Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / lib / kstrtox.c

diff --git a/kernel/lib/kstrtox.c b/kernel/lib/kstrtox.c
index 94be244..d8a5cf6 100644 (file)
--- a/kernel/lib/kstrtox.c
+++ b/kernel/lib/kstrtox.c
@@ -321,6 +321,70 @@ int kstrtos8(const char *s, unsigned int base, s8 *res)
 }
 EXPORT_SYMBOL(kstrtos8);
 
+/**
+ * kstrtobool - convert common user inputs into boolean values
+ * @s: input string
+ * @res: result
+ *
+ * This routine returns 0 iff the first character is one of 'Yy1Nn0', or
+ * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL.  Value
+ * pointed to by res is updated upon finding a match.
+ */
+int kstrtobool(const char *s, bool *res)
+{
+       if (!s)
+               return -EINVAL;
+
+       switch (s[0]) {
+       case 'y':
+       case 'Y':
+       case '1':
+               *res = true;
+               return 0;
+       case 'n':
+       case 'N':
+       case '0':
+               *res = false;
+               return 0;
+       case 'o':
+       case 'O':
+               switch (s[1]) {
+               case 'n':
+               case 'N':
+                       *res = true;
+                       return 0;
+               case 'f':
+               case 'F':
+                       *res = false;
+                       return 0;
+               default:
+                       break;
+               }
+       default:
+               break;
+       }
+
+       return -EINVAL;
+}
+EXPORT_SYMBOL(kstrtobool);
+
+/*
+ * Since "base" would be a nonsense argument, this open-codes the
+ * _from_user helper instead of using the helper macro below.
+ */
+int kstrtobool_from_user(const char __user *s, size_t count, bool *res)
+{
+       /* Longest string needed to differentiate, newline, terminator */
+       char buf[4];
+
+       count = min(count, sizeof(buf) - 1);
+       if (copy_from_user(buf, s, count))
+               return -EFAULT;
+       buf[count] = '\0';
+       return kstrtobool(buf, res);
+}
+EXPORT_SYMBOL(kstrtobool_from_user);
+
 #define kstrto_from_user(f, g, type)                                   \
 int f(const char __user *s, size_t count, unsigned int base, type *res)        \
 {                                                                      \