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Why does $$parms show value as "?"
- From: Grant Edwards <grant dot b dot edwards at gmail dot com>
- To: systemtap at sources dot redhat dot com
- Date: Thu, 25 Aug 2011 17:15:25 +0000 (UTC)
- Subject: Why does $$parms show value as "?"
Here's the function in the module I'm debugging:
int xmit_packet(struct sk_buff *skb)
{
return dev_queue_xmit(skb);
}
Here's my systemtap script:
probe begin
{
print("systemtap begin\n");
}
probe module("nslink").function("xmit_packet")
{
printf("%s\n",$$parms);
}
probe end
{
print("systemtap end\n");
}
And here's what happens when I run it:
# stap transmit.stp
systemtap begin
skb=?
skb=?
skb=?
skb=?
skb=?
skb=?
skb=?
skb=?
skb=?
skb=?
^Csystemtap end
#
Why isn't systemtap printing the value of the parameter "skb"?
The module in question is built "out of tree" and then installed in
/lib/modules/VERSION/misc, and according to "file" it's not stripped.
--
Grant Edwards grant.b.edwards Yow! I didn't order any
at WOO-WOO ... Maybe a YUBBA
gmail.com ... But no WOO-WOO!