Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754910AbaLJKRX (ORCPT ); Wed, 10 Dec 2014 05:17:23 -0500 Received: from ozlabs.org ([103.22.144.67]:56053 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754464AbaLJKRW (ORCPT ); Wed, 10 Dec 2014 05:17:22 -0500 Message-ID: <1418206640.9279.10.camel@ellerman.id.au> Subject: Re: [RFC PATCH 7/8] perf probe powerpc: Use DWARF info only if necessary From: Michael Ellerman To: "Naveen N. Rao" Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, acme@kernel.org, ananth@in.ibm.com Date: Wed, 10 Dec 2014 21:17:20 +1100 In-Reply-To: <50dd0fedb50e3a56ff8f25c44098db3e2a2d6374.1418146300.git.naveen.n.rao@linux.vnet.ibm.com> References: <50dd0fedb50e3a56ff8f25c44098db3e2a2d6374.1418146300.git.naveen.n.rao@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.7-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2014-12-09 at 23:04 +0530, Naveen N. Rao wrote: > Use symbol table lookups by default if DWARF is not necessary, since > powerpc ABIv2 encodes local entry points in the symbol table and the > function entry address in DWARF may not be appropriate for kprobes, > as described here: > https://sourceware.org/bugzilla/show_bug.cgi?id=17638 Needs a better changelog. > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > index 174c22e..adcdbd2 100644 > --- a/tools/perf/util/probe-event.c > +++ b/tools/perf/util/probe-event.c > @@ -2382,6 +2382,14 @@ static int convert_to_probe_trace_events(struct perf_probe_event *pev, > } > } > > +#if defined(__powerpc64__) && defined(_CALL_ELF) && _CALL_ELF == 2 > + if (!perf_probe_event_need_dwarf(pev)) { > + ret = find_probe_trace_events_from_map(pev, tevs, max_tevs, target); > + if (ret > 0) > + return ret; /* Found in symbol table */ > + } > +#endif And should be in an arch helper, not a big powerpc wart dropped in the middle of the generic code. cheers -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/