Subject: panic in vmapbuf
To: None <>
From: Frank van der Linden <>
List: current-users
Date: 06/25/1994 17:41:20
 Can anyone reproduce the panic I get when I compile and execute the
following program using the latest (June 24) kernel:
 * Using 68K or less as amount of bytes in the read call isn't giving
 * me a panic. Note that 64K equals MAXPHYS (maximum raw I/O size),
 * has this 'problem' anything to do with MAXPHYS ??
#include <fcntl.h>

char	buf[81920];

main(int argc, char *argv[])
	int	fd;

	fd = open(argv[1], O_RDONLY);
	if (fd < 0) exit(1);
	read(fd, buf, sizeof buf);

a.out /dev/drum
a.out /dev/rwd0a (if you have a wd disk)
a.out /dev/rfd0a (don't forget the floppy).

The result:
panic: vmapbuf: null pageframe

The stacktrace from ddb:

 I'm pretty sure my sources are up to date. 

Onno van der Linden   c/o (Frank van der Linden)