Re: Segmentation fault with core dump

Tom Lane wrote:
> Glauco Torres <torres(dot)glauco(at)gmail(dot)com> writes:
> > (gdb) bt
> > #0 ckpt_buforder_comparator (pa=pa(at)entry=0x7f6fa9ef4b2c,
> > pb=pb(at)entry=0x1be06d2d06644)
> > at bufmgr.c:4137
> > #1 0x0000000000801268 in med3 (a=0x7f6fa9ef4b2c "\177\006",
> > b=0x1be06d2d06644 <Address 0x1be06d2d06644 out of bounds>,
> > c=0x2fc9dfbb1815c <Address 0x2fc9dfbb1815c out of bounds>, cmp=0x6a4d20
> > <ckpt_buforder_comparator>)
> > at qsort.c:107
> > #2 0x0000000000801621 in pg_qsort (a=0x7f6fa9ef4b2c, a(at)entry=0x7f6fa9ea8380,
> > n=<optimized out>, es=es(at)entry=20, cmp=cmp(at)entry=0x6a4d20
> > <ckpt_buforder_comparator>) at qsort.c:157
> > #3 0x00000000008015e2 in pg_qsort (a=0x7f6fa9ea8380, n=<optimized out>,
> > n(at)entry=111473, es=es(at)entry=20, cmp=cmp(at)entry=0x6a4d20
> > <ckpt_buforder_comparator>) at qsort.c:203
> > #4 0x00000000006a81cf in BufferSync (flags=flags(at)entry=128) at
> > bufmgr.c:1863
>
> Hm. I'm not normally one to jump to the conclusion that something is a
> compiler bug, but it's hard to explain this stack trace any other way.
> The value of "n" passed to the inner invocation of pg_qsort should not
> have been more than 29914, but working from either the value of d or the
> value of pn leads to the conclusion that it was 0x7f6fa9f3a470, which
> looks a lot more like an address in the array than a proper value of n.
>
> I suppose this might be due to a corrupted copy of the postgres executable
> rather than an actual compiler bug. Did you build it yourself?

Hmm, is this something that can be explained by using a different
postgres executable in GDB than the one that produced the core file?

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Álvaro Herrera https://www.2ndQuadrant.com/
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