Re: [PATCH] markers: modpost

Mathieu Desnoyers wrote:
* David Smith (dsmith@xxxxxxxxxx) wrote:
Mathieu Desnoyers wrote:
* Roland McGrath (roland@xxxxxxxxxx) wrote:
If we want to do it safely, I think we should iterate from
__start___markers to __stop___markers symbols of vmlinux and get the
pointers to the name/format string pairs.

The same can then be done with modules using the __markers section.

Or maybe is there some reason not to do that ?
It's just rather a pain in the ass, a whole lot more fiddly work.
cf "somewhat crude" and "foreseeable future" in my patch's log entry.
Knock yourself out if you're looking for more tedious hacking to do in
modpost.c, but I say fix it when it breaks.

Hmmmm, I have rarely seen code go into mainline without addressing valid
technical criticism first. Please fix.

I'll look into it if I find the time.

Mathieu
Mathieu,

Here's an updated patch, written by Roland (that I tested for him), that
looks for all marker symbols in the __markers_strings section. It doesn't
get the pointers from the __markers section because that is very difficult
to do in modpost (having to handle the architecture-dependent relocations
applied to those pointers).


Hrm, what would happen if a gcc optimization eventually decides to mix
the memory layout of the strings ? Is there something that specifies
that they won't ?

I don't believe there is anything in gcc that specifies that the strings
won't get mixed around. But, I believe this code is good for the
foreseeable future. We could fix this code if the future breakage does
happen.

--
David Smith
dsmith@xxxxxxxxxx
Red Hat
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