microblaze: use generic strncpy/strnlen from_user

Remove the microblaze implemenation of strncpy/strnlen and instead use
the generic versions.  The microblaze version is fairly slow because it
always does byte accesses even for aligned data, and it lacks a checks
for user_addr_max().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 14a67a4..10dfa7b 100644 (file)
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -21,6 +21,8 @@ config MICROBLAZE
        select GENERIC_IRQ_SHOW
        select GENERIC_PCI_IOMAP
        select GENERIC_SCHED_CLOCK
+       select GENERIC_STRNCPY_FROM_USER
+       select GENERIC_STRNLEN_USER
        select HAVE_ARCH_HASH
        select HAVE_ARCH_KGDB
        select HAVE_ARCH_SECCOMP

diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
index c44b594..d2a8ef9 100644 (file)
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -35,6 +35,7 @@
 
 # define get_fs()      (current_thread_info()->addr_limit)
 # define set_fs(val)   (current_thread_info()->addr_limit = (val))
+# define user_addr_max() get_fs().seg
 
 # define uaccess_kernel()      (get_fs().seg == KERNEL_DS.seg)
 
@@ -296,28 +297,14 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 /*
  * Copy a null terminated string from userspace.
  */
-extern int __strncpy_user(char *to, const char __user *from, int len);
-
-static inline long
-strncpy_from_user(char *dst, const char __user *src, long count)
-{
-       if (!access_ok(src, 1))
-               return -EFAULT;
-       return __strncpy_user(dst, src, count);
-}
+__must_check long strncpy_from_user(char *dst, const char __user *src,
+                                   long count);
 
 /*
  * Return the size of a string (including the ending 0)
  *
  * Return 0 on exception, a value greater than N if too long
  */
-extern int __strnlen_user(const char __user *sstr, int len);
-
-static inline long strnlen_user(const char __user *src, long n)
-{
-       if (!access_ok(src, 1))
-               return 0;
-       return __strnlen_user(src, n);
-}
+__must_check long strnlen_user(const char __user *sstr, long len);
 
 #endif /* _ASM_MICROBLAZE_UACCESS_H */

diff --git a/arch/microblaze/kernel/microblaze_ksyms.c b/arch/microblaze/kernel/microblaze_ksyms.c
index 303aaf1..c892e17 100644 (file)
--- a/arch/microblaze/kernel/microblaze_ksyms.c
+++ b/arch/microblaze/kernel/microblaze_ksyms.c
@@ -26,7 +26,6 @@ EXPORT_SYMBOL(_mcount);
  * Assembly functions that may be used (directly or indirectly) by modules
  */
 EXPORT_SYMBOL(__copy_tofrom_user);
-EXPORT_SYMBOL(__strncpy_user);
 
 #ifdef CONFIG_OPT_LIB_ASM
 EXPORT_SYMBOL(memcpy);

diff --git a/arch/microblaze/lib/uaccess_old.S b/arch/microblaze/lib/uaccess_old.S
index eca2900..dd5f3bf 100644 (file)
--- a/arch/microblaze/lib/uaccess_old.S
+++ b/arch/microblaze/lib/uaccess_old.S
@@ -12,96 +12,6 @@
 #include <linux/linkage.h>
 #include <asm/page.h>
 
-/*
- * int __strncpy_user(char *to, char *from, int len);
- *
- * Returns:
- *  -EFAULT  for an exception
- *  len      if we hit the buffer limit
- *  bytes copied
- */
-
-       .text
-.globl __strncpy_user;
-.type  __strncpy_user, @function
-.align 4;
-__strncpy_user:
-
-       /*
-        * r5 - to
-        * r6 - from
-        * r7 - len
-        * r3 - temp count
-        * r4 - temp val
-        */
-       beqid   r7,3f
-       addik   r3,r7,0         /* temp_count = len */
-1:
-       lbu     r4,r6,r0
-       beqid   r4,2f
-       sb      r4,r5,r0
-
-       addik   r5,r5,1
-       addik   r6,r6,1         /* delay slot */
-
-       addik   r3,r3,-1
-       bnei    r3,1b           /* break on len */
-2:
-       rsubk   r3,r3,r7        /* temp_count = len - temp_count */
-3:
-       rtsd    r15,8
-       nop
-       .size   __strncpy_user, . - __strncpy_user
-
-       .section        .fixup, "ax"
-       .align  2
-4:
-       brid    3b
-       addik   r3,r0, -EFAULT
-
-       .section        __ex_table, "a"
-       .word   1b,4b
-
-/*
- * int __strnlen_user(char __user *str, int maxlen);
- *
- * Returns:
- *  0 on error
- *  maxlen + 1  if no NUL byte found within maxlen bytes
- *  size of the string (including NUL byte)
- */
-
-       .text
-.globl __strnlen_user;
-.type  __strnlen_user, @function
-.align 4;
-__strnlen_user:
-       beqid   r6,3f
-       addik   r3,r6,0
-1:
-       lbu     r4,r5,r0
-       beqid   r4,2f           /* break on NUL */
-       addik   r3,r3,-1        /* delay slot */
-
-       bneid   r3,1b
-       addik   r5,r5,1         /* delay slot */
-
-       addik   r3,r3,-1        /* for break on len */
-2:
-       rsubk   r3,r3,r6
-3:
-       rtsd    r15,8
-       nop
-       .size   __strnlen_user, . - __strnlen_user
-
-       .section        .fixup,"ax"
-4:
-       brid    3b
-       addk    r3,r0,r0
-
-       .section        __ex_table,"a"
-       .word   1b,4b
-
 /* Loop unrolling for __copy_tofrom_user */
 #define COPY(offset)   \
 1:     lwi     r4 , r6, 0x0000 + offset;       \