Re: kernel BUG at mm/mmap.c:1990

On Mon, Dec 11, 2006 at 11:38:13PM +0100, Helge Deller wrote:
> Maybe someone has an idea ?
> 
> The "adjtimex02" test from the Linux Test Project (http://ltp.sf.net) seems to pass all test, but triggers a kernel BUG in mm/mmap.c:1990 when exiting.
> strace is attached below.
> 

iirc this only bites on 32bit kernels.

This is what Jeff is referring to:

/*
 * Testcase reduced from ltp, adjtimex02
 *
 * 1) adjtimex(2) fails with errno set to EFAULT if buf does
 *	   not point to writable memory
 */

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/timex.h>

int
main()
{
	int x;
	struct timex *buffp = (struct timex *) -1;

	/* Check whether we are root */
	if (geteuid() != 0) {
		fprintf(stderr, "This needs to run as root.\n");
		return(-1);
	}
	
	/* Call adjtimex(2) */
	x = adjtimex(buffp);

	return x;
}