Don't use C runtime versions of toupper() and tolower()

It seems that, despite their trivial functionality, the runtime
implementation insists on converting to Unicode! This means those functions
are actually only safe at PASSIVE_LEVEL.
This patch implements __toupper() and __tolower() as replacements with
no such hidden nastiness and modifies callers to use those.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>

diff --git a/src/common/util.h b/src/common/util.h
index 1a2bb86665a791b081b7922ab88e8ad08f56ccfe..c772b1e1b9ead55696179e0d09934ca8a8741ec9 100644 (file)
--- a/src/common/util.h
+++ b/src/common/util.h
@@ -278,4 +278,26 @@ __strtok_r(
     return Token;
 }
 
+static FORCEINLINE CHAR
+__toupper(
+    IN  CHAR    Character
+    )
+{
+    if (Character < 'a' || Character > 'z')
+        return Character;
+
+    return 'A' + Character - 'a';
+}
+
+static FORCEINLINE CHAR
+__tolower(
+    IN  CHAR    Character
+    )
+{
+    if (Character < 'A' || Character > 'Z')
+        return Character;
+
+    return 'a' + Character - 'A';
+}
+
 #endif  // _COMMON_UTIL_H

diff --git a/src/xen/module.c b/src/xen/module.c
index ed8838a293d1314990348a72cbe17296074a9932..a5bf3c707b11ff004a5c4b00b791000e54e063b4 100644 (file)
--- a/src/xen/module.c
+++ b/src/xen/module.c
@@ -155,7 +155,7 @@ ModuleAdd(
         if (Name[Index] == '\0')
             break;
 
-        New->Name[Index] = (CHAR)tolower(Name[Index]);
+        New->Name[Index] = __tolower(Name[Index]);
     }
 
     New->Start = Start;

diff --git a/src/xenbus/fdo.c b/src/xenbus/fdo.c
index 00801c9811e224fc0f575eb6b9f2f31ef193cbc0..d079928a3af44a61fd2839c16fc310a505e139ea 100644 (file)
--- a/src/xenbus/fdo.c
+++ b/src/xenbus/fdo.c
@@ -1129,7 +1129,7 @@ FdoMultiSzToUpcaseAnsi(
             if (Buffer[Index] == '\0')
                 break;
         } else {
-            Buffer[Index] = (CHAR)toupper(Buffer[Index]);
+            Buffer[Index] = __toupper(Buffer[Index]);
             Index++;
         }
     }