cvs commit: src Makefile.inc1 src/lib/libc/gen __xuname.c getosreldate.c

[Doug Ambrisko]

Pawel Jakub Dawidek writes:
| On Fri, Dec 02, 2005 at 12:50:30AM +0000, Doug Ambrisko wrote:
| +> ambrisko    2005-12-02 00:50:30 UTC
| +> 
| +>   FreeBSD src repository
| +> 
| +>   Modified files:
| +>     .                    Makefile.inc1 
| +>     lib/libc/gen         __xuname.c getosreldate.c 
| +>   Log:
| +>   Add support to easily build FreeBSD unpacked in a chroot of another
| +>   FreeBSD machine.  To do this add the man 1 uname changes to __xuname.c
| +>   so we can override the settings it reports.  Add OSVERSION override
| +>   to getosreldate.  Finally which Makefile.inc1 to use uname -m instead
| +>   of  sysctl -n hw.machine_arch to get the arch. type.
| +>   
| +>   With these change you can put a complete FreeBSD OS image into a
| +>   chroot set:
| +>           UNAME_s=FreeBSD
| +>           UNAME_r=4.7-RELEASE
| +>           UNAME_v="FreeBSD $UNAME_r #1: Fri Jul 22 20:32:52 PDT 2005 fake at fake:/usr/obj/usr/src/sys/FAKE"
| +>           UNAME_m=i386
| +>           UNAME_p=i386
| +>           OSVERSION=470000
| +>   on an amd64 or i386 and it just work including building ports and using
| +>   pkg_add -r etc.  The caveat for this example is that these patches
| +>   have to be applied to FreeBSD 4.7 and the uname(1) changes need to
| +>   be merged.  This also addresses issue with libtool.
| +>   
| +>   This is usefull for when a build machine has been trashed for an
| +>   old release and we want to do a build on a new machine that FreeBSD
| +>   4.7 won't run on ...
| [...]
| +>  	name->sysname[sizeof(name->sysname) - 1] = '\0';
| +> +	if ((p = getenv("UNAME_s")))
| +> +		strncpy(name->sysname, p, sizeof(name->sysname));
| [...]
| +>  	name->release[sizeof(name->release) - 1] = '\0';
| +> +	if ((p = getenv("UNAME_r")))
| +> +		strncpy(name->release, p, sizeof(name->release));
| [...]
| +> +	if ((p = getenv("UNAME_v")))
| +> +		strncpy(name->version, p, sizeof(name->version));
| [...]
| +>  	name->machine[sizeof(name->machine) - 1] = '\0';
| +> +	if ((p = getenv("UNAME_m")))
| +> +		strncpy(name->machine, p, sizeof(name->machine));
| 
| As you can see, previous code tried to NULL-terminate buffers copied using
| strncpy(3) properly and you inserted your changes after these
| terminations. Please, NULL-terminate the buffers after using strncpy(3).

The prior code had to NULL-terminate by hand since the data could come
from the sysctl not NULL-terminate.  I thought the strncpy would
NULL-terminate but you are correct.

I'll fix this when I add the man-page changes this morning and finish
a make buildworld/installworld/buildworld cycle.

Thanks,

Doug A.