[PATCH net] flow_dissect: call init_default_flow_dissectors() earlier

[PATCH net] flow_dissect: call init_default_flow_dissectors() earlier

[Eric Dumazet]

From: Eric Dumazet <edumazet@google.com>

Andre Noll reported panics after my recent fix (commit 34fad54c2537
"net: __skb_flow_dissect() must cap its return value")

After some more headaches, Alexander root caused the problem to
init_default_flow_dissectors() being called too late, in case
a network driver like IGB is not a module and receives DHCP message
very early.

Fix is to call init_default_flow_dissectors() much earlier,
as it is a core infrastructure and does not depend on another
kernel service.

Fixes: 06635a35d13d4 ("flow_dissect: use programable dissector in skb_flow_dissect and friends")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andre Noll <maan@tuebingen.mpg.de>
Diagnosed-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 net/core/flow_dissector.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 69e4463a4b1b..c6d8207ffa7e 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -1013,4 +1013,4 @@ static int __init init_default_flow_dissectors(void)
 	return 0;
 }
 
-late_initcall_sync(init_default_flow_dissectors);
+core_initcall(init_default_flow_dissectors);

Re: [PATCH net] flow_dissect: call init_default_flow_dissectors() earlier

[Andre Noll]

[-- Attachment #1: Type: text/plain, Size: 424 bytes --]

On Tue, Nov 22, 11:17, Eric Dumazet wrote
> -late_initcall_sync(init_default_flow_dissectors);
> +core_initcall(init_default_flow_dissectors);

Indeed, that fixed it. Feel free to add

Tested-by: Andre Noll <maan@tuebingen.mpg.de>

Thanks a lot
Andre
-- 
Max Planck Institute for Developmental Biology
Spemannstraße 35, 72076 Tübingen, Germany. Phone: (+49) 7071 601 829
http://people.tuebingen.mpg.de/maan/

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 181 bytes --]

Re: [PATCH net] flow_dissect: call init_default_flow_dissectors() earlier

[David Miller]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 22 Nov 2016 11:17:30 -0800

> From: Eric Dumazet <edumazet@google.com>
> 
> Andre Noll reported panics after my recent fix (commit 34fad54c2537
> "net: __skb_flow_dissect() must cap its return value")
> 
> After some more headaches, Alexander root caused the problem to
> init_default_flow_dissectors() being called too late, in case
> a network driver like IGB is not a module and receives DHCP message
> very early.
> 
> Fix is to call init_default_flow_dissectors() much earlier,
> as it is a core infrastructure and does not depend on another
> kernel service.
> 
> Fixes: 06635a35d13d4 ("flow_dissect: use programable dissector in skb_flow_dissect and friends")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Andre Noll <maan@tuebingen.mpg.de>
> Diagnosed-by: Alexander Duyck <alexander.h.duyck@intel.com>

Applied and queued up for -stable, I'll try to fast-track this.