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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/cris/include/asm/uaccess.h
Initial import
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diff --git a/arch/cris/include/asm/uaccess.h b/arch/cris/include/asm/uaccess.h
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+/*
+ * Authors: Bjorn Wesen (bjornw@axis.com)
+ * Hans-Peter Nilsson (hp@axis.com)
+ */
+
+/* Asm:s have been tweaked (within the domain of correctness) to give
+ satisfactory results for "gcc version 2.96 20000427 (experimental)".
+
+ Check regularly...
+
+ Register $r9 is chosen for temporaries, being a call-clobbered register
+ first in line to be used (notably for local blocks), not colliding with
+ parameter registers. */
+
+#ifndef _CRIS_UACCESS_H
+#define _CRIS_UACCESS_H
+
+#ifndef __ASSEMBLY__
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <asm/processor.h>
+#include <asm/page.h>
+
+#define VERIFY_READ 0
+#define VERIFY_WRITE 1
+
+/*
+ * The fs value determines whether argument validity checking should be
+ * performed or not. If get_fs() == USER_DS, checking is performed, with
+ * get_fs() == KERNEL_DS, checking is bypassed.
+ *
+ * For historical reasons, these macros are grossly misnamed.
+ */
+
+#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
+
+/* addr_limit is the maximum accessible address for the task. we misuse
+ * the KERNEL_DS and USER_DS values to both assign and compare the
+ * addr_limit values through the equally misnamed get/set_fs macros.
+ * (see above)
+ */
+
+#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
+#define USER_DS MAKE_MM_SEG(TASK_SIZE)
+
+#define get_ds() (KERNEL_DS)
+#define get_fs() (current_thread_info()->addr_limit)
+#define set_fs(x) (current_thread_info()->addr_limit = (x))
+
+#define segment_eq(a, b) ((a).seg == (b).seg)
+
+#define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
+#define __user_ok(addr, size) \
+ (((size) <= TASK_SIZE) && ((addr) <= TASK_SIZE-(size)))
+#define __access_ok(addr, size) (__kernel_ok || __user_ok((addr), (size)))
+#define access_ok(type, addr, size) __access_ok((unsigned long)(addr), (size))
+
+#include <arch/uaccess.h>
+
+/*
+ * The exception table consists of pairs of addresses: the first is the
+ * address of an instruction that is allowed to fault, and the second is
+ * the address at which the program should continue. No registers are
+ * modified, so it is entirely up to the continuation code to figure out
+ * what to do.
+ *
+ * All the routines below use bits of fixup code that are out of line
+ * with the main instruction path. This means when everything is well,
+ * we don't even have to jump over them. Further, they do not intrude
+ * on our cache or tlb entries.
+ */
+
+struct exception_table_entry {
+ unsigned long insn, fixup;
+};
+
+/*
+ * These are the main single-value transfer routines. They automatically
+ * use the right size if we just have the right pointer type.
+ *
+ * This gets kind of ugly. We want to return _two_ values in "get_user()"
+ * and yet we don't want to do any pointers, because that is too much
+ * of a performance impact. Thus we have a few rather ugly macros here,
+ * and hide all the ugliness from the user.
+ *
+ * The "__xxx" versions of the user access functions are versions that
+ * do not verify the address space, that must have been done previously
+ * with a separate "access_ok()" call (this is used when we do multiple
+ * accesses to the same area of user memory).
+ *
+ * As we use the same address space for kernel and user data on
+ * CRIS, we can just do these as direct assignments. (Of course, the
+ * exception handling means that it's no longer "just"...)
