~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/ia64/include/asm/uaccess.h

Version: ~ [ linux-5.12-rc7 ] ~ [ linux-5.11.13 ] ~ [ linux-5.10.29 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.111 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.186 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.230 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.266 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.266 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /* SPDX-License-Identifier: GPL-2.0 */
  2 #ifndef _ASM_IA64_UACCESS_H
  3 #define _ASM_IA64_UACCESS_H
  4 
  5 /*
  6  * This file defines various macros to transfer memory areas across
  7  * the user/kernel boundary.  This needs to be done carefully because
  8  * this code is executed in kernel mode and uses user-specified
  9  * addresses.  Thus, we need to be careful not to let the user to
 10  * trick us into accessing kernel memory that would normally be
 11  * inaccessible.  This code is also fairly performance sensitive,
 12  * so we want to spend as little time doing safety checks as
 13  * possible.
 14  *
 15  * To make matters a bit more interesting, these macros sometimes also
 16  * called from within the kernel itself, in which case the address
 17  * validity check must be skipped.  The get_fs() macro tells us what
 18  * to do: if get_fs()==USER_DS, checking is performed, if
 19  * get_fs()==KERNEL_DS, checking is bypassed.
 20  *
 21  * Note that even if the memory area specified by the user is in a
 22  * valid address range, it is still possible that we'll get a page
 23  * fault while accessing it.  This is handled by filling out an
 24  * exception handler fixup entry for each instruction that has the
 25  * potential to fault.  When such a fault occurs, the page fault
 26  * handler checks to see whether the faulting instruction has a fixup
 27  * associated and, if so, sets r8 to -EFAULT and clears r9 to 0 and
 28  * then resumes execution at the continuation point.
 29  *
 30  * Based on <asm-alpha/uaccess.h>.
 31  *
 32  * Copyright (C) 1998, 1999, 2001-2004 Hewlett-Packard Co
 33  *      David Mosberger-Tang <davidm@hpl.hp.com>
 34  */
 35 
 36 #include <linux/compiler.h>
 37 #include <linux/page-flags.h>
 38 #include <linux/mm.h>
 39 
 40 #include <asm/intrinsics.h>
 41 #include <asm/pgtable.h>
 42 #include <asm/io.h>
 43 #include <asm/extable.h>
 44 
 45 /*
 46  * For historical reasons, the following macros are grossly misnamed:
 47  */
 48 #define KERNEL_DS       ((mm_segment_t) { ~0UL })               /* cf. access_ok() */
 49 #define USER_DS         ((mm_segment_t) { TASK_SIZE-1 })        /* cf. access_ok() */
 50 
 51 #define get_fs()  (current_thread_info()->addr_limit)
 52 #define set_fs(x) (current_thread_info()->addr_limit = (x))
 53 
 54 #define segment_eq(a, b)        ((a).seg == (b).seg)
 55 
 56 /*
 57  * When accessing user memory, we need to make sure the entire area really is in
 58  * user-level space.  In order to do this efficiently, we make sure that the page at
 59  * address TASK_SIZE is never valid.  We also need to make sure that the address doesn't
 60  * point inside the virtually mapped linear page table.
 61  */
 62 static inline int __access_ok(const void __user *p, unsigned long size)
 63 {
 64         unsigned long addr = (unsigned long)p;
 65         unsigned long seg = get_fs().seg;
 66         return likely(addr <= seg) &&
 67          (seg == KERNEL_DS.seg || likely(REGION_OFFSET(addr) < RGN_MAP_LIMIT));
 68 }
 69 #define access_ok(addr, size)   __access_ok((addr), (size))
 70 
 71 /*
 72  * These are the main single-value transfer routines.  They automatically
 73  * use the right size if we just have the right pointer type.
