From owner-freebsd-bugs Mon Jan 22 04:38:48 1996 Return-Path: owner-bugs Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id EAA07915 for bugs-outgoing; Mon, 22 Jan 1996 04:38:48 -0800 (PST) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id EAA07905 for ; Mon, 22 Jan 1996 04:38:31 -0800 (PST) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id NAA05157 for bugs@freebsd.org; Mon, 22 Jan 1996 13:36:59 +0100 From: Luigi Rizzo Message-Id: <199601221236.NAA05157@labinfo.iet.unipi.it> Subject: dd /dev/mem ... To: bugs@freebsd.org Date: Mon, 22 Jan 1996 13:36:59 +0100 (MET) X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-bugs@freebsd.org Precedence: bulk Running 2.1R, I tried the following running as root: dd if=/dev/mem bs=32k skip=512 count=1 | dd bs=32 count=1 | hexdump and my P100 w/ 16MB was frozen: no keyboard, no mouse, everything still on the X screen. the manpage says "Only offsets within the bounds of /dev/mem are allowed.", and 512*32K is right beyond the physical RAM. However, I have run C programs which would read beyond the limit with no problems. Is it a bug in /dev/mem, "dd" or me ? Luigi ==================================================================== Luigi Rizzo Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it Universita' di Pisa tel: +39-50-568533 via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 http://www.iet.unipi.it/~luigi/ ====================================================================