8 files changed, 136 insertions, 198 deletions

diff --git a/arch/sparc/include/asm/uaccess.h b/arch/sparc/include/asm/uaccess.h
index e88fbe5c0457..42a28cfd941f 100644
--- a/arch/sparc/include/asm/uaccess.h
+++ b/arch/sparc/include/asm/uaccess.h
@@ -5,4 +5,7 @@
 #else
 #include <asm/uaccess_32.h>
 #endif
+
+extern long strncpy_from_user(char *dest, const char __user *src, long count);
+
 #endif
diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h
index d50c310f5d38..59586b57ef1a 100644
--- a/arch/sparc/include/asm/uaccess_32.h
+++ b/arch/sparc/include/asm/uaccess_32.h
@@ -304,16 +304,6 @@ static inline unsigned long clear_user(void __user *addr, unsigned long n)
                 return n;
 }
 
-extern long __strncpy_from_user(char *dest, const char __user *src, long count);
-
-static inline long strncpy_from_user(char *dest, const char __user *src, long count)
-{
-        if (__access_ok((unsigned long) src, count))
-                return __strncpy_from_user(dest, src, count);
-        else
-                return -EFAULT;
-}
-
 extern long __strlen_user(const char __user *);
 extern long __strnlen_user(const char __user *, long len);
 
diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h
index a1091afb8831..dcdfb89cbf3f 100644
--- a/arch/sparc/include/asm/uaccess_64.h
+++ b/arch/sparc/include/asm/uaccess_64.h
@@ -257,10 +257,6 @@ extern unsigned long __must_check __clear_user(void __user *, unsigned long);
 
 #define clear_user __clear_user
 
-extern long __must_check __strncpy_from_user(char *dest, const char __user *src, long count);
-
-#define strncpy_from_user __strncpy_from_user
-
 extern long __strlen_user(const char __user *);
 extern long __strnlen_user(const char __user *, long len);
 
diff --git a/arch/sparc/lib/Makefile b/arch/sparc/lib/Makefile
index 389628f50a15..943d98dc4cdb 100644
--- a/arch/sparc/lib/Makefile
+++ b/arch/sparc/lib/Makefile
@@ -10,7 +10,7 @@ lib-y                 += strlen.o
 lib-y                 += checksum_$(BITS).o
 lib-$(CONFIG_SPARC32) += blockops.o
 lib-y                 += memscan_$(BITS).o memcmp.o strncmp_$(BITS).o
-lib-y                 += strncpy_from_user_$(BITS).o strlen_user_$(BITS).o
+lib-y                 += strlen_user_$(BITS).o
 lib-$(CONFIG_SPARC32) += divdi3.o udivdi3.o
 lib-$(CONFIG_SPARC32) += copy_user.o locks.o
 lib-$(CONFIG_SPARC64) += atomic_64.o
diff --git a/arch/sparc/lib/ksyms.c b/arch/sparc/lib/ksyms.c
index 2dc30875c8bc..6b278abdb63d 100644
--- a/arch/sparc/lib/ksyms.c
+++ b/arch/sparc/lib/ksyms.c
@@ -33,9 +33,6 @@ EXPORT_SYMBOL(memset);
 EXPORT_SYMBOL(memmove);
 EXPORT_SYMBOL(__bzero);
 
-/* Moving data to/from/in userspace. */
-EXPORT_SYMBOL(__strncpy_from_user);
-
 /* Networking helper routines. */
 EXPORT_SYMBOL(csum_partial);
 
