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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-ppc64/uaccess.h
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-ppc64/uaccess.h')
-rw-r--r--include/asm-ppc64/uaccess.h346
1 files changed, 346 insertions, 0 deletions
diff --git a/include/asm-ppc64/uaccess.h b/include/asm-ppc64/uaccess.h
new file mode 100644
index 000000000000..05b5943ab1ee
--- /dev/null
+++ b/include/asm-ppc64/uaccess.h
@@ -0,0 +1,346 @@
+#ifndef _PPC64_UACCESS_H
+#define _PPC64_UACCESS_H
+
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef __ASSEMBLY__
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <asm/processor.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(0UL)
+#define USER_DS MAKE_MM_SEG(0xf000000000000000UL)
+
+#define get_ds() (KERNEL_DS)
+#define get_fs() (current->thread.fs)
+#define set_fs(val) (current->thread.fs = (val))
+
+#define segment_eq(a,b) ((a).seg == (b).seg)
+
+/*
+ * Use the alpha trick for checking ranges:
+ *
+ * Is a address valid? This does a straightforward calculation rather
+ * than tests.
+ *
+ * Address valid if:
+ * - "addr" doesn't have any high-bits set
+ * - AND "size" doesn't have any high-bits set
+ * - OR we are in kernel mode.
+ *
+ * We dont have to check for high bits in (addr+size) because the first
+ * two checks force the maximum result to be below the start of the
+ * kernel region.
+ */
+#define __access_ok(addr,size,segment) \
+ (((segment).seg & (addr | size )) == 0)
+
+#define access_ok(type,addr,size) \
+ __access_ok(((__force unsigned long)(addr)),(size),get_fs())
+
+/* this function will go away soon - use access_ok() instead */
+static inline int __deprecated verify_area(int type, const void __user *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;
+};
+
+/* Returns 0 if exception not found and fixup otherwise. */
+extern unsigned long search_exception_table(unsigned long);
+
+/*
+ * 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 the
+ * PowerPC, 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)))
+
+#define __get_user_unaligned __get_user
+#define __put_user_unaligned __put_user
+
+extern long __put_user_bad(void);
+
+#define __put_user_nocheck(x,ptr,size) \
+({ \
+ long __pu_err; \
+ might_sleep(); \
+ __chk_user_ptr(ptr); \
+ __put_user_size((x),(ptr),(size),__pu_err,-EFAULT); \
+ __pu_err; \
+})
+
+#define __put_user_check(x,ptr,size) \
+({ \
+ long __pu_err = -EFAULT; \
+ void __user *__pu_addr = (ptr); \
+ might_sleep(); \
+ if (access_ok(VERIFY_WRITE,__pu_addr,size)) \
+ __put_user_size((x),__pu_addr,(size),__pu_err,-EFAULT); \
+ __pu_err; \
+})
+
+#define __put_user_size(x,ptr,size,retval,errret) \
+do { \
+ retval = 0; \
+ switch (size) { \
+ case 1: __put_user_asm(x,ptr,retval,"stb",errret); break; \
+ case 2: __put_user_asm(x,ptr,retval,"sth",errret); break; \
+ case 4: __put_user_asm(x,ptr,retval,"stw",errret); break; \
+ case 8: __put_user_asm(x,ptr,retval,"std",errret); break; \
+ default: __put_user_bad(); \
+ } \
+} while (0)
+
+/*
+ * We don't tell gcc that we are accessing memory, but this is OK
+ * because we do not write to any memory gcc knows about, so there
+ * are no aliasing issues.
