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From: Kris Van Hees <kris.van.hees@oracle.com>
To: Alan Maguire <alan.maguire@oracle.com>
Cc: Kris Van Hees <kris.van.hees@oracle.com>,
	Eugene Loh <eugene.loh@oracle.com>,
	dtrace@lists.linux.dev, dtrace-devel@oss.oracle.com
Subject: Re: [DTrace-devel] [PATCH] test/utils: add more reliable "get remote address" approach
Date: Tue, 8 Jul 2025 16:13:49 -0400	[thread overview]
Message-ID: <aG17/ZbpZHUCkE+J@oracle.com> (raw)
In-Reply-To: <db9e497a-b2b5-4b44-840c-efdead15fb9e@oracle.com>

On Tue, Jul 08, 2025 at 08:04:41PM +0100, Alan Maguire wrote:
<< omitted >>
> thanks; tried with build/run-dtrace with same result. However by adding
> some debug logging I think I've discovered the root cause; the order of
> .d file sorting seems to be different in the build/dlibs versus
> /usr/lib64/dtrace case, and the problem is that tcp.d actually
> implicitly relies on ip.d for ipinfo_t . We get lucky in the sort order for
> /usr/lib64/dtrace, and because an ipaddr_t * gets added during ip.d
> processing, by the time we lookup "ipaddr_t *" in tcp.d it's already in
> the D CTF dict. I _think_ the ipaddr_t * gets added as a side effect of
> the fact that there are fields of type ipaddr_t in the translated
> ipv4info_t in ip.d
> 
> However in the problematic case with build/run-dtrace , net.d is still
> loaded first, and then tcp.d is loaded immediately after without an
> intervening load of ip.d. As a result we have no "ipaddr_t *", hence
> 
> dtrace: invalid probe specifier ip:::send /args[4]->ipv4_protocol ==
> IPPROTO_TCP/ { @c[args[2]->ip_saddr, args[4]->ipv4_protocol] = count();
> } END { printa(@c); }:
> "/home/opc/src/dtrace-utils/build/dlibs/6.10/tcp.d", line 183: failed to
> resolve type of inet_ntoa arg#1 (ipaddr_t *): Unknown type name
> 
> To fix this I think the right answer is to change the dependency tcp.d
> has on ip.d, from
> 
> #pragma D depends_on provider ip
> 
> to
> 
> #pragma D depends_on library ip.d
> 
> This is needed for other reasons (ipinfo_t declaration for example), but
> with that change the problem is resolved.

Sounds like a good solution!

      reply	other threads:[~2025-07-08 20:13 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-03 11:33 [PATCH] test/utils: add more reliable "get remote address" approach Alan Maguire
2025-07-03 16:43 ` [DTrace-devel] " Eugene Loh
2025-07-03 16:59   ` Alan Maguire
2025-07-03 17:06     ` Eugene Loh
2025-07-03 18:02       ` Alan Maguire
2025-07-03 18:26         ` Kris Van Hees
2025-07-03 18:41           ` Alan Maguire
2025-07-03 19:03             ` Kris Van Hees
2025-07-03 20:23               ` Alan Maguire
2025-07-03 20:59                 ` Kris Van Hees
2025-07-03 22:36                   ` Kris Van Hees
2025-07-07 16:32                     ` Alan Maguire
2025-07-07 16:53                       ` Kris Van Hees
2025-07-07 18:14                         ` Alan Maguire
2025-07-07 19:55                           ` Kris Van Hees
2025-07-07 21:51                             ` Alan Maguire
2025-07-08  1:34                               ` Kris Van Hees
2025-07-08 17:19                                 ` Alan Maguire
2025-07-08 17:30                                   ` Kris Van Hees
2025-07-08 19:04                                     ` Alan Maguire
2025-07-08 20:13                                       ` Kris Van Hees [this message]

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