+ */
+#define get_user(x, ptr) \
+ __get_user_check((x), (ptr), sizeof(*(ptr)))
+#define put_user(x, ptr) \
+ __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+
+#define __get_user(x, ptr) \
+ __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
+#define __put_user(x, ptr) \
+ __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+
+extern long __put_user_bad(void);
+
+#define __put_user_size(x, ptr, size, retval) \
+do { \
+ retval = 0; \
+ switch (size) { \
+ case 1: \
+ __put_user_asm(x, ptr, retval, "move.b"); \
+ break; \
+ case 2: \
+ __put_user_asm(x, ptr, retval, "move.w"); \
+ break; \
+ case 4: \
+ __put_user_asm(x, ptr, retval, "move.d"); \
+ break; \
+ case 8: \
+ __put_user_asm_64(x, ptr, retval); \
+ break; \
+ default: \
+ __put_user_bad(); \
+ } \
+} while (0)
+
+#define __get_user_size(x, ptr, size, retval) \
+do { \
+ retval = 0; \
+ switch (size) { \
+ case 1: \
+ __get_user_asm(x, ptr, retval, "move.b"); \
+ break; \
+ case 2: \
+ __get_user_asm(x, ptr, retval, "move.w"); \
+ break; \
+ case 4: \
+ __get_user_asm(x, ptr, retval, "move.d"); \
+ break; \
+ case 8: \
+ __get_user_asm_64(x, ptr, retval); \
+ break; \
+ default: \
+ (x) = __get_user_bad(); \
+ } \
+} while (0)
+
+#define __put_user_nocheck(x, ptr, size) \
+({ \
+ long __pu_err; \
+ __put_user_size((x), (ptr), (size), __pu_err); \
+ __pu_err; \
+})
+
+#define __put_user_check(x, ptr, size) \
+({ \
+ long __pu_err = -EFAULT; \
+ __typeof__(*(ptr)) *__pu_addr = (ptr); \
+ if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
+ __put_user_size((x), __pu_addr, (size), __pu_err); \
+ __pu_err; \
+})
+
+struct __large_struct { unsigned long buf[100]; };
+#define __m(x) (*(struct __large_struct *)(x))
+
+
+
+#define __get_user_nocheck(x, ptr, size) \
+({ \
+ long __gu_err, __gu_val; \
+ __get_user_size(__gu_val, (ptr), (size), __gu_err); \
+ (x) = (__force __typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+
+#define __get_user_check(x, ptr, size) \
+({ \
+ long __gu_err = -EFAULT, __gu_val = 0; \
+ const __typeof__(*(ptr)) *__gu_addr = (ptr); \
+ if (access_ok(VERIFY_READ, __gu_addr, size)) \
+ __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
+ (x) = (__force __typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+
+extern long __get_user_bad(void);
+
+/* More complex functions. Most are inline, but some call functions that
+ live in lib/usercopy.c */
+
+extern unsigned long __copy_user(void __user *to, const void *from, unsigned long n);
+extern unsigned long __copy_user_zeroing(void *to, const void __user *from, unsigned long n);
+extern unsigned long __do_clear_user(void __user *to, unsigned long n);
+
+static inline unsigned long
+__generic_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ if (access_ok(VERIFY_WRITE, to, n))
+ return __copy_user(to, from, n);
+ return n;
+}
+
+static inline unsigned long
+__generic_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ if (access_ok(VERIFY_READ, from, n))
+ return __copy_user_zeroing(to, from, n);
+ return n;
+}
+
+static inline unsigned long
+__generic_clear_user(void __user *to, unsigned long n)
+{
+ if (access_ok(VERIFY_WRITE, to, n))
+ return __do_clear_user(to, n);
+ return n;
+}
+
+static inline long
+__strncpy_from_user(char *dst, const char __user *src, long count)
+{
+ return __do_strncpy_from_user(dst, src, count);
+}
+
+static inline long
+strncpy_from_user(char *dst, const char __user *src, long count)
+{
+ long res = -EFAULT;
+
+ if (access_ok(VERIFY_READ, src, 1))
+ res = __do_strncpy_from_user(dst, src, count);
+ return res;
+}
+
+
+/* Note that these expand awfully if made into switch constructs, so
+ don't do that. */
+
+static inline unsigned long
+__constant_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ unsigned long ret = 0;
+
+ if (n == 0)
+ ;
+ else if (n == 1)
+ __asm_copy_from_user_1(to, from, ret);
+ else if (n == 2)
+ __asm_copy_from_user_2(to, from, ret);
+ else if (n == 3)
+ __asm_copy_from_user_3(to, from, ret);
+ else if (n == 4)
+ __asm_copy_from_user_4(to, from, ret);
+ else if (n == 5)
+ __asm_copy_from_user_5(to, from, ret);
+ else if (n == 6)
+ __asm_copy_from_user_6(to, from, ret);
+ else if (n == 7)
+ __asm_copy_from_user_7(to, from, ret);
+ else if (n == 8)