 74  *
 75  * Careful to not
 76  * (a) re-use the arguments for side effects (sizeof/typeof is ok)
 77  * (b) require any knowledge of processes at this stage
 78  */
 79 #define put_user(x, ptr)        __put_user_check((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)))
 80 #define get_user(x, ptr)        __get_user_check((x), (ptr), sizeof(*(ptr)))
 81 
 82 /*
 83  * The "__xxx" versions do not do address space checking, useful when
 84  * doing multiple accesses to the same area (the programmer has to do the
 85  * checks by hand with "access_ok()")
 86  */
 87 #define __put_user(x, ptr)      __put_user_nocheck((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)))
 88 #define __get_user(x, ptr)      __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
 89 
 90 #ifdef ASM_SUPPORTED
 91   struct __large_struct { unsigned long buf[100]; };
 92 # define __m(x) (*(struct __large_struct __user *)(x))
 93 
 94 /* We need to declare the __ex_table section before we can use it in .xdata.  */
 95 asm (".section \"__ex_table\", \"a\"\n\t.previous");
 96 
 97 # define __get_user_size(val, addr, n, err)                                                     \
 98 do {                                                                                            \
 99         register long __gu_r8 asm ("r8") = 0;                                                   \
100         register long __gu_r9 asm ("r9");                                                       \
101         asm ("\n[1:]\tld"#n" %0=%2%P2\t// %0 and %1 get overwritten by exception handler\n"     \
102              "\t.xdata4 \"__ex_table\", 1b-., 1f-.+4\n"                                         \
103              "[1:]"                                                                             \
104              : "=r"(__gu_r9), "=r"(__gu_r8) : "m"(__m(addr)), "1"(__gu_r8));                    \
105         (err) = __gu_r8;                                                                        \
106         (val) = __gu_r9;                                                                        \
107 } while (0)
108 
109 /*
110  * The "__put_user_size()" macro tells gcc it reads from memory instead of writing it.  This
111  * is because they do not write to any memory gcc knows about, so there are no aliasing
112  * issues.
113  */
114 # define __put_user_size(val, addr, n, err)                                                     \
115 do {                                                                                            \
116         register long __pu_r8 asm ("r8") = 0;                                                   \
117         asm volatile ("\n[1:]\tst"#n" %1=%r2%P1\t// %0 gets overwritten by exception handler\n" \
118                       "\t.xdata4 \"__ex_table\", 1b-., 1f-.\n"                                  \
119                       "[1:]"                                                                    \
120                       : "=r"(__pu_r8) : "m"(__m(addr)), "rO"(val), ""(__pu_r8));               \
121         (err) = __pu_r8;                                                                        \
122 } while (0)
123 
124 #else /* !ASM_SUPPORTED */
125 # define RELOC_TYPE     2       /* ip-rel */
126 # define __get_user_size(val, addr, n, err)                             \
127 do {                                                                    \
128         __ld_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE);   \
129         (err) = ia64_getreg(_IA64_REG_R8);                              \
130         (val) = ia64_getreg(_IA64_REG_R9);                              \
131 } while (0)
132 # define __put_user_size(val, addr, n, err)                             \
133 do {                                                                    \
134         __st_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE,    \
135                   (__force unsigned long) (val));                       \
136         (err) = ia64_getreg(_IA64_REG_R8);                              \
137 } while (0)
138 #endif /* !ASM_SUPPORTED */
139 
140 extern void __get_user_unknown (void);
141 
142 /*
143  * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which
144  * could clobber r8 and r9 (among others).  Thus, be careful not to evaluate it while
145  * using r8/r9.
146  */
147 #define __do_get_user(check, x, ptr, size)                                              \
148 ({                                                                                      \
149         const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);                              \
150         __typeof__ (size) __gu_size = (size);                                           \
151         long __gu_err = -EFAULT;                                                        \
152         unsigned long __gu_val = 0;                                                     \
153         if (!check || __access_ok(__gu_ptr, size))                                      \
154                 switch (__gu_size) {                                                    \
155                       case 1: __get_user_size(__gu_val, __gu_ptr, 1, __gu_err); break;  \
156                       case 2: __get_user_size(__gu_val, __gu_ptr, 2, __gu_err); break;  \
157                       case 4: __get_user_size(__gu_val, __gu_ptr, 4, __gu_err); break;  \
158                       case 8: __get_user_size(__gu_val, __gu_ptr, 8, __gu_err); break;  \
159                       default: __get_user_unknown(); break;                             \
160                 }                                                                       \
161         (x) = (__force __typeof__(*(__gu_ptr))) __gu_val;                               \
162         __gu_err;                                                                       \
163 })
164 
165 #define __get_user_nocheck(x, ptr, size)        __do_get_user(0, x, ptr, size)
166 #define __get_user_check(x, ptr, size)  __do_get_user(1, x, ptr, size)
167 
168 extern void __put_user_unknown (void);
169 
170 /*
171  * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which
172  * could clobber r8 (among others).  Thus, be careful not to evaluate them while using r8.
