bin/86805: [PATCH] savecore fails to byteswap architectureversion field

[Gavin Atkinson]

>Number:         86805
>Category:       bin
>Synopsis:       [PATCH] savecore fails to byteswap architectureversion field
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Oct 01 21:00:33 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Gavin Atkinson
>Release:        FreeBSD 6.0-BETA5 i386
>Organization:
>Environment:
System: FreeBSD buffy.york.ac.uk 6.0-BETA5 FreeBSD 6.0-BETA5 #1: Fri Sep 30 12:26:25 BST 2005 root at buffy.york.ac.uk:/usr/obj/usr/src/sys/BUFFY i386

>Description:

	When savecore runs and finds a core, it will create an info.X file
with an ASCII representation of the dump header.  Five of the fields within
this header are supposed to be in "dump byte order", which is the same as
network byte order (see the comment in sys/kerneldump.h).

The current version of the AMD64 dump is 2, however the contents of the info
file corresponding to an amd64 dump is as follows:

wiggum# cat /var/crash/info.0
Dump header from device /dev/da0s1b
  Architecture: amd64
  Architecture Version: 33554432
  [...]

Note that 33554432 = 0x02000000, i.e. it needs to be byte swapped but hasn't
been.  This problem isn't amd64 specific, it seems to affect all little-endian
platforms, and was introduced (seemingly accidentally) in version 1.71 of
src/sbin/savecore.c

See http://lists.freebsd.org/pipermail/freebsd-hackers/2005-May/012028.html for
an i386 example of the bug.

>How-To-Repeat:
	Panic a system with dumps enabled, look at /var/crash/info.X and compare
the architecture version to that defined in /usr/include/sys/kerneldump.h

>Fix:

--- savecore.diff begins here ---
Index: src/sbin/savecore/savecore.c
===================================================================
RCS file: /usr/cvs/src/sbin/savecore/savecore.c,v
retrieving revision 1.76
diff -u -r1.76 savecore.c
--- src/sbin/savecore/savecore.c	13 Sep 2005 19:15:28 -0000	1.76
+++ src/sbin/savecore/savecore.c	1 Oct 2005 20:30:47 -0000
@@ -107,7 +107,8 @@
 
 	fprintf(f, "Dump header from device %s\n", device);
 	fprintf(f, "  Architecture: %s\n", h->architecture);
-	fprintf(f, "  Architecture Version: %u\n", h->architectureversion);
+	fprintf(f, "  Architecture Version: %u\n",
+	    dtoh32(h->architectureversion));
 	dumplen = dtoh64(h->dumplength);
 	fprintf(f, "  Dump Length: %lldB (%lld MB)\n", (long long)dumplen,
 	    (long long)(dumplen >> 20));
--- savecore.diff ends here ---


>Release-Note:
>Audit-Trail:
>Unformatted: