From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751849AbcGVCrn (ORCPT ); Thu, 21 Jul 2016 22:47:43 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:2094 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750791AbcGVCrm (ORCPT ); Thu, 21 Jul 2016 22:47:42 -0400 X-IBM-Helo: d03dlp01.boulder.ibm.com X-IBM-MailFrom: gongss@linux.vnet.ibm.com Subject: Re: [PATCH] s390/perf: fix 'start' address of module's map To: acme@kernel.org, jolsa@kernel.org References: <1469070651-6447-1-git-send-email-gongss@linux.vnet.ibm.com> <1469070651-6447-2-git-send-email-gongss@linux.vnet.ibm.com> Cc: dsahern@gmail.com, linux-kernel@vger.kernel.org, borntraeger@de.ibm.com From: Songshan Gong Date: Fri, 22 Jul 2016 10:47:34 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <1469070651-6447-2-git-send-email-gongss@linux.vnet.ibm.com> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16072202-0028-0000-0000-00000537D63D X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16072202-0029-0000-0000-00002DBBEABC Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-07-22_01:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1607220033 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Has the patch been accepted by upstream? ÔÚ 7/21/2016 11:10 AM, Song Shan Gong дµÀ: > At preset, when creating module's map, perf gets 'start' address by parsing > '/proc/modules', but it's module base address, isn't the start address of > '.text' section. In most archs, it's OK. But for s390, it places 'GOT' and > 'PLT' relocations before '.text' section. So there exists an offset between > module base address and '.text' section, which will incur wrong symbol > resolution for modules. > > Fix this bug by getting 'start' address of module's map from parsing > '/sys/module/[module name]/sections/.text', not from '/proc/modules'. > > Signed-off-by: Song Shan Gong > Acked-by: Jiri Olsa > --- > tools/perf/arch/s390/util/Build | 2 ++ > tools/perf/arch/s390/util/machine.c | 19 +++++++++++++++++++ > tools/perf/util/machine.c | 8 ++++++++ > tools/perf/util/machine.h | 1 + > 4 files changed, 30 insertions(+) > create mode 100644 tools/perf/arch/s390/util/machine.c > > diff --git a/tools/perf/arch/s390/util/Build b/tools/perf/arch/s390/util/Build > index 8a61372..5bd7b92 100644 > --- a/tools/perf/arch/s390/util/Build > +++ b/tools/perf/arch/s390/util/Build > @@ -2,3 +2,5 @@ libperf-y += header.o > libperf-y += kvm-stat.o > > libperf-$(CONFIG_DWARF) += dwarf-regs.o > + > +libperf-y += machine.o > diff --git a/tools/perf/arch/s390/util/machine.c b/tools/perf/arch/s390/util/machine.c > new file mode 100644 > index 0000000..b9a95a1 > --- /dev/null > +++ b/tools/perf/arch/s390/util/machine.c > @@ -0,0 +1,19 @@ > +#include > +#include > +#include > +#include "util.h" > +#include "machine.h" > +#include "api/fs/fs.h" > + > +int arch__fix_module_text_start(u64 *start, const char *name) > +{ > + char path[PATH_MAX]; > + > + snprintf(path, PATH_MAX, "module/%.*s/sections/.text", > + (int)strlen(name) - 2, name + 1); > + > + if (sysfs__read_ull(path, (unsigned long long *)start) < 0) > + return -1; > + > + return 0; > +} > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c > index b177218..97cc9f0 100644 > --- a/tools/perf/util/machine.c > +++ b/tools/perf/util/machine.c > @@ -1091,12 +1091,20 @@ static int machine__set_modules_path(struct machine *machine) > > return map_groups__set_modules_path_dir(&machine->kmaps, modules_path, 0); > } > +int __weak arch__fix_module_text_start(u64 *start __maybe_unused, > + const char *name __maybe_unused) > +{ > + return 0; > +} > > static int machine__create_module(void *arg, const char *name, u64 start) > { > struct machine *machine = arg; > struct map *map; > > + if (arch__fix_module_text_start(&start, name) < 0) > + return -1; > + > map = machine__findnew_module_map(machine, start, name); > if (map == NULL) > return -1; > diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h > index 41ac9cf..20739f7 100644 > --- a/tools/perf/util/machine.h > +++ b/tools/perf/util/machine.h > @@ -216,6 +216,7 @@ struct symbol *machine__find_kernel_function_by_name(struct machine *machine, > > struct map *machine__findnew_module_map(struct machine *machine, u64 start, > const char *filename); > +int arch__fix_module_text_start(u64 *start, const char *name); > > int __machine__load_kallsyms(struct machine *machine, const char *filename, > enum map_type type, bool no_kcore, symbol_filter_t filter); > -- SongShan Gong