On Wed, Feb 1, 2017 at 1:25 AM, Sasha Goldshtein wrote:
>
> Do you expect the data_loc field structure to change? E.g., do you expect
> the size to be != 4 bytes, and the two words (length, offset) to mean
> something
> else in the future?
I don't expect it to change any time soon, but it can.
__
Awesome, thanks Derek and Alexei!
>
>
> yeah that's a bug. bcc needs to have some field in there to cover dataloc.
> The offset will be pointing past the normal fields and
> it's accessible via bpf_probe_read. When tracepoint is fired,
> kernel already copied skb->dev->name into that buffer.
> Tec
On Tue, Jan 31, 2017 at 4:19 AM, Sasha Goldshtein via iovisor-dev
wrote:
> Hi all,
>
> I'm trying to attach a BPF program to a tracepoint that has a __string
> field, such as net:net_dev_start_xmit. This tracepoint has the following
> format (from debugfs/events/.../format):
>
> name: net_dev_star
Hi Sasha
> 1) How do we get access to the __data_loc field? (I can fetch the same
info from skb->dev->name but if there's a way to work with the __data_loc
field directly, it's even better.)
It is a dynamic array in kernel, the size can't be determined during
compiling time. At run time, kernel wi
Hi all,
I'm trying to attach a BPF program to a tracepoint that has a __string
field, such as net:net_dev_start_xmit. This tracepoint has the following
format (from debugfs/events/.../format):
name: net_dev_start_xmit
ID: 1159
format:
field:unsigned short common_type; offset:0; size:2; signed:0;