diff --git a/arch/sparc/lib/strncpy_from_user_32.S b/arch/sparc/lib/strncpy_from_user_32.S
deleted file mode 100644
index db0ed2964bdb..000000000000
--- a/arch/sparc/lib/strncpy_from_user_32.S
+++ /dev/null
@@ -1,47 +0,0 @@
-/* strncpy_from_user.S: Sparc strncpy from userspace.
- *
- *  Copyright(C) 1996 David S. Miller
- */
-
-#include <linux/linkage.h>
-#include <asm/ptrace.h>
-#include <asm/errno.h>
-
-        .text
-
-        /* Must return:
-         *
-         * -EFAULT              for an exception
-         * count                if we hit the buffer limit
-         * bytes copied         if we hit a null byte
-         */
-
-ENTRY(__strncpy_from_user)
-        /* %o0=dest, %o1=src, %o2=count */
-        mov     %o2, %o3
-1:
-        subcc   %o2, 1, %o2
-        bneg    2f
-         nop
-10:
-        ldub    [%o1], %o4
-        add     %o0, 1, %o0
-        cmp     %o4, 0
-        add     %o1, 1, %o1
-        bne     1b
-         stb    %o4, [%o0 - 1]
-2:
-        add     %o2, 1, %o0
-        retl
-         sub    %o3, %o0, %o0
-ENDPROC(__strncpy_from_user)
-
-        .section .fixup,#alloc,#execinstr
-        .align  4
-4:
-        retl
-         mov    -EFAULT, %o0
-
-        .section __ex_table,#alloc
-        .align  4
-        .word   10b, 4b
diff --git a/arch/sparc/lib/strncpy_from_user_64.S b/arch/sparc/lib/strncpy_from_user_64.S
deleted file mode 100644
index d1246b713077..000000000000
--- a/arch/sparc/lib/strncpy_from_user_64.S
+++ /dev/null
@@ -1,133 +0,0 @@
-/*
- * strncpy_from_user.S: Sparc64 strncpy from userspace.
- *
- *  Copyright (C) 1997, 1999 Jakub Jelinek (jj@ultra.linux.cz)
- */
-
-#include <linux/linkage.h>
-#include <asm/asi.h>
-#include <asm/errno.h>
-
-        .data
-        .align  8
-0:      .xword  0x0101010101010101
-
-        .text
-
-        /* 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)
-         *
-         * This implementation assumes:
-         * %o1 is 8 aligned => !(%o2 & 7)
-         * %o0 is 8 aligned (if not, it will be slooooow, but will work)
-         *
-         * This is optimized for the common case:
-         * in my stats, 90% of src are 8 aligned (even on sparc32)
-         * and average length is 18 or so.
-         */
-
-ENTRY(__strncpy_from_user)
-        /* %o0=dest, %o1=src, %o2=count */
-        andcc   %o1, 7, %g0             ! IEU1  Group
-        bne,pn  %icc, 30f               ! CTI
-         add    %o0, %o2, %g3           ! IEU0
-60:     ldxa    [%o1] %asi, %g1         ! Load  Group
-        brlez,pn %o2, 10f               ! CTI
-         mov    %o0, %o3                ! IEU0
-50:     sethi   %hi(0b), %o4            ! IEU0  Group
-        ldx     [%o4 + %lo(0b)], %o4    ! Load
-        sllx    %o4, 7, %o5             ! IEU1  Group
-1:      sub     %g1, %o4, %g2           ! IEU0  Group
-        stx     %g1, [%o0]              ! Store
-        add     %o0, 8, %o0             ! IEU1
-        andcc   %g2, %o5, %g0           ! IEU1  Group
-        bne,pn  %xcc, 5f                ! CTI
-         add    %o1, 8, %o1             ! IEU0
-        cmp     %o0, %g3                ! IEU1  Group
-        bl,a,pt %xcc, 1b                ! CTI
-61:      ldxa   [%o1] %asi, %g1         ! Load