173  */
174 #define __do_put_user(check, x, ptr, size)                                              \
175 ({                                                                                      \
176         __typeof__ (x) __pu_x = (x);                                                    \
177         __typeof__ (*(ptr)) __user *__pu_ptr = (ptr);                                   \
178         __typeof__ (size) __pu_size = (size);                                           \
179         long __pu_err = -EFAULT;                                                        \
180                                                                                         \
181         if (!check || __access_ok(__pu_ptr, __pu_size))                                 \
182                 switch (__pu_size) {                                                    \
183                       case 1: __put_user_size(__pu_x, __pu_ptr, 1, __pu_err); break;    \
184                       case 2: __put_user_size(__pu_x, __pu_ptr, 2, __pu_err); break;    \
185                       case 4: __put_user_size(__pu_x, __pu_ptr, 4, __pu_err); break;    \
186                       case 8: __put_user_size(__pu_x, __pu_ptr, 8, __pu_err); break;    \
187                       default: __put_user_unknown(); break;                             \
188                 }                                                                       \
189         __pu_err;                                                                       \
190 })
191 
192 #define __put_user_nocheck(x, ptr, size)        __do_put_user(0, x, ptr, size)
193 #define __put_user_check(x, ptr, size)  __do_put_user(1, x, ptr, size)
194 
195 /*
196  * Complex access routines
197  */
198 extern unsigned long __must_check __copy_user (void __user *to, const void __user *from,
199                                                unsigned long count);
200 
201 static inline unsigned long
202 raw_copy_to_user(void __user *to, const void *from, unsigned long count)
203 {
204         return __copy_user(to, (__force void __user *) from, count);
205 }
206 
207 static inline unsigned long
208 raw_copy_from_user(void *to, const void __user *from, unsigned long count)
209 {
210         return __copy_user((__force void __user *) to, from, count);
211 }
212 
213 #define INLINE_COPY_FROM_USER
214 #define INLINE_COPY_TO_USER
215 
216 extern unsigned long __do_clear_user (void __user *, unsigned long);
217 
218 #define __clear_user(to, n)             __do_clear_user(to, n)
219 
220 #define clear_user(to, n)                                       \
221 ({                                                              \
222         unsigned long __cu_len = (n);                           \
223         if (__access_ok(to, __cu_len))                          \
224                 __cu_len = __do_clear_user(to, __cu_len);       \
225         __cu_len;                                               \
226 })
227 
228 
229 /*
230  * Returns: -EFAULT if exception before terminator, N if the entire buffer filled, else
231  * strlen.
232  */
233 extern long __must_check __strncpy_from_user (char *to, const char __user *from, long to_len);
234 
235 #define strncpy_from_user(to, from, n)                                  \
236 ({                                                                      \
237         const char __user * __sfu_from = (from);                        \
238         long __sfu_ret = -EFAULT;                                       \
239         if (__access_ok(__sfu_from, 0))                                 \
240                 __sfu_ret = __strncpy_from_user((to), __sfu_from, (n)); \
241         __sfu_ret;                                                      \
242 })
243 
244 /*
245  * Returns: 0 if exception before NUL or reaching the supplied limit
246  * (N), a value greater than N if the limit would be exceeded, else
247  * strlen.
248  */
249 extern unsigned long __strnlen_user (const char __user *, long);
250 
251 #define strnlen_user(str, len)                                  \
252 ({                                                              \
253         const char __user *__su_str = (str);                    \
254         unsigned long __su_ret = 0;                             \
255         if (__access_ok(__su_str, 0))                           \
256                 __su_ret = __strnlen_user(__su_str, len);       \
257         __su_ret;                                               \
258 })
259 
260 #define ARCH_HAS_TRANSLATE_MEM_PTR      1
261 static __inline__ void *
262 xlate_dev_mem_ptr(phys_addr_t p)
263 {
264         struct page *page;
265         void *ptr;
266 
267         page = pfn_to_page(p >> PAGE_SHIFT);
268         if (PageUncached(page))
269                 ptr = (void *)p + __IA64_UNCACHED_OFFSET;
270         else
271                 ptr = __va(p);
272 
273         return ptr;
274 }
275 
276 /*
277  * Convert a virtual cached kernel memory pointer to an uncached pointer
278  */
279 static __inline__ void *
280 xlate_dev_kmem_ptr(void *p)
281 {
282         struct page *page;
283         void *ptr;
284 
285         page = virt_to_page((unsigned long)p);
286         if (PageUncached(page))
287                 ptr = (void *)__pa(p) + __IA64_UNCACHED_OFFSET;
288         else
289                 ptr = p;
290 
291         return ptr;
292 }
293 
294 #endif /* _ASM_IA64_UACCESS_H */
295 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp