Commands like gmirror, graid3, ... and others which use dlopen() to load

classes from say, /lib/geom, cannot be statically linked completely.
Moreover, those shared objects may require other shared objects (i.e.
 for geom, libraries like -lmd, -lcrypto).

The libs_so extension to crunchgen fixes this by allowing some libraries
to be linked in dynamically.  This requires that a copy of rtld and the
shared libraries be made available to the crunched binary, and so is not
suitable for all environments.  Crunchgen configurations which do not
use the 'libs_so' keyword are unaffected and produce identical binaries
with and without this commit.

Approved by:		murray (mentor, in spirit), jhb
In collaboration with:	Adrian Steinmann <ast at marabu dot ch>
MFC After:		6 weeks

1 files changed, 30 insertions, 2 deletions

diff --git a/usr.sbin/crunch/crunchgen/crunchgen.1 b/usr.sbin/crunch/crunchgen/crunchgen.1
index 4333866..3c8d213 100644
--- a/usr.sbin/crunch/crunchgen/crunchgen.1
+++ b/usr.sbin/crunch/crunchgen/crunchgen.1
@@ -139,7 +139,7 @@ generated by
 .Nm .
 This is useful to define some make variables such as
 .Va RELEASE_CRUNCH
-or similar, which might affect the behaviour of
+or similar, which might affect the behavior of
 .Xr make 1
 and are annoying to pass through environment variables.
 .It Fl m Ar makefile-name
@@ -210,6 +210,21 @@ A list of library specifications to be included in the crunched binary link.
 Multiple
 .Ic libs
 lines can be specified.
+.It Ic libs_so Ar libspec ...
+A list of library specifications to be dynamically linked in the
+crunched binary.
+These libraries will need to be made available via the run-time link-editor
+.Xr rtld 1
+when the component program that requires them is executed from
+the crunched binary.
+Multiple
+.Ic libs_so
+lines can be specified.
+The
+.Ic libs_so
+directive overrides a library specified gratuitously on a
+.Ic libs
+line.
 .It Ic buildopts Ar buildopts ...
 A list of build options to be added to every make target.
 .It Ic ln Ar progname linkname
@@ -417,9 +432,15 @@ At this point the binary
 .Dq Pa kcopy
 can be copied onto an install floppy
 and hard-linked to the names of the component programs.
+.Pp
+Note that if the 
+.Ic libs_so
+command had been used, copies of the libraries so named
+would also need to be copied to the install floppy.
 .Sh SEE ALSO
 .Xr crunchide 1 ,
-.Xr make 1
+.Xr make 1 ,
+.Xr rtld 1
 .Sh CAVEATS
 While
 .Nm
@@ -446,3 +467,10 @@ utility was written by
 .Pp
 Copyright (c) 1994 University of Maryland.
 All Rights Reserved.
+.Pp
+The 
+.Ic libs_so
+keyword was added in 2005 by
+.An Adrian Steinmann Aq ast@marabu.ch
+and
+.An Ceri Davies Aq ceri@FreeBSD.org .