Create index concurrently hanging with big table on pgsql 9.3.12

Hi,

We are trying to create a index concurrently but, at least apparently, it
hangs in a infinite loop and never ends.

Our version:

flip=# select version();
version
--------------------------------
PostgreSQL 9.3.12 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.4.7
2012
0313 (Red Hat 4.4.7-16), 64-bit
(1 row)

Index creation:

CREATE INDEX CONCURRENTLY index_texto
ON flip_pagina_edicao
USING hash
(texto COLLATE pg_catalog."default"); -- texto is a text data type.

Size of the table:

flip=# select pg_size_pretty(pg_total_relation_size('flip_pagina_edicao'));
pg_size_pretty
----------------
956 GB
(1 row)

Process strace:

....
semop(622611, {{6, 1, 0}}, 1) = 0
semop(655380, {{5, -1, 0}}, 1) = 0
select(0, NULL, NULL, NULL, {0, 1000}) = 0 (Timeout)
semop(655380, {{5, -1, 0}}, 1) = 0
semop(622611, {{6, 1, 0}}, 1) = 0
semop(655380, {{5, -1, 0}}, 1) = 0
semop(622611, {{6, 1, 0}}, 1) = 0
semop(622611, {{6, 1, 0}}, 1) = 0
semop(622611, {{6, 1, 0}}, 1) = 0
semop(655380, {{5, -1, 0}}, 1) = 0
semop(622611, {{6, 1, 0}}, 1) = 0
semop(655380, {{5, -1, 0}}, 1) = 0
semop(622611, {{6, 1, 0}}, 1) = 0
semop(557073, {{2, 1, 0}}, 1) = 0
semop(655380, {{5, -1, 0}}, 1) = 0
semop(655380, {{5, -1, 0}}, 1) = 0
semop(655380, {{5, -1, 0}}, 1) = 0
semop(655380, {{5, -1, 0}}, 1) = 0
...

Thanks in advance.

Robert