x86: use the new generic strnlen_user() function

This throws away the old x86-specific functions in favor of the generic
optimized version.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 4 insertions, 109 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 3220d44e24d0..d700811785ea 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -94,6 +94,7 @@ config X86
         select GENERIC_TIME_VSYSCALL if X86_64
         select KTIME_SCALAR if X86_32
         select GENERIC_STRNCPY_FROM_USER
+        select GENERIC_STRNLEN_USER
 
 config INSTRUCTION_DECODER
         def_bool (KPROBES || PERF_EVENTS || UPROBES)
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 1354facd8f63..04cd6882308e 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -566,6 +566,9 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n);
 extern __must_check long
 strncpy_from_user(char *dst, const char __user *src, long count);
 
+extern __must_check long strlen_user(const char __user *str);
+extern __must_check long strnlen_user(const char __user *str, long n);
+
 /*
  * movsl can be slow when source and dest are not both 8-byte aligned
  */
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h
index 8084bc73b18c..576e39bca6ad 100644
--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -213,23 +213,6 @@ static inline unsigned long __must_check copy_from_user(void *to,
         return n;
 }
 
-/**
- * strlen_user: - Get the size of a string in user space.
- * @str: The string to measure.
- *
- * Context: User context only.  This function may sleep.
- *
- * Get the size of a NUL-terminated string in user space.
- *
- * Returns the size of the string INCLUDING the terminating NUL.
- * On exception, returns 0.
- *
- * If there is a limit on the length of a valid string, you may wish to
- * consider using strnlen_user() instead.
- */
-#define strlen_user(str) strnlen_user(str, LONG_MAX)
-
-long strnlen_user(const char __user *str, long n);
 unsigned long __must_check clear_user(void __user *mem, unsigned long len);
 unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
 
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index fcd4b6f3ef02..8e796fbbf9c6 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -208,9 +208,6 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
         }
 }
 
-__must_check long strnlen_user(const char __user *str, long n);
-__must_check long __strnlen_user(const char __user *str, long n);
-__must_check long strlen_user(const char __user *str);
 __must_check unsigned long clear_user(void __user *mem, unsigned long len);
 __must_check unsigned long __clear_user(void __user *mem, unsigned long len);
 
diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index 883b216c60b2..1781b2f950e2 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -95,47 +95,6 @@ __clear_user(void __user *to, unsigned long n)
 }
 EXPORT_SYMBOL(__clear_user);
 
-/**
- * strnlen_user: - Get the size of a string in user space.
- * @s: The string to measure.
- * @n: The maximum valid length
- *
- * Get the size of a NUL-terminated string in user space.
- *
- * Returns the size of the string INCLUDING the terminating NUL.
- * On exception, returns 0.
- * If the string is too long, returns a value greater than @n.
- */
-long strnlen_user(const char __user *s, long n)
-{
-        unsigned long mask = -__addr_ok(s);
-        unsigned long res, tmp;
-
-        might_fault();
-
-        __asm__ __volatile__(
-                "       testl %0, %0\n"
-                "       jz 3f\n"
-                "       andl %0,%%ecx\n"
-                "0:     repne; scasb\n"
-                "       setne %%al\n"
-                "       subl %%ecx,%0\n"
-                "       addl %0,%%eax\n"
-                "1:\n"
-                ".section .fixup,\"ax\"\n"
-                "2:     xorl %%eax,%%eax\n"
-                "       jmp 1b\n"
-                "3:     movb $1,%%al\n"
-                "       jmp 1b\n"
-                ".previous\n"
-                _ASM_EXTABLE(0b,2b)
-                :"=&r" (n), "=&D" (s), "=&a" (res), "=&c" (tmp)
-                :"0" (n), "1" (s), "2" (0), "3" (mask)
-                :"cc");
-        return res & mask;
-}
-EXPORT_SYMBOL(strnlen_user);
-
 #ifdef CONFIG_X86_INTEL_USERCOPY
 static unsigned long
 __copy_user_intel(void __user *to, const void *from, unsigned long size)
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index 0d0326f388c0..e5b130bc2d0e 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -52,54 +52,6 @@ unsigned long clear_user(void __user *to, unsigned long n)
 }
 EXPORT_SYMBOL(clear_user);
 
-/*
- * Return the size of a string (including the ending 0)
- *
- * Return 0 on exception, a value greater than N if too long
- */
-
-long __strnlen_user(const char __user *s, long n)
-{
-        long res = 0;
-        char c;
-
-        while (1) {
-                if (res>n)
-                        return n+1;
-                if (__get_user(c, s))
-                        return 0;
-                if (!c)
-                        return res+1;
-                res++;
-                s++;
-        }
-}
-EXPORT_SYMBOL(__strnlen_user);
-
-long strnlen_user(const char __user *s, long n)
-{
-        if (!access_ok(VERIFY_READ, s, 1))
-                return 0;
-        return __strnlen_user(s, n);
-}
-EXPORT_SYMBOL(strnlen_user);
-
-long strlen_user(const char __user *s)
-{
-        long res = 0;
-        char c;
-
-        for (;;) {
-                if (get_user(c, s))
-                        return 0;
-                if (!c)
-                        return res+1;
-                res++;
-                s++;
-        }
-}
-EXPORT_SYMBOL(strlen_user);
-
 unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len)
 {
         if (access_ok(VERIFY_WRITE, to, len) && access_ok(VERIFY_READ, from, len)) {