Re: 9.4 beta1 crash on Debian sid/i386

Andres Freund <andres(at)2ndquadrant(dot)com> writes:
> Isn't the far more obvious thing ot just not build postgres with -pie on
> 32bit? It's hardly a security benefit if it allows plain user to crash
> the server.

Yeah, that's what I was doing when I was at Red Hat --- PIE mode would
be nice, but not when it breaks basic functionality.

I think throwing an error out of a SIGBUS handler is right out. There
would be no way to know exactly what code we were interrupting. It's
the same reason we don't let, eg, the SIGALRM handler throw a timeout
error directly (in most places anyway).

>> * PostgreSQL allocates lots of heap using brk() instead of mmap()

> It doesn't really do that, btw. It's the libc's mmap that makes those
> decisions, not postgres.

It occurs to me that maybe this is a glibc bug, not a kernel bug?

regards, tom lane