openrisc: use generic strncpy_from_user

As per commits 2922585b9329 ("lib: Sparc's strncpy_from_user is generic
enough, move under lib/") and 92ae03f2ef99 ("x86: merge 32/64-bit
versions of 'strncpy_from_user()' and speed it up"), and corresponding
discussion on linux-arch.

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 4 insertions, 59 deletions

diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 4932247d078a..065623215c58 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -19,6 +19,7 @@ config OPENRISC
         select GENERIC_CPU_DEVICES
         select GENERIC_ATOMIC64
         select GENERIC_CLOCKEVENTS
+        select GENERIC_STRNCPY_FROM_USER
 
 config MMU
         def_bool y
diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h
index f5abaa0ffc38..04b93de92636 100644
--- a/arch/openrisc/include/asm/uaccess.h
+++ b/arch/openrisc/include/asm/uaccess.h
@@ -313,14 +313,10 @@ clear_user(void *addr, unsigned long size)
         return size;
 }
 
-extern int __strncpy_from_user(char *dst, const char *src, long count);
+#define user_addr_max() \
+        (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)
 
-static inline long strncpy_from_user(char *dst, const char *src, long count)
-{
-        if (access_ok(VERIFY_READ, src, 1))
-                return __strncpy_from_user(dst, src, count);
-        return -EFAULT;
-}
+extern long strncpy_from_user(char *dest, const char __user *src, long count);
 
 /*
  * Return the size of a string (including the ending 0)
diff --git a/arch/openrisc/lib/string.S b/arch/openrisc/lib/string.S
index 465f04bc7deb..8ceb11ebafb9 100644
--- a/arch/openrisc/lib/string.S
+++ b/arch/openrisc/lib/string.S
@@ -104,58 +104,6 @@ __clear_user:
                 .long 9b, 99b           // write fault
         .previous
 
-/*
- * long strncpy_from_user(char *dst, const char *src, long count)
- *
- *
- */
-        .global __strncpy_from_user
-__strncpy_from_user:
-        l.addi  r1,r1,-16
-        l.sw    0(r1),r6
-        l.sw    4(r1),r5
-        l.sw    8(r1),r4
-        l.sw    12(r1),r3
-
-        l.addi  r11,r5,0
-2:      l.sfeq  r5,r0
-        l.bf    1f
-        l.addi  r5,r5,-1
-8:      l.lbz   r6,0(r4)
-        l.sfeq  r6,r0
-        l.bf    1f
-9:      l.sb    0(r3),r6
-        l.addi  r3,r3,1
-        l.j     2b
-        l.addi  r4,r4,1
-1:
-        l.lwz   r6,0(r1)
-        l.addi  r5,r5,1
-        l.sub   r11,r11,r5              // r11 holds the return value
-
-        l.lwz   r6,0(r1)
-        l.lwz   r5,4(r1)
-        l.lwz   r4,8(r1)
-        l.lwz   r3,12(r1)
-        l.jr    r9
-        l.addi  r1,r1,16
-
-        .section .fixup, "ax"
-99:
-                l.movhi r11,hi(-EFAULT)
-                l.ori   r11,r11,lo(-EFAULT)
-
-                l.lwz   r6,0(r1)
-                l.lwz   r5,4(r1)
-                l.lwz   r4,8(r1)
-                l.lwz   r3,12(r1)
-                l.jr    r9
-                l.addi  r1,r1,16
-        .previous
-
-        .section __ex_table, "a"
-                .long 8b, 99b           // read fault
-        .previous
 
 /*
  * extern int __strnlen_user(const char *str, long len, unsigned long top);