Re: backend crash following load command - Mailing list pgsql-general

From Tom Lane
Subject Re: backend crash following load command
Date
Msg-id 6106.1164746650@sss.pgh.pa.us
Whole thread Raw
In response to Re: backend crash following load command  (Martijn van Oosterhout <kleptog@svana.org>)
List pgsql-general
Martijn van Oosterhout <kleptog@svana.org> writes:
> Err, that means copy is just rewriting the executable code in the
> backend of the server, while it's running, which understandably
> crashes.

No, I don't think so.  "cp -f" means "unlink the old file and create a
new one", as opposed to plain cp which would overwrite in place.  Your
theory would explain an observation that plain cp causes a crash while
cp -f does not, but that's the exact opposite of Merlin's report.

The actual situation is that the mmap is referencing a file that's
disappeared from the directory structure (but still exists on disk,
as long as it's held open).  dlsym seems unable to cope with that
case.  I call that a bug --- it'd be OK for it to return a failure
indication, but not to SIGSEGV.

            regards, tom lane

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