Re: [PATCH v4 03/15] perf util: refactor inline_list to operate on symbols

Milian Wolff
2017-10-08T19:53:25Z

On Donnerstag, 5. Oktober 2017 03:56:13 CEST Namhyung Kim wrote:
> Hi Milian,
>
> On Sun, Oct 01, 2017 at 04:30:48PM +0200, Milian Wolff wrote:
> > This is a requirement to create real callchain entries for inlined
> > frames.
> >
> > Since the list of inlines usually contains the target symbol too,
> > i.e. the location where the frames get inlined to, we alias that
> > symbol and reuse it as-is is. This ensures that other dependent
> > functionality keeps working, most notably annotation of the
> > target frames.
> >
> > For all other entries in the inline_list, a fake symbol is created.
> > These are marked by new 'inlined' member which is set to true. Only
> > those symbols are managed by the inline_list and get freed when
> > the inline_list is deleted from within inline_node__delete.
> >
> > Cc: Jiri Olsa <jolsa@redhat.com>
> > Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> > Cc: David Ahern <dsahern@gmail.com>
> > Cc: Namhyung Kim <namhyung@kernel.org>
> > Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> > Cc: Yao Jin <yao.jin@linux.intel.com>
> > Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
> > ---
>
> [SNIP]
>
> > +static struct symbol *new_inline_sym(struct dso *dso,
> > + struct symbol *base_sym,
> > + const char *funcname)
> > +{
> > + struct symbol *inline_sym;
> > + char *demangled = NULL;
> > +
> > + if (dso) {
> > + demangled = dso__demangle_sym(dso, 0, funcname);
> > + if (demangled)
> > + funcname = demangled;
> > + }
> > +
> > + if (strcmp(funcname, base_sym->name) == 0) {
>
> It seems you need to check availability of base_sym first as 'else'
> statement below checks it. Or if it's guaranteed not NULL (I think
> you make it so later), remove the check (and add an assert?) instead.

I'll make it fail-safe by adding the check before calling strcmp. Well
spotted, many thanks!

--
Milian Wolff | milian.wolff@kdab.com | Senior Software Engineer
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