Re: pg_upgrade segfault (was: pg_migrator segfault)

hernan gonzalez <hgonzalez(at)gmail(dot)com> writes:
> Running gbd with the core generated by the segfault, it outputs this:

> Program terminated with signal 11, Segmentation fault.
> #0 0xb7df84ed in _int_realloc () from /lib/libc.so.6
> Missing separate debuginfos, use: debuginfo-install glibc-2.11.1-4.i686
> (gdb) bt
> #0 0xb7df84ed in _int_realloc () from /lib/libc.so.6
> #1 0xb7df88a0 in realloc () from /lib/libc.so.6
> #2 0xb7db2a5e in __add_to_environ () from /lib/libc.so.6
> #3 0xb7db27b7 in putenv () from /lib/libc.so.6
> #4 0x0804aa11 in putenv2 ()
> #5 0x0804af93 in get_control_data ()
> #6 0x08049801 in check_cluster_compatibility ()
> #7 0x0804eb88 in main ()

Hmm, this suggests that pg_upgrade has managed to clobber malloc's
internal data structures, probably by writing past the end of an
allocated chunk. You should be able to identify where if you can
run pg_upgrade under valgrind or ElectricFence.

regards, tom lane