-10:     retl                            ! CTI   Group
-         mov    %o2, %o0                ! IEU0
-5:      srlx    %g2, 32, %g7            ! IEU0  Group
-        sethi   %hi(0xff00), %o4        ! IEU1
-        andcc   %g7, %o5, %g0           ! IEU1  Group
-        be,pn   %icc, 2f                ! CTI
-         or     %o4, %lo(0xff00), %o4   ! IEU0
-        srlx    %g1, 48, %g7            ! IEU0  Group
-        andcc   %g7, %o4, %g0           ! IEU1  Group
-        be,pn   %icc, 50f               ! CTI
-         andcc  %g7, 0xff, %g0          ! IEU1  Group
-        be,pn   %icc, 51f               ! CTI
-         srlx   %g1, 32, %g7            ! IEU0
-        andcc   %g7, %o4, %g0           ! IEU1  Group
-        be,pn   %icc, 52f               ! CTI
-         andcc  %g7, 0xff, %g0          ! IEU1  Group
-        be,pn   %icc, 53f               ! CTI
-2:       andcc  %g2, %o5, %g0           ! IEU1  Group
-        be,pn   %icc, 2f                ! CTI
-         srl    %g1, 16, %g7            ! IEU0
-        andcc   %g7, %o4, %g0           ! IEU1  Group
-        be,pn   %icc, 54f               ! CTI
-         andcc  %g7, 0xff, %g0          ! IEU1  Group
-        be,pn   %icc, 55f               ! CTI
-         andcc  %g1, %o4, %g0           ! IEU1  Group
-        be,pn   %icc, 56f               ! CTI
-         andcc  %g1, 0xff, %g0          ! IEU1  Group
-        be,a,pn %icc, 57f               ! CTI
-         sub    %o0, %o3, %o0           ! IEU0
-2:      cmp     %o0, %g3                ! IEU1  Group
-        bl,a,pt %xcc, 50b               ! CTI
-62:      ldxa   [%o1] %asi, %g1         ! Load
-        retl                            ! CTI   Group
-         mov    %o2, %o0                ! IEU0
-50:     sub     %o0, %o3, %o0
-        retl
-         sub    %o0, 8, %o0
-51:     sub     %o0, %o3, %o0
-        retl
-         sub    %o0, 7, %o0
-52:     sub     %o0, %o3, %o0
-        retl
-         sub    %o0, 6, %o0
-53:     sub     %o0, %o3, %o0
-        retl
-         sub    %o0, 5, %o0
-54:     sub     %o0, %o3, %o0
-        retl
-         sub    %o0, 4, %o0
-55:     sub     %o0, %o3, %o0
-        retl
-         sub    %o0, 3, %o0
-56:     sub     %o0, %o3, %o0
-        retl
-         sub    %o0, 2, %o0
-57:     retl
-         sub    %o0, 1, %o0
-30:     brlez,pn %o2, 3f
-         sub    %g0, %o2, %o3
-        add     %o0, %o2, %o0
-63:     lduba   [%o1] %asi, %o4
-1:      add     %o1, 1, %o1
-        brz,pn  %o4, 2f
-         stb    %o4, [%o0 + %o3]
-        addcc   %o3, 1, %o3
-        bne,pt  %xcc, 1b
-64:      lduba  [%o1] %asi, %o4
-3:      retl
-         mov    %o2, %o0
-2:      retl
-         add    %o2, %o3, %o0
-ENDPROC(__strncpy_from_user)
-
-        .section __ex_table,"a"
-        .align  4
-        .word   60b, __retl_efault
-        .word   61b, __retl_efault
-        .word   62b, __retl_efault
-        .word   63b, __retl_efault
-        .word   64b, __retl_efault
-        .previous
diff --git a/arch/sparc/lib/usercopy.c b/arch/sparc/lib/usercopy.c
index 14b363fec8a2..851cb75ce189 100644
--- a/arch/sparc/lib/usercopy.c
+++ b/arch/sparc/lib/usercopy.c
@@ -1,4 +1,6 @@
 #include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/errno.h>
 #include <linux/bug.h>
 
