powerpc: merge uaccess.h
There is still a bug to be fixed and more merging to be done.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
diff --git a/include/asm-powerpc/uaccess.h b/include/asm-powerpc/uaccess.h
new file mode 100644
index 0000000..2ecc3e1
--- /dev/null
+++ b/include/asm-powerpc/uaccess.h
@@ -0,0 +1,504 @@
+#ifndef _ARCH_POWERPC_UACCESS_H
+#define _ARCH_POWERPC_UACCESS_H
+
+#ifdef __KERNEL__
+#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.
+ *
+ * The fs/ds values are now the highest legal address in the "segment".
+ * This simplifies the checking in the routines below.
+ */
+
+#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
+
+#ifdef __powerpc64__
+#define KERNEL_DS MAKE_MM_SEG(0UL)
+#define USER_DS MAKE_MM_SEG(0xf000000000000000UL)
+#else
+#define KERNEL_DS MAKE_MM_SEG(~0UL)
+#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
+#endif
+
+#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)
+
+#ifdef __powerpc64__
+/*
+ * 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)
+
+#else
+
+#define __access_ok(addr, size, segment) \
+ (((addr) <= (segment).seg) && \
+ (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr)))))
+
+#endif
+
+#define access_ok(type, addr, size) \
+ (__chk_user_ptr(addr), \
+ __access_ok((__force unsigned long)(addr), (size), get_fs()))
+
+/*
+ * 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;
+ unsigned long 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 the
+ * PowerPC, we can just do these as direct assignments. (Of course, the
+ * exception handling means that it's no longer "just"...)
+ *
+ * The "user64" versions of the user access functions are versions that
+ * allow access of 64-bit data. The "get_user" functions do not
+ * properly handle 64-bit data because the value gets down cast to a long.
+ * The "put_user" functions already handle 64-bit data properly but we add
+ * "user64" versions for completeness
+ */
+#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)))
+#ifndef __powerpc64__
+#define __get_user64(x, ptr) \
+ __get_user64_nocheck((x), (ptr), sizeof(*(ptr)))
+#define __put_user64(x, ptr) __put_user(x, ptr)
+#endif
+
+#ifdef __powerpc64__
+#define __get_user_unaligned __get_user
+#define __put_user_unaligned __put_user
+#endif
+
+extern long __put_user_bad(void);
+
+#ifdef __powerpc64__
+#define __EX_TABLE_ALIGN "3"
+#define __EX_TABLE_TYPE "llong"
+#else
+#define __EX_TABLE_ALIGN "2"
+#define __EX_TABLE_TYPE "long"
+#endif
+
+/*
+ * 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) \
+ __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 " __EX_TABLE_ALIGN "\n" \
+ " ."__EX_TABLE_TYPE" 1b,3b\n" \
+ ".previous" \
+ : "=r" (err) \
+ : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))
+
+#ifndef __powerpc64__
+#define __put_user_asm2(x, addr, err) \
+ __asm__ __volatile__( \
+ "1: stw %1,0(%2)\n" \
+ "2: stw %1+1,4(%2)\n" \
+ "3:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "4: li %0,%3\n" \
+ " b 3b\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .align " __EX_TABLE_ALIGN "\n" \
+ " ." __EX_TABLE_TYPE " 1b,4b\n" \
+ " ." __EX_TABLE_TYPE " 2b,4b\n" \
+ ".previous" \
+ : "=r" (err) \
+ : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))
+#else /* __powerpc64__ */
+#define __put_user_asm2(x, ptr, retval) \
+ __put_user_asm(x, ptr, retval, "std")
+#endif /* __powerpc64__ */
+
+#define __put_user_size(x, ptr, size, retval) \
+do { \
+ retval = 0; \
+ switch (size) { \
+ case 1: __put_user_asm(x, ptr, retval, "stb"); break; \
