aboutsummaryrefslogtreecommitdiff
path: root/arch/metag/include/asm/uaccess.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/metag/include/asm/uaccess.h')
-rw-r--r--arch/metag/include/asm/uaccess.h241
1 files changed, 241 insertions, 0 deletions
diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h
new file mode 100644
index 000000000000..0748b0a97986
--- /dev/null
+++ b/arch/metag/include/asm/uaccess.h
@@ -0,0 +1,241 @@
+#ifndef __METAG_UACCESS_H
+#define __METAG_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/sched.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) })
+
+#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
+#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
+
+#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))
+/*
+ * Explicitly allow NULL pointers here. Parts of the kernel such
+ * as readv/writev use access_ok to validate pointers, but want
+ * to allow NULL pointers for various reasons. NULL pointers are
+ * safe to allow through because the first page is not mappable on
+ * Meta.
+ *
+ * We also wish to avoid letting user code access the system area
+ * and the kernel half of the address space.
+ */
+#define __user_bad(addr, size) (((addr) > 0 && (addr) < META_MEMORY_BASE) || \
+ ((addr) > PAGE_OFFSET && \
+ (addr) < LINCORE_BASE))
+
+static inline int __access_ok(unsigned long addr, unsigned long size)
+{
+ return __kernel_ok || !__user_bad(addr, size);
+}
+
+#define access_ok(type, addr, size) __access_ok((unsigned long)(addr), \
+ (unsigned long)(size))
+
+static inline int verify_area(int type, const void *addr, unsigned long size)
+{
+ return access_ok(type, addr, size) ? 0 : -EFAULT;
+}
+
+/*
+ * 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;
+};
+
+extern int fixup_exception(struct pt_regs *regs);
+
+/*
+ * These are the main single-value transfer routines. They automatically
+ * use the right size if we just have the right pointer type.
+ */
+
+#define put_user(x, ptr) \
+ __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+#define __put_user(x, ptr) \
+ __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+
+extern void __put_user_bad(void);
+
+#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)) __user *__pu_addr = (ptr); \
+ if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
+ __put_user_size((x), __pu_addr, (size), __pu_err); \
+ __pu_err; \
+})
+
+extern long __put_user_asm_b(unsigned int x, void __user *addr);
+extern long __put_user_asm_w(unsigned int x, void __user *addr);
+extern long __put_user_asm_d(unsigned int x, void __user *addr);
+extern long __put_user_asm_l(unsigned long long x, void __user *addr);
+
+#define __put_user_size(x, ptr, size, retval) \
+do { \
+ retval = 0; \
+ switch (size) { \
+ case 1: \
+ retval = __put_user_asm_b((unsigned int)x, ptr); break; \
+ case 2: \
+ retval = __put_user_asm_w((unsigned int)x, ptr); break; \
+ case 4: \
+ retval = __put_user_asm_d((unsigned int)x, ptr); break; \
+ case 8: \
+ retval = __put_user_asm_l((unsigned long long)x, ptr); break; \
+ default: \
+ __put_user_bad(); \
+ } \
+} while (0)
+
+#define get_user(x, ptr) \
+ __get_user_check((x), (ptr), sizeof(*(ptr)))
+#define __get_user(x, ptr) \
+ __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
+
+extern long __get_user_bad(void);
+
+#define __get_user_nocheck(x, ptr, size) \
+({ \
+ long __gu_err, __gu_val; \
+ __get_user_size(__gu_val, (ptr), (size), __gu_err); \
+ (x) = (__typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+
+#define __get_user_check(x, ptr, size) \
+({ \
+ long __gu_err = -EFAULT, __gu_val = 0; \
+ const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
+ if (access_ok(VERIFY_READ, __gu_addr, size)) \
+ __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
+ (x) = (__typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+
+extern unsigned char __get_user_asm_b(const void __user *addr, long *err);
+extern unsigned short __get_user_asm_w(const void __user *addr, long *err);
+extern unsigned int __get_user_asm_d(const void __user *addr, long *err);
+
+#define __get_user_size(x, ptr, size, retval) \
+do { \
+ retval = 0; \
+ switch (size) { \
+ case 1: \
+ x = __get_user_asm_b(ptr, &retval); break; \
+ case 2: \
+ x = __get_user_asm_w(ptr, &retval); break; \
+ case 4: \
+ x = __get_user_asm_d(ptr, &retval); break; \
+ default: \
+ (x) = __get_user_bad(); \
+ } \
+} while (0)
+
+/*
+ * Copy a null terminated string from userspace.
+ *
+ * Must return:
+ * -EFAULT for an exception
+ * count if we hit the buffer limit
+ * bytes copied if we hit a null byte
+ * (without the null byte)
+ */
+
+extern long __must_check __strncpy_from_user(char *dst, const char __user *src,
+ long count);
+
+#define strncpy_from_user(dst, src, count) __strncpy_from_user(dst, src, count)
+
+/*
+ * Return the size of a string (including the ending 0)
+ *
+ * Return 0 on exception, a value greater than N if too long
+ */
+extern long __must_check strnlen_user(const char __user *src, long count);
+
+#define strlen_user(str) strnlen_user(str, 32767)
+
+extern unsigned long __must_check __copy_user_zeroing(void *to,
+ const void __user *from,
+ unsigned long n);
+
+static inline unsigned long
+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;
+}
+
+#define __copy_from_user(to, from, n) __copy_user_zeroing(to, from, n)
+#define __copy_from_user_inatomic __copy_from_user
+
+extern unsigned long __must_check __copy_user(void __user *to,
+ const void *from,
+ unsigned long n);
+
+static inline unsigned long 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;
+}
+
+#define __copy_to_user(to, from, n) __copy_user(to, from, n)
+#define __copy_to_user_inatomic __copy_to_user
+
+/*
+ * Zero Userspace
+ */
+
+extern unsigned long __must_check __do_clear_user(void __user *to,
+ unsigned long n);
+
+static inline unsigned long clear_user(void __user *to, unsigned long n)
+{
+ if (access_ok(VERIFY_WRITE, to, n))
+ return __do_clear_user(to, n);
+ return n;
+}
+
+#define __clear_user(to, n) __do_clear_user(to, n)
+
+#endif /* _METAG_UACCESS_H */