Index: uspace/lib/c/include/macros.h
===================================================================
--- uspace/lib/c/include/macros.h	(revision 062d9000625057300f609429080872d6492b542e)
+++ uspace/lib/c/include/macros.h	(revision 991d2d88d7bd9717574341fafeefffc28890114c)
@@ -38,4 +38,6 @@
 #define min(a, b)  ((a) < (b) ? (a) : (b))
 #define max(a, b)  ((a) > (b) ? (a) : (b))
+#define abs(a)     ((a) >= 0 ? (a) : (-a))
+
 
 #define KiB2SIZE(kb)  ((kb) << 10)