On Tue, Aug 27, 2013 at 10:12:08AM -0600, David Ahern wrote: > [Added Jiri who added the feature to perf] > > On 8/27/13 5:58 AM, Jean Pihet wrote: > >Hi! > > > >I am looking for info and help on the libunwind API. > > > >What I am trying to achieve is to allow the callchain feature on perf > >for ARM (v7 to start with, then ARMv8), from the DWARF info found in > >the .debug_frame section. > > > > From the source code in tools/perf I have added the call to > >dwarf_find_debug_frame to load and parse the debug info from > >.debug_frame. This works correctly, all IP ranges are found from the > >debug code (test program and libraries). Then at some point I get an > >assertion: 'perf: dwarf/Gparser.c:459: fetch_proc_info: Assertion > >`c->pi.unwind_info' failed.' At that point c->pi is NULL. Cf. below > >for more info.
I checked the patch and it looks ok, thought I've never touched the .debug_frames code paths which are separated to some extend in the libunwind code.. > > > >It looks like I am not using the libunwind API as it should, so that > >the perf code apparently builds a list of IP ranges to resolve but > >cannot use it later on to gather statistics on the runtime info. > > > >Any idea on how to progress? I am also looking at the *_proc_info API > >of libunwind. keep digging ;-) also I dont have that assert exactly at dwarf/Gparser.c:459 so maybe try latest code git://git.sv.gnu.org/libunwind.git sorry not to help help you much, you might try to ask Arun Sharma <asha...@fb.com> who helped me before. jirka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