+ case 2: __put_user_asm(x, ptr, retval, "sth"); break; \
+ case 4: __put_user_asm(x, ptr, retval, "stw"); break; \
+ case 8: __put_user_asm2(x, ptr, retval); break; \
+ default: __put_user_bad(); \
+ } \
+} while (0)
+
+#define __put_user_nocheck(x, ptr, size) \
+({ \
+ long __pu_err; \
+ might_sleep(); \
+ __chk_user_ptr(ptr); \
+ __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); \
+ might_sleep(); \
+ if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
+ __put_user_size((x), __pu_addr, (size), __pu_err); \
+ __pu_err; \
+})
+
+extern long __get_user_bad(void);
+
+#define __get_user_asm(x, addr, err, op) \
+ __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 "__EX_TABLE_ALIGN "\n" \
+ " ." __EX_TABLE_TYPE " 1b,3b\n" \
+ ".previous" \
+ : "=r" (err), "=r" (x) \
+ : "b" (addr), "i" (-EFAULT), "0" (err))
+
+#ifndef __powerpc64__
+#define __get_user_asm2(x, addr, err) \
+ __asm__ __volatile__( \
+ "1: lwz %1,0(%2)\n" \
+ "2: lwz %1+1,4(%2)\n" \
+ "3:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "4: li %0,%3\n" \
+ " li %1,0\n" \
+ " li %1+1,0\n" \
+ " b 3b\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .align " __EX_TABLE_ALIGN "\n" \
+ " ." __EX_TABLE_TYPE " 1b,4b\n" \
+ " ." __EX_TABLE_TYPE " 2b,4b\n" \
+ ".previous" \
+ : "=r" (err), "=&r" (x) \
+ : "b" (addr), "i" (-EFAULT), "0" (err))
+#else
+#define __get_user_asm2(x, addr, err) \
+ __get_user_asm(x, addr, err, "ld")
+#endif /* __powerpc64__ */
+
+#define __get_user_size(x, ptr, size, retval) \
+do { \
+ retval = 0; \
+ __chk_user_ptr(ptr); \
+ if (size > sizeof(x)) \
+ (x) = __get_user_bad(); \
+ switch (size) { \
+ case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \
+ case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \
+ case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \
+ case 8: __get_user_asm2(x, ptr, retval); break; \
+ default: (x) = __get_user_bad(); \
+ } \
+} while (0)
+
+#define __get_user_nocheck(x, ptr, size) \
+({ \
+ long __gu_err; \
+ unsigned long __gu_val; \
+ __chk_user_ptr(ptr); \
+ might_sleep(); \
+ __get_user_size(__gu_val, (ptr), (size), __gu_err); \
+ (x) = (__typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+
+#ifndef __powerpc64__
+#define __get_user64_nocheck(x, ptr, size) \
+({ \
+ long __gu_err; \
+ long long __gu_val; \
+ __chk_user_ptr(ptr); \
+ might_sleep(); \
+ __get_user_size(__gu_val, (ptr), (size), __gu_err); \
+ (x) = (__typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+#endif /* __powerpc64__ */
+
+#define __get_user_check(x, ptr, size) \
+({ \
+ long __gu_err = -EFAULT; \
+ unsigned long __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); \
+ (x) = (__typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+
+/* more complex routines */
+
+extern unsigned long __copy_tofrom_user(void __user *to,
+ const void __user *from, unsigned long size);
+
+#ifndef __powerpc64__
+extern inline unsigned long
+copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ unsigned long over;
+
+ if (access_ok(VERIFY_READ, from, n))
+ return __copy_tofrom_user((__force void __user *)to, from, n);
+ if ((unsigned long)from < TASK_SIZE) {
+ over = (unsigned long)from + n - TASK_SIZE;
+ return __copy_tofrom_user((__force void __user *)to, from,
+ n - over) + over;
+ }
+ return n;
+}
+
+extern inline unsigned long
+copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ unsigned long over;
+
+ if (access_ok(VERIFY_WRITE, to, n))
+ return __copy_tofrom_user(to, (__force void __user *)from, n);
