Commit b48b2c3e authored by Jonas Bonn's avatar Jonas Bonn Committed by Linus Torvalds
Browse files

openrisc: use generic strnlen_user() function

The generic version is both easier to support and more correct.
Signed-off-by: default avatarJonas Bonn <>
Signed-off-by: default avatarLinus Torvalds <>
parent 1629372c
......@@ -20,6 +20,7 @@ config OPENRISC
config MMU
def_bool y
......@@ -318,33 +318,7 @@ clear_user(void *addr, unsigned long size)
extern long strncpy_from_user(char *dest, const char __user *src, long count);
* Return the size of a string (including the ending 0)
* Return 0 for error
extern int __strnlen_user(const char *str, long len, unsigned long top);
* 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 long strnlen_user(const char __user *str, long len)
unsigned long top = (unsigned long)get_fs();
unsigned long res = 0;
if (__addr_ok(str))
res = __strnlen_user(str, len, top);
return res;
#define strlen_user(str) strnlen_user(str, TASK_SIZE-1)
extern __must_check long strlen_user(const char __user *str);
extern __must_check long strnlen_user(const char __user *str, long n);
......@@ -103,50 +103,3 @@ __clear_user:
.section __ex_table, "a"
.long 9b, 99b // write fault
* extern int __strnlen_user(const char *str, long len, unsigned long top);
* RTRN: - length of a string including NUL termination character
* - on page fault 0
.global __strnlen_user
l.addi r1,r1,-8
l.sw 0(r1),r6
l.sw 4(r1),r3
l.addi r11,r0,0
2: l.sfeq r11,r4 1f
l.addi r11,r11,1
8: l.lbz r6,0(r3)
l.sfeq r6,r0 1f
l.sfgeu r3,r5 // are we over the top ? 99f
l.j 2b
l.addi r3,r3,1
l.lwz r6,0(r1)
l.lwz r3,4(r1)
l.jr r9
l.addi r1,r1,8
.section .fixup, "ax"
l.addi r11,r0,0
l.lwz r6,0(r1)
l.lwz r3,4(r1)
l.jr r9
l.addi r1,r1,8
.section __ex_table, "a"
.long 8b, 99b // read fault
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