Document POSIX stupidity: Attempts to mmap zero bytes will succeed (and

have no effect), while attempts to munmap zero bytes will fail.
2004-04-18 23:36:45 +00:00 · 2004-04-18 23:36:45 +00:00 · c8b8f2e516
commit c8b8f2e516
parent ab7a6b9362
1 changed files with 7 additions and 0 deletions
--- a/lib/libc/sys/mmap.2
+++ b/lib/libc/sys/mmap.2
@ -363,3 +363,10 @@ the file system code that causes the limit to be further restricted to
 .Pp
 Another reason for the 2GB limit is that file system metadata can
 reside at negative offsets.
+.Pp
+Note that an attempt to
+.Fn mmap
+zero bytes has no effect and succeeds, while an attempt to
+.Fn munmap
+zero bytes will return
+.Bq Er EINVAL .