Re: [PATCH 4/4] perf tools: Add support for breakpoint events in perf tools

[Arnaldo Carvalho de Melo <acme@ghostprotocols.net>]

Em Mon, Nov 23, 2009 at 10:19:47PM +0100, Frederic Weisbecker escreveu:
> On Mon, Nov 23, 2009 at 07:09:39PM -0200, Arnaldo Carvalho de Melo wrote:
> > Em Mon, Nov 23, 2009 at 09:25:28PM +0100, Frederic Weisbecker escreveu:
> > > I think we should find this symbol length from userspace. I'm not sure
> > > how yet, probably using Dwarf. Arnaldo, do you have an idea about that?
> > 
> > DWARF has the type for each variable or struct member, getting its size
> > is straightforward.
> 
> Ok.
> 
> > Using just /proc/kallsyms all we can do is find the size of a variable
> > by looking at its address and the address of the next one.
> 
> Hmm, but I worry a bit about alignment which would return us
> the wrong size.
> 
> May be can we first try to get the address from /proc/kallsyms,
> and if we have dwarf, get the size from it, otherwise try some
> magic with /proc/kallsysms...

Yeah, I'll get the variables-from-kallsyms bit just after I get a new
mechanism for expressing configuration for the perf symbol resolving
machinery.

Should have this done ASAP.

- Arnaldo