+ */
+#define __put_user_asm(x, addr, err, op, errret) \
+ __asm__ __volatile__( \
+ "1: "op" %1,0(%2) # put_user\n" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: li %0,%3\n" \
+ " b 2b\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .align 3\n" \
+ " .llong 1b,3b\n" \
+ ".previous" \
+ : "=r"(err) \
+ : "r"(x), "b"(addr), "i"(errret), "0"(err))
+
+
+#define __get_user_nocheck(x,ptr,size) \
+({ \
+ long __gu_err, __gu_val; \
+ might_sleep(); \
+ __get_user_size(__gu_val,(ptr),(size),__gu_err,-EFAULT);\
+ (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); \
+ might_sleep(); \
+ if (access_ok(VERIFY_READ,__gu_addr,size)) \
+ __get_user_size(__gu_val,__gu_addr,(size),__gu_err,-EFAULT);\
+ (x) = (__typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+
+extern long __get_user_bad(void);
+
+#define __get_user_size(x,ptr,size,retval,errret) \
+do { \
+ retval = 0; \
+ __chk_user_ptr(ptr); \
+ switch (size) { \
+ case 1: __get_user_asm(x,ptr,retval,"lbz",errret); break; \
+ case 2: __get_user_asm(x,ptr,retval,"lhz",errret); break; \
+ case 4: __get_user_asm(x,ptr,retval,"lwz",errret); break; \
+ case 8: __get_user_asm(x,ptr,retval,"ld",errret); break; \
+ default: (x) = __get_user_bad(); \
+ } \
+} while (0)
+
+#define __get_user_asm(x, addr, err, op, errret) \
+ __asm__ __volatile__( \
+ "1: "op" %1,0(%2) # get_user\n" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: li %0,%3\n" \
+ " li %1,0\n" \
+ " b 2b\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .align 3\n" \
+ " .llong 1b,3b\n" \
+ ".previous" \
+ : "=r"(err), "=r"(x) \
+ : "b"(addr), "i"(errret), "0"(err))
+
+/* more complex routines */
+
+extern unsigned long __copy_tofrom_user(void __user *to, const void __user *from,
+ unsigned long size);
+
+static inline unsigned long
+__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
+{
+ if (__builtin_constant_p(n)) {
+ unsigned long ret;
+
+ switch (n) {
+ case 1:
+ __get_user_size(*(u8 *)to, from, 1, ret, 1);
+ return ret;
+ case 2:
+ __get_user_size(*(u16 *)to, from, 2, ret, 2);
+ return ret;
+ case 4:
+ __get_user_size(*(u32 *)to, from, 4, ret, 4);
+ return ret;
+ case 8:
+ __get_user_size(*(u64 *)to, from, 8, ret, 8);
+ return ret;
+ }
+ }
+ return __copy_tofrom_user((__force void __user *) to, from, n);
+}
+
+static inline unsigned long
+__copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ might_sleep();
+ return __copy_from_user_inatomic(to, from, n);
+}
+
+static inline unsigned long
+__copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
+{
+ if (__builtin_constant_p(n)) {
+ unsigned long ret;
+
+ switch (n) {
+ case 1:
+ __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret, 1);
+ return ret;
+ case 2:
+ __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret, 2);
+ return ret;
+ case 4:
+ __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret, 4);
+ return ret;
+ case 8:
+ __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret, 8);
+ return ret;
+ }
+ }
+ return __copy_tofrom_user(to, (__force const void __user *) from, n);
+}
+
+static inline unsigned long
+__copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ might_sleep();
+ return __copy_to_user_inatomic(to, from, n);
+}
+
+#define __copy_in_user(to, from, size) \
+ __copy_tofrom_user((to), (from), (size))
+
+extern unsigned long copy_from_user(void *to, const void __user *from,
+ unsigned long n);
+extern unsigned long copy_to_user(void __user *to, const void *from,
+ unsigned long n);
+extern unsigned long copy_in_user(void __user *to, const void __user *from,
+ unsigned long n);
+
+extern unsigned long __clear_user(void __user *addr, unsigned long size);
+
+static inline unsigned long
+clear_user(void __user *addr, unsigned long size)
+{
+ might_sleep();
+ if (likely(access_ok(VERIFY_WRITE, addr, size)))
+ size = __clear_user(addr, size);
+ return size;
+}
+
+extern int __strncpy_from_user(char *dst, const char __user *src, long count);
+
+static inline long
+strncpy_from_user(char *dst, const char __user *src, long count)
+{
+ might_sleep();
+ if (likely(access_ok(VERIFY_READ, src, 1)))
+ return __strncpy_from_user(dst, src, count);
+ return -EFAULT;
+}
+
+/*
+ * Return the size of a string (including the ending 0)
+ *
+ * Return 0 for error
+ */
+extern int __strnlen_user(const char __user *str, long len);
+
+/*
+ * Returns the length of the string at str (including the null byte),
+ * or 0 if we hit a page we can't access,
+ * or something > len if we didn't find a null byte.
+ */
+static inline int strnlen_user(const char __user *str, long len)
+{
+ might_sleep();
+ if (likely(access_ok(VERIFY_READ, str, 1)))
+ return __strnlen_user(str, len);
+ return 0;
+}
+
+#define strlen_user(str) strnlen_user((str), 0x7ffffffe)
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _PPC64_UACCESS_H */