Re: [Nagios-db-devel] Segfaults with the postgres ned

[Tim V. <dj...@ro...>]

On Wed, 19 Jan 2005, Ben wrote:

...snip...

>> I'm using :
>> 
>> gcc -g -O2 -o inserter.o inserter.c -shared -I /usr/include/nagios 
>> -I/usr/include/pgsql -lpq
>
> That should be fine. Just to be sure what's actually getting used, would you 
> run an ldd on inserter.o and see what the linker will add at runtime?

This is the output from ldd, looks fine to me :
         libpq.so.3 => /usr/lib/libpq.so.3 (0x009b8000)
         libc.so.6 => /lib/tls/libc.so.6 (0x00111000)
         libssl.so.4 => /lib/libssl.so.4 (0x0027b000)
         libcrypto.so.4 => /lib/libcrypto.so.4 (0x003cf000)
         libkrb5.so.3 => /usr/lib/libkrb5.so.3 (0x0032a000)
         libcrypt.so.1 => /lib/libcrypt.so.1 (0x0024a000)
         libresolv.so.2 => /lib/libresolv.so.2 (0x00e9d000)
         libnsl.so.1 => /lib/libnsl.so.1 (0x002b0000)
         /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x00314000)
         libgssapi_krb5.so.2 => /usr/lib/libgssapi_krb5.so.2 (0x007e1000)
         libcom_err.so.2 => /lib/libcom_err.so.2 (0x005d9000)
         libk5crypto.so.3 => /usr/lib/libk5crypto.so.3 (0x00f5c000)
         libdl.so.2 => /lib/libdl.so.2 (0x0068a000)
         libz.so.1 => /usr/lib/libz.so.1 (0x004c1000)

>> I've then started from a empty database. When I then start nagios I get 
>> this error :

...snip...

> That really shouldn't fail. Try turning on debug logging on your postgres 
> server and see what it says about things.

Enabling some extensive logging helped. I've found a couple of issues in 
the stored procedures. One in host.sql is already fixed in CVS. This is 
the other :

diff -u -r1.3 restart.sql
--- restart.sql 16 Jan 2005 20:21:43 -0000      1.3
+++ restart.sql 20 Jan 2005 16:23:32 -0000
@@ -28,7 +28,7 @@
                 thisHostID      int;
         BEGIN
          -- get the host id. If this is a new host, insert the host and 
get the id
-        select into thisHostID id FROM host WHERE name = thisHostName;
+        select into thisHostID id FROM host WHERE name = hostName;

                 if thisHostID is not null
                 then


>> Finaly I get a segfault at the PQclear function for the processStatus call 
>> for the host data.
...snip...
> It's possible that maybe the result which PQclear is trying to clear is null. 
> I cannot recall at the moment if PQclear(0) will result in badness.

The error is always at the same place the PQclear in processStatus. I've 
did a run with gdb and the segfault occurs in :

Program received signal SIGSEGV, Segmentation fault.
0x0039d50d in malloc_consolidate () from /lib/tls/libc.so.6

That seems a strange place for a segfault to happen, so I'm a bit lost 
what to make of it.

Kind regards,
Tim

--
Tim Verhoeven - dj...@ro... - 0479 / 88 11 83

/* This is total bullshit: */
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