+ if ((unsigned long)to < TASK_SIZE) {
+ over = (unsigned long)to + n - TASK_SIZE;
+ return __copy_tofrom_user(to, (__force void __user *)from,
+ n - over) + over;
+ }
+ return n;
+}
+
+#else /* __powerpc64__ */
+
+static inline unsigned long
+__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
+{
+ if (__builtin_constant_p(n) && (n <= 8)) {
+ unsigned long ret;
+
+ switch (n) {
+ case 1:
+ __get_user_size(*(u8 *)to, from, 1, ret);
+ break;
+ case 2:
+ __get_user_size(*(u16 *)to, from, 2, ret);
+ break;
+ case 4:
+ __get_user_size(*(u32 *)to, from, 4, ret);
+ break;
+ case 8:
+ __get_user_size(*(u64 *)to, from, 8, ret);
+ break;
+ }
+ return (ret == -EFAULT) ? n : 0;
+ }
+ return __copy_tofrom_user((__force void __user *) 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) && (n <= 8)) {
+ unsigned long ret;
+
+ switch (n) {
+ case 1:
+ __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret);
+ break;
+ case 2:
+ __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret);
+ break;
+ case 4:
+ __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret);
+ break;
+ case 8:
+ __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret);
+ break;
+ }
+ return (ret == -EFAULT) ? n : 0;
+ }
+ return __copy_tofrom_user(to, (__force const void __user *) from, n);
+}
+
+#endif /* __powerpc64__ */
+
+static inline unsigned long
+__copy_from_user(void *to, const void __user *from, unsigned long size)
+{
+ might_sleep();
+#ifndef __powerpc64__
+ return __copy_tofrom_user((__force void __user *)to, from, size);
+#else /* __powerpc64__ */
+ return __copy_from_user_inatomic(to, from, size);
+#endif /* __powerpc64__ */
+}
+
+static inline unsigned long
+__copy_to_user(void __user *to, const void *from, unsigned long size)
+{
+ might_sleep();
+#ifndef __powerpc64__
+ return __copy_tofrom_user(to, (__force void __user *)from, size);
+#else /* __powerpc64__ */
+ return __copy_to_user_inatomic(to, from, size);
+#endif /* __powerpc64__ */
+}
+
+#ifndef __powerpc64__
+#define __copy_to_user_inatomic __copy_to_user
+#define __copy_from_user_inatomic __copy_from_user
+#else /* __powerpc64__ */
+#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);
+#endif /* __powerpc64__ */
+
+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)))
+ return __clear_user(addr, size);
+#ifndef __powerpc64__
+ if ((unsigned long)addr < TASK_SIZE) {
+ unsigned long over = (unsigned long)addr + size - TASK_SIZE;
+ return __clear_user(addr, size - over) + over;
+ }
+#endif /* __powerpc64__ */
+ 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
+ */
+#ifndef __powerpc64__
+extern int __strnlen_user(const char __user *str, long len, unsigned long top);
+#else /* __powerpc64__ */
+extern int __strnlen_user(const char __user *str, long len);
+#endif /* __powerpc64__ */
+
+/*
+ * 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.
+ *
+ * The `top' parameter to __strnlen_user is to make sure that
+ * we can never overflow from the user area into kernel space.
+ */
+static inline int strnlen_user(const char __user *str, long len)
+{
+#ifndef __powerpc64__
+ unsigned long top = current->thread.fs.seg;
+
+ if ((unsigned long)str > top)
+ return 0;
+ return __strnlen_user(str, len, top);
+#else /* __powerpc64__ */
+ might_sleep();
+ if (likely(access_ok(VERIFY_READ, str, 1)))
+ return __strnlen_user(str, len);
+ return 0;
+#endif /* __powerpc64__ */
+}
+
+#define strlen_user(str) strnlen_user((str), 0x7ffffffe)
+
+#endif /* __ASSEMBLY__ */
+#endif /* __KERNEL__ */
+
+#endif /* _ARCH_POWERPC_UACCESS_H */