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From: Greg KH on 10 May 2010 19:20
2.6.32-stable review patch. If anyone has any objections, please let us know.

------------------

From: Neil Horman <nhorman(a)tuxdriver.com>

commit 38ff3e6bb987ec583268da8eb22628293095d43b upstream.

This was just recently reported to me. When built as modules, the
dccp_probe module has a silent dependency on the dccp module. This
stems from the fact that the module_init routine of dccp_probe
registers a jprobe on the dccp_sendmsg symbol. Since the symbol is
only referenced as a text string (the .symbol_name field in the jprobe
struct) rather than the address of the symbol itself, depmod never
picks this dependency up, and so if you load the dccp_probe module
without the dccp module loaded, the register_jprobe call fails with an
-EINVAL, and the whole module load fails.

The fix is pretty easy, we can just wrap the register_jprobe call in a
try_then_request_module call, which forces the dependency to get
satisfied prior to the probe registration.

Signed-off-by: Neil Horman <nhorman(a)tuxdriver.com>
Acked-by: Arnaldo Carvalho de Melo <acme(a)redhat.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Cc: maximilian attems <max(a)stro.at>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de>

---
net/dccp/probe.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/dccp/probe.c
+++ b/net/dccp/probe.c
@@ -164,7 +164,8 @@ static __init int dccpprobe_init(void)
if (!proc_net_fops_create(&init_net, procname, S_IRUSR, &dccpprobe_fops))
goto err0;

- ret = register_jprobe(&dccp_send_probe);
+ ret = try_then_request_module((register_jprobe(&dccp_send_probe) == 0),
+ "dccp");
if (ret)
goto err1;



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