm__ ("l1"); \
 152switch (size) { \
 153case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 154case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 155case 4: __get_user_asm_ret(__gu_val,uw,addr,retval); break; \
 156case 8: __get_user_asm_ret(__gu_val,x,addr,retval); break; \
 157default: if (__get_user_bad()) return retval; \
 158} data = (type) __gu_val; })
 159
 160#define __get_user_asm(x,size,addr,ret)                                 \
 161__asm__ __volatile__(                                                   \
 162        "/* Get user asm, inline. */\n"                                 \
 163"1:\t"  "ld"#size "a [%2] %%asi, %1\n\t"                                \
 164        "clr    %0\n"                                                   \
 165"2:\n\n\t"                                                              \
 166        ".section .fixup,#alloc,#execinstr\n\t"                         \
 167        ".align 4\n"                                                    \
 168"3:\n\t"                                                                \
 169        "sethi  %%hi(2b), %0\n\t"                                       \
 170        "clr    %1\n\t"                                                 \
 171        "jmpl   %0 + %%lo(2b), %%g0\n\t"                                \
 172        " mov   %3, %0\n\n\t"                                           \
 173        ".previous\n\t"                                                 \
 174        ".section __ex_table,\"a\"\n\t"                                 \
 175        ".align 4\n\t"                                                  \
 176        ".word  1b, 3b\n\n\t"                                           \
 177        ".previous\n\t"                                                 \
 178       : "=r" (ret), "=r" (x) : "r" (__m(addr)),                        \
 179         "i" (-EFAULT))
 180
 181#define __get_user_asm_ret(x,size,addr,retval)                          \
 182if (__builtin_constant_p(retval) && retval == -EFAULT)                  \
 183__asm__ __volatile__(                                                   \
 184        "/* Get user asm ret, inline. */\n"                             \
 185"1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
 186        ".section __ex_table,\"a\"\n\t"                                 \
 187        ".align 4\n\t"                                                  \
 188        ".word  1b,__ret_efault\n\n\t"                                  \
 189        ".previous\n\t"                                                 \
 190       : "=r" (x) : "r" (__m(addr)));                                   \
 191else                                                                    \
 192__asm__ __volatile__(                                                   \
 193        "/* Get user asm ret, inline. */\n"                             \
 194"1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
 195        ".section .fixup,#alloc,#execinstr\n\t"                         \
 196        ".align 4\n"                                                    \
 197"3:\n\t"                                                                \
 198        "ret\n\t"                                                       \
 199        " restore %%g0, %2, %%o0\n\n\t"                                 \
 200        ".previous\n\t"                                                 \
 201        ".section __ex_table,\"a\"\n\t"                                 \
 202        ".align 4\n\t"                                                  \
 203        ".word  1b, 3b\n\n\t"                                           \
 204        ".previous\n\t"                                                 \
 205       : "=r" (x) : "r" (__m(addr)), "i" (retval))
 206
 207extern int __get_user_bad(void);
 208
 209extern unsigned long __must_check ___copy_from_user(void *to,
 210                                                    const void __user *from,
 211                                                    unsigned long size);
 212extern unsigned long copy_from_user_fixup(void *to, const void __user *from,
 213                                          unsigned long size);
 214static inline unsigned long __must_check
 215copy_from_user(void *to, const void __user *from, unsigned long size)
 216{
 217        unsigned long ret = ___copy_from_user(to, from, size);
 218
 219        if (unlikely(ret))
 220                ret = copy_from_user_fixup(to, from, size);
 221
 222        return ret;
 223}
 224#define __copy_from_user copy_from_user
 225
 226extern unsigned long __must_check ___copy_to_user(void __user *to,
 227                                                  const void *from,
 228                                                  unsigned long size);
 229extern unsigned long copy_to_user_fixup(void __user *to, const void *from,
 230                                        unsigned long size);
 231static inline unsigned long __must_check
 232copy_to_user(void __user *to, const void *from, unsigned long size)
 233{
 234        unsigned long ret = ___copy_to_user(to, from, size);
 235
 236        if (unlikely(ret))
 237                ret = copy_to_user_fixup(to, from, size);
 238        return ret;
 239}
 240#define __copy_to_user copy_to_user
 241
 242extern unsigned long __must_check ___copy_in_user(void __user *to,
 243                                                  const void __user *from,
 244                                                  unsigned long size);
 245extern unsigned long copy_in_user_fixup(void __user *to, void __user *from,
 246                                        unsigned long size);
 247static inline unsigned long __must_check
 248copy_in_user(void __user *to, void __user *from, unsigned long size)
 249{
 250        unsigned long ret = ___copy_in_user(to, from, size);
 251
 252        if (unlikely(ret))
 253                ret = copy_in_user_fixup(to, from, size);
 254        return ret;
 255}
 256#define __copy_in_user copy_in_user
 257
 258extern unsigned long __must_check __clear_user(void __user *, unsigned long);
 259
 260#define clear_user __clear_user
 261
 262extern __must_check long strlen_user(const char __user *str);
 263extern __must_check long strnlen_user(const char __user *str, long n);
 264
 265#define __copy_to_user_inatomic ___copy_to_user
 266#define __copy_from_user_inatomic ___copy_from_user
 267
 268struct pt_regs;
 269extern unsigned long compute_effective_address(struct pt_regs *,
 270                                               unsigned int insn,
 271                                               unsigned int rd);
 272
 273#endif  /* __ASSEMBLY__ */
 274
 275#endif /* _ASM_UACCESS_H */
 276