3 files changed, 137 insertions, 10 deletions

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 8f28d35867f8..2df44e773270 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -141,6 +141,10 @@ extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 extern long simple_strtol(const char *,char **,unsigned int);
 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 extern long long simple_strtoll(const char *,char **,unsigned int);
+extern int strict_strtoul(const char *, unsigned int, unsigned long *);
+extern int strict_strtol(const char *, unsigned int, long *);
+extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
+extern int strict_strtoll(const char *, unsigned int, long long *);
 extern int sprintf(char * buf, const char * fmt, ...)
         __attribute__ ((format (printf, 2, 3)));
 extern int vsprintf(char *buf, const char *, va_list)
diff --git a/kernel/params.c b/kernel/params.c
index e28c70628bb7..afc46a23eb6d 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -180,12 +180,12 @@ int parse_args(const char *name,
 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn)       \
         int param_set_##name(const char *val, struct kernel_param *kp)  \
         {                                                               \
-                char *endp;                                             \
                 tmptype l;                                              \
+                int ret;                                                \
                                                                         \
                 if (!val) return -EINVAL;                               \
-                l = strtolfn(val, &endp, 0);                            \
-                if (endp == val || ((type)l != l))                      \
+                ret = strtolfn(val, 0, &l);                             \
+                if (ret == -EINVAL || ((type)l != l))                   \
                         return -EINVAL;                                 \
                 *((type *)kp->arg) = l;                                 \
                 return 0;                                               \
@@ -195,13 +195,13 @@ int parse_args(const char *name,
                 return sprintf(buffer, format, *((type *)kp->arg));     \
         }
 
-STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, simple_strtoul);
-STANDARD_PARAM_DEF(short, short, "%hi", long, simple_strtol);
-STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, simple_strtoul);
-STANDARD_PARAM_DEF(int, int, "%i", long, simple_strtol);
-STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, simple_strtoul);
-STANDARD_PARAM_DEF(long, long, "%li", long, simple_strtol);
-STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, simple_strtoul);
+STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
+STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
+STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
+STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
+STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
+STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
+STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
 
 int param_set_charp(const char *val, struct kernel_param *kp)
 {
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 7b481cea54ae..419993f58c6b 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -126,6 +126,129 @@ long long simple_strtoll(const char *cp,char **endp,unsigned int base)
         return simple_strtoull(cp,endp,base);
 }
 
+
+/**
+ * strict_strtoul - convert a string to an unsigned long strictly
+ * @cp: The string to be converted
+ * @base: The number base to use
+ * @res: The converted result value
+ *
+ * strict_strtoul converts a string to an unsigned long only if the
+ * string is really an unsigned long string, any string containing
+ * any invalid char at the tail will be rejected and -EINVAL is returned,
+ * only a newline char at the tail is acceptible because people generally
+ * change a module parameter in the following way:
+ *
+ *      echo 1024 > /sys/module/e1000/parameters/copybreak
+ *
+ * echo will append a newline to the tail.
+ *
+ * It returns 0 if conversion is successful and *res is set to the converted
+ * value, otherwise it returns -EINVAL and *res is set to 0.
+ *
+ * simple_strtoul just ignores the successive invalid characters and
+ * return the converted value of prefix part of the string.
+ */
+int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
+
+/**
+ * strict_strtol - convert a string to a long strictly
+ * @cp: The string to be converted
+ * @base: The number base to use
+ * @res: The converted result value
+ *
+ * strict_strtol is similiar to strict_strtoul, but it allows the first
+ * character of a string is '-'.
+ *
+ * It returns 0 if conversion is successful and *res is set to the converted
+ * value, otherwise it returns -EINVAL and *res is set to 0.
+ */
+int strict_strtol(const char *cp, unsigned int base, long *res);
+
+/**
+ * strict_strtoull - convert a string to an unsigned long long strictly
+ * @cp: The string to be converted
+ * @base: The number base to use
+ * @res: The converted result value
+ *
+ * strict_strtoull converts a string to an unsigned long long only if the
+ * string is really an unsigned long long string, any string containing
+ * any invalid char at the tail will be rejected and -EINVAL is returned,
+ * only a newline char at the tail is acceptible because people generally
+ * change a module parameter in the following way:
+ *
+ *      echo 1024 > /sys/module/e1000/parameters/copybreak
+ *
+ * echo will append a newline to the tail of the string.
+ *
+ * It returns 0 if conversion is successful and *res is set to the converted
+ * value, otherwise it returns -EINVAL and *res is set to 0.
+ *
+ * simple_strtoull just ignores the successive invalid characters and
+ * return the converted value of prefix part of the string.
+ */
+int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res);
+
+/**
+ * strict_strtoll - convert a string to a long long strictly
+ * @cp: The string to be converted
+ * @base: The number base to use
+ * @res: The converted result value
+ *
+ * strict_strtoll is similiar to strict_strtoull, but it allows the first
+ * character of a string is '-'.
+ *
+ * It returns 0 if conversion is successful and *res is set to the converted
+ * value, otherwise it returns -EINVAL and *res is set to 0.
+ */
+int strict_strtoll(const char *cp, unsigned int base, long long *res);
+
+#define define_strict_strtoux(type, valtype)                            \
+int strict_strtou##type(const char *cp, unsigned int base, valtype *res)\
+{                                                                       \
+        char *tail;                                                     \
+        valtype val;                                                    \
+        size_t len;                                                     \
+                                                                        \
+        *res = 0;                                                       \
+        len = strlen(cp);                                               \
+        if (len == 0)                                                   \
+                return -EINVAL;                                         \
+                                                                        \
+        val = simple_strtoul(cp, &tail, base);                          \
+        if ((*tail == '\0') ||                                          \
+                ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {\
+                *res = val;                                             \
+                return 0;                                               \
+        }                                                               \
+                                                                        \
+        return -EINVAL;                                                 \
+}                                                                       \
+
+#define define_strict_strtox(type, valtype)                             \
+int strict_strto##type(const char *cp, unsigned int base, valtype *res) \
+{                                                                       \
+        int ret;                                                        \
+        if (*cp == '-') {                                               \
+                ret = strict_strtou##type(cp+1, base, res);             \
+                if (ret != 0)                                           \
+                        *res = -(*res);                                 \
+        } else                                                          \
+                ret = strict_strtou##type(cp, base, res);               \
+                                                                        \
+        return ret;                                                     \
+}                                                                       \
+
+define_strict_strtoux(l, unsigned long)
+define_strict_strtox(l, long)
+define_strict_strtoux(ll, unsigned long long)
+define_strict_strtox(ll, long long)
+
+EXPORT_SYMBOL(strict_strtoul);
+EXPORT_SYMBOL(strict_strtol);
+EXPORT_SYMBOL(strict_strtoll);
+EXPORT_SYMBOL(strict_strtoull);
+
 static int skip_atoi(const char **s)
 {
         int i=0;