 void copy_from_user_overflow(void)
@@ -6,3 +8,133 @@ void copy_from_user_overflow(void)
         WARN(1, "Buffer overflow detected!\n");
 }
 EXPORT_SYMBOL(copy_from_user_overflow);
+
+#define REPEAT_BYTE(x)  ((~0ul / 0xff) * (x))
+
+/* Return the high bit set in the first byte that is a zero */
+static inline unsigned long has_zero(unsigned long a)
+{
+        return ((a - REPEAT_BYTE(0x01)) & ~a) & REPEAT_BYTE(0x80);
+}
+
+static inline long find_zero(unsigned long c)
+{
+#ifdef CONFIG_64BIT
+        if (!(c & 0xff00000000000000UL))
+                return 0;
+        if (!(c & 0x00ff000000000000UL))
+                return 1;
+        if (!(c & 0x0000ff0000000000UL))
+                return 2;
+        if (!(c & 0x000000ff00000000UL))
+                return 3;
+#define __OFF 4
+#else
+#define __OFF 0
+#endif
+        if (!(c & 0xff000000))
+                return __OFF + 0;
+        if (!(c & 0x00ff0000))
+                return __OFF + 1;
+        if (!(c & 0x0000ff00))
+                return __OFF + 2;
+        return __OFF + 3;
+#undef __OFF
+}
+
+/*
+ * Do a strncpy, return length of string without final '\0'.
+ * 'count' is the user-supplied count (return 'count' if we
+ * hit it), 'max' is the address space maximum (and we return
+ * -EFAULT if we hit it).
+ */
+static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, unsigned long max)
+{
+        long res = 0;
+
+        /*
+         * Truncate 'max' to the user-specified limit, so that
+         * we only have one limit we need to check in the loop
+         */
+        if (max > count)
+                max = count;
+
+        if (((long) dst | (long) src) & (sizeof(long) - 1))
+                goto byte_at_a_time;
+
+        while (max >= sizeof(unsigned long)) {
+                unsigned long c;
+
+                /* Fall back to byte-at-a-time if we get a page fault */
+                if (unlikely(__get_user(c,(unsigned long __user *)(src+res))))
+                        break;
+                *(unsigned long *)(dst+res) = c;
+                if (has_zero(c))
+                        return res + find_zero(c);
+                res += sizeof(unsigned long);
+                max -= sizeof(unsigned long);
+        }
+
+byte_at_a_time:
+        while (max) {
+                char c;
+
+                if (unlikely(__get_user(c,src+res)))
+                        return -EFAULT;
+                dst[res] = c;
+                if (!c)
+                        return res;
+                res++;
+                max--;
+        }
+
+        /*
+         * Uhhuh. We hit 'max'. But was that the user-specified maximum
+         * too? If so, that's ok - we got as much as the user asked for.
+         */
+        if (res >= count)
+                return res;
+
+        /*
+         * Nope: we hit the address space limit, and we still had more
+         * characters the caller would have wanted. That's an EFAULT.
+         */
+        return -EFAULT;
+}
+
+/**
+ * strncpy_from_user: - Copy a NUL terminated string from userspace.
+ * @dst:   Destination address, in kernel space.  This buffer must be at
+ *         least @count bytes long.
+ * @src:   Source address, in user space.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from userspace to kernel space.
+ *
+ * On success, returns the length of the string (not including the trailing
+ * NUL).
+ *
+ * If access to userspace fails, returns -EFAULT (some data may have been
+ * copied).
+ *
+ * If @count is smaller than the length of the string, copies @count bytes
+ * and returns @count.
+ */
+long strncpy_from_user(char *dst, const char __user *src, long count)
+{
+        unsigned long max_addr, src_addr;
+
+        if (unlikely(count <= 0))
+                return 0;
+
+        max_addr = ~0UL;
+        if (likely(segment_eq(get_fs(), USER_DS)))
+                max_addr = STACK_TOP;
+        src_addr = (unsigned long)src;
+        if (likely(src_addr < max_addr)) {
+                unsigned long max = max_addr - src_addr;
+                return do_strncpy_from_user(dst, src, count, max);
+        }
+        return -EFAULT;
+}
+EXPORT_SYMBOL(strncpy_from_user);