+ __asm_copy_from_user_8(to, from, ret);
+ else if (n == 9)
+ __asm_copy_from_user_9(to, from, ret);
+ else if (n == 10)
+ __asm_copy_from_user_10(to, from, ret);
+ else if (n == 11)
+ __asm_copy_from_user_11(to, from, ret);
+ else if (n == 12)
+ __asm_copy_from_user_12(to, from, ret);
+ else if (n == 13)
+ __asm_copy_from_user_13(to, from, ret);
+ else if (n == 14)
+ __asm_copy_from_user_14(to, from, ret);
+ else if (n == 15)
+ __asm_copy_from_user_15(to, from, ret);
+ else if (n == 16)
+ __asm_copy_from_user_16(to, from, ret);
+ else if (n == 20)
+ __asm_copy_from_user_20(to, from, ret);
+ else if (n == 24)
+ __asm_copy_from_user_24(to, from, ret);
+ else
+ ret = __generic_copy_from_user(to, from, n);
+
+ return ret;
+}
+
+/* Ditto, don't make a switch out of this. */
+
+static inline unsigned long
+__constant_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ unsigned long ret = 0;
+
+ if (n == 0)
+ ;
+ else if (n == 1)
+ __asm_copy_to_user_1(to, from, ret);
+ else if (n == 2)
+ __asm_copy_to_user_2(to, from, ret);
+ else if (n == 3)
+ __asm_copy_to_user_3(to, from, ret);
+ else if (n == 4)
+ __asm_copy_to_user_4(to, from, ret);
+ else if (n == 5)
+ __asm_copy_to_user_5(to, from, ret);
+ else if (n == 6)
+ __asm_copy_to_user_6(to, from, ret);
+ else if (n == 7)
+ __asm_copy_to_user_7(to, from, ret);
+ else if (n == 8)
+ __asm_copy_to_user_8(to, from, ret);
+ else if (n == 9)
+ __asm_copy_to_user_9(to, from, ret);
+ else if (n == 10)
+ __asm_copy_to_user_10(to, from, ret);
+ else if (n == 11)
+ __asm_copy_to_user_11(to, from, ret);
+ else if (n == 12)
+ __asm_copy_to_user_12(to, from, ret);
+ else if (n == 13)
+ __asm_copy_to_user_13(to, from, ret);
+ else if (n == 14)
+ __asm_copy_to_user_14(to, from, ret);
+ else if (n == 15)
+ __asm_copy_to_user_15(to, from, ret);
+ else if (n == 16)
+ __asm_copy_to_user_16(to, from, ret);
+ else if (n == 20)
+ __asm_copy_to_user_20(to, from, ret);
+ else if (n == 24)
+ __asm_copy_to_user_24(to, from, ret);
+ else
+ ret = __generic_copy_to_user(to, from, n);
+
+ return ret;
+}
+
+/* No switch, please. */
+
+static inline unsigned long
+__constant_clear_user(void __user *to, unsigned long n)
+{
+ unsigned long ret = 0;
+
+ if (n == 0)
+ ;
+ else if (n == 1)
+ __asm_clear_1(to, ret);
+ else if (n == 2)
+ __asm_clear_2(to, ret);
+ else if (n == 3)
+ __asm_clear_3(to, ret);
+ else if (n == 4)
+ __asm_clear_4(to, ret);
+ else if (n == 8)
+ __asm_clear_8(to, ret);
+ else if (n == 12)
+ __asm_clear_12(to, ret);
+ else if (n == 16)
+ __asm_clear_16(to, ret);
+ else if (n == 20)
+ __asm_clear_20(to, ret);
+ else if (n == 24)
+ __asm_clear_24(to, ret);
+ else
+ ret = __generic_clear_user(to, n);
+
+ return ret;
+}
+
+
+#define clear_user(to, n) \
+ (__builtin_constant_p(n) ? \
+ __constant_clear_user(to, n) : \
+ __generic_clear_user(to, n))
+
+#define copy_from_user(to, from, n) \
+ (__builtin_constant_p(n) ? \
+ __constant_copy_from_user(to, from, n) : \
+ __generic_copy_from_user(to, from, n))
+
+#define copy_to_user(to, from, n) \
+ (__builtin_constant_p(n) ? \
+ __constant_copy_to_user(to, from, n) : \
+ __generic_copy_to_user(to, from, n))
+
+/* We let the __ versions of copy_from/to_user inline, because they're often
+ * used in fast paths and have only a small space overhead.
+ */
+
+static inline unsigned long
+__generic_copy_from_user_nocheck(void *to, const void __user *from,
+ unsigned long n)
+{
+ return __copy_user_zeroing(to, from, n);
+}
+
+static inline unsigned long
+__generic_copy_to_user_nocheck(void __user *to, const void *from,
+ unsigned long n)
+{
+ return __copy_user(to, from, n);
+}
+
+static inline unsigned long
+__generic_clear_user_nocheck(void __user *to, unsigned long n)
+{
+ return __do_clear_user(to, n);
+}
+
+/* without checking */
+
+#define __copy_to_user(to, from, n) \
+ __generic_copy_to_user_nocheck((to), (from), (n))
+#define __copy_from_user(to, from, n) \
+ __generic_copy_from_user_nocheck((to), (from), (n))
+#define __copy_to_user_inatomic __copy_to_user
+#define __copy_from_user_inatomic __copy_from_user
+#define __clear_user(to, n) __generic_clear_user_nocheck((to), (n))
+
+#define strlen_user(str) strnlen_user((str), 0x7ffffffe)
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _CRIS_UACCESS_H */