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Re: Tapset porting to 2.6.38
On 03/14/2011 05:40 PM, Turgis, Frederic wrote:
> Very interesting patch for us.
> We did not dig that much as we were convinced that we could only dereference
> pointers. Therefore, we thought we could not do something like
> @cast(sock, "inet_sock")->sk->__sk_common->skc_daddr because in C,
> it would be pointer->sk.__sk_common.skc_addr (so no pointer as soon as
you want __sk_common).
That has confused people before. In systemtap script language, you
always just use '->'.
If you want to see the C source code that systemtap produces for
__ip_sock_daddr(), you can do the following:
# stap -vp3 -e 'probe begin { print(__ip_sock_daddr(0)) }'
> On top of that, we had bad experience in the past with derefencing V4L2 structures
> but we finally discovered issue was more related to the use of "enum".
Hmm, I'm not aware of any issues we have with enums. Have you got an
example?
--
David Smith
dsmith@redhat.com
Red Hat
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