Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932198AbdCFNrX (ORCPT ); Mon, 6 Mar 2017 08:47:23 -0500 Received: from mail.kernel.org ([198.145.29.136]:34002 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932130AbdCFNq1 (ORCPT ); Mon, 6 Mar 2017 08:46:27 -0500 Date: Mon, 6 Mar 2017 14:39:15 +0100 From: Masami Hiramatsu To: Alexis Berlemont Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com Subject: Re: [PATCH v5 1/2] perf sdt: add scanning of sdt probles arguments Message-Id: <20170306143915.f7778227b43e90ba7a799a55@kernel.org> In-Reply-To: <20161214000732.1710-2-alexis.berlemont@gmail.com> References: <20161214000732.1710-1-alexis.berlemont@gmail.com> <20161214000732.1710-2-alexis.berlemont@gmail.com> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.30; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3159 Lines: 100 On Wed, 14 Dec 2016 01:07:31 +0100 Alexis Berlemont wrote: > During a "perf buildid-cache --add" command, the section > ".note.stapsdt" of the "added" binary is scanned in order to list the > available SDT markers available in a binary. The parts containing the > probes arguments were left unscanned. > > The whole section is now parsed; the probe arguments are extracted for > later use. > Looks good to me. Acked-by: Masami Hiramatsu Thanks! > Signed-off-by: Alexis Berlemont > --- > tools/perf/util/symbol-elf.c | 25 +++++++++++++++++++++++-- > tools/perf/util/symbol.h | 1 + > 2 files changed, 24 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c > index 99400b0..7725c3f 100644 > --- a/tools/perf/util/symbol-elf.c > +++ b/tools/perf/util/symbol-elf.c > @@ -1822,7 +1822,7 @@ void kcore_extract__delete(struct kcore_extract *kce) > static int populate_sdt_note(Elf **elf, const char *data, size_t len, > struct list_head *sdt_notes) > { > - const char *provider, *name; > + const char *provider, *name, *args; > struct sdt_note *tmp = NULL; > GElf_Ehdr ehdr; > GElf_Addr base_off = 0; > @@ -1881,6 +1881,25 @@ static int populate_sdt_note(Elf **elf, const char *data, size_t len, > goto out_free_prov; > } > > + args = memchr(name, '\0', data + len - name); > + > + /* > + * There is no argument if: > + * - We reached the end of the note; > + * - There is not enough room to hold a potential string; > + * - The argument string is empty or just contains ':'. > + */ > + if (args == NULL || data + len - args < 2 || > + args[1] == ':' || args[1] == '\0') > + tmp->args = NULL; > + else { > + tmp->args = strdup(++args); > + if (!tmp->args) { > + ret = -ENOMEM; > + goto out_free_name; > + } > + } > + > if (gelf_getclass(*elf) == ELFCLASS32) { > memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr)); > tmp->bit32 = true; > @@ -1892,7 +1911,7 @@ static int populate_sdt_note(Elf **elf, const char *data, size_t len, > if (!gelf_getehdr(*elf, &ehdr)) { > pr_debug("%s : cannot get elf header.\n", __func__); > ret = -EBADF; > - goto out_free_name; > + goto out_free_args; > } > > /* Adjust the prelink effect : > @@ -1917,6 +1936,8 @@ static int populate_sdt_note(Elf **elf, const char *data, size_t len, > list_add_tail(&tmp->note_list, sdt_notes); > return 0; > > +out_free_args: > + free(tmp->args); > out_free_name: > free(tmp->name); > out_free_prov: > diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h > index 6c358b7..9222c7e 100644 > --- a/tools/perf/util/symbol.h > +++ b/tools/perf/util/symbol.h > @@ -351,6 +351,7 @@ int arch__choose_best_symbol(struct symbol *syma, struct symbol *symb); > struct sdt_note { > char *name; /* name of the note*/ > char *provider; /* provider name */ > + char *args; > bool bit32; /* whether the location is 32 bits? */ > union { /* location, base and semaphore addrs */ > Elf64_Addr a64[3]; > -- > 2.10.2 > -- Masami Hiramatsu