diff options
Diffstat (limited to 'lib/libc/sys/mmap.2')
| -rw-r--r-- | lib/libc/sys/mmap.2 | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/lib/libc/sys/mmap.2 b/lib/libc/sys/mmap.2 index e9a15ad530d..8c057b230eb 100644 --- a/lib/libc/sys/mmap.2 +++ b/lib/libc/sys/mmap.2 @@ -1,4 +1,4 @@ -.\" $OpenBSD: mmap.2,v 1.22 2001/05/11 14:54:25 art Exp $ +.\" $OpenBSD: mmap.2,v 1.23 2001/08/03 19:44:21 espie Exp $ .\" $NetBSD: mmap.2,v 1.5 1995/06/24 10:48:59 cgd Exp $ .\" .\" Copyright (c) 1991, 1993 @@ -217,6 +217,19 @@ parameter wasn't available. .Dv MAP_ANON was specified and insufficient memory was available. .El +.Sh BUGS +Due to a limitation of the current vm system (see +.Xr uvm 9 ), +mapping descriptors +.Dv PROT_WRITE +without also specifying +.Dv PROT_READ +is useless +(results in a segmentation fault when first accessing the mapping). +This means that such descriptors must be opened with +.Dv O_RDWR , +for which you need both read and write permissions on the underlying +object. .Sh SEE ALSO .Xr madvise 2 , .Xr mincore 2 , |