--- /dev/null
+diff -up diffutils-2.8.1/src/cmp.c.cmp-s-empty diffutils-2.8.1/src/cmp.c
+--- diffutils-2.8.1/src/cmp.c.cmp-s-empty 2002-04-05 21:37:31.000000000 +0100
++++ diffutils-2.8.1/src/cmp.c 2010-06-25 14:56:08.464802321 +0100
+@@ -316,12 +316,15 @@ main (int argc, char **argv)
+
+ /* If only a return code is needed,
+ and if both input descriptors are associated with plain files,
++ and if both files are larger than 0 bytes (procfs files are always 0),
+ conclude that the files differ if they have different sizes
+ and if more bytes will be compared than are in the smaller file. */
+
+ if (comparison_type == type_status
+ && S_ISREG (stat_buf[0].st_mode)
+- && S_ISREG (stat_buf[1].st_mode))
++ && S_ISREG (stat_buf[1].st_mode)
++ && stat_buf[0].st_size > 0
++ && stat_buf[1].st_size > 0)
+ {
+ off_t s0 = stat_buf[0].st_size - file_position (0);
+ off_t s1 = stat_buf[1].st_size - file_position (1);