Re: Possible issue with expanded object infrastructure on Postgres 9.6.1

On Thu, Jan 19, 2017 at 5:45 PM, Peter Geoghegan <pg(at)heroku(dot)com> wrote:
> A customer is on 9.6.1, and complains of a segfault observed at least
> 3 times.

> I can use GDB to get details of the instruction pointer that appeared
> in the kernel trap error, which shows a function from the expanded
> value representation infrastructure:
>
> (gdb) info symbol 0x55fcf08b0491
> EOH_get_flat_size + 1 in section .text of /usr/lib/postgresql/9.6/bin/postgres
> (gdb) info symbol 0x55fcf08b0490
> EOH_get_flat_size in section .text of /usr/lib/postgresql/9.6/bin/postgres
> (gdb) disassemble 0x55fcf08b0490
> Dump of assembler code for function EOH_get_flat_size:
> 0x000055fcf08b0490 <+0>: push %rbp
> 0x000055fcf08b0491 <+1>: mov 0x8(%rdi),%rax
> 0x000055fcf08b0495 <+5>: mov %rsp,%rbp
> 0x000055fcf08b0498 <+8>: pop %rbp
> 0x000055fcf08b0499 <+9>: mov (%rax),%rax
> 0x000055fcf08b049c <+12>: jmpq *%rax
> End of assembler dump.

For the sake of the archives: this now looks very much like the issue
that Tom just fixed with commit
9bf4068cc321a4d44ac54089ab651a49d89bb567.

--
Peter Geoghegan