Kernel oops while duming user core.

[Scott Wood]

On Thu, Jan 31, 2008 at 10:15:27AM -0600, Nathan Lynch wrote:
> Rune Torgersen wrote:
> > Hi
> > 
> > I get the following kernel core while a user program I have is dumping
> > core.
> > Any DIeas at what to look for? (this is runnign 2.6.24, arch/powerpc on
> > a 8280)
> > When runnign the program on 2.6.18 arch/ppc, the program gets a sig 11
> > and dumps core.
> > On 2.6.24, I ghet the kernel oops, and then the program hangs sround
> > forever and is unkillable.
> 
> Hmm, this is the second report of 2.6.24 crashing in
> __flush_dcache_icache during a core dump; see:
> http://ozlabs.org/pipermail/linuxppc-dev/2007-December/048662.html
> 
> Is this easily recreatable?

Yes, this program does it reliably:

#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
#include <signal.h>

void *threadfn(void *arg)
{
	fprintf(stderr, "threadfn\n");
	fflush(stderr);
	sleep(1);
	*(char *)0=0;
	return NULL;
}

int main(void)
{
	pthread_t thread[4];
	int i;

	for (i = 0; i < 4; i++)
		pthread_create(&thread[0], NULL, threadfn, NULL);

	for (;;);
}