Re: [HACKERS] pg_user crash - Mailing list pgsql-hackers

From Vadim Mikheev
Subject Re: [HACKERS] pg_user crash
Date
Msg-id 35F87C9F.C66EACF4@krs.ru
Whole thread Raw
In response to pg_user crash  (Bruce Momjian <maillist@candle.pha.pa.us>)
List pgsql-hackers
Bruce Momjian wrote:
>
> OK, I have a way to debug this.
>
> Add to palloc and pfree a printf like:
>
>         printf("palloc: %d\n", mem);
>         printf("pfree : %d\n", mem);
>
> The printf's should go after the memory is allocated in palloc, and
> before it is free'ed in pfree().
>
> and then run the backend and issue the query causing the problem, and
> grab the lines from the postmaster log file.  Check the last pfree
> value, because that is the one that is crashing it.  Check the list to
> see if it has been palloc'ed.  If it has, was it pfree'ed by someone
> else, and who palloc'ed it.  If it is not on the list, figure out how it
> got on to the palloc list.

Crash comes from AllocSetReset()->AllocSetFree() - printf in
pfree will not help.

I would suggest to add printf to AllocSetFree()/AllocSetAlloc()...

Vadim

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