From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by lists.ozlabs.org (Postfix) with ESMTP id 168601A0407 for ; Fri, 13 Mar 2015 07:23:47 +1100 (AEDT) Date: Thu, 12 Mar 2015 17:23:40 -0300 From: Arnaldo Carvalho de Melo To: "Naveen N. Rao" Subject: Re: [PATCHv2 3/8] perf probe powerpc: Fix symbol fixup issues due to ELF type Message-ID: <20150312202340.GC3550@kernel.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Em Mon, Dec 15, 2014 at 08:20:33PM +0530, Naveen N. Rao escreveu: > If using the symbol table, symbol addresses are not being fixed up > properly, resulting in probes being placed at wrong addresses: > > # perf probe do_fork > Added new event: > probe:do_fork (on do_fork) > > You can now use it in all perf tools, such as: > > perf record -e probe:do_fork -aR sleep 1 > > # cat /sys/kernel/debug/tracing/kprobe_events > p:probe/do_fork _text+635952 > # printf "%x" 635952 > 9b430 > # grep do_fork /boot/System.map > c0000000000ab430 T .do_fork > > Fix by checking for ELF type ET_DYN used by ppc64 kernels. Sorry if this was answered already, its been a while since this was posted/discussed... Are you completely sure this is not a problem on !ppc? Woudln't it be more conservative to somehow only adjust symbols for this ET_DYN type if the arch is ppc? I.e. something like moving that adjust_symbols logic to be arch_adjust_symbols(), provide a default and then override it for ppc to include also ET_DYN? Looking at the other patches... - Arnaldo > Signed-off-by: Naveen N. Rao > --- > tools/perf/util/symbol-elf.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c > index 06fcd1b..7ac4e4c 100644 > --- a/tools/perf/util/symbol-elf.c > +++ b/tools/perf/util/symbol-elf.c > @@ -683,7 +683,8 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, > NULL) != NULL); > } else { > ss->adjust_symbols = ehdr.e_type == ET_EXEC || > - ehdr.e_type == ET_REL; > + ehdr.e_type == ET_REL || > + ehdr.e_type == ET_DYN; > } > > ss->name = strdup(name); > -- > 2.1.3