From: Jarod Wilson <jarod@redhat.com>
Date: Mon, 8 Mar 2010 21:07:46 -0500
Subject: [misc] backport upstream strict_strto* functions
Message-id: <20100308210746.GA32500@redhat.com>
Patchwork-id: 23514
O-Subject: [RHEL5 PATCH 1/2] backport upstream strict_strto* functions
Bugzilla: 517586
RH-Acked-by: Chris Wright <chrisw@redhat.com>
RH-Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Bugzilla #517586

Backport upstream strict_strto*() functions, as strict_strtoul is
used by latest upstream amd cache handling code.

Signed-off-by: Jarod Wilson <jarod@redhat.com>


diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 1e93921..a4bf3ff 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -138,6 +138,10 @@ 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/lib/vsprintf.c b/lib/vsprintf.c
index e1202d0..5c0f814 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -136,6 +136,153 @@ 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)
+{
+	char *tail;
+	unsigned long val;
+	size_t len;
+
+	*res = 0;
+	len = strlen(cp);
+	if (len == 0)
+		return -EINVAL;
+
+	val = simple_strtoul(cp, &tail, base);
+	if (tail == cp)
+		return -EINVAL;
+
+	if ((*tail == '\0') ||
+		((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
+		*res = val;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(strict_strtoul);
+
+/**
+ * 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)
+{
+	int ret;
+	if (*cp == '-') {
+		ret = strict_strtoul(cp + 1, base, (unsigned long *)res);
+		if (!ret)
+			*res = -(*res);
+	} else {
+		ret = strict_strtoul(cp, base, (unsigned long *)res);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(strict_strtol);
+
+/**
+ * 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)
+{
+	char *tail;
+	unsigned long long val;
+	size_t len;
+
+	*res = 0;
+	len = strlen(cp);
+	if (len == 0)
+		return -EINVAL;
+
+	val = simple_strtoull(cp, &tail, base);
+	if (tail == cp)
+		return -EINVAL;
+	if ((*tail == '\0') ||
+		((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
+		*res = val;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(strict_strtoull);
+
+/**
+ * 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)
+{
+	int ret;
+	if (*cp == '-') {
+		ret = strict_strtoull(cp + 1, base, (unsigned long long *)res);
+		if (!ret)
+			*res = -(*res);
+	} else {
+		ret = strict_strtoull(cp, base, (unsigned long long *)res);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(strict_strtoll);
+
 static int skip_atoi(const char **s)
 {
